Title,Author,Year,Publisher,File,Volume,Issue,Pagination,DOI,Abstract,Notes,Related Subnetworks,Related LTSEs,Related SFTSs,Keywords,Publication Type "A chronosequence of soils and vegetation near Mt. Shasta, California: I and II","Dickson, B.A. and R.L. Crocker","1953","Journal of Soil Science","Dickson_BA1953 and Crocker I and II.pdf","4","2","123-156","","","The pdf contains parts I and II.","","","Mt. Shasta CA Mudflow Chronosequence","","Journal Article " "A chronosequence of soils and vegetation near Mt. Shasta, California: III","Dickson, B.A. and R.L. Crocker","1954","Journal of Soil Science","Dickson_BA1954 and Crocker III Mt Shasta.pdf","5","2","173-191","","","","","","Mt. Shasta CA Mudflow Chronosequence","","Journal Article " "A comparison of strategies for ameliorating subsoil acidity: I. Long-term growth effects","Farina MPW, Channon P, Thibaud GR","2000","SOIL SCIENCE SOCIETY OF AMERICA JOURNAL","646.pdf","64","2","646-651","","Subsoil acidity is an important yield-limiting factor. Mechanical procedures of deep lime incorporation and surface applications of gypsum have been shown to be beneficial, but no long-term comparisons of these strategies have been published. Without such information it is difficult to make appropriate management decisions. The work reported here was conducted toward this end. In a long-term study with maize (Zea mays L.) on a strongly acidic Plinthic Paleudult, conventional moldboard incorporation of lime (15 Mg ha(-1)) was compared with (i) deeper incorporation of the same quantity of lime,vith plowing and subsoiling operations, and (ii) treatments where large additional quantities of lime were similarly introduced below normal plow depth. The efficacy of gypsum was tested by adding 10 Mg ha(-1) to conventionally limed plots. For 11 seasons, the average grain yield benefit ranged from 5 to 17% in the case of mechanical strategies and was 25% in the case of gypsum. Yields were increased only marginally by extra lime applications and segmental (slotted) amelioration proved inferior to deep-plowing procedures. The gypsum treatment proved profitable only in the fourth season, but by the eighth season had proved more profitable than the best mechanical procedure; and by the 11th season, the gypsum treatment had resulted in a cumulative yield advantage of 3.8 Mg ha(-1). Long-term superiority of the gypsum treatment was unquestionable in this study, but gypsum is often unavailable and acidic soils are frequently unresponsive to gypsum. In such situations, deep plowing should not, as is often the case, be discarded as impractical.","","","A comparison of strategies for ameliorating subsoil acidity: I. Long-term growth effects","","WATER SOILS GYPSUM ","Journal Article " "A comparison of strategies for ameliorating subsoil acidity: II. Long-term soil effects","Farina MPW, Channon P, Thibaud GR","2000","SOIL SCIENCE SOCIETY OF AMERICA JOURNAL","652.pdf","64","2","652-658","","Acid-subsoil amelioration is complicated by differences in the efficacy of lime and gypsum across the diverse soil environments in which the problem occurs. This study was conducted to explain long-term growth responses to lime and gypsum on a Plinthic Paleudult of mixed clay mineralogy. In a 10-season experiment that monitored treatment effects on profile chemical properties, we compared the effects of (i) incorporating 15 Mg ha(-1) of lime to different depths, (ii) incorporating 25 Mg ha(-1) of lime to about 0.5 m, and (iii) conventionally incorporating 15 Mg ha(-1) of lime plus 10 Mg ha(-1) of gypsum. Even at the highest application rate, lime had minimal effects on acidity below the depth of incorporation. Gypsum, however, markedly improved the rooting environment to a depth of 0.75 m. Sulfate sorption against extraction with dilute CaCl2 was accompanied by pH, increases of approximate to 0.4 units, by similar increases in Delta pH (pH(w) - pH(s)), by depressions in exchangeable acidity of as much as 1.5 cmol(c) L-1, and by decreases in acid saturation of more than 30%. The rate of subsoil amelioration was, however, much slower than that reported in more intensely weathered soils of similar texture. Only in the sixth season were benefits evident in the 0.60- to 0.75-m horizon, and acidity in the 0.75- to 0.90-m horizon actually increased significantly. It is speculated that this resulted from NO3 accumulation and ionic strength-induced dissolution of interlayer Al. These findings indicate that acid-subsoil amelioration in soils with Al-hydroxy-interlayer minerals requires greater quantities of gypsum than soils that are dominantly kaolinitic.","","","A comparison of strategies for ameliorating subsoil acidity: I. Long-term growth effects","","","Journal Article " "Adsorption of Dissolved Organic Carbon and Nitrogen in Soils of a Weathering Chronosequence","Lilienfein, J., R.G. Qualls, S.M. Uselman, and S.D. Bridgham","2004","Soil Sci. Soc . Am. J","Lilienfein_J2004 Mt Shasta DOC.pdf","68","","292-305","","","","","","Mt. Shasta CA Mudflow Chronosequence","","Journal Article " "Advancing the frontiers of soil science towards a geoscience","Wilding, L.P. and H. Lin.","2006","Geoderma","Wilding_LP2006 Critical zone and soil.pdf","131","","257-274","","The visions, directions, and images of soil science are changing. Historically, soil science has followed a circuitous path in its evolution from a discipline with foundational roots in geology, to an applied agricultural and environmental discipline, and now to a bio- and geo-science through the Earth’s Critical Zone investigations. This closes the loop or spiral, but along the way, soil science has become more comprehensive, extensive, integrative, analytical, and quantitative. In spite of the challenges described in this paper, now is a golden era for soil science to integrate its expertise more closely with other bio- and geosciences. This will significantly enhance the opportunity to obtain extramural funding and public support, as well as the advancement of soil science. As such, soil science needs to vigorously become more interactive and extend its role beyond traditional agriculture. The knowledge of spatial soil diversity and landscape dynamics is a fundamental underpinning critical to the success of this venture. Pedology, as a unique subdiscipline of soil science, contributes inordinately to Earth science, including, for example, elucidation of field variability, surficial weathering processes, Earth system dynamics, and vadose zone flow and transport. With the blooming of hydrogeosciences, hydropedology is a timely addition in this era of interdisciplinary, multidisciplinary, and systems approaches for developing comprehensive prioritization of science and applications in Earth science. Hydropedology has a niche in this march with other bio- and geo-sciences in addressing global Earth science priorities. Soil scientists support changing paradigms and favor closer linkages with the bio- and geo-sciences community. In this regard, hydropedology has a unique role to play.","","","","","","Journal Article " "Assessment of Climate Impact on Carbon Exchange Betweeen an Agroecosystem and the Atmosphere","Buyanovsky, G.A., Hu, Qi,","1998","unknown","Buyanovsky_GA1998.pdf","","","","","","","","Sanborn Field","","","Journal Article " "BFG Biology of Forest Growth","Paul, K. ?","2004","Unpublished descriptive notes","Biology of Forest Growth.pdf","","","","","","","","Biology of Forest Growth","","Pinus radiata plantation ","Journal Article " "Bioavailability of slowly cycling soil phosphorus: Major restructuring of soil-P fractions over four decades in an aggrading forest","Richter, D.D., H.L. Allen, J.W. Li, D. Markewitz, J. Raikes","2006","Oecologia","Richter_DD2006 Calhoun P_0_0.pdf","In Review","","","","","","","Calhoun Long-Term Soil-Ecosystem Experiments","","","Journal Article " "Brief on the Long term DNPK experiment in Samaru northern Nigeria","Amapu, I.Y.","2007","Summary of research accomplished at Nigerias DNPK Trials","Brief on the DNPK experiment in Samaru northern Nigeria-1.pdf","","","","","The Samaru (Lat. 110 11’N; Long. 70 38’E, altitude 686 m asl) long-term DNPK (Dung, Nitrogen, Phosphorus and Potassium) experiments, modelled after the classical Rothamsted Long-term Trials, was laid down in 1949. This was a time when clear signals were being received with respect to the fact that the burgeoning population, coupled with the introduction of more high yielding and nutrient-demanding crop varieties, could no longer allow farmers continue with the practice of shifting cultivation nor adapt intensive cultivation without use of external inputs. The experiment was therefore started in 1950 to compare the effectiveness of inorganic fertilizers with or without Dung (FYM) on soil properties, crop performance and yield under continuous cultivation. A multidisciplinary outlook was given to the experiment and other objectives now include: (i) to monitor weed growth, (ii) insect and pest incidences and (iii) to evaluate the cost and returns associated with all operations. The treatments consist of three levels of D, N, P and K applied annually in all possible combinations. It is a 34 singly replicated randomized complete factorial design, giving a total of 81 plots arranged in 9 blocks. Each treatment combination occupies 1/45th hectare plot, with bunds separating the blocks.","","","DNPK Trial","","","Journal Article " "Burning causes long-term changes in soil organic matter content of a South African grassland","Fynn RWS, Haynes RJ, O'Connor TG","2003","SOIL BIOLOGY & BIOCHEMISTRY","fynn.pdf","35","5","677-687","10.1016/S0038-0717(03)00054-3","The effects of burning a native grassland on soil organic matter status was investigated on a long-term (50 years) field experiment where different times and frequencies of burning were compared. Significant decreases in organic C were observed only in the surface 0-2 cm layer and only under annual and biennial winter burning and biennial and triennial autumn burning. Burning in spring did not significantly affect organic C content presumably because substantial amounts of litter decomposed and/or were incorporated into the soil by faunal activity prior to burning. Total N content was decreased substantially to a depth of 6 cm by all burning treatments and as a result, the C:N ratio of soil organic matter was widened. In addition, the amount of potentially mineralizable N, as measured by either aerobic incubation or plant N uptake in a pot experiment, was much reduced. Burning also induced a decrease in light fraction and hot water-extractable C in the 0-2 cm layer but an increase in these parameters, and in microbial biomass C and root density, in the 4-10 cm layer. This was attributed to burning causing a decrease in above-ground litter inputs but increased turnover of root material below the surface. Despite the decrease in organic C and total N content with increasing soil depth, potentially mineralizable N showed the opposite trend. This unexpected finding was confirmed at a nearby site under native grassland and contrasted with decreasing potentially mineralizable N with depth which was measured under a fertilized kikuyu grass dairy pasture. The wide C:N ratio of litter from native grassland, in association with the decreasing size and activity of the microbial biomass with depth results in greater N immobilization (thus less net mineralization) occurring in soil samples taken from close to the soil surface. (C) 2003 Elsevier Science Ltd. All rights reserved.","","","Burning causes long-term changes in soil organic matter content of a South African grassland","","TALLGRASS PRAIRIE SURFACE SOIL NITROGEN MINERALIZATION N MINERALIZATION MICROBIAL BIOMASS-C GRADIENTS FIRE; DYNAMICS EXTRACTION METHOD AGRICULTURAL SOILS ","Journal Article " "Carbon Balance of the Breton Classical Plots over Half a Century","R. C. Izaurralde,* W. B. McGill, J. A. Robertson, N. G. Juma, and J. J. Thurston","2001","Soil Sci. Soc. Am. J.","Izaurralde.pdf","65","","431-441","","","","","Breton Plots","","","Journal Article " "Carbon sequestration and plant community dynamics following reforestation of tropical pasture","Silver WL, Kueppers LM, Lugo AE, Ostertag R, Matzek V","2004","Ecological Applications","silver.pdf","14","4","1115-1127","","","","","Luquillo Puerto Rico","","tropical reforestation Puerto Rico productivity nonnative species Luquillo experimental forest C sequestration C isotopes biomass biodiversity ","Journal Article " "Changes in stable isotopic signatures of soil nitrogen and carbon during 40 years of forest development","Billings SA, Richter DD","2006","OECOLOGIA","billings.pdf","148","2","325-333","","Understanding what governs patterns of soil delta N-15 and delta C-13 is limited by the absence of these data assembled throughout the development of individual ecosystems. These patterns are important because stable isotopes of soil organic N and C are integrative indicators of biogeochemical processing of soil organic matter. We examined 615 N of soil organic matter (delta N-15(SOM)) and delta C-13(SOM) of archived soil samples across four decades from four depths of an aggrading forest in southeastern USA. The site supports an old-field pine forest in which the N cycle is affected by former agricultural fertilization, massive accumulation of soil N by aggrading trees over four decades, and small to insignificant fluxes of N via NH3 volatilization, nitrification, and denitrification. We examine isotopic data and the N and C dynamics of this ecosystem to evaluate mechanisms driving isotopic shifts over time. With forest development, delta C-13(SOM) became depth-dependent. This trend resulted from a decline of similar to 2 parts per thousand. in the surficial 15 cm of mineral soil to -26.07 parts per thousand, due to organic matter inputs from forest vegetation. Deeper layers exhibited relatively little trend in delta C-13(SOM) with time. In contrast, delta N-15(SOM) was most dynamic in deeper layers. During the four decades of forest development, the deepest layer (35-60 cm) reached a maximum delta N-15 value of 9.1 parts per thousand, increasing by 7.6 parts per thousand, The transfer of > 800 kg ha(-1) of soil organic N into aggrading vegetation and the forest floor and the apparent large proportion of ectomycorrhizal (ECM) fungi in these soils suggest that fractionation via microbial transformations must be the major process changing delta N-15 in these soils. Accretion of isotopically enriched compounds derived from microbial cells (i.e., ECM fungi) likely promote isotopic enrichment of soils over time. The work indicates the rapid rate at which ecosystem development can impart delta N-15(SOM) and delta C-13(SOM) signatures associated with undisturbed soil profiles.","","","Calhoun Long-Term Soil-Ecosystem Experiments","","Stable isotopes soil profile reforestation ","Journal Article " "Changes in the grassland-forest boundary at Ta-Ta-Chia long term ecological research (LTER) site detected by stable isotope ratios of soil organic matter","Chiang, PN et al.","2004","Chemosphere","chiang.pdf","54","2","217-224","10.1016/j.chemosphere.2003.07.005","The carbon isotope analysis [δ13C values] of organic samples can be a useful research in ecological studies because δ13C values are indicative of the plant source. This study investigated the changes in plant communities along the grassland-forest boundary in the alpine forest at Ta-Ta-Chia long term ecological research (LTER) site in central Taiwan using carbon isotope data. The aim of this study was focused on the forest fire affected the change of vegetation community. Four pedons from grassland dominated by Miscanthus transmorrisonensis (pedons 1 and 2), transition zone by Tsuga and Yushania nittakeyamensis (pedon 3), and forest zone by Tsuga and nittakeyamensis (pedon 4) were examined. Soil organic matter (SOM) δ13C values in the upper soil horizon were similar to δ13C values of the overlaying vegetation types. This indicates that the boundary between these plant communities remained the same in the past decades. The δ13C values of the grassland SOM ranged from −19.4‰ to −24.1‰, showing decrease with soil depth. This suggests that C4 plants (transmorrisonensis) have replaced C3 plants of Tsuga and nittakeyamensis. The δ13C values of the Tsuga forest area (pedon 4) range from −27.0‰ to −23.5‰ and showed only slight change with soil depth, implying that C3 plants have remained the major species in the forest.","","","Stable isotopes grassland-forest border, SOM","","Stable isotopes Long term ecological research (LTER) site Grassland Forest ","Journal Article " "Comparative Analyses of Carbon Dynamics in Native and Cultivated Ecosystems","Buyanovsky, G.A., Kucera, C.L., Wagner, G.H.","1987","Ecology","Buyanovsky_GA1987.pdf","68","6","2023-2031","","","","","Sanborn Field","","winter wheat tallgrass praire soil respiration soil organic matter plant productivity litter decay constant Carbon flow ","Journal Article " "Creating and Restoring Wetlands","Mitsch, W.J., et al.","1998","BioScience","Mitsch_W_BioSci_1998.pdf","48","12","1019-1030","","Wetland creation and restoration are carried out frequently in the United States to mitigate the loss of wetlands due to almost any human development (e.g., shopping centers, highways, suburban developments, and coastline manipulation). These practices have been controversial because of uncertainty about what is necessary to create and restore these important ecosystems and what constitutes ""success"" of the new wetlands (Roberts 1993, Mitsch and Wilson 1996, Young 1996, Zedler 1996, Malakoff 1998). Yet if done properly, the creation and restoration of ecosystems in general, and of wetlands in particular, provide opportunities for enhancing the ecosystem services to humans, which have been estimated to provide the equivalent of $33 trillion per year worldwide (Costanza et al. 1997, Daily 1997). Ecosystem creation and restoration in general, which is sometimes referred to as ecological engineering (Mitsch 1993, 1996a), is a relatively new field that, although well developed in practice, needs a sound foundation in ecological theory to support its many empirical findings. Indeed, ecosystem restoration has been called the ""acid test"" of some ecological theories (Bradshaw 1987, 1997) because attempts to put ecosystems back together have often shown that theory does not always match practice. If done in a research setting, ecosystem creation and restoration make it possible to investigate theories about ecosystems, such as self-design and self-organization. ","ALSO SEE: http://scholar.google.com/scholar?hl=en&lr=&q=cache:AZ3ndLsLEXcJ:https://dspace.lib.ohio-state.edu/retrieve/146/2.06%2BEx.%2BWetland%2BSoils.pdf+Temporal+and+Spatial+Development+of+Surface+Soil+Conditions+at+Two+Created+Riverine+Marshes+","","The Olentangy River Wetland Research Park","","","Journal Article " "Creating riverine wetlands: Ecological succession, nutrient retention, and pulsing effects","Mitsch, William J., Li Zhang, Christopher J. Anderson, Anne E. Altor, Maria E. Hernandez","2005","Ecological Engineering","Mitsch_W_EcoEng_2005.pdf","","","","","Successional patterns, water quality changes, and effects of hydrologic pulsing are documented for a whole-ecosystem experiment involving two created wetlands that have been subjected to continuous inflow of pumped river water for more than 10 years. At the beginning of the growing season in the first year of the experiment (1994), 2400 individuals representing 13 macrophyte species were introduced to one of the wetland basins. The other basin was an unplanted control. Patterns of succession are illustrated by macrophyte community diversity and net aboveground primary productivity, soil development, water quality changes, and nutrient retention for the two basins. The planted wetland continued to be more diverse in plant cover 10 years after planting and the unplanted wetland appeared to be more productive but more susceptible to stress. Soil color and organic content continued to change after wetland creation and wetlands had robust features of hydric soils within a few years of flooding. Organic matter content in surface soils in the wetlands increased by approximately 1% per 3-year period. Plant diversity and species differences led to some differences in the basins in macrophyte productivity, carbon sequestration, water quality changes and nutrient retention. The wetlands continued to retain nitrate–nitrogen and soluble reactive phosphorus 10 years after their creation. There are some signs that sediment and total phosphorus retention are diminishing after 10 years of river flow. Preliminary results from the beginnings of a flood pulsing experiment in the two basins in 2003–2004 are described for water quality, nutrient retention, aboveground productivity, and methane and nitrous oxide gaseous fluxes. © 2005 Elsevier B.V. All rights reserved.","","","The Olentangy River Wetland Research Park","","Wetland succession Wetland restoration Olentangy River Wetland Research Park Floodplain wetlands Created wetlands ","Journal Article " "Critical loads and exceedances of acid deposition and associated forest growth in the northern hardwood and boreal coniferous forests in Quebec, Canada","Ouimet, R., L. Duchesne, D. Houle, P.A. Arp","2001","Water, Air and Soil Pollution: Focus","","1","","119-134","","","","","Quebec long-term forest soil monitoring network","","","Journal Article " "Crop and nitrogen yield in legume-based rotations practiced with zero tillage and low-input methods","IZURRALDE, R. C. ; CHOUDHARY M. ; JUMA N. G. ; MCGILL W. B.; HADERLEIN L.","1995","Agronomy journal (Agron. j.) CODEN AGJOAT ","","Vol. 87, no5, pp. 958-964 (28 ref.)","","","","Though legumes are beneficial in crop rotations, there is limited information on how tillage system-crop sequence interactions influence crop yield and N production. To see if biomass and N yields in short-term legume-based rotations under zero tillage (ZT) and low-input (LI) production methods can equal those in cereal monocultures under ZT and conventional tillage (CT), field experiments were conducted in Alberta, Canada, from 1989 to 1992 at Ellerslie (Typic Cryoboroll soil) and Breton (Typic Cryoboralf). Treatments at each site consisted of (i) two 4-yr rotations, each with the same crop sequence but different tillage methods, and (ii) four continuous barley treatments in 2 x 2 factorial combination of tillage and fertilizer N. The crop sequence was barley (Hordeum vulgare L.)-barley and field pea (Pisum sativum L.) intercrop-barley-fababean (Viciafaba L.). At Ellerslie, tillage for weed control and seedbed preparation was either CT-LI or ZT. At Breton, one rotation used the LI approach ; the second used deep tillage (DT). Weeds on CT and ZT were controlled with either pre- or postemergence herbicides. No herbicides were applied to LI treatments at either site or to the DT treatment at Breton. Yields of barley following legumes under ZT were similar to those of fertilized continuous barley. With nonchemical weed-control methods, weed competition reduced yields of barley following legumes by 24% compared with fertilized continuous barley. The increased fababean yield measured under DT was associated with improved rooting conditions and water extraction. The equivalent N-fertilizer value of legume residues with similar weed-control levels averaged 19 kg ha[-1] Except for the LI system, legume-based rotations produced, over the 4-yr cycle, amounts of N equivalent to continuous cereal systems. Resource use efficiency of legume-based rotations, as measured by net-N yields, was equivalent to continuous systems at Breton, but somewhat reduced at Ellerslie.","","","Breton Plots","","Zero tillage Yield Vicia faba Soil tillage Pisum arvense Nitrogen Monoculture Monocotyle Low Leguminosae Interaction Hordeum vulgare Gramineae Field experiment Farm input Crop rotation biomass Alternative method Alberta ","Journal Article " "Do organic amendments improve yield trends and profitability in intensive rice systems?","Dawe D. et al.","2003","Field Crops Research ","Dawe_D2003.pdf","83","2","191-213","10.1016/S0378-4290(03)00074-1","Opinions differ as to the importance of organic amendments (OA) for sustaining crop productivity in the intensive, irrigated rice systems of Asia. Our objectives were to (1) quantify the effects of farmyard manure (FYM) and straw incorporation on yield trends in long-term experiments (LTEs) with rice–rice (R–R) (Oryza sativa L.) and rice–wheat (R–W) (Triticum aestivum L.) systems and (2) assess the potential effects of OA on profitability, taking into account long-term effects on yield. We analyzed yield trends in 25 LTE (seven R–R, 18 R–W systems) across a wide geographical range in Asia. Three main conclusions emerged from this analysis. First, application of either manure or straw did not improve grain yield trends in R–R and R–W cropping systems. Second, depending on socio-economic conditions, use of manure or straw in these cropping systems may be profitable, provided these OA are used as a complement to a recommended dose of inorganic NPK (i.e. organic materials should not be used as the primary nutrient source). Third, current experimental designs to assess the suitability of OA need to be improved in order to allow a better comparison of the relative advantages of inorganic and organic fertilizers. The major shortcoming of current designs is that they do not properly adjust mineral fertilizer rates in the inorganic treatments to account for the macronutrient input from OA. Thus, our tentative estimates of the profitability of OA may be overstated. # 2003 Elsevier Science B.V. All rights reserved.","","","OM and rice profitability","","","Journal Article " "Dynamics of FYM on Physical Properties and Organic Matter Build-up of Soil","Jagan Nath, M.C.Sarkar and Mewa Singh","1972","Harayan Agricultural University Journal of Research","","2","3","165-168","","","","","Long-term effect of farmyard manure and N on yield of pearl millet-wheat cropping sequence.","","","Journal Article " "Effect of Continuous Application of Farm Yard Manure and Nitrogen on Organic Carbon and Available N, P and K content in Soil","D.S. Ruhal and R.C. Shukla","1979","Indian Journal of Agricultural Chemistry","","12","1","11-18","","","","","Long-term effect of farmyard manure and N on yield of pearl millet-wheat cropping sequence.","","","Journal Article " "Effect of Irrigation on Maize Yield (Zea mays L.)","Nagy, Janos","2003","AGRÁRTUDOMÁNYI KÖZLEMÉNYEK-DEBRECEN","nagy.pdf","","","30-35 ","","We have been continually examining the fertilizer and irrigation reaction of commonly cultivated maize hybrids for nearly twenty years at the Látókép experimental station of the Center for Agricultural Sciences, Debrecen University. Upon evaluating the results, it can be established that year significantly influences the size of yield. Between the years of 1999 and 2002, in the average of applied fertilizers the difference is 3,4 t/ha, but even in irrigated treatments it reaches 3 t/ha. This is more than the effect of irrigation. Of the applied agrotechnical elements, the yield increasing effect of fertilization is the greatest and can even be greater than the effect of year. The yield increasing effect of fertilization can be reliably detected with small and medium doses, but at higher doses a plateau section is reached, where it is not worth applying more nutrients. Cultivation with irrigation can only be done with appropriate nutrient supply, due to the positive correlation of the two factors. The positive correlation also means that if the water supply of the plant declines, less fertilizer is needed for safe production. The two factors (irrigation and fertilization) have to be increased or decreased at the same time. According to the experiment, in unirrigated treatments, 90 kg/ha nitrogen and the related phosphorus and potassium are enough, while in irrigated treatments this was 120 kg.","","","Debrecen Long-term experiment","","","Journal Article " "Effect of long-term application of farmyard manure on soil micronutrient status.","Chaudhary, M. and R.P. Narwal.","2005","Archives of Agronomy and Soil Science ","Chaudhary_M2005 longterm manure in Hisar India.pdf","51","3","351-359","","","","","","","","Journal Article " "Effect of manure- fertilizer schedules on nitrogen balance under rice monoculture in a permanent manurial experiment","Jegadeeswari, P.V., P. S. Senthil Kumar and K.Kumaraswamy","2001","Indian Journal of Environment and Ecoplaning","","5","1","65-69","","","","","Permanent Manurial Experiment under rice monoculture, Madurai, Tamil Nadu, India","","","Journal Article " "Effect of manure-fertilizer schedules on phosphorus balance under rice-monoculture in a permanent manurial experiment","P. S. SENTHIL KUMAR, S. ARUNA GEETHA AND K. KUMARASWAMY","2004","Crop Research","","28","1,2,3"," 22-27 ","","","","","Permanent Manurial Experiment under rice monoculture, Madurai, Tamil Nadu, India","","","Journal Article " "Effect of manure-fertilizer schedules on potassium indices in a permanent manurial experiment under rice monoculture","P. S. Senthil Kumar and K.Kumaraswamy","2001","Crop research","","22","1","19-24","","","","","Permanent Manurial Experiment under rice monoculture, Madurai, Tamil Nadu, India","","","Journal Article " "Effect of manure-fertilizer schedules on potassium supplying power of soil under rice monoculture in and long-term experiment","P. S. Senthil Kumar, B. Anandakrishnan and K. Kumaraswamy","2001","Environmental pollution and agriculture","","Book Chapter, 13","","101-106","","","","","Permanent Manurial Experiment under rice monoculture, Madurai, Tamil Nadu, India","","","Journal Article " "Effect of manure-fertilizer schedules on quantity intensity parameters of soil under rice monoculture in a permanent manurial experiment","P. S. Senthil Kumar and K.Kumaraswamy","2000","Research on Crops","","1","3","271-277","","","","","Permanent Manurial Experiment under rice monoculture, Madurai, Tamil Nadu, India","","","Journal Article " "Effect of manure-fertilizer schedules on soil properties and different forms of potassium in a permanent manurial experiment","P. S. Senthil Kumar and K.Kumaraswamy","2000","Research on Crops","","1","1","98-104","","","","","Permanent Manurial Experiment under rice monoculture, Madurai, Tamil Nadu, India","","","Journal Article " "Effects of farmyard manure, ferilizers and green manuring in rice-wheat systems in Bhutan: results from a long-term study","Chettri, G.B., Ghimiray, M., Floyd, C.N.","2003","Experimental Agriculture","","39","","129-144","10.1017/s0014479702001163","An experiment conducted from 1988 to 1997 to determine the effects of the timing of application and nutrient supply (particularly of phosphorus) is reported. The sources of applied nutrients that were compared were farmyard manure, pre-rice green-manuring with Sesbania aculeata and fertilizer application in a rice-wheat rotation on a typic ustifluvent. The application of seven tonnes farmyard manure per hectare to both the rice and the wheat crops over eight years increased organic carbon levels from 1.4 to 1.6% but had no yield effect on either crop. Phosphorus application through farmyard manure was not adequate for rice, whilst an application of 34 kg P ha[minus sign]1 to the rotation gave an economic yield increase only in rice and then only in the first four years of the experiment. From the third year, green manuring was able to replace the effects of the recommended nitrogen, phosphorus and potassium fertilizer applications in increasing rice yield. Green manuring had no effect on the wheat yield but the recommended fertilizer application increased yield. Green manuring increased soil total nitrogen