Species Mix As Cover Crop To Practice No Tillage In Organic Arable Production

Cover crop no tillage (CCNT) technique could provide a diversity of benