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Paul Mader - One of the best experts on this subject based on the ideXlab platform.

  • yield and economic performance of organic and Conventional cotton based Farming systems results from a field trial in india
    PLOS ONE, 2013
    Co-Authors: Dionys Forster, Christian Andres, Rajeev Kumar Verma, Christine Zundel, Monika Messmer, Paul Mader
    Abstract:

    The debate on the relative benefits of Conventional and organic Farming systems has in recent time gained significant interest. So far, global agricultural development has focused on increased productivity rather than on a holistic natural resource management for food security. Thus, developing more sustainable Farming practices on a large scale is of utmost importance. However, information concerning the performance of Farming systems under organic and Conventional management in tropical and subtropical regions is scarce. This study presents agronomic and economic data from the conversion phase (2007–2010) of a Farming systems comparison trial on a Vertisol soil in Madhya Pradesh, central India. A cotton-soybean-wheat crop rotation under biodynamic, organic and Conventional (with and without Bt cotton) management was investigated. We observed a significant yield gap between organic and Conventional Farming systems in the 1st crop cycle (cycle 1: 2007–2008) for cotton (−29%) and wheat (−27%), whereas in the 2nd crop cycle (cycle 2: 2009–2010) cotton and wheat yields were similar in all Farming systems due to lower yields in the Conventional systems. In contrast, organic soybean (a nitrogen fixing leguminous plant) yields were marginally lower than Conventional yields (−1% in cycle 1, −11% in cycle 2). Averaged across all crops, Conventional Farming systems achieved significantly higher gross margins in cycle 1 (+29%), whereas in cycle 2 gross margins in organic Farming systems were significantly higher (+25%) due to lower variable production costs but similar yields. Soybean gross margin was significantly higher in the organic system (+11%) across the four harvest years compared to the Conventional systems. Our results suggest that organic soybean production is a viable option for smallholder farmers under the prevailing semi-arid conditions in India. Future research needs to elucidate the long-term productivity and profitability, particularly of cotton and wheat, and the ecological impact of the different Farming systems.

  • soil organic matter and biological soil quality indicators after 21 years of organic and Conventional Farming
    Agriculture Ecosystems & Environment, 2007
    Co-Authors: Andreas Fliesbach, Hansrudolf Oberholzer, Lucie Gunst, Paul Mader
    Abstract:

    Organic Farming systems often comprise crops and livestock, recycle farmyard manure for fertilization, and preventive or biocontrol measures are used for plant protection. We determined indicators for soil quality changes in the DOK long-term comparison trial that was initiated in 1978. This replicated field trial comprises organic and integrated (Conventional) Farming systems that are typical for Swiss agriculture. Livestock based bio-organic (BIOORG), bio-dynamic (BIODYN) and integrated Farming systems (CONFYM) were compared at reduced and normal fertilization intensity (0.7 and 1.4 livestock units, LU) in a 7 year crop rotation. A stockless integrated system is fertilized with mineral fertilizers exclusively (CONMIN) and one control treatment remained unfertilized (NOFERT). The CONFYM system is amended with stacked manure, supplemental mineral fertilizers, as well as chemical pesticides. Manure of the BIOORG system is slightly rotted and in BIODYN it is composted aerobically with some herbal additives. In the third crop rotation period at normal fertiliser intensity soil organic carbon (Corg, w/w) in the plough layer (0–20 cm) of the BIODYN system remained constant and decreased by 7% in CONFYM and 9% in BIOORG as compared to the starting values. With no manure application Corg-loss was severest in NOFERT (22%), followed by CONMIN together with the systems at reduced fertiliser intensity (14–16%). Soil pH tended to increase in the organic systems, whereas the integrated systems had the lowest pH values. At the end of the third crop rotation period in 1998 biological soil quality indicators were determined. Compared to soil microbial biomass in the BIODYN systems the CONFYM soils showed 25% lower values and the systems without manure application were lower by 34%. Relative to the BIODYN soils at the same fertilization intensity dehydrogenase activity was 39–42% lower in CONFYM soils and even 62% lower in soils of CONMIN. Soil basal respiration did not differ between Farming systems at the same intensity, but when related to microbial biomass (qCO2) it was 20% higher in CONFYM soils and 52% higher in CONMIN as compared to BIODYN, suggesting a higher maintenance requirement of microbial biomass in soils of the integrated systems. The manure based Farming systems of the DOK trial are likely to favour an active and fertile soil. Both, Corg and biological soil quality indicators were clearly depending on the quantity and quality of the applied manure types, but soil microbial biomass and activities were much more affected than Corg.

  • Impact of long-term Conventional and organic Farming on the diversity of arbuscular mycorrhizal fungi
    Oecologia, 2004
    Co-Authors: Fritz Oehl, Kurt Ineichen, Ewald Sieverding, David Dubois, Thomas Boller, Paul Mader, Andres Wiemken
    Abstract:

    Previous work has shown considerably enhanced soil fertility in agroecosystems managed by organic Farming as compared to Conventional Farming. Arbuscular mycorrhizal fungi (AMF) play a crucial role in nutrient acquisition and soil fertility. The objective of this study was to investigate the diversity of AMF in the context of a long-term study in which replicated field plots, at a single site in Central Europe, had been cultivated for 22 years according to two “organic” and two “Conventional” Farming systems. In the 23rd year, the field plots, carrying an 18-month-old grass-clover stand, were examined in two ways with respect to AMF diversity. Firstly, AMF spores were isolated and morphologically identified from soil samples. The study revealed that the AMF spore abundance and species diversity was significantly higher in the organic than in the Conventional systems. Furthermore, the AMF community differed in the Conventional and organic systems: Glomus species were similarly abundant in all systems but spores of Acaulospora and Scutellospora species were more abundant in the organic systems. Secondly, the soils were used to establish AMF-trap cultures using a consortium of Plantago lanceolata, Trifolium pratense and Lolium perenne as host plants. The AMF spore community developing in the trap cultures differed: after 12 months, two species of the Acaulosporaceae (A. paulinae and A. longula) were consistently found to account for a large part of the spore community in the trap cultures from the organic systems but were found rarely in the ones from the Conventional systems. The findings show that some AMF species present in natural ecosystems are maintained under organic Farming but severely depressed under Conventional Farming, indicating a potentially severe loss of ecosystem function under Conventional Farming.

  • arbuscular mycorrhizae in a long term field trial comparing low input organic biological and high input Conventional Farming systems in a crop rotation
    Biology and Fertility of Soils, 2000
    Co-Authors: Paul Mader, Thomas Boller, Andres Wiemken, Stephan Edenhofer, Urs Niggli
    Abstract:

    Arbuscular mycorrhizal (AM) root colonization was studied in a long-term field trial in which four Farming systems currently in use in Switzerland were continuously applied to a randomized set of plots at a single field site from 1978 till 1993. There were two low-input Farming systems (organic and bio-dynamic) and two high-input (Conventional) Farming systems (according to Swiss guidelines of integrated plant production with and without farmyard manure). The systems had an identical 7-year crop rotation and tillage scheme and differed essentially only in the amount and type of fertilizer supplied and in plant protection management. The percentage of root colonization by AM fungi was determined in field samples 2–3 times over the growing season in crops in the rotation, namely in winter wheat (Triticum aestivum L. cv. Sardona), vetch-rye and grass-clover. We found the percentage of root length colonized by AM fungi to be 30–60% higher (P≤0.05) in the plants grown in soils from the low-input Farming systems than in those grown in Conventionally farmed soils. Approximately 50% of the variation of AM root colonization was explained by chemical properties of the soils (pH, soluble P and K, exchangeable Mg), the effect of soluble soil P being most pronounced. The potential of the field soils from the differently managed plots to cause symbiosis with AM fungi was tested in a glasshouse experiment, using wheat as a host plant. Soils from the low-input Farming systems had a greatly enhanced capacity to initiate AM symbiosis. The relative differences in this capacity remained similar when propagules of the AM fungus Glomus mosseae were experimentally added to the soils, although overall root colonization by AM fungi was 2.8 times higher.

Paul Made - One of the best experts on this subject based on the ideXlab platform.

  • distinct soil microbial diversity under long term organic and Conventional Farming
    The ISME Journal, 2015
    Co-Authors: Marti Hartma, Ea Frey, Joche Maye, Paul Made, Franco Widme
    Abstract:

    Low-input agricultural systems aim at reducing the use of synthetic fertilizers and pesticides in order to improve sustainable production and ecosystem health. Despite the integral role of the soil microbiome in agricultural production, we still have a limited understanding of the complex response of microbial diversity to organic and Conventional Farming. Here we report on the structural response of the soil microbiome to more than two decades of different agricultural management in a long-term field experiment using a high-throughput pyrosequencing approach of bacterial and fungal ribosomal markers. Organic Farming increased richness, decreased evenness, reduced dispersion and shifted the structure of the soil microbiota when compared with Conventionally managed soils under exclusively mineral fertilization. This effect was largely attributed to the use and quality of organic fertilizers, as differences became smaller when Conventionally managed soils under an integrated fertilization scheme were examined. The impact of the plant protection regime, characterized by moderate and targeted application of pesticides, was of subordinate importance. Systems not receiving manure harboured a dispersed and functionally versatile community characterized by presumably oligotrophic organisms adapted to nutrient-limited environments. Systems receiving organic fertilizer were characterized by specific microbial guilds known to be involved in degradation of complex organic compounds such as manure and compost. The throughput and resolution of the sequencing approach permitted to detect specific structural shifts at the level of individual microbial taxa that harbours a novel potential for managing the soil environment by means of promoting beneficial and suppressing detrimental organisms.

  • metabolite profiling on wheat grain to enable a distinction of samples from organic and Conventional Farming systems
    Journal of the Science of Food and Agriculture, 2014
    Co-Authors: Paul Made, Anja Onte, Heiko Neuwege, Alexande Goesma, Cecile Thona, Georg Langenkampe, Karste Niehaus
    Abstract:

    BACKGROUND: Identification of biomarkers capable of distinguishing organic and Conventional products would be highly welcome to improve the strength of food quality assurance. Metabolite profiling was used for biomarker search in organic and Conventional wheat grain (Triticum aestivum L.) of 11 different old and new bread wheat cultivars grown in the DOK system comparison trial. Metabolites were extracted using methanol and analysed by gas chromatography-mass spectrometry. RESULTS: Altogether 48 metabolites and 245 non-identified metabolites (TAGs) were detected in the cultivar Runal. Principal component analysis showed a sample clustering according to Farming systems and significant differences in peak areas between the Farming systems for 10 Runal metabolites. Results obtained from all 11 cultivars indicated a greater influence of the cultivar than the Farming system on metabolite concentrations. Nevertheless, a t-test on data of all cultivars still detected 5 metabolites and 11 TAGs with significant differences between the Farming systems. CONCLUSION: Based on individual cultivars, metabolite profiling showed promising results for the categorization of organic and Conventional wheat. Further investigations are necessary with wheat from more growing seasons and locations before definite conclusions can be drawn concerning the feasibility to evolve a combined set of biomarkers for organically grown wheat using metabolite profiles. © 2014 Society of Chemical Industry.

  • phosphorus forms and enzymatic hydrolyzability of organic phosphorus in soils after 30 years of organic and Conventional Farming
    Journal of Plant Nutrition and Soil Science, 2012
    Co-Authors: Martina Kelle, Joche Maye, Paul Made, Astrid Oberso, Kathri E Annaheim, Federica Tamburini, Emmanuel Frossard, Else K Unema
    Abstract:

    Lower P-input levels in organic than Conventional Farming can decrease soil total and available P, which can potentially be resupplied from soil organic P. We studied the effect of 30 y of Conventional and organic Farming on soil P forms, focussing especially on organic P. Soil samples (0–20 cm) were taken in a field experiment with a nonfertilized control, two organic systems receiving P inputs as animal manure, and two Conventional systems receiving only mineral P or mineral P and manure. Soils were analyzed for total, inorganic, organic, and microbial P, by sequential P fractionation and by enzyme additions to alkaline soil extracts. Samples taken prior to starting the experiment were also analyzed. Average annual P balances ranged from –20 to +5 kg ha–1. For systems with a negative balance, labile and moderately labile inorganic P fractions decreased, while organic and stable inorganic P fractions were hardly affected. Similar quantities and proportions of organic P extracted with NaOH-EDTA were hydrolyzed in all soils after addition of an acid phosphatase, a nuclease, and a phytase, and enzyme-stable organic P was also similar among soils. Thus, neither sequential fractionation nor enzyme addition to alkaline soil extracts showed an effect of the type of applied P (manure vs. mineral) on organic P, suggesting that organic P from manure has largely been mineralized. Thus far, we have no indication that the greater microbial activity of the organic systems resulted in a use of stable P forms.