and available potassium levels and reduced base saturation. After adjusting rice yields for variation in transplanting date between years there was no statistical evidence of a yield trend in either crop over the period of the experiment. Farmers' practice of applying seven tonnes farmyard manure per hectare appears adequate to produce stable rice paddy yields of 4–6 t ha[minus sign]1 a[minus sign]1.","","","Farmyard Manure, fertilizers and green manuring in rice-wheat systems in Bhutan","","","Journal Article " "Effects of deforestation on grass biomass and soil nutrient status in miombo woodland, Zambia","Chidumayo EN, Kwibisa L","2003","AGRICULTURE ECOSYSTEMS & ENVIRONMENT","chidumayo.pdf","96","1-3","97-105","10.1016/S0167-8809(02)00229-3","There is a growing concern in central and southern Africa about the negative effects. of deforestation caused by shifting cultivation and charcoal production. In the absence of long-term studies that document and assess impacts of tropical deforestation, it is difficult to evaluate the relevance of current policy interventions that address the negative effects of deforestation. To contribute to the knowledge, about impacts of tropical, deforestation, the effects of clearing Brachystegia-Julbernardia (miombo) woodland on grass biomass and soil nutrient status were assessed at four sites over a 10-years period, from 1991 to 2000 in central Zambia. Woodland clearing increased grass biomass by 20-50% and although its impacts on topsoil organic matter and available phosphor-us were apparent, these were not statistically significant. Site and year had the most significant effects on soil nutrient stocks, regardless of the woodland clearing treatment. Generally, fire did not affect grass production but reduced topsoil organic matter and nitrogen at three of the study sites. Deforestation followed by cultivation significantly reduced soil organic matter in the study area. Based on these results, it is recommended that local cultivation practices should incorporate measures that minimize loss of soil organic matter in order to sustain long-term soil fertility. (C) 2003 Elsevier Science B.V. All rights reserved.","","","Effects of deforestation on grass biomass and soil nutrient status in miombo woodland, Zambia","","Zambia soil nutrients re-growth grass biomass fire Brachystegia-Julbernardia woodland ","Journal Article " "Effects of Long-Term Compost and Fertilizer Application on Soil Phosphorus Status Under Paddy Cropping System","Park, M., et al.","2004","COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS","Park_M2004.pdf","35","11-12","1635–1644","10.1081/CSS-120038559","External phosphorus (P) fertilization in intensive cropping systems often exceeds P demand by crops, which leads to P accumulation in soils. Levels of different pools of soil P have been affected not only by soil properties and climatic condition but also by rate and type of P applied. This experiment was conducted to investigate the long-term applications of compost and chemical fertilizer on soil phosphorus status in paddy cropping system after addition of compost and chemical fertilizers for 34 years in rice monoculture production at National Youngnam Agricultural Experiment Station, Miryang, Korea. Four different treatments of soil amendments were selected in this study: control, compost application, NPK (nitrogen– phosphorus–potassium) fertilizer application, and compost plus NPK fertilizer application. Phosphorus status varied with the longterm applications of compost and fertilizers, and the compost plus NPK fertilizer treatment significantly increased total P in soil. Available P was increased in the treatments that received chemical fertilizers. Applications of compost and chemical fertilizers increased organic P fraction but the ratio of organic P to total P declined with application of compost or chemical fertilizers. Phosphorus-fixation was significantly increased due to the long-term application of compost and chemical fertilizers. The P fixation was highest with iron (Fe) than with aluminum (Al) and calcium (Ca) in the paddy soil. The highest Fe-P content occurred in the compost plus NPK fertilizer treatment. These results represented that the higher level of P remaining in the soil is accumulated by long-term annual application of compost and chemical fertilizers than by that of chemical fertilizer, and P accumulation might be a gradual saturation of the P-sorption capacity.","","","Long-term compost and fertilizer application on soil phosphorus status under paddy cropping system","","Phosphorus Paddy soil P-fractionation Long-term fertilization Compost ","Journal Article " "Effects of long-term soil acidification due to nitrogen fertilizer inputs in Wisconsin","Barak P, Jobe BO, Krueger AR, Peterson LA, Laird DA","1997","PLANT AND SOIL","Barak.pdf","197","1","61-69","","Agroecosystems are domesticated ecosystems intermediate between natural ecosystems and fabricated ecosystems, and occupy nearly one-third of the land areas of the earth. Chemical perturbations as a result of human activity are particularly likely in agroecosystems because of the intensity of that activity, which include nutrient inputs intended to supplement native nutrient pools and to support greater biomass production and removal. At a long-term fertility trial in South-Central Wisconsin, USA, significant increases in exchangeable acidity were accompanied by decreases in cation exchange capacity (CEC), base saturation, and exchangeable Ca2+ and Mg2+ with application of ammoniacal N fertilizer. Plant analysis shows that a considerable portion of the alkalinity generated by assimilation of N (and to a lesser extent by S) is sequestered in the above-ground plant parts as organic anions and is not returned to the soil if harvested. Elemental analysis of Ca-saturated soil clays indicates an loss of 16% of the CEC of the soil clay and minor increases in Fe and Al. The reversibility of these changes due to prolonged acidification is doubtful if the changes are due to soil weathering.","","","Arlington Plots, Wisconsin","","organic anions N fertilizers exchangeable acidity cation exchange capacity acidity ","Journal Article " "Effects of Manure- fertilizer schedules on properties and fertility status of soil and response of rice to NPK under rice monoculture","Jagadeeswari, P.V., P. S. Senthil Kumar, D. Vasanthy, R.K. Kaleeswari and K. Kumaraswwamy","1998","Abstracts in National Seminar on Developments of Soil Science","","","","135","","","","","Permanent Manurial Experiment under rice monoculture, Madurai, Tamil Nadu, India","","","Journal Article " "Evaluation of the different soil organic matter pools stability in Long-Term field experiments of Germany by physical fractionation","Travnikova LS, Titova NA, Kogut BM, Schulz E, Korschens M","2002","Archives of Agronomy and Soil Science","Travnikova_LS2002.pdf","48","6","565-576","10.1080/0365034021000041506","Samples of Ap horizons of different soil types with different clay content selected from nil plot and different fertilized plots of the long-term field experiments Thyrow, Groß Kreutz, Seehausen, Methau, Bad Lauchstädt, Straußfurt located in closely related climatic conditions had been analyzed by method of granulo-densimetric fractionation developed in Dokuchaev Soil Science Institute (Moscow). For comparison mountainous soil from long-term experiment Lauterbach located in more moist and cold conditions had been studied. Three groups of functional significant SOM fractions had been isolated: (1) light fraction (d < 2g·cm-3), clay fraction (< 1 μm) and fraction rest. The partition of C and N accumulated in these fractions related to the level of soil fertilization and clay content had been estimated. Light fraction is the least stable: it is sensitive to the level and forms of fertilizers as well as to the changing ecological conditions. SOM interacting with clay minerals is a main factor of soil carbon level stabilization. Light fraction is responsible for decomposable SOM pool dynamics and may be appropriate criteria of its estimation.","","","Statischer Duengungsversuch Bad Lauchstaedt","","soil organic matter pools mineral-organic fractions granulo-densimetric fractionation method ","Journal Article " "Exposure to an enriched CO2 atmosphere alters carbon assimilation and allocation in a pine forest ecosystem","KARINA SCHAFER, R. OREN, D.S. ELLSWORTH, C. LAI, J.D . HERRICK, A.C. FINZI, D.D. RICHTER, & G. KATUL","2003","Global Change Biology","karina_et_al_2003_GCB.pdf","9","","1378-1400","","We linked a leaf-level CO2 assimilation model with a model that accounts for light attenuation in the canopy and measurements of sap-flux-based canopy conductance into a new canopy conductance-constrained carbon assimilation (4C-A) model. We estimated canopy CO2 uptake (AnC) at the Duke Forest free-air CO2 enrichment (FACE) study. Rates of AnC estimated from the 4C-A model agreed well with leaf gas exchange measurements (Anet) in both CO2 treatments. Under ambient conditions, monthly sums of net CO2 uptake by the canopy (AnC) were 13% higher than estimates based on eddy-covariance and chamber measurements. Annual estimates of AnC were only 3% higher than carbon (C) accumulations and losses estimated from ground-based measurements for the entire stand. The C budget for the Pinus taeda component was well constrained (within 1% of ground-based measurements). Although the closure of the C budget for the broadleaf species was poorer (within 20%), these species are a minor component of the forest. Under elevated CO2, the C used annually for growth, turnover, and respiration balanced only 80% of the AnC. Of the extra 700 g Cm2 a1 (1999 and 2000 average), 86% is attributable to surface soil CO2 efflux. This suggests that the production and turnover of fine roots was underestimated or that mycorrhizae and rhizodeposition became an increasingly important component of the C balance. Under elevated CO2, net ecosystem production increased by 272 g Cm2 a1: 44% greater than under ambient CO2. The majority (87%) of this C was sequestered in a moderately long-term C pool in wood, with the remainder in the forest floor–soil subsystem.","","","Duke Forest CO2 Experiment (FACE)","","respiration plant canopy modelling net primary productivity net ecosystem exchange Free air CO2 enrichment Canopy stomatal conductance ","Journal Article " "Framework for man-made soil changes - an outline of metapedogenesis","Yaalon, D.H. and B. Yaron.","1966","Soil Science","Yaalon_D1966.pdf","102","","272-278","","","","","","","","Journal Article " "Frontiers in Exploration of the Critical Zone.","Brantley, S.L., T.S. White, A.F. White, D. Sparks, D.D. Richter, K. Pregitzer, L. Derry, J. Chorover, O. Chadwick, R. April, S. Anderson, and R. Amundson.","2006","NSF Workshop Report","CZEN Booklet July 06_0.pdf","Univ. Delaware, Newark, USA.","","30 p.",""," The surface of the Earth is rapidly changing, largely in response to anthropogenic perturbation. How will such change unfold, and how will it affect humankind? The Critical Zone is defined as the external terrestrial layer extending from the outer limits of vegetation down to and including the zone of groundwater. This zone sustains most terrestrial life on the planet. Despite its importance for life, scientific approaches and funding paradigms have not promoted and emphasized integrated research agendas to investigate the coupling between physical, biological, geological, and chemical processes in the Critical Zone. A national initiative is needed that incorporates a systems approach to investigation of Critical Zone processes across a broad array of sciences: geology, soil science, biology, ecology, geochemistry, geomorphology, and hydrology. Only with such an approach will we be able to answer the following question: This initiative will enable prediction of complex feedbacks among processes in the Critical Zone, including changes in fluxes driven by climatic, tectonic, and anthropogenic forcing over a wide range of temporal and spatial scales. Of particularly pressing importance is the need to understand how the Critical Zone is being transformed by rapid anthropogenic change. This effort will require a network of observatories and people to quantify responses of the Critical Zone to environmental change. The Critical Zone Exploration Network will include short-term deployments of instrumentation at field sites along environmental gradients as well as long-term sites that will be instrumented hierarchically and intensively. Importantly, sites will be chosen by peer review to answer fundamental questions requiring the entire network. By choosing sites with important questions in mind, the Critical Zone Exploration Network will thus tackle questions of great societal and global importance by uniting a multi-disciplinary and diverse community of scientists and their students.","","","","","","Journal Article " "Groundwater and soil chemical changes under phreatophytic tree plantations.","Jobbágy, E.G. and R.B. Jackson.","2007","JGR Biogeosciences","Jobbagy_EG2007 - Groundwater and soil chemistry.pdf","in press","","","","","","","Grassland Afforestation - Flooding Pampas","","","Journal Article " "Groundwater use and salinization with grassland afforestation","Jobbágy, E.G. and R.B. Jackson.","2004","Global Change Biology","Jobbagy_EG2004 - Salinization and afforestation.pdf","10","","1299-1312","10.1111/j.1365-2486.2004.00806.x","","","","Grassland Afforestation - Flooding Pampas","","","Journal Article " "Guide to the Classical and other Long-term Experiments, Datasets and Sample Archive.","Rothamsted Research","2006","Lawes Agricultural Trust Report","Poulton_PR2006 LTEs at Roth Guide.pdf","","","52 p.","","","","Rothamsted","","","","Journal Article " "How extensive are yield declines in long-term rice-wheat experiments in Asia?","Ladha JK, Dawe D, Pathak H, Padre AT, Yadav RL, Singh B, Singh Y, Singh Y, Singh P, Kundu AL, Sakal R, Ram N, Regmi AP, Gami SK,","2003","FIELD CROPS RESEARCH","ladha.pdf","81","2-3","159-180","","The rice-wheat cropping system, occupying 24 million hectares of the productive area in South Asia and China, is important for food security. Monitoring long-term changes in crop yields and identifying the factors associated with such changes are essential to maintain and/or improve crop productivity. Long-term experiments (LTE) provide these opportunities. We analyzed 33 rice-wheat LTE in the Indo-Gangetic Plains (IGP) of South Asia, non-IGP in India, and China to investigate the extent of yield stagnation or decline and identify possible causes of yield decline. In treatments where recommended rates of N, P and K were applied, yields of rice and wheat stagnated in 72 and 85% of the LTE, respectively, while 22 and 6% of the LTE showed a significant (P < 0.05) declining trend for rice and wheat yields, respectively. In the rice-wheat system, particularly in the IGP, rice yields are declining more rapidly than wheat. The causes of yield decline are mostly location-specific but depletion of soil K seems to be a general cause. In over 90% of the LTE, the fertilizer K rates used were not sufficient to sustain a neutral K input-output balance. Depletion of soil C, N and Zn and reduced availability of P, delays in planting, decreases in solar radiation and increases in minimum temperatures are the other potential causes of yield decline. A more efficient, integrated strategy with detailed data collection is required to identify the specific causes of yield decline. Constant monitoring of LTEs and analysis of the data using improved statistical and simulation tools should be done to unravel the cause-effect relationships of productivity and sustainability of rice-wheat systems. (C) 2002 Elsevier Science B.V. All rights reserved.","","","Yield declines in long-term rice-wheat experiments in Asia","","yield trends yield decline soil