Nutrient Management in Organic Farming Systems: the Case of Nitrogen

Köpke, Ulrich

doi:10.1080/01448765.1995.9754690

Cited by 31 publications

(15 citation statements)

References 4 publications

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“…Other limiting factors such as weeds (Angonin et al, 1996;McGloskey et al, 1998), water deficit (Sebillotte et al, 1978) and/or soil compaction (Wibawa, 1992) have limited crop N nutrition. Finally, the substantial effect of crop rotation and preceding crop on N plant status concurs with earlier statements (Köpke, 1995) emphasizing the importance of long-term N management strategies using nitrogen-fixing legumes.…”

Section: Nitrogen Nutritionsupporting

confidence: 85%

“…In the late 90s, nitrogen management was based on the assumption that organic fertilizer (e.g. feather meal, guano) should be applied early in the crop cycle to be available during stem elongation (Köpke, 1995). This resulted in early (before Feekes 4), single and low application rates (under 100 kg.N·ha -1 ), also because of the high price of organic fertilizers (from 1.7 to 4.5 € kg -1 N).…”

Section: Nitrogen Nutritionmentioning

confidence: 99%

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Yield variation in organic winter wheat: a diagnostic study in the Southeast of France

David

Jeuffroy

Henning

et al. 2005

Agron. Sustain. Dev.

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A diagnostic method for assessing regional variations in yield was implemented for a network of 24 organic wheat fields located in two neighboring regions, Diois and Val de Drôme (France). We studied: yield and its components; field environmental conditions of the fields; relations between indicators of potential limiting factors and yield components; and linkages between crop management and yield-limiting factors. The yield performances were low and variable (3.5 ± 1.4 t·ha -1 ). The relative kernel number (RKN) was significantly related to nitrogen nutrition and weed density at flowering. The nitrogen nutrition index (NNIf) had a strong and positive effect on relative kernel number, while weed density (1/WF) had a negative effect. The percentage of kernel number variation explained by the regression model (RKN = 0.112 + 0.609 × NNIf + 0.2 × 1/WF) was adequate (Adj. R 2 = 0.53) with a RMSE of 0.09. The duration of the period of grain filling, reflected in the temperature sum, had a strong and positive effect on relative kernel weight (RTKW), while soil compaction and high temperature had a negative influence. Adjusted R 2 for the model was 0.42 with a RMSE of 0.16. The results confirm that legumes preceding crops improve nitrogen nutrition on subsequent winter wheat, e.g. the Nitrogen Nutrition Index at flowering (NNIf) = 0.51 ± 0.12 for a crop rotation with a rate of legumes over 37% vs. 0.41 ± 0.11 for a crop rotation with a rate of legumes under 25%. Alfalfa preceding crops significantly limited the weed density at harvest while stony soils and early sowing (before November 1st) enhanced weed density. organic farming / winter wheat / yield / limiting factors / diagnostic method * Corresponding author: davidc@isara.fr Article published by EDP Sciences and available at http://www.edpsciences.org/agro or http://dx.doi.org/10.1051/agro:2005016 214 C. David et al.for each field, as described by Boiffin et al. (1981) and Meynard and David (1992). For instance, Leterme et al. (1994) analyzed the effect of crop management and environment on wheat yield variation in Thymerais, France (48.3°N, 1.3°E). It was established that the major factors responsible for yield differences were drought stress during stem elongation and meiosis, root and stem diseases and soil structure. Then these factors were explained by differences in soil moisture capacity, rainfall distribution, sowing date and the nature of the preceding crops.This paper focuses on understanding organic wheat yield performance in terms of yield-limiting factors and crop management characteristics. The analysis consisted of four stages: (i) yield and its components were described, (ii) we characterized the environmental conditions of the fields, (iii) we analyzed the relations between indicators of possible limiting factors and yield components, and (iv) determined the relations between crop management and yield-limiting factors.

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Section: Nitrogen Nutritionsupporting

confidence: 85%

Section: Nitrogen Nutritionmentioning

confidence: 99%

Yield variation in organic winter wheat: a diagnostic study in the Southeast of France

David

Jeuffroy

Henning

et al. 2005

Agron. Sustain. Dev.

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“…By keeping external inputs as limited as possible, organic agriculture reduces negative external effects often associated with intensive farming and is able to enhance eco-system services and ecological benefits [5,27,28]. Apart from accredited non-mineral nitrogen fertilizers, biological N2-fixation through leguminous ley and cover crops is the sole nitrogen input in organic farming [29]. Nutrient cycling via livestock manures and the incorporation of leguminous leys may provide adequate amounts of N to meet cash crop demands.…”

Section: Biogas Production In Organic Agriculturementioning

confidence: 99%

Integrated Bioenergy and Food Production—A German Survey on Structure and Developments of Anaerobic Digestion in Organic Farming Systems

et al. 2015

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Rising global energy needs and limited fossil fuel reserves have led to increased use of renewable energies. In Germany, this has entailed massive exploitation of agricultural biomass for biogas generation, associated with unsustainable farming practices. Organic agriculture not only reduces negative environmental impacts, organic farmers were also prime movers in anaerobic digestion (AD) in Germany. This study's aim was to identify the structure, development, and characteristics of biogas production associated with organic farming systems in order to estimate further development, as well as energetic and associated agronomic potentials. Surveys were conducted among organic farms with AD technology. 144 biogas plants could be included in the analysis. Total installed electrical capacity was 30.8 MWel, accounting for only 0.8% of the total installed electrical capacity in the German biogas sector. Recently, larger plant types (>250 kWel) with increased use of (also purchased) energy crops have emerged. Farmers noticed increases in yields (22% on average) and quality of cash crops in arable farming through integrated biogas production. In conclusion, although the share of AD in organic farming is relatively small it can provide various complementary socio-ecological benefits such as the enhancement of food output through digestate fertilization without additional need for land, while simultaneously reducing greenhouse gas emissions from livestock manures and soils. However, to achieve this OPEN ACCESSSustainability 2015, 7 10710 eco-functional intensification, AD systems and their management have to be well adapted to farm size and production focus and based primarily on residue biomass.

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“…The main source of nitrogen input in organic farming is symbiotic rhizobia in legume crops (Köpke, 1995). The management of legume leys significantly affects the amount of fixed N 2 (see section 4.1.2).…”

Section: Indirect Effectsmentioning

confidence: 99%