  • wheat quality in organic and Conventional Farming results of a 21 year field experiment
    Journal of the Science of Food and Agriculture, 2007
    Co-Authors: Paul Made, David Dubois, Diana Hah, Lucie Guns, Thomas Alfoldi, Hans Ergma, Michael Oehme, Renato Amado, Hanna Schneide
    Abstract:

    Consumers have become more aware of healthy and safe food produced with low environmental impact. Organic agriculture is of particular interest in this respect, as manifested by 5.768 million hectares managed pursuant to Council Regulation (EEC) 2092/91 in Europe. However, there can be a considerable risk that the avoidance of chemical inputs in organic Farming will result in poor food quality. Here the results of a study on the quality of wheat (Triticum aestivum L.) grown in a 21 year agrosystem comparison between organic and Conventional Farming in central Europe are reported. Wheat was grown in a ley (grass/clover) rotation. The 71% lower addition of plant-available nitrogen and the reduced input of other means of production to the organic field plots led to 14% lower wheat yields. However, nutritional value (protein content, amino acid composition and mineral and trace element contents) and baking quality were not affected by the Farming systems. Despite exclusion of fungicides from the organic production systems, the quantities of mycotoxins detected in wheat grains were low in all systems and did not differ. In food preference tests, as an integrative method, rats significantly preferred organically over Conventionally produced wheat. The findings indicate that high wheat quality in organic Farming is achievable by lower inputs, thereby safeguarding natural resources.

  • phosphorus budget and phosphorus availability in soils under organic and Conventional Farming
    Nutrient Cycling in Agroecosystems, 2002
    Co-Authors: F Oehl, David Dubois, Paul Made, Astrid Oberso, H U Tagma, J M Esso, H R Roth, Emmanuel Frossard
    Abstract:

    The aim of this work was to assess to which extent organic Farming practices would affect the accumulation of total and available phosphorus (P) in a cropped soil in comparison to Conventional practices. In order to achieve this, soil samples were taken from a long-term field trial comparing a non-fertilised control (NON), two Conventionally cultivated treatments (MIN, CON), and two organically cultivated treatments (ORG, DYN). Soil samples were taken from each treatment at two depths (0-20 and 30-50 cm) before starting the field trial (1977) and at the end of every three crop rotations (1984, 1991 and 1998). They were then analysed for total P (Pt), total inorganic P (Pi), total organic P (Po) and isotopically exchangeable Pi. After 21 years, the average P input-output budget reached -20.9 kg P ha−1 a−1 for NON, -7.8 for DYN, -5.7 for ORG, -5.0 for MIN and +3.8 for CON. Total P, Pi as well as the amount of Pi isotopically exchangeable within 1 minute (E1) were positively correlated to the P budget. Comparison between P budget and Pt in the top- and subsoils of the fertilised treatments suggested a net transfer of P from the 0–20 to the 30–50 cm layers between 13 and 26 kg P ha−1 a−1during the first rotation and between 3 and 12 kg P ha−1 a−1during the second rotation. During the third rotation a net upward movement of P from the subsurface to the topsoil ranging between 3.7 and 10.5 kg P ha−1 a−1was estimated. In the topsoil, E1decreased from an initial value of 12 mg P kg−1 to 11 in CON, 8 in MIN, 6 in ORG, 5 in DYN and 2 in NON after 21 years. In the subsoil, E1 increased from an initial value of 2 mg P kg−1 to 4 in MIN, ORG, DYN and NON and to 6 in CON. These results show that, with the exception of NON, all treatments had still an adequate level of available P after 21 years of trial and that, in this low to moderately P sorbing soil, an equilibrated input-output budget allows to maintain P availability at a constant level. In the organic systems, yields have so far partly been attained at the expense of soil reserves or residual P from earlier fertiliser applications.

Kurtjurge Hulsberge - One of the best experts on this subject based on the ideXlab platform.

  • a new method for analyzing agricultural land use efficiency and its application in organic and Conventional Farming systems in southern germany
    European Journal of Agronomy, 2017
    Co-Authors: Kurtjurge Hulsberge
    Abstract:

    Abstract Improving the land-use efficiency (LUE) of Farming systems could satisfy increasing global food, feed, biomass and bioenergy demand in a sustainable manner. This study presents a new method for calculating LUE, beginning with an overview of different approaches to assessing agricultural LUE. This new method takes into account the quality and function of agricultural products and the relationship between the yield of the assessed farm and the average yield of the reference region with comparable soils, climate and socio-economic conditions. The new approach was tested using data from long-term experiments at the Scheyern Research Farm in southern Germany, which include different Farming systems (organic mixed Farming, arable Farming, and agroforestry; Conventional arable Farming and agroforestry). In our case studies, the LUE of Conventional systems (arable Farming: 1.00; improved arable Farming: 1.06; agroforestry: 0.98) was higher than those of the organic systems (mixed Farming: 0.69; arable Farming: 0.33; agroforestry: 0.43) due to different crop rotations, dry matter yields, and biomass usage (harvest ratio). The conversion of high-input arable Farming systems (Conventional Farming) to agroforestry systems is an extensification with negative effects on the dry matter yield and land-use efficiency. Nevertheless, the conversion to agroforestry systems can increase dry matter yield and land-use efficiency in low-input arable Farming systems (organic Farming). LUE should be used in combination with agri-environmental indicators, in order to ensure both efficient and sustainable land use.

  • effects of changing farm management and farm structure on energy balance and energy use efficiency a case study of organic and Conventional Farming systems in southern germany
    European Journal of Agronomy, 2017
    Co-Authors: Julia Hube, Georg Gerl, Kurtjurge Hulsberge
    Abstract:

    Abstract Fossil energy input, energy output, and energy use- efficiency (EUE) are important indicators of the environmental effects, resource consumption and economic performance of Farming systems. In this study, the energy balance (process analysis) and EUE of different organic and Conventional Farming systems – mixed Farming, arable Farming, and agroforestry (AGFS) systems – were analyzed due to their importance in Germany. The analysis was based on long-term experiments at the Scheyern Research Farm in southern Germany. The results showed that the conversion from multi-structured organic mixed Farming to a specialized organic arable Farming system reduced the fossil energy input in crop production only marginally (from 5.9 to 5.5 GJ ha −1  yr −1 ), but considerably decreased dry matter yield (from 5.4 to 2.5 Mg ha −1  yr −1 ), energy output (from 99 to 46 GJ ha −1  yr −1 ) and EUE (from 16.8 to 8.3). Improved management in the Conventional arable Farming system (with high-yielding varieties and better N management) reduced the energy input from 14.0 to 12.2 GJ ha −1  yr −1 , increased the energy output from 155 to 179 GJ ha −1  yr −1 , and elevated the EUE from 11.1 to 14.6. The establishment of AGFS with short rotation trees (without fertilization and pesticide use) led to the reduction of energy input. Based on the results, we concluded that mixed Farming is one of the best ways of producing food with high EUE under the conditions of organic Farming. Therefore the conversion from organic mixed Farming to an organic arable Farming system is not recommended. Our AGFS results were from the first stage of a long-term experiment; it showed no negative effects on DM yield and energy output and positive effects on energy-use efficiency at this stage. However, further research is needed to know the long-term influence of AGFS.

  • organic matter returns to soils must be higher under organic compared to Conventional Farming
    Journal of Plant Nutrition and Soil Science, 2015
    Co-Authors: Gunte Leithold, Kurtjurge Hulsberge, Christophe Ock
    Abstract:

    The aim of this paper is to discuss the demand of fresh organic matter (FOM) supply to maintain soil organic matter (SOM) levels and productivity of arable soils under organic management. The basic question is whether the different frame conditions in organic vs. Conventional Farming result in a different and system-specific FOM demand. If this is the case, it would follow that the Farming system has to be considered in the calculation of SOM balances. SOM balances are the most common decision support tools in organic matter management. A conversion to organic Farming in practice usually leads to an increase of SOM levels as well as soil microbial activity over time. The system-specific driver of this effect is the indispensable extension of the share of (perennial) legumes in crop rotations at the expense of non-legumes such as cereals, row crops, and maize. Extended legume cropping is essential for N supply in crop rotations as the import of N fertilizer in total is limited by organic Farming regulations and mineral N fertilizer may not be used at all. Based on this characteristic of organic management, we argue that the demand of FOM supply to soils must be higher than in Conventional crop production. The most relevant factors are (1) the non-existence of mineral N fertilizer as an external N source that supports the maintenance of SOM by decreasing the demand for SOM-N, (2) benefits of increasing SOM stocks and turnover for soil productivity under organic management, and, (3) increased mass-losses of FOM and easily degradable SOM compartments due to higher microbial activity in soils. These effects have to be quantified and must be considered in SOM balances in order to avoid misleading assessments and erroneous decisions.