fertility Rice-wheat system nutrient budget long-term experiments Indo-Gangetic plains ","Journal Article " "How widespread are yield declines in long-term rice experiments in Asia?","Dawe et al. ","2000","Field Crops Research","Dawe_D2000.pdf LT rice prod in Asia.pdf","66","","175-193","","","","","","","","Journal Article " "Humanity's transformation of Earth's soil: Pedology's new frontier","Richter, D. deB.","2007","Soil Science","Richter_DD2007 Soil Science b.pdf","172","12","957-967","","Pedology was born in the 18th and 19th centuries, when soil was first conceived as a natural body worthy of its own scientific investigation. For well over a century, pedology explored soil as a system developed from a complex of natural processes. By the mid-20th century, however, human activities began to affect substantial global soil changes with influence on the dynamics of the Earth’s environment. Such anthropedogenesis was first defined as metapedogenesis by Yaalon and Yaron (1966), a definition that we propose here to be as important to the development of pedology as the natural-body concept of soil first articulated by Dokuchaev and Hilgard more than a century ago. In this article, we distinguish between humanity’s contemporary and historic influences on soil, as it is increasingly important for ecosystem analysis and management to distinguish contemporary changes that are overlain on those from the past. Although our understanding of global soil change is strikingly elementary, it is fundamental to establishing greater management control over Earth’s rapidly changing ecosystems. Humanity’s transformation of Earth’s soil challenges scientists to develop a pedology with broad purview and decades’ time scale, a pedology that supports the science and management of the environment, ecosystems, and global change.","","","","","","Journal Article " "Influence of Long-term Cropping Systems on Soil Physical Properties Related to Soil Erodibility","Rachman, A., S.H. Anderson, C.J. Gantzer, and A.L. Thompson","2003","Soil Sci. Soc. Am. J.","Rachman_A2003 Sanborn physical changes.pdf","67","","637-644","","","","","Sanborn Field","","","Journal Article " "Influence of long-term tillage, straw and N fertilizer on barley yield, plant-N uptake and soil-N balance","M. Nyborg , E. D. Solberg , R. C. Izaurralde , , S. S. Malhi and M. Molina-Ayala ","1995","Soil & Tillage Research ","","36:165-174","","","","Long-term influence of N fertilizer, tillage and straw on crop production and soil properties are not well known in central Alberta. Field experiments were established in autumn 1979, on a Black Chernozemic soil and on a Gray Luvisolic soil in north-central Alberta to determine the long-term effect of tillage, straw and N fertilizer on yield and N uptake of barley (Hordeum vulgare L.). Fertilizer N was applied annually at 56 kg ha−1. The 11 year averages of barley yields and N uptake under zero tillage were lower than under conventional tillage. Retention rather than removal of straw tended to reduce barley yield for the initial 6 years and 2 year at Site 1 and Site 2, respectively. A simple mathematical model of average annual plant N uptake and grain yield could account for most of the variation in the data observed at both sites (R2 = 0.907; P < 0.01). Final values of soil N, calculated using a mass balance approach, agree closely with values measured at the end of the eleventh year. Conventional tillage and zero tillage, with addition of fertilizer N and retention of straw, were the only treatments with apparent but small net addition of N to soil at Site 1 (40 kg ha−1 and 117 kg ha−1, respectively). At Site 2, only the zero tillage treatment with addition of fertilizer and retention of straw gained soil N (29 kg ha−1). In conclusion, soil ecosystems functioning in subhumid environments with slight to moderate heat limitations such as those in central Alberta can adapt, within a few years, to zero tillage practices with full retention of straw.","","","Breton Plots","","Zero tillage Soil quality nitrate leaching N mineralization-immobilization denitrification ","Journal Article " "Influence of Long-Term Wheat residue management on some Fertility Indicators of an Avalon soils at Bethlehem","Kotze, Elmarie.","2004","unknown","Kotzee_E2004.pdf","","","","","","A Dissertation submitted in accordance with the requirements for the Magister Scientiae degree in the Department of Soil, Crop and Climate Sciences Faculty of Natural and Agricultral Sciences University of the Free State Bloemfontein","","Long-term effects of wheat residue management on some fertility indicators of a semi-arid Plinthosol","","","Journal Article " "Integrating no-till into crop–pasture rotations in Uruguay","Fernando García-Préchac, Oswaldo Ernst b, Guillermo, Guillermo Siri-Prieto and José A. Terra","2004","Soil and Tillage Research","garciaprechac.pdf","77","1","1-13","10.1016/j.still.2003.12.002","Crop–pasture rotations (CPR) are unusual around the world but have been the predominant cropping system in Uruguay since the 1960s. Uruguay has a temperate sub-humid climate, 80% of its landscape (16 Mha) is climax grasslands C3 and C4 species. Beef, wool, and dairy are the main commodities. Crops occupy a portion of the remaining 20% land area, primarily on Argiudolls and Vertisols, rotated with seeded grass and legume pastures. Continuous cropping (CC) with conventional tillage (CT) has proven unsustainable due to decreased soil productivity. Seeded pasture periods increased soil productivity. CPR adoption created less variable inter-annual economic results, but soil degradation remained a major concern during the crop cycle using CT. Farmers and technicians became interested in no-till (NT) to reduce erosion and production cost. Currently, approximately 52% of crop producing farms and 25% of dairy farms have adopted NT. This paper synthesizes research results (mainly from long-term experiments) contrasting CC versus CPR with CT (1960–1990) and NT (from 1990). Soil erosion was reduced more than six times with NT in CC, and almost three times in CPR compared with CC using CT; but combining the use of CPR and NT resulted in the same low erosion rate as under natural pasture. The transition from CT to NT is not always easy. The time between herbicide application to pasture and planting of the first crop of the rotation crop cycle with NT is a critical transition factor to optimize N and water availability, and soil tilth. Chiseling or paraplowing can alleviate plow-pans inherited by NT from previous CT; but higher soil strength at the soil surface under NT contributes to better forage utilization under grazing. Soil organic carbon (SOC) content in CC decreased with CT, and was maintained with NT only if grain was harvested. In CC systems with harvested forage, SOC decreased even with NT. CPR with NT maintained or increased the original SOC content. The paper concludes with a discussion on the relative sustainability of CC versus CPR with NT. Both are sustainable from the soil quality and productivity standpoints. But compared with CC, CPR is a more economically and climatically buffered system, due to higher diversity. Also, CPR systems are more environmentally sustainable since fuel and agrochemicals usage is reduced approximately 50%.","","","Uruguary Crop-Pasture Rotations","","Soil quality soil organic carbon Soil erosion Soil compaction Pastures No-till crop rotations ","Journal Article " "Integrating rice and wheat productivity trends using the SAS mixed-procedure and meta-analysis","Tirol-Padre, A. and J.K. Ladha","2006","Field Crops Research","TirolPadre_A2006 Rice Wheat studies.pdf","95","","75-88","","","","","","","","Journal Article " "Interaction of soil and mankind in Britain","Bridges, E.M.","1978","Journal of Soil Science (now European Journal of Soil Science)","Bridges_1978.pdf","29","","125-139","","","","","","","","Journal Article " "Legacies of agriculture and forest regrowth in the nitrogen of old-field soils","Richter DD, Markewitz D, Heine PR, Jin V, Raikes J, Tian K, Wells CG","2000","FOREST ECOLOGY AND MANAGEMENT","richter2000.pdf","138","1-3","233-248","","In the Carolina Piedmont of the USA, agricultural and forest management in the 19th and 20th centuries has greatly altered soil organic nitrogen (N). The objective of this study is to evaluate effects of two centuries of land use on N in upland Piedmont soils that are derived from the region's most common bedrock, granitic gneiss. Effects of agriculture on total soil N were examined by comparing soils cropped mainly for cotton since about 1800 with soils that remained under hardwood forest without cultivation or fertilization. Effects of forest regrowth on the N of old-field soils were examined in eight permanent plots resampled on seven occasions from 1962 to 1997 at the Calhoun Experimental Forest in South Carolina. Together, the soil-comparative study and the four-decade field experiment illustrate how soil N in the southern Piedmont has been altered by agricultural management during the 19th and 20th centuries. Not only have agricultural harvests removed considerable N from Piedmont soils, but soil organic matter has been enriched in N by agricultural fertilization, a practice that has now contributed greatly to N cycles of many old-field forests in the region. In old-field pine stands (Pinus taeda) at the Calhoun Experimental Forest, 40 years of forest growth accumulated 366 kg ha(-1) of N (CV=9.3%) in tree biomass and 740 kg ha(-1) (CV=9.7%) in forest floor between planting in 1957 and the last sampling in 1997. In the four decades, mineral-soil N was diminished by 823 kg ha(-1) (CV=39.5%), a reduction in N accompanied by substantial decreases in mineralizable N as well. On the other hand, N accretion in the whole forest ecosystem averaged 5.9 kg ha(-1) per year over this period (significant at a probability of <0.07), an accretion attributed mainly to atmospheric N deposition rather than N-2 fixation, Despite the N accretion and legacy of agricultural fertilization, the 40-year-old Calhoun forest has grown into a state of acute N deficiency. Future N research should include support for a network of long-term field studies which investigates N dynamics in forest floor and logging slash, and estimates N-use and N-retention efficiencies of fertilized pine-forest ecosystems. (C) 2000 Elsevier Science B.V. All rights reserved.","","","Calhoun Long-Term Soil-Ecosystem Experiments","","nitrogen cycling long-term soil-ecosystem experiments forest ecosystems biogeochemistry agro-ecosystems ","Journal Article " "List of Publications on the OARDC/OSU Longterm Tillage Sites","Multiple","1963","Multiple","Long-term.pdf","","","","","","","","Long-Term Tillage Study (Wooster Triplett-VanDoren)","","","Journal Article " "Literature List","From Peter Christie","2006","none","LTS.pdf","","","","","","","","Effects of long-term application of slurry on grassland cut for silage","","","Journal Article " "Long term impact of rotation tillage and dtubble management on the loss of soil organic carbon and nitrogen from a chromic luvisol","D P Heenan, K Y Chan and P G Knight","2004","Soil & Tillage Research","","76","","59-68","","","","","S.A.T.W.A.G.L.","","Tillage Stubble soil organic carbon Rotation ","Journal Article " "Long term rice","unknown","","unknown","Aichi_Rice_LTSE.pdf","","","","","","","","Aichi rice studies","","","Journal Article " "Long-term application of animal slurries to grassland alters soil cation balance","P.N.C. Murphy, P.N.C., R.J. Stevens, & P. Christie","2005","Soil Use and Management","Murphy_PNC2005.pdf","21","","240-244","10.1079/SUM2005317","Soil samples from a 32-year grassland field experiment were taken from 0–5, 5–10, and 10–15 cm soil depths in February 2002. Plots received annual treatments of unamended control, mineral fertilizer, three rates of pig slurry and three rates of cow slurry, each with six replicates. Samples were analysed for cation exchange capacity (CEC), exchangeable cations (Naþ, Kþ, Ca2þ, Mg2 þ), pH and Olsen P. Exchangeable sodium percentage (ESP) was calculated as a sodicity indicator. Mean ESP was generally greater for slurry treatments than the control, with a trend of increasing ESP with application rate. This was particularly marked for cow slurry. At 0–5 cm depth ESP increased from 1.18 in the control to 1.75 at the highest rate of pig slurry and 5.60 at the highest rate of cow slurry. Similar trends were shown for CEC, exchangeable Naþ, Kþ and Mg2þ, Ca2þ and Olsen P. The build-up of soil P due to slurry applications, together with this combination of physical and chemical factors, may increase the risk of P loss to surface waters, particularly from soils receiving high rates of cow slurry.","","","Effects of long-term application of slurry on grassland cut for silage","","sodicity phosphorus loss Phosphorus infiltration cation exchange capacity animal slurry ","Journal Article " "Long-Term Changes in Soil Carbon under Different Fertilizer, Manure, and Rotation: Testing the Mathematical Model ecosys with Data from the Breton Plots","Grant, R. F., N. G. Juma, J. A. Robertson, R. C. Izaurralde, and W. B. McGill","2001","Soil Science Society of America Journal ","","65:205–214 ","","","","Soil C contents can be raised by land use practices in which rates of C input exceed those of C oxidation. Rates of C inputs to soil can be raised by continuous cropping, especially with perennial legumes, and by soil amendments, especially manure. We have summarized our understanding of the processes by which changes in soil C content are determined by rates of soil C input in the mathematical model ecosys. We compared model output for changes in soil C with those measured in a Gray Luvisol (Typic Cryoboralf) at Breton, Alberta, during 70 yr of a 2-yr wheat (Triticum aestivum L.)–fallow rotation vs. a 5-yr wheat–oat (Avena sativa L.)–barley (Hordeum vulgare L.)–forage–forage rotation with unamended, fertilized, and manured treatments. Model results indicated that rates of C input in the 2-yr rotation were inadequate to maintain soil C in the upper 0.15 m of the soil profile unless manure was added, but that those in the 5-yr rotation were more than adequate. Consequent changes of soil C in the model were corroborated by declines of 14 and 7 g C m-2 yr-1 measured in the control and fertilized treatments of the 2-yr rotation; by gains of 7 g C m-2 yr-1 measured in the manured treatment of the 2-yr rotation; and by gains of 4, 14, and 28 g C m-2 yr-1 measured in the control, fertilized, and manured treatments of the 5-yr rotation. Model results indicated that soil C below 0.15 m declined in all treatments of both rotations, but more so in the 2-yr than in the 5-yr rotation. These declines were corroborated by lower soil C contents measured between 0.15 and 0.40 m after 70 yr in the 2- vs. 5-yr rotation. Land use practices that favor C storage appear to interact positively with each other, so that gains in soil C under one such practice are greater when it is combined with other such practices.","","Long-term Tillage Study - Northwest ARS","Breton Plots","","","Journal Article " "Long-term comparison of rotation and fallow tillage systems of wheat in Australia","Latta J, O'Leary GJ","2003","FIELD CROPS RESEARCH","Latta.pdf","83","2","173-190","10.1016/S0378-4290(03)00073-X","A long-term experiment was established in 1982 at the Mallee Research Station, Walpeup, Vic., Australia, to investigate the impact of different farming practices in this semi-arid region on the growth and yield of wheat, and the water balance of the soil/ crop system. Two fallow management systems (a zero-tilled fallow with direct drilling and a traditional cultivated fallow without direct drilling) within three rotation systems (fallow-wheat (FW), pasture-wheat (PW) and pasture-fallow-wheat (PFW)) were evaluated in the study. Phosphorus was applied to each wheat crop but no nitrogen fertilisers were used. Simulation analysis was used to compare model performance against 16 years of observed data. Over the course of the experiment grain yields ranged from 0.44 to 3.90 Mg ha(-1). Rotation had the greatest effect on yield with the long fallow (PFW) treatment averaging 0.46 Mg ha(-1) more yield compared with the short fallow (PW). Whilst this yield increase was accompanied by an extra 11-33 mm (mean 16 mm) of pre-sowing root zone soil water in 9 of the 16 years, any causal relationship was at best limited. More important was the marked interaction of seasonal conditions and yield with the FW, and to a lesser extent the PW, suffering yield losses not evident in the PFW rotation in years of high yield potential; a result largely attributed to differences in mineral nitrogen. Conventionally tilled and zero-tilled fallow were similar in grain yield, stored soil water, water use and water use efficiency. As with the rotation treatments, there was a strong interaction of seasonal conditions and tillage response with the zero-tilled system reporting consistently lower yields than the conventional system in all but the very low and high yield potential seasons. The simulation analysis showed similar rotational and seasonal effects on yield (R-2 = 0.47, RMSE = 0.78 Mg ha(-1)) and water use (R-2 = 0.67, RMSE = 60 mm). However, the model overestimated water use at low yield and predicted higher yields in response to zero tillage over the 16-year period in contrast to the measured data. Whilst further attention to the model in this respect is needed the use of this model in similar environments should not be minimised because the problem is not large. New experiments that look critically at the evaporation reduction from stubble residues on light textured soils are needed. (C) 2003 Elsevier B.V. All rights reserved.","","","Mallee wheat rotation and fallow experiment","","soil water soil nitrogen crop modelling Conservation tillage ","Journal Article " "Long-term ecological research and the invisible present.","Magnuson, J.J.","1990","BioScience","magnuson_jj_1990.pdf","40","7","495-501","","In the absence of long-term research, serious misjudgments can occur in attempts to manage the environment.","","","","","","Journal Article " "Long-term effects of a forest amelioration experiment","Jandl R, Starlinger F, Englisch M, Herzberger E, Johann E","2002","CANADIAN JOURNAL OF FOREST RESEARCH","8713494.pdf","32","1","120-128","10-1139/X01-169","We evaluated the soil chemistry, plant species composition, and forest growth rate on a site where a site amelioration project had been realized 30 years earlier. The initial goal of the project was the improvement of a site that had been degraded by litter raking. We wanted to know which amelioration method produced a sustainable result and how different treatments might be rated by today's standards. Treatments included fertilization, underplanting with N-fixing plants, and a combination of both. The amelioration was combined with stand conversion by means of natural regeneration and spruce underplanting. In all treatments, a spruce-dominated stand replaced the secondary pine stand. The biomass of the formerly recalcitrant forest floor (143 Mg.ha(-1)) was reduced by 30 to 50% in treated plots, thereby reducing the total soil pool of C, N, and exchangeable cations. The mineral soil of treated plots was enriched with N, Ca, and Mg. An increase in pH was restricted to the forest floor. The C pool of treated soils was much smaller than that of the control plots. However, the loss from the soil was at least partly offset by increased growth rates of the aboveground tree biomass. In treated plots, the stem volume was more than twice that of control plots (38.3 m(3)). Soil chemical data and the composition of the ground vegetation suggest that even the control plots have changed compared with pre-treatment conditions. Comparison of different blocks of the experiment suggests that the exclusion of roe deer (Capreolus capreolus) by fencing was the most significant treatment required for successful stand conversion. Prior to fencing, deer browsing inhibited the establishment of a new stand.","","","Dobrowa Forest Amelioration Experiment","","CARBON SEQUESTRATION ","Journal Article " "Long-term effects of fertilization on the forms and availability of soil phosphorus in rice paddy","Lee CH, Park CY, Park KD, Jeon WT, Kim PJ","2004","CHEMOSPHERE","lee.pdf","56","3","299-304","10.1016/j.chemosphere.2004.02.027","The changes in total P accumulation and P compounds with time in the plough layer in a paddy soil in southern Korea were investigated in relation to the continuous application of chemical fertilizers (NPK), straw based compost (Compost), combination these two (NPK + Compost) for 31 years. Continuous fertilization increased the total and inorganic P contents in plough layers. In NPK, inorganic P fraction did not change with time, but organic P content increased significantly. Long-term application of chemical fertilizer together with compost accelerated the decrease in the organic P fraction, presumably due to promoting microbial activity in the plow layer, and then increased significantly inorganic P fraction. Compost application decreased the residual P and Fe-P fractions and then increased inorganic P fraction, in spite of continuous compost application. Increase in total, inorganic and extractable P with time may be closely related to the increase in the availability of accumulated P for rice growth. (C) 2004 Elsevier Ltd. All rights reserved.","","","Long-term effects of fertilization on the forms and availability of soil phosphorus in rice paddy","","Paddy soil P fraction Long-term fertilization Compost chemical fertilizer ","Journal Article " "Long-Term Field Experiment in Sweden: Effects of Organic and Inorganic Fertilizers on Soil Fertility and Crop Quality","Granstedt, A. and L. Kjellenberg.","1997","Proceedings: International Conference in Boston, Tufts University, Agricultural Production and Nutrition, Massachusetts March 19","Granstedt_A1997.pdf","","","","","","","","LT Field Expiment in Sweden: effects of org. and inorganic fertilizers on soil fertility and crop quality","","","Journal Article " "Long-term field experiments in Organic Farming","Raupp, J.","2006","unknown","Raupp_J.pdf","","","","","","","","Long-term Fertilization Trial","","","Journal Article " "Long-term impact of rotation, tillage and stubble management on the loss of soil organic carbon and nitrogen from a Chromic Luvisol","Heenan DP, Chan KY, Knight PG","2004","Soil and Tillage Research ","heenan.pdf","76","1","59-68","10.1016/j.still.2003.08.005","","","","Wagga Wagga soil organic carbon experiment","","Tillage Stubble Soil total nitrogen soil organic carbon Rotation ","Journal Article " "Long-term influence of cropping systems, tillage methods, and N sources on nitrate leaching","Izaurralde, RC; Feng, Y; Robertson, JA; McGill, WB; Juma, NG; Olson, BM ","1995","Canadian Journal of Soil Science [CAN. J. SOIL SCI./REV. CAN. SCI. SOL]. ","","Vol. 75, no. 4, pp. 497-505.","","","","The extent of nitrate leaching in cultivated soils of Alberta is unknown. We studied how long- and short-term agricultural practices influenced nitrate leaching in a cryoboreal subhumid soil-climate of north-central Alberta. The study used plots from three crop rotation-tillage studies at Breton on an Orthic Gray Luvisol, and from one at Ellerslie on an Orthic Black Chernozem. Soil samples were taken in the fall of 1993 from selected treatments as well as native forest sites in 0.3-m depth increments from 0 to 3.9 m and analyzed for NO sub(3)-N. No NO sub(3) super(-) were found under native forest vegetation. NO sub(3)-N accumulated below 0.9-m depth of agricultural ecosystems cultivated for as long as 64 yr ranged from 0 to 67 kg N ha super(-1). At Breton, fallow-wheat rotation plots receiving fertilizer N and manure contained eight times more NO sub(3)-N below 0.9 m depth than non-fertilized plots. NO sub(3)-N levels in an 8-yr legume-based rotation and in continuous-barley plots were similar but greater than in continuous-forage plots. Eighty-seven percent of NO sub(3) super(-) found under continuous barley occurred below the root zone compared with only 35% in the 8-yr rotation. At Ellerslie, NO sub(3)-N mass was related to fertilizer N and mineralization of soil organic matter. Increased efforts should be directed towards better synchronizing N release from or addition to soils with plant uptake. Evidence of greater nitrate leaching under zero tillage than under conventional warrants further confirmation.","","","Breton Plots","","","Journal Article " "Long-term maize, sorghum, and millet monoculture effects on an Argentina Typic Ustipsamment.","Buschiazzo, D.E., S.B. Aimar, J.M. Garcia Queijeiro","1999","Arid Soil Research and Rehabilitation","","13","1-15","","","","","","Long-Term Maize, Sorghum, and Millet Monoculture Effects on an Argentina Typic Ustipsamment","","","Journal Article " "Long-term nitrogen, phosphorus and potassium fertilization of cassava influences soil chemical properties in North Vietnam","Nguyen H, Schoenau JJ, Van Rees K, Nguyen D, Qian R","2001","CANADIAN JOURNAL OF SOIL SCIENCE","","81","3","481-488","","The long-term effects of Yearly fertilizer applications on soil chemical properties and nutrient availability are not well documented for cassava (Manihot esculenta) production in Vietnam. In 1990, research plots were established (randomized complete block design) with 12 treatments to test effects of different rates of N, P and K on soil properties in Acrisols (FAO-UNESCO Soil Classification) at Thai Nguyen University, North Vietnam. In June 1998, composite soil samples (0- to 10-cm and 10- to 20-cm depth) were collected from each plot. Nine years of N application significantly reduced the labile pools of soil inorganic P, total soil P and soil extractable K and Mg. Total soil N was only slightly increased in the 10- to 30-cm depth. Long-term applications of P significantly increased soil inorganic P fractions, but reduced concentrations and supply rates of nitrate and K. Moreover, 9 yr of K application significantly increased soil organic C (two depths), soil total N (10-30 cm) and soil extractable K in the 0- to 10-cm depth. Generally, the results show that long-term applications of mineral fertilizers in a ratio of N:P2O5:K2O of 2:1:2 (at the rates of 80 N:40 P2O5:80 K2O or 160 N: 80 P2O5:160 K2O) are effective in maintaining the total content and availability of applied nutrients, but when applied alone are associated with decreases in other nutrients.","","","Long-term N, P, K fertilization of cassava and soil chemical properties in N Vietnam","","soil properties potassium fertilizers Phosphorus Nitrogen ion exchange resin cassava ","Journal Article " "Long-Term Soil Chemistry Changes in Aggrading Forest Ecosystems","Knoepp, J.D. and W.T. Swank","1994","Soil Science Society of America Journal","Knoepp_JD1994.pdf","58","","325-331","","Assessing potential long-term forest productivity requires identification of the processes regulating chemical changes in forest soils. We resampled the litter layer and upper two mineral soil horizons, A and AB/BA, in two aggrading southern Appalachian watersheds 20 yr after an earlier sampling. Soils from a mixed-hardwood watershed exhibited a small but significant decrease in soil pH. Extractable base cation content declined substantially in both mineral horizons. For example, Ca2+ levels in the A horizon fell from 236 kg ha""1 in 1970 to 80 kg ha""1 in 1990. Proportionally, the decline was greatest for Mg2""1"", which dropped from 111 to 20 kg ha""1. A white pine (Pinus strobus L.) plantation was planted in 1956, after clear-felling hardwoods and recutting sprouts for 15 yr. Soil pH and base cation concentrations declined in the A horizon from 1970 to 1990. Soil pH declined from 5.9 to 5.0 and Ca2+ levels from 534 to 288 kg ha""1. Cation content did not change significantly in the AB/BA soil horizon. Nutrient budgets were constructed using these soil and litter data plus existing data on weathering rates, forest productivity, and hydrologic fluxes and associated chemistry. Decreases in soil base cations and soil pH are attributed to leaching and to the sequestration of nutrients in biomass.","","","Coweeta Hydrologic Laboratory - USDA Forest Service","","","Journal Article " "Long-Term Soil Experiments: Keys for Managing Earth's Rapidly Changing Ecosystems","Richter, D.D., M. Hofmockel, M.A. Callaham, D.S. Powlson, and P. Smith.","2007","Soil Science Society of America Journal","Richter_DD2007 LTSEs_0.pdf","71","2","266-279","10.2136/sssaj2006.0061","To meet economic and environmental demands for about 10 billion people by the mid-21st century, humanity will be challenged to double food production from the Earth’s soil and diminish adverse effects of soil management on the wider environment. To meet these challenges, an array of scientific approaches is being used to increase understanding of long-term soil trends and soil–environment interactions. One of these approaches, that of long-term soil experiments (LTSEs), provides direct observations of soil change and functioning across time scales of decades, data critical for biological, biogeochemical, and environmental assessments of sustainability; for predictions of soil productivity and soil–environment interactions; and for developing models at a wide range of scales. Although LTSEs take years to mature, are vulnerable to loss, and have yet to be comprehensively inventoried or networked, LTSEs address a number of contemporary issues and yield data of special signifi cance to soil management. The objective of this study was to evaluate how LTSEs address three questions that fundamentally challenge modern society: how soils can sustain a doubling of food production in the coming decades, how soils interact with the global C cycle, and how soil management can establish greater control over nutrient cycling. Results demonstrate how LTSEs produce significant data and perspectives for all three questions. Results also suggest the need for a review of the state of our long-term soil-research base and the establishment of an efficiently run network of LTSEs aimed at soil-management sustainability and improving management control over C and nutrient cycling.","","","","","","Journal Article " "Long-term Soil Fertility Experiment in Rice-Wheat cropping system in West Bengal","Kundu AL., Samui RC.","2000","unknown","Kundu_AL2000.pdf","","","","","A long-term experiment in rice-wheat cropping system was conducted in the New Alluvial Zone of West Bengal in India to develop a suitable integrated nutrient supply system using inorganic fertilizers with organic materials. The experiment was conducted for 9 years, starting from kharif (rainy season) 1986. Highest grain yield of rice was recorded in plots receiving 50% recommended NPK (nitrogen, phosphorus, potassium) through inorganic source and remaining 50% through green manure or 75% NPK through inorganic fertilizer and 25% N through green manure. In rabi (postrainy season) high grain yield of wheat was found with 100% NPK through fertilizer. There was a reduction in wheat yield when fertilizer applied to wheat was reduced. Total rice-wheat grain yield in a year was high when 75% of the recommended NPK through inorganic source was applied to rice along with 25% N through farmyard manure and 75% NPK to wheat. There was not much change in soil pH over years. Phosphorus and potash content of the soil increased to a small extent when 100% recommended NPK was applied in both seasons.","","","Long-term Soil Fertility Experiment in Rice-Wheat","","","Journal Article " "Long-term soil potassium availability from a Kanhapludult to an aggrading loblolly pine ecosystem","Markewitz D, Richter DD","2000","FOREST ECOLOGY AND