  • modeling carbon cycles and estimation of greenhouse gas emissions from organic and Conventional Farming systems
    Renewable Agriculture and Food Systems, 2008
    Co-Authors: Jo Kusterma, Maximilia Kainz, Kurtjurge Hulsberge
    Abstract:

    The paper describes the model software REPRO (REPROduction of soil fertility) designed for analyzing interlinked carbon (C) and nitrogen (N) fluxes in the system soil–plant–animal–environment. The model couples the balancing of C, N and energy fluxes with the target to estimate the climate-relevant CO 2 , CH 4 and N 2 O sources and sinks of Farming systems. For the determination of the net greenhouse effect, calculations of C sequestration in the soil, CO 2 emissions from the use of fossil energy, CH 4 emissions from livestock keeping and N 2 O emissions from the soil have been made. The results were converted into CO 2 equivalents using its specific global warming potential (GWP). The model has been applied in the experimental farm Scheyern in southern Germany, which had been divided into an organic (org) and a Conventional (con) Farming system in 1992. Rather detailed series of long-term measuring data are available for the farm in Scheyern, which have been used for validating the software for its efficiency and applicability under very different management yet nearly equal site conditions. The organic farm is multi-structured with a legume-based crop rotation (N 2 fixation: 83 kg ha −1 yr −1 ). The livestock density (LSU=Livestock Unit according to FAO) is 1.4 LSU ha −1 . The farm is oriented on closed mass cycles; from the energetic point of view it represents a low-input system (energy input 4.5 GJ ha −1 yr −1 ). The Conventional farm is a simple-structured cash crop system, based on mineral N (N input 145 kg ha −1 yr −1 ). Regarding the energy consumption, the system is run on high inputs (energy input 14.0 GJ ha −1 yr −1 ). The organic crop rotation reaches about 57% (8.3 Mg ha −1 yr −1 ) of the DM yield, about 66% (163 kg ha −1 yr −1 ) of the N removal and roughly 56% (3741 kg ha −1 yr −1 ) of the C fixation of the Conventional crop rotation. In the organic rotation, 18 GJ per GJ of fossil energy input are bound in the harvested biomass vis-a-vis 11.1 GJ in the Conventional rotation. The strongest influence on the greenhouse effect is exerted by C sequestration and N 2 O emissions. In Scheyern, C sequestration has set in under organic management (+0.37 Mg ha −1 yr −1 ), while humus depletion has been recorded in the Conventional system (−0.25 Mg ha −1 yr −1 ). Greenhouse gas emissions (GGEs) due to fuel consumption and the use of machines are nearly on the same level in both crop rotations. However, the Conventional system emits an additional 637 kg CO 2 eq ha −1 yr −1 , which had been consumed in the manufacture of mineral N and pesticides in the upstream industry. Besides the analyses in the experimental farm Scheyern, the model has been applied in 28 commercial farms (18 org and 10 con) with comparable soil and climate conditions in the surroundings of Scheyern (mean distance 60 km). The program calculations are aimed at benchmarking the results obtained in the Farming systems Scheyern; they are expected to disclose management-specific variations in the emission of climate-relevant gases and to rate the suitability of the model for describing such management-specific effects. In order to make the situation in the farms comparable, only the emissions from cropping systems were analyzed. Livestock keeping remained unconsidered. Due to lower N and energy inputs, clearly lower N 2 O and CO 2 emissions were obtained for the organic farms than for the Conventional systems. The analyses have shown possibilities for the optimization of management and the mitigation of GGE. Our findings underline that organic Farming includes a high potential for C sequestration and the reduction of GGEs. Currently, the model REPRO is tested by 90 farms in the Federal Republic of Germany with the aim to apply it in the future not only in the field of research but also in the management of commercial farms.

M M Pullema - One of the best experts on this subject based on the ideXlab platform.

  • soil physical quality in contrasting tillage systems in organic and Conventional Farming
    Soil & Tillage Research, 2015
    Co-Authors: Stephe Crittende, N Poo, M Heine, D J M Van Bale, M M Pullema
    Abstract:

    Reduced tillage can improve soil physical quality relative to mouldboard ploughing by lessening soil disturbance, leaving organic matter at the soil surface, and stimulating soil biological activity. In organic Farming, continuous ploughing may negate benefits to soil structure and function from increased use of manures and more diverse crop rotations, which are particularly important components of organic Farming. The current study examined soil physical quality (i.e., properties and functioning) of a 4-year old reduced tillage system under organic and Conventional Farming with crop rotations that included root crops. Reduced tillage was compared to Conventional mouldboard ploughing (MP) in 2 organic fields at different points of the same crop rotation (Org A and Org B) and 1 Conventional field (Conv A). Reduced tillage consisted of non-inversion tillage (NIT) to 18–23 cm depth whereas MP was characterised by annual mouldboard ploughing to 23–25 cm depth. NIT improved soil water retention in Org B but had no effect in Org A. NIT increased soil aggregate stability at 10–20 cm depth compared to MP in all fields, and additionally at 0–10 cm in Conv A. Penetration resistance was higher in NIT in all fields. Furthermore, soil organic matter content was higher in NIT than MP at 0–10 cm depth in all fields and at 10–20 cm in Org B and Conv A. NIT increased carbon stocks in Org B but not in Org A. NIT statistically increased crop yields in spring wheat/faba bean mixture in Org A, and there was no yield penalty from NIT in Org B spring wheat nor Conv A sugar beet. In contrast, field-saturated hydraulic conductivity in all fields in autumn was lower in NIT. Differences in crop (i.e., phase of rotation) and associated organic inputs between Org A and B likely accounted for the differences in effects of tillage system. Overall, the NIT system improved or imposed no penalty on soil physical quality (except field-saturated hydraulic conductivity) and improved or imposed no penalty on crop yields and could therefore be considered as a viable alternative for farmers.

  • effect of tillage on earthworms over short and medium term in Conventional and organic Farming
    Applied Soil Ecology, 2014
    Co-Authors: Stephe Crittende, T Eswaramurthy, R G M De Goede, L Ussaard, M M Pullema
    Abstract:

    Abstract Earthworms play an important role in many soil functions and are affected by soil tillage in agricultural soils. However, effects of tillage on earthworms are often studied without considering species and their interactions with soil properties. Furthermore, many field studies are based on one-time samplings that do not allow for characterisation of temporal variation. The current study monitored the short (up to 53 days) and medium term (up to 4 years) effects of soil tillage on earthworms in Conventional and organic Farming. Earthworm abundances decreased one and three weeks after mouldboard ploughing in both Conventional and organic Farming, suggesting direct and indirect mechanisms. However, the medium-term study revealed that earthworm populations in mouldboard ploughing systems recovered by spring. The endogeic species Aporrectodea caliginosa strongly dominated the earthworm community (76%), whereas anecic species remained −2 ) than mouldboard ploughing (MP; 130 m −2 ). However, reduced tillage in Conventional Farming significantly increased the epigeic species Lumbricus rubellus from 0.1 m −2 in mouldboard ploughing to 9 m −2 averaged over 4 years. Contrastingly, in organic Farming mean total earthworm abundance was 45% lower in reduced tillage (297 m −2 ) than MP (430 m −2 ), across all sampling dates over the medium-term study (significant at 3 of 6 sampling dates). Reduced tillage in organic Farming decreased A. caliginosa from 304 m −2 in mouldboard ploughing to 169 m −2 averaged over 4 years (significant at all sampling dates). Multivariate analysis revealed clear separation between Farming and tillage systems. Earthworm species abundances, soil moisture, and soil organic matter were positively correlated, whereas earthworm abundances and penetration resistance where negatively correlated. Variability demonstrated between sampling dates highlights the importance of multiple samplings in time to ascertain management effects on earthworms. Findings indicate that a reduction in tillage intensity in Conventional Farming affects earthworms differently than in organic Farming. Differing earthworm species or ecological group response to interactions between soil tillage, crop, and organic matter management in Conventional and organic Farming has implications for management to maximise soil ecosystem functions.

Michelle M Wande - One of the best experts on this subject based on the ideXlab platform.

  • organic n and particulate organic matter fractions in organic and Conventional Farming systems with a history of manure application
    Plant and Soil, 2007
    Co-Authors: Michelle M Wande, W A Goldstei, S Aref, S A Kha
    Abstract:

    Indicators of soil fertility are needed for the effective management of organic Farming systems. Sustainable management hinges upon our gaining an improved understanding of C and N dynamics. The influence of cropping systems and amendments applied in the Lakeland Wisconsin Integrated Cropping Systems Trial on total hydrolyzable organic N (THN) fractions and particulate organic matter (POM) was investigated after a decade in a Conventional cash grain system (Conv) of continuous maize amended with inorganic fertilizer, an organic cash-grain system (Org-CG) that relied on legume N, and an organic animal-based system (Org-AN) that included alfalfa and manure additions. Maize yields had consistently ranked Org-CG Org-CG > Conv. Amino sugar-N (AS-N) contents, which reflect microbially derived N, did not differ among systems and concentrations were quite high (346.5 mg AS-N/kg soil in the 0–50 cm depth). This, and soil variability were attributed to the sites’ history of manure application. The amount (1.3 g POM-C/kg soil) and proportion (≈7.5% of total SOC) of POM-C were quite low and did not differ among systems. Failure to accumulate SOC or POM in these soils, even under organic management, is attributed to rapid C decay and/or limited root growth. An N rate study was added the fall before samples were taken and N addition did increase yield in the Conv and Org-CG systems despite evidence of soil N surplus. This suggests that either amino N is unavailable to plants or that root N acquisition is limited by other constraints. Low POM-C contents accompanied by high AS-N and AA-N levels reveal an imbalance in these soils which are likely to be C limited. Based on this, we conclude excess N has prevented use of organic practices from enhancing soil quality at this site.

  • qualitative and quantitative differences in particulate organic matter fractions in organic and Conventional Farming systems
    Soil Biology & Biochemistry, 2006
    Co-Authors: Emily E Marrio, Michelle M Wande
    Abstract:

    Abstract To quantify functionally important differences in soil organic matter (SOM) that result from use of different Farming practices, soils from 9 long-term trials comparing manure+legume-based organic, legume-based organic, and Conventional Farming systems were collected and particulate organic matter (POM) was fractionated to reflect its position within the soil matrix. The free, light POM (FPOM; 53 μm) obtained by wet sieving. Fraction C, N, and hydrolyzable N (quantified using the Illinois test (IL-N)) were determined. Organic Farming systems had greater quantities of C and N in the OPOM and CF and, greater IL-N contents in all POM fractions considered. The OPOM's C:N ratio (16–19) and was least in the manure+legume-based organic, intermediate in the legume-based organic, and greatest in the Conventional systems ( P 0.10 ). Trends in OPOM C:N and IL-N abundance suggested occluded POM was most decomposed, and possibly a greater N reservoir, in the manured soils. The FPOM quality reflected the residues added to each system and its removal improved resolution of quality-based differences in POM associated with long-term management. Subdivision of POM revealed differences in its quality that were not evident using the undifferentiated CF. Quantification of hydrolysable N (IL-N) in POM did not enhance our understanding of management's affect on SOM quality. This multi-site comparison showed organic management simultaneously increased the size of the labile N reservoir and the amount of POM protected within aggregates; and that, occluded POM is more decomposed in manure+legume- than in legume-based organic systems. The characteristics of POM reveal how organic practices improve SOM and suggest the nutrient and substrate decay dynamics of organic systems may differ as a result of the N fertilization strategies they employ.

  • total and labile soil organic matter in organic and Conventional Farming systems
    Soil Science Society of America Journal, 2006
    Co-Authors: Emily E Marrio, Michelle M Wande
    Abstract:

    Even though organic management practices are intended to enhance soil performance by altering the quantity or quality of soil organic matter (SOM), there is no consensus on how to measure or manage SOM status. We investigated the veracity of common perceptions about SOM quantity in organically and Conventionally managed soils by evaluating the relative responsiveness to organic management of particulate organic matter (POM) and the Illinois Soil N Test (IL-N), which has been proposed as a direct measure of labile N. Soil samples were obtained from nine Farming systems trials in the USA. Soil organic C (SOC), total N (TN), POM-C, POM-N, and IL-N were compared among manure 1 legume-based organic, legume-based organic, and Conventional Farming systems. The organic systems had higher SOC and TN concentrations than Conventional systems whether or not manure was applied. The POM-C, POM-N, and IL-N concentrations did not differ between manure 1 legumeand legume-based organic systems. The amount of N recovered in POM and IL-N was similar. Organic management enriched soil POMC and -N by 30 to 40% relative to the Conventional control and this level of enrichment was two to four times greater than that in any other fraction. The IL-N fraction was not a good measure of labile N as it was less enriched than POM and included recalcitrant components. This is evidenced by the strong correlation between IL-N and SOC, TN, climate and textural characteristics. Particulate organic matter provided clearer evidence of SOM and labile N accrual under organic management. Direct links between POM status and soil N supply and physical condition are being pursued to help farmers manage biologically based fertility.