MANAGEMENT","markewitz.pdf","130","1-3","109-129","","A long-term (1962 to 1990) forest biogeochemistry study in the southeastern Piedmont of the USA provided estimates of soil K release in response to forest regrowth. We investigated the sources of soil K that buffered the exchangeable K pools during forest growth and we estimated soil K release rates through greenhouse and acid extraction studies for comparison to our field estimate. In these acid Kanhapludults, derived from granitic-gneiss, the disparity between measured depletions of soil exchangeable K and estimated forest removals indicated a buffering of exchangeable K on the order of 0.31 kmol(c) ha(-1) per year. Nonexchangeable K extracted by boiling with 1 M HNO3 exceeded exchangeable K by up to 40-fold. Non-exchangeable K was not depleted during the three decades of stand growth, however, thus was not the long-term source of exchangeable K buffering. Total K in these soils ranged from 0.4 to 3.8% by weight. Mineralogical data indicated a presence of hydroxy-interlayered vermiculite throughout the upper 4 m of soil for <2 mu m clay fraction and a presence of micaceous minerals in the 2 to 45 mu m silt fraction. XRD analysis of micaceous flakes extracted from 4 to 8 m in the soil indicated a presence of muscovite mica. Estimated K releases in the greenhouse and extraction studies were generally consistent with long-term results. The accumulation of K during two rotations of pine seedling growth in the greenhouse exceeded the measured depletions in exchangeable and non-exchangeable K over all soil depths tested by 0.007 to 0.026 cmol(c) kg(-1). Potassium removal by sequential extraction/incubations with 1 mM HCl and 1 mM oxalic acid continued through 24 extractions and K recovered in extract solutions exceeded the sum of depletions in exchangeable and non-exchangeable K pools by 0.001 to 0.028 cmol(c) kg(-1). These excess removals in plant uptake or solution recovery indicate a release of mineral K. Thirty-day extractions with H+-resins in both 1 mM HCl and 1 mM oxalic acid were well fit by the Elovich equation but were not well correlated with plant K uptake in the greenhouse study. The release rate coefficients ranged from 0.012 to 0.025(cmol(c) kg(-1)) h(-1). Extrapolations to annual releases of K in the greenhouse and sequential extraction studies were a similar order of magnitude as long-term releases estimated at the long-term Calhoun plots. Surface soil (0 to 15 cm) releases ranged from 0.15 to 0.65 kmol(c) ha(-1) per year while deeper soils ranged up to 1.54 kmol(c) ha(-1) per year. Results indicate that soils similar to those at Calhoun that contain a similar micaceous and HIV component will be able to supply K at rates adequate to keep pare with demands of forest regrowth even under intensive forest management. (C) 2000 Elsevier Science B.V. All rights reserved.","","","Calhoun Long-Term Soil-Ecosystem Experiments","","soil supply potassium bioavailability mineral weathering ","Journal Article " "Long-term tillage and crop rotation effects on microbial biomass and C and N mineralization in a Brazilian Oxisol","Balota EL, Colozzi A, Andrade DS, Dick RP","2004","SOIL & TILLAGE RESEARCH","Balota_EL2004.pdf","77","2","137-145","10.1016/j.still.2003.12.003","Crop rotation and tillage impact microbial C dynamics, which are important for sequestering C to offset global climate change and to promote sustainable crop production. Little information is available for these processes in tropical/subtropical agroecosystems, which cover vast areas of terrestrial ecosystems. Consequently, a study of crop rotation in combination with no tillage (NT) and conventional tillage (CT) systems was conducted on an Oxisol (Typic Haplorthox) in an experiment established in 1976 at Londrina, Brazil. Soil samples were taken at 0-50, 50-100 and 100-200 mm depths in August 1997 and 1998 and evaluated for microbial biomass carbon (MBC) and mineralizable C and N. There were few differences due to crop rotation, however there were significant differences due to tillage. No tillage systems increased total C by 45%, microbial biomass by 83% and MBC:total C ratio by 23% at 0-50 mm depth over CT. C and N mineralization increased 74% with NT compared to CT systems for the 0-200 mm depth. Under NT, the metabolic quotient (CO2 evolved per unit of MBC) decreased by 32% averaged across soil depths, which suggests CT produced a microbial pool that was more metabolically active than under NT systems. These soil microbial properties were shown to be sensitive indicators of long-term tillage management under tropical conditions. (C) 2003 Elsevier B.V. All rights reserved.","","","Long-term tillage and crop rotation in southern Brazil","","tillage systems microbial biomass crop rotations carbon and nitrogen mineralization basal respiration ","Journal Article " "Long-term tillage and maize monoculture effects on a tropical Alfisol in western Nigeria .1. Crop yield and soil physical","Lal R","1997","SOIL & TILLAGE RESEARCH","lal1.pdf","42","3","145-160","","A wide range of tillage methods (e.g. mouldboard ploughing, discing, harrowing, chiselling, notill, ridge till, and their combinations) are used for continuous maize (Zea mays L.) cropping in western Nigeria without the benefits of experimental data on their comparative effects on soil properties and crop response. Therefore, the main objective of this experiment was to evaluate the impact of a range of tillage methods and continuous maize culture on grain and stover yields and degradative effects on soil properties. Tillage-induced changes in soil physical properties and maize yields were studied for 8 consecutive years from 1980 through 1987. Two crops were grown every year in the two rainy seasons. Season I lasted from April through July and Season 2 from August to November. The eight tillage treatments studied were: (1) notill + residue mulch, (2) notill + chiselling in the row zone to 50 cm depth, (3) mouldboard ploughing + harrowing, (4) disc ploughing + rotovation, (5) notill - residue mulch, (6) mouldboard ploughing at the end of rains or summer ploughing, (7) mouldboard ploughing and harrowing + residue mulch, (8) mouldboard ploughing and harrowing + ridging or ridge till. The experiment was established on a newly cleared land that had been under fallow (native vegetation regrowth) for about 6 years. With some exceptions, soil physical properties were measured in the dry season from 1980 through 1987, year by year. Maize grain yield was significantly affected by tillage treatments in 3 of 8 years only in Season 1. Notill + residue mulch produced the highest yield in both seasons. In addition, ploughing + residue mulch produced high yield in the first season only. Mean maize grain yield (averaged for 8 years) was 3.1 Mg ha(-1) in the first season compared with 1.4 Mg ha(-1) in the second. Maize gain yield in the first season increased from 2.3 Mg ha(-1) in 1980 to 4.4 Mg ha(-1) in 1984 and then progressively declined to 1.6 Mg ha(-1) in 1987. In the second season, grain yield was highly variable and depended on the rainfall amount and distribution. Complete crop failure occurred in Season 2 of 1983. The highest seasonal yield of 2.5 Mg ha(-1) was in 1984, and yield progressively declined to 0.6 Mg ha(-1) in 1987. Tillage treatments had no effect on soil bulk density of the surface 0 to 10 cm depth which progressively increased with cultivation duration. After 8 years, sand content was significantly lower and clay content significantly higher in the surface 0-10-cm layer of notill + mulch compared with plough-based and unmulched treatments. Equilibrium infiltration rate was rapid in all treatments, but significantly higher in notill compared with ridged treatment. Maize monocropping had drastic adverse effects on soil quality and crop yield. Adverse effects were more drastic in plough-based systems - residue mulch than with the notill system + residue mulch. (C) 1997 Elsevier Science B.V.","","","Long-term tillage and maize monoculture effects on a tropical Alfisol in western Nigeria. II. Soil chemical properties","","West Africa Sub-soiling Soil quality Soil degradation Soil bulk density Mulch farming Moisture retention characteristics Infiltration rate consecration tillage Available water capacity ","Journal Article " "Long-term tillage and maize monoculture effects on a tropical Alfisol in western Nigeria .2. Soil chemical properties","Lal R","1997","SOIL & TILLAGE RESEARCH","lal2.pdf","42","3","161-174","","Intensive monocropping of maize is widely practised in densely populated regions of west Africa. A wide range of tillage systems are used for seedbed preparation without the benefits of research information from long-term experiments relating tillage method to soil properties. Soil chemical effects of eight tillage and residue management treatments were studied for 8 years or 16 consecutive maize monoculture crops for a western Nigerian soil with a coarse-textured surface horizon. Treatments established on a newly cleared land were: (1) notill +/- crop residue mulch, (2) notill +/- chiselling in the row zone at 50 cm depth, (3) mouldboard ploughing +/- harrowing, (4) disc ploughing +/- rotovation, (5) notill - residue mulch, (6) mouldboard ploughing at the end of rains or summer ploughing, (7) mouldboard ploughing +/- residue mulch, and (8) mouldboard ploughing and harrowing +/- ridging or ridge till. Soil chemical properties of the 0-5-cm and 5-10-cm depths were measured during the dry season every year beginning with base line characterization soon after land clearing in 1980. Soil pH declined with cultivation duration from 6.6 in 1981 to 5.4 in 1987 for the 0-5-cm depth, and from 6.5 in 1981 to 5.5 in 1987 for the 5-10-cm depth. Mean soil pH for the 0-5-cm depth declined from 6.7 to 5.6 in notill +/- residue mulch, and from 6.7 to 5.4 with mouldboard ploughing. Soil content of Bray P increased with cultivation duration due to application of phosphatic fertilizers. There occurred a significant decrease in soil organic carbon (SOC) and total soil nitrogen (TSN), and an increase in C:N ratio with cultivation duration. Mean SOC content in 1987 of the 0-5-cm depth was 13.9 g kg(-1) for the notill treatment compared with 11.0 g kg(-1) for the plough-based methods. Soil concentration Ca and Mg and total cation exchange capacity (CEC) increased with cultivation duration. Maize grain yield was significantly correlated with SOC, exchangeable Ca2+, and CEC. Continuous cropping decreased soil chemical quality, and the rate of decreases was more with plough-based than notill methods. (C) 1997 Elsevier Science B.V.","","","Long-term tillage and maize monoculture effects on a tropical Alfisol in western Nigeria. II. Soil chemical properties","","West Africa total soil nitrogen Sub-soiling Soil quality soil organic carbon Soil degradation maize cropping systems Conservation tillage cation exchange capacity acidification ","Journal Article " "Long-term tillage and maize monoculture effects on a tropical Alfisol in western Nigeria.","Lal. R.","1997","Soil & Tillage Research","Lal_R1997.pdf","42","3","145-160","10.1016/S0167-1987(97)00006-8","A wide range of tillage methods (e.g. mouldboard ploughing, discing, harrowing, chiselling, notill, ridge till, and their combinations) are used for continuous maize (Zea mays L.) cropping in western Nigeria without the benefits of experimental data on their comparative effects on soil properties and crop response. Therefore, the main objective of this experiment was to evaluate the impact of a range of tillage methods and continuous maize culture on grain and stover yields and degradative effects on soil properties. Tillage-induced changes in soil physical properties and maize yields were studied for 8 consecutive years from 1980 through 1987. Two crops were grown every year in the two rainy seasons. Season 1 lasted from April through July and Season 2 from August to November. The eight tillage treatments studied were: (1) notill + residue mulch, (2) notill + chiselling in the row zone to 50 cm depth, (3) mouldboard ploughing + harrowing, (4) disc ploughing + rotovation, (5) notill — residue mulch, (6) mouldboard ploughing at the end of rains or summer ploughing, (7) mouldboard ploughing and harrowing + residue mulch, (8) mouldboard ploughing and harrowing + ridging or ridge till. The experiment was established on a newly cleared land that had been under fallow (native vegetation regrowth) for about 6 years. With some exceptions, soil physical properties were measured in the dry season from 1980 through 1987, year by year. Maize grain yield was significantly affected by tillage treatments in 3 of 8 years only in Season 1. Notill + residue mulch produced the highest yield in both seasons. In addition, ploughing + residue mulch produced high yield in the first season only. Mean maize grain yield (averaged for 8 years) was 3.1 Mg ha−1 in the first season compared with 1.4 Mg ha−1 in the second. Maize grain yield in the first season increased from 2.3 mg ha−1 in 1980 to 4.4 Mg ha−1 in 1984 and then progressively declined to 1.6 Mg ha−1 in 1987. In the second season, grain yield was highly variable and depended on the rainfall amount and distribution. Complete crop failure occurred in Season 2 of 1983. The highest seasonal yield of 2.5 Mg ha−1 was in 1984, and yield progressively declined to 0.6 Mg ha−1 in 1987. Tillage treatments had no effect on soil bulk density of the surface 0 to 10 cm depth which progressively increased with cultivation duration. After 8 years, sand content was significantly lower and clay content significantly higher in the surface 0–10-cm layer of notill + mulch compared with plough-based and unmulched treatments. Equilibrium infiltration rate was rapid in all treatments, but significantly higher in notill compared with ridged treatment. Maize monocropping had drastic adverse effects on soil quality and crop yield. Adverse effects were more drastic in plough-based systems — residue mulch than with the notill system + residue mulch.","","","Long-term tillage and maize monoculture effects on a tropical Alfisol in western Nigeria","","West Africa Sub-soiling Soil quality Soil degradation Soil bulk density Mulch farming Moisture retention characteristics Infiltration rate Conservation tillage Available water capacity ","Journal Article " "Long-Term Tillage Study Bibliography","Multiple","2005","Multiple","Long-term_0.pdf","","","","","","","Long-term Tillage Study - Northwest ARS","Long-term Tillage Study (Hoytville - Northwest ARS)Long-term Tillage Study (S. Charleston - Western ARS)Long-Term Tillage Study (Wooster Triplett-VanDoren)","","","Journal Article " "Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass","Callaham MA, Blair JM, Todd TC, Kitchen DJ, Whiles MR","2003","SOIL BIOLOGY & BIOCHEMISTRY","Callaham_MA2003.pdf","35","2003","1079-1093","10.1016/S0038-0717(03)00153-6","The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. q 2003 Elsevier Science Ltd. All rights reserved.","","","Konza Prairie","","Scarabaeidae Phosphorus Nitrogen Insect herbivores Grassland fire Fertilizer Fertilization Elateridae Earthworms Disturbance Curculionidae Cicadidae biomass ","Journal Article " "Management effects on the dynamics and storage rates of organic matter in long-term crop rotations","Paul, E. A., H. P. Collins, K. Paustian, E. T. Elliott, S. Frey, N. Juma, H. Janzen, C. A. Campbell, R. P. Zentner, G. P. Lafond, and A. P. Moulin","2004","Canadian Journal of Soil Science ","","84: 49-61","","","","Factors controlling soil organic matter (SOM) dynamics in soil C sequestration and N fertility were determined from multi-site analysis of long-term, crop rotation experiments in Western Canada. Analyses included bulk density, organic and inorganic C and N, particulate organic C (POM-C) and N (POM-N), and CO2-C evolved during laboratory incubation. The POM-C and POM-N contents varied with soil type. Differences in POM-C contents between treatments at a site (δPOM-C) were related (r2 = 0.68) to treatment differences in soil C (δSOC). The CO2-C, evolved during laboratory incubation, was the most sensitive indicator of management effects. The Gray Luvisol (Breton, AB) cultivated plots had a fivefold difference in CO2 -C release relative to a twofold difference in soil organic carbon (SOC). Soils from cropped, Black Chernozems (Melfort and Indian Head, SK) and Dark Brown Chernozems (Lethbridge, AB) released 50 to 60% as much CO2 -C as grassland soils. Differences in CO2 evolution from the treatment with the lowest SOM on a site and that of other treatments (δCO2 -C) in the early stages of the incubation were correlated to δPOM-C and this pool reflects short-term SOC storage. Management for soil fertility, such as N release, may differ from management for C sequestration.","","","Breton Plots","","soil management soil C and N POM-C and N Multi-site analysis CO2 evolution ","Journal Article " "Manure Fertilization for Soil Organic Matter Maintenance and its Effects Upon Crops, and the Environment, Evaluated in a Long-term Trial","Raupp, J.","2001","In: Sustainable Management of Soil Organic Matter; CABI Publishing, Wallingford, Oxon UK","Raupt_J2001.pdf","","","301-308","","","","","Long-term Fertilization Trial","","","Journal Article " "Methods for determining organic carbon in Podzolic sands","LOWTHER J. R. (1) ; SMETHURST P. J. ; CARLYLE J. C. ; NAMBIAR E. K. S.","1990","Communications in soil science and plant analysis (Commun. soil sci. plant anal.) ","","vol. 21, no5-6, pp. 457-470 (23 ref.)","","","","Dichromate oxidation with and without external heating recovered 99.1 and 88.8% of total carbon respectively, indicating that all carbon was organically bound, and that the «heat of reaction» was not sufficient for total oxidation of organic carbon. Because the organic carbon content of the organic matter varied from 38% to 55% a mean value of 46% would be more appropriate for these soils than the Van Bemmelen factor of 58% for converting organic matter to organic carbon concentration. The loss-on-ignition procedure represents a precise technique for the estimation of organic matter and, when calibrated, organic carbon in surface sandy soils.","","","","","","Journal Article " "Multiple","Multiple","","Multiple","CEFS.pdf","","","","","","","","Center for Environmental Farming Systems","","","Journal Article " "Nitrogen balance in the Magruder plots following 109 years in continuous winter wheat","Davis RL, Patton JJ, Teal RK, Tang Y, Humphreys MT, Mosali J, Girma K, Lawles JW, Moges SM, Malapati A, Si J, Zhang H, Deng S, J","2003","JOURNAL OF PLANT NUTRITION","9947228.pdf","26","8","1561-1580","10.1081/PLN-120022364","The Magruder plots are the oldest continuous soil fertility wheat research plots in the Great Plains region, and are one of the oldest continuous soil fertility wheat plots in the world. They were initiated in 1892 by Alexander C. Magruder who was interested in the productivity of native prairie soils when sown continuously to winter wheat. This study reports on a simple estimate of nitrogen (N) balance in the Magruder plots, accounting for N applied, N removed in the grain, plant N loss, denitrification, nonsymbiotic N fixation, nitrate (NO3-) leaching, N applied in the rainfall, estimated total soil N (0-30 cm) at the beginning of the experiment and that measured in 2001. In the Manure plots, total soil N decreased from 6890 kg N ha(-1) in the surface 0-30 cm in 1892, to 3198 kg N ha(-1) in 2002. In the Check plots (no nutrients applied for 109 years) only 2411 kg N ha(-1) or 35% of the original total soil organic N remains. Nitrogen removed in the grain averaged 38.4 kg N ha(-1) yr(-1) and N additions (manure, N in rainfall, N via symbiotic N fixation) averaged 44.5 kg N ha(-1) yr(-1) in the Manure plots. Following 109 years, unaccounted N ranged from 229 to 1395 kg N ha(-1). On a by year basis, this would translate into 2-13 kg N ha(-1) y(-1) that were unaccounted for, increasing with increased N application. For the Manure plots, the estimate of nitrogen use efficiency (NUE) (N removed in the grain, minus N removed in the grain of the Check plots, divided by the rate of N applied) was 32.8%, similar to the 33% NUE for world cereal production reported in 1999.","","","Magruder Plots","","wheat production nitrogen use efficiency manure ","Journal Article " "Nitrogen mineralization, N 2O production and soil microbiological properties as affected by long-term applications of sewage sludge","Zaman, M. et al.","2004","Biology and Fertility of Soils","zaman.pdf","40","2","101-109","10.1007/s00374-004-0746-2","A field study was conducted to investigate the long-term effect of surface application of sewage sludge composts vs chemical N fertilizer on total N, total C, soluble organic C, pH, EC, microbial biomass C and N, protease activity, deaminase activity, urease activity, gross and net rates of N mineralization and nitrification, CO2 evolution, and N2O production. Soil samples were taken from five depths (0–15, 15–20, 20–30, 30–40, and 40–50 cm) of a long-term experiment at the University of Tokyo, Japan. Three fields have been receiving sewage sludge composted with rice husk (RH), sawdust (SD), or mixed chemical fertilizer NPK (CF), applied at the rate of 240 kg N ha–1 each in split applications in summer and autumn since 1978. Significantly higher amounts of total N and C and soluble organic C were found in the compost than in the CF treatments up to the 40-cm soil depth, indicating improved soil quality in the former. In the CF treatment, soil pH values were significantly lower and electrical conductivity values were significantly higher than those of compost-treated soils of up to 50 cm depth. Soil microbial biomass C and N, CO2 evolution, protease, deaminase, and urease activities were significantly higher in the compost than in the CF treatments due to greater availability of organic substrates that stimulated microbial activity. Gross N mineralization rates determined by 15N dilution technique were eight and five times higher in the SD and RH treatments than in the CF treatment, respectively, probably due to high levels of microbial and enzyme activities. Net N mineralization rates were also significantly higher in the compost treatments and were negative in the CF treatment indicating immobilization. Net nitrification rates were higher in compost treatments and negative in the CF treatment. Nitrous oxide productions from compost treatments were higher than the CF treatment due to the greater availability of mineral N as a result of higher mineralization and nitrification rates and soluble organic C in the former. Most of the measured parameters were highest in the surface soil (0–15 cm) and were significantly higher in the SD treatment than in the RH treatment.","","","N Mineralization, N20 production, microbes and sewage sludge","","Nitrification N2O microbial biomass Gross N mineralization CO2 ","Journal Article " "Organic Phosphorus in Soil Size Separates Characterized by Phosphorus-31 Nuclear Magnetic Resonance and Resin Extraction","Rubaek GH, Guggenberger G, Zech W, Christensen BT","1999","SOIL SCIENCE SOCIETY OF AMERICA JOURNAL","1123.pdf","63","5","1123-1132","","Land use and soil management affect soil organic C in whole soil and size separates, but knowledge of the accompanying soil organic P (P-o) is limited. The objectives of this study were (i) to identify the structure of P-o in soil size separates by solution P-31-nuclear magnetic resonance (NMR) spectroscopy, (ii) to determine the labile P-o pool in:the size separates by anion-exchange resin extraction, and (iii) to characterize the labile P-o pool, We used soils from two long-term experimental: sites, one in Bavaria (under spruce and deciduous forests, permanent grassland, and arable farming) and one in Denmark (with arable rotation and different fertilization strategies - unfertilized, mineral fertilizer, and animal manure), Total P-o content increased with decreasing particle size. The dialyzed NaOH extracts of clay were enriched in microbial-derived teichoic acid-P and other diester-P forms compared with silt and sand. Clay from permanently vegetated soil had larger proportions of teichoic acid-P and other diester-P forms and was richer in resin extractable P-o than clay from arable soil. There was a linear relationship between the proportion of the P-31-NMR spectra allocated to diester-P (including teichoic acid-P) and resin-P-o Our results suggest that the highly active and easily mineralized soil P-o was mainly associated with clay. The larger part of the day-associated P-o was tightly bound and not extractable. Although the composition of this P-o remained unknown, it was probably inaccessible to rapid microbial utilization. The composition of NaOH-extractable P-o in the clay fraction was influenced to a greater extent by land use than bg fertilizer inputs.","","Askov Long-Term Experiments","Askov Long-Term Experiments on Animal Manure and Mineral Fertilizers - LermarkenAskov Long-Term Experiments on Animal Manure and Mineral Fertilizers - Sandmarken","","STRAW INCORPORATION SPECTROSCOPY MATTER LONG-TERM FIELD EXPERIMENTS LAND-USE Grassland FRACTIONS CULTIVATION CARBON C-13 NMR ","Journal Article " "Patterns and mechanisms of soil acidification in the conversion of grasslands to forests","Jobbágy, E.G. and R.B. Jackson.","2003","Biogeochemistry","Jobbagy_EG2003 - Acidification and afforestation.pdf","64","","205-229","","","","","Grassland Afforestation - Flooding Pampas","","","Journal Article " "Phosphorus removal in created wetland ponds receiving","Nairn, Robert W. and William J. Mitsch","2000","Ecological Engineering","Nairn_R_EcoEng_2000.pdf","14","","107 - 126","","Water quality changes and biogeochemical development were evaluated over 2 years in two newly created freshwater riparian wetland ponds (1 ha each) in an agricultural and urban watershed. Both wetlands received pumped river water and had similar hydrologic regimes. One wetland was planted with 13 species of vegetation typical of Midwestern US marshes; the other received no planted vegetation. Water quality sampling was conducted weekly and detailed hydrologic budgets were developed from data collected twice daily. Hydrologic budgets were dominated by pumped surface flows (mean inflow1480 m3 day1). Two floods accounted for 32% of inflow in 1 year. Both wetlands significantly decreased turbidity (62 to 27 NTU) and increased dissolved oxygen (9–11 mg l1). Inflow dissolved reactive phosphorus (DRP) and total phosphorus (TP) concentrations (1793 and 169911 mg P l1) were significantly higher (PB0.05) than outflow concentrations (DRP: 591 and 691 mg P l1; TP: 6998 and 7499 mg P l1) for planted and unplanted wetlands, respectively. Phosphorus removal was related to decreases in turbidity and the level of biological activity. Extensive and highly productive algal coverage in both wetlands and the subsequent deposition and decomposition of the algal mat influenced P retention through biological uptake and chemical sorption and coprecipitation. Mean removal rates were 1.0 g P m2 year1 for DRP and 5.4 g P m2 year1 for TP and did not differ significantly between wetlands (PB0.05). Approximately 35% of TP mass removal occurred during two floods. A conservative tracer (Cl) indicated limited and negligible effects of dilution on decreases in P concentration. Water flow rate and P concentration did not affect P removal which was loading-limited and seasonal. Initial development of macrophytic vegetation demonstrated no influence on water quality changes. Both wetlands acted as effective P sinks in the initial 2 years of operation. © 2000 Elsevier Science B.V. All rights reserved.","","","The Olentangy River Wetland Research Park","","Nonpoint source pollution Water quality Created wetlands Phosphorus Pollutant removal Wetland Freshwater marsh Olentangy River Olentangy River Wetland Research Park Ohio ","Journal Article " "Potassium balance and uptake under continuous cropping of rice in an Alfisol","Jegadeeswari, P.V., P. S. Senthil Kumar and K. Kumaraswamy","2001","Crop Research","","22","2","194-200","","","","","Permanent Manurial Experiment under rice monoculture, Madurai, Tamil Nadu, India","","","Journal Article " "PROCESSES OF SOIL ORGANIC-MATTER ACCRETION AT A MUDFLOW CHRONOSEQUENCE, MT. SHASTA, CALIFORNIA","Sollins, P., G. Spycher, and C. Topik.","1983","Ecology","Sollins_P1983 Carbon accretion on mudfloe Mt Shasta CA.pdf","64","5","1273-1282","","Amounts of carbon and nitrogen were measured in bulk soils and component density fractions from four mudflows (A. B. D. E) of increasing age at Mt. Shasta. California. in order to gain insight into mechanisms of soil organic-matter accretion. Soil was divided into a light fraction (specific gravity < 1.65 g/cm^2 in which organic matter consisted mainly of root fragments and other plant remnants and a heavy fraction in which most of the organic matter was adsorbed on mineral surfaces and occluded within organomineral microaggregates. In bulk soil and the heavy fraction, amounts of C and N increased consistently with How age and were even greater at an older, mineralogically similar site previously studied in the Oregon Cascade Range. Amounts of light-fraction C and N increased from flow A to D but were lower at flow E. Regardless of soil age, the heavy fraction contained 55-88% of the total soil N and 37-72% of the total soil C. Thus. the heavy fraction is the major long-term sink for N and an important sink for C. Soil properties and vegetation were exceptionally variable at the D and E flows. A multiple regression on rockiness of the soil (volume of fragments > 2 mm) and a tree index (reflecting number and size of trees near each soil-sampling point and their proximity) accounted for 50-80% of the variability in light-fraction C and N at the D and E Hows but not at the A and B flows. where all parameters were less variable. Rockiness and the tree index accounted for little of the variability in heavy-fraction C and N. indicating that light- and heavy-fraction organic-matter accumulate in response to different factors. It appears that mass and composition of light-fraction organic matter correlate with short-term changes in biological activity, whereas heavy-fraction organic matter accumulates steadily and correlates with long-term processes such as mineral weathering and soil horizon formation.","","Long-term Tillage Study - Northwest ARS","","Mt. Shasta CA Mudflow Chronosequence","","Journal Article " "Rapid accumulation and turnover of soil carbon in a re-establishing forest","Richter DD, Markewitz D, Trumbore SE, Wells CG","1999","NATURE","2004568.pdf","400","6739","56-58","","Present understanding of the global carbon cycle is limited by uncertainty over soil-carbon dynamics(1-6). The clearing of the world's forests, mainly for agricultural uses, releases large amounts of carbon to the atmosphere (up to 2 x 10(15) g yr(-1)), much of which arises from the cultivation driving an accelerated decomposition of soil organic matter(1-4). Although the effects of cultivation on soil carbon are well studied, studies of soil-carbon recovery after cultivation are limited(4-11). Here we present a four-decade-long field study of carbon accumulation by pine ecosystems established on previously cultivated soils in South Carolina, USA(7). Newly accumulated carbon is tracked by its distinctive C-14 signature, acquired around the onset of forest growth from thermonuclear bomb testing that nearly doubled atmospheric (CO2)-C-14 in the 1960s. Field data combined with model simulations indicate that the young aggrading forest rapidly incorporated bomb radiocarbon into the forest floor and the upper 60 cm of underlying mineral soil. By the 1990s, however, carbon accumulated only in forest biomass, forest floor, and the upper 7.5 cm of the mineral soil. Although the forest was a strong carbon sink, trees accounted for about 80%, the forest floor 20%, and mineral soil <1%, of the carbon accretion. Despite high carbon inputs to the mineral soil, carbon sequestration was limited by rapid decomposition, facilitated by the coarse soil texture and low-activity clay mineralogy.","","","Calhoun Long-Term Soil-Ecosystem Experiments","","TEMPERATE STORAGE long-term experiments LOBLOLLY-PINE ECOSYSTEMS CYCLE 3 DECADES ","Journal Article " "Reducing tillage intensity - a review of results from a long-term study in Germany","Tebrugge F, During RA","1999","SOIL & TILLAGE RESEARCH","Tebrügge.pdf","53","1","15-28","","This paper reviews research performed at the Justus-Liebig-University of Giessen, Germany into the impact of different tillage systems on soil properties and quality. The impact of intensive soil tillage treatments on several soil properties was described by means of selected data obtained through long-term interdisciplinary research. The experiments were based on comparative application (long-term, up to 18 years investigations) of the respective tillage options on different soils (e.g. Eutric Cambisol, Eutric Fluvisol) ranging in texture from sand to a silt loam. These soils are located at five field sites with different crop rotations in the central German state of Hesse. Tillage intensity of the systems was considered to decrease in the following sequence: Conventional plough tillage (CT), reduced tillage (RT), and no-tillage (NT). For elucidating the impact of tillage intensity, the tillage extremes CT and NT were compared. Physical conditions of soil as influenced by the application of RT were considered to be intermediate between CT and NT. In general, bulk density in the upper layer of NT soils was increased, resulting in a decrease in the amount of coarse pores, and a lower saturated hydraulic conductivity when compared with the CT and RT soils. Surface cover by crop residues and higher aggregate stability under NT protected soil fertility by avoiding surface sealing and erosion. Lateral losses of herbicides were also reduced under NT conditions, whereas the susceptibility for preferential vertical transport of herbicides needs further evaluation. Accumulation of organic matter and nutrients near the soil surface under NT and RT were favorable consequences of not inverting the soil and by maintaining a mulch layer on the surface. Those improvements were associated with enhanced biological activities in NT and RT topsoils. Increased earthworm activity in NT treatments was associated with a system of continuous macropores which improved water infiltration rates. Earthworms support decomposition and incorporation of straw. Soils which have not been tilled for many years were more resistant to vehicle passage; consequently, the compaction by traffic was lower. Penetration resistance curves indicate that a uniformly stable structure had developed over the years in NT soils. Overall, the results show that RT and NT were beneficial to the investigated soil properties. If crop rotation, machinery, and plant protection are well adapted for the introduction of conservation tillage, these systems may replace conventional ploughing systems in many cases in German agriculture. (C) 1999 Elsevier Science B.V. All rights reserved.","","","Crop rotation/fertilization trial F1-07 (Seehausen)","","Tillage soil structure soil protection no-tillage herbicide displacement erosion ","Journal Article " "Reflections on the nature of soil and its biomantle.","Johnson, D.L., J.E.J. Domier, and D.N. Johnson.","2005","Annals of the Association of American Geographers","Johnson_DL2005 reflections on soil.pdf","95","","11-31","","Apart from the engineering approach to soil as movable regolith, most specialists who study soil view it as a plantlinked, land-only, and Earth-only entity whose character and properties are explained by a mix of four environmental factors—climate, organisms, relief, and parent material—that operate over time. These factors function to produce soil, where S5f (cl, o, r, p, t . . .). This relationship constitutes the five-factors, ‘‘clorpt,’’ explanatory model of soil formation that lends itself to the survey, classification, and mapping of soil for agricultural and environmental purposes and aids in soil valuations and soil conservation-management needs. In geomorphology and Quaternary research, it has met success in soil chronosequence and age-dating studies. But inasmuch as soil is the most complex and unparsimonious of all natural science entities, is any model so conceptually endowed that it allows a deep understanding of the full range and nuances of soil-forming processes? Can a conventional model provide new visions and different levels of knowledge beyond conventional levels? We present a multifaceted and biodynamic approach that views soil in different ways. One is that soil is the outer integument, or ‘‘skin’’ of all lithic-composed celestial bodies, planets, their satellites, and such. But Earth differs from others because water covers nearly three-fourths of its surface and life covers nearly all of its surface and produces a biodynamically mediated ‘‘epidermis’’—a biomantle that other planets lack. The biomantle constitutes a subaerial-subaqueous continuum across the globe. Life imparts myriad biomechanical and biochemical processes— biodynamic processes—to the soil-biomantle continuum, and these coact with physical processes in producing soil landscapes. This multifaceted approach is embedded as a component of the dynamic denudation framework of landscape evolution, which carries useful and different explanatory and predictive powers for studying the global soil-biomantle that may be invisible, unacknowledged, or unstressed in other frameworks, including one where ‘‘organisms’’ essentially means plants. To appreciate how our approach differs from conventional views of soil formation, and to provide a historic context, we reflect on the nineteenth- and twentiethcentury turning points in Earth sciences, mainly in geography, geology, and soils, which led to the five-factors (clorpt) model as the sine qua non way to explain soils. The details of our approach then follow. Key Words: soil, biomantle, bioturbation, biodynamic processes, dynamic denudation, ichnology, subaerial-subaqueous soils, Darwin, Dokuchaev.","","","","","","Journal Article " "Response of radish to varying levels of irrigation water and fertilizer potassium on clay terrace soil of Bangladesh","Bokhtiar Shaikh Md., A. J. M. Sirajul Karim, Khandaker Majidul Hossain, Tofazzal Hossain, and Kazuhiko Egashira","2001","Commun. Soil Sci. Plant Anal.","Bokhtiar_S_M_2001.pdf","32","17-18","2979-299","","A field experiment was conducted in the rabi (dry) season of 1998–99 on a clay terrace soil of Bangladesh, in order to study the effects of irrigation and potassium (K) fertilization on the yield, total water use, and water use efficiency of radish. Both irrigation and K application were found to be indispensable for increasing the yield of radish, due to their individually significant impact on the yield. The interaction effect of irrigation and K application was insignificant, but the highest yield of 30.1 Mg ha21 was obtained under the highest levels of irrigation and K application (four irrigations with 160 kg K2O ha-1) as the positive effects of both treatments on the radish yield. From the economic viewpoint, the yield of 29.9 Mg ha-1 under four irrigation levels with 120 kg K2O ha-1 gave the highest net benefit. The total water use in this case was 101 mm, having the water use efficiency 297 kg ha-1mm-1. Based on the acceptable economic yield, high water use efficiency, and the maintenance of proper soil fertility, four irrigation levels and K application at the level of 120 kg K2O ha-1 proved to be the best combination for the sustainable radish cultivation in Shallow Red–Brown Terrace Soil of Bangladesh.","","","Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU) research farm","","","Journal Article " "Response of soil phosphorus content, growth and yield of wheat to long-term phosphorus fertilization in a conventional cropping system","Otto WM, Kilian WH","2001","NUTRIENT CYCLING IN AGROECOSYSTEMS","otto.pdf","61","3","283-292","10.1023/A:1013725207016","The effect of annual banding of superphosphate (0-45 kg P ha(-1)) on soil phosphorus (P) content, growth, and yield of wheat was investigated from 1982 to 1998 in a major rainfed wheat production area of South Africa. Conventional tillage practices in a wheat monoculture cropping system were followed under summer rainfall conditions. The responses of wheat growth to fertilizer P application were evident during early and late tillering growth stages, with decreased responses towards maturity. Although average yields varied between cropping seasons (0.881 to 3.261 t ha(-1)) due to climatic conditions, significant exponential response patterns between yield and fertilizer P applications existed. Optimum yields were achieved with P applications of 10 to 15 kg P ha(-1). The recovery of fertilizer P in the grain decreased with increasing P applications. Results of soil P analyses and calculated P balance indicated a more rapid increase in soil P content with application of fertilizer P at levels above 20 kg P ha(-1), with gradual increases occurring at lower levels.","","","Response of soil phosphorus content, growth and yield of wheat to long-term phosphorus fertilization in a conventional cropping system","","Triticum aestivum soil analysis values Phosphorus banding ","Journal Article " "Reversal of rice yield decline in a long-term continuous cropping experiment","Dobermann, Achim","2000","Agronomy Journal","Dobermann_A2000.pdf","92","","633-643","","In a long-term continuous cropping experiment at Los Ban˜ os, Philippines, three rice (Oryza sativa L.) crops were grown each year with the goals of maximum annual grain production and high N use efficiency. Our objective was to identify the factors responsible for the restoration of yields occurring after 1991. From 1968 to 1991, grain yields declined at an annual rate of 1.4 to 2.0%. From 1991 to 1995, dry season (DS) yields in the highest N treatment increased towithin 80 to 100% of the simulated yield potential; yields in the unfertilized control did not increase. Increased solar radiation, increased N rate, and improved timing of N applications accounted for the restoration of yields in the DS. Wet season yields increased in fertilized and unfertilized plots due to greater solar radiation, im- proved timing of N applications, and increased soil N supply due to fallow periods in three years. Residual benefits of soil aerationwere short-term. Reducing preplant N fertilizer and increasing the number of split applications had a greater effect on increasing yield than the increase in the amount of N applied. Our results provide evidence that N deficiency caused the yield decline before 1991. However, the actual processes that caused a decline in soil N supply or plant N uptake remain to be determined. It is possible to sustain high yields and high N use efficiency if fertilizer regimes are updated regularly to maintain the congruence between crop N demand and the N supply from soil and fertilizer.","","","Long-Term Continuous Cropping Experiment","","","Journal Article " "Review of long-term agronomic experiments in Victoria","Crawford, M., R. Sonogan, M. Unkovich and I. Yunusa","2003","Centre for Land Protection Research (Vic.). Research Report 35","VictoriaDPI2003 review of LTEs in Victoria AU.pdf","","","","","","","","","","","Journal Article " "Seasonal Changes in N2 Fixation Activity and N Enrichment in Paddy Soils as Affected by Soil Management in the Northern Area of","Kondo, Motohiko and Michio Yasuda","2003","JARQ","N2.pdf","37","2","105-111","","Enhancing the indigenous ability of biological N2 fixation (BNF) in paddy soils to increase N fertility is important to develop sustainable rice cultivation systems. This study aimed at evaluating the effect of light conditions and long-term soil management on the seasonal changes in the BNF activity of paddy soils associated with the decomposition of rice straw and cellulose, by determining the acetylene reduction activity (ARA) and N enrichment in the Tohoku region of Japan under cool temperate conditions. ARA of the straw applied on the soil surface showed a peak in the mid-cropping season in the summer. The ARA of the straw applied in autumn was 30% of that in spring application. Carbon use efficiency for N enrichment with cellulose was about 3 times higher under light than dark conditions. Among the long-term soil management practices, continuous application of fresh organic materials such as rice straw and manure considerably enhanced N enrichment and ARA. In the soil without P, the inhibition of N enrichment by the low P availability appeared in the early cropping season. Soils from paddy fields converted to upland fields (hereafter referred to as “converted upland soils”) showed the highest level of N enrichment when the soils were amended with cellulose. The highest level of N enrichment with and without cellulose amendment was estimated to be 1.6–2.0 g m–2 in one cropping season. The results indicated the important contribution of BNF even under cool temperate conditions and the significant effect of soil management related to organic matter application and the water regime on the magnitude of BNF and, therefore, possibly on the N cycling of the paddy soil systems.","","","N2 fixation in paddy soils","","Tohoku region straw SOILS plant nutrition fertilizers cellulose ","Journal Article " "SERRANA INTA - A WIDELY ADAPTED, VIRUS RESISTANT POTATO CULTIVAR FROM ARGENTINA","HUARTE MA, MENDIBURU AO, MONTI MC, BUTZONITCH IP","1986","AMERICAN POTATO JOURNAL","","63","12","695-699","","","","","Breeding of Improved Potato Cultivars","","","Journal Article " "Simulating soil C dynamics with EPIC: Model description and testing against long-term data","Izaurralde RC, Williams JR, McGill WB, Rosenberg NJ, Jakas MCQ","2006","ECOLOGICAL MODELLING","Izaurralde2.pdf","192","3-4","362-384","10.1016/j.ecolmodel.2005.07.010","Soil carbon sequestration (SCS) has emerged as a technology with significant potential to help stabilize atmospheric CO2 concentrations and thus reduce the threat of global warming. Methods and models are needed to evaluate and recommend SCS practices based on their effects on carbon dynamics and environmental quality. Environment Policy Integrated Climate (EPIC) is a widely used and tested model for simulating many agroecosystem processes including plant growth, crop yield, tillage, wind and water erosion, runoff, soil density, and leaching. Here we describe new C and N modules developed in EPIC built on concepts from the Century model to connect the simulation of soil C dynamics to crop management, tillage methods, and erosion processes. The added C and N routines interact directly with soil moisture, temperature, erosion, tillage, soil density, leaching, and translocation functions in EPIC. Equations were also added to describe the effects of soil texture on soil C stabilization. Lignin concentration is modeled as a sigmoidal function of plant age. EPIC was tested against data from a conservation reserve program (CRP) 6-year experiment at five sites in three U.S. Great Plains states and a 61-year long-term agronomic experiment near Breton, Canada. Mean square deviations (MSD) calculated for CRP sites were less than 0.01 (kg C m(-2))(2), except for one site where it reached 0.025 (kg C m(-2))(2). MSD values in the 61-year experiment ranged between 0.047 and 0.077 (kg C m(-2))(2). The version of the EPIC model presented and tested here contains the necessary algorithms to simulate SCS and improve understanding of the interactions among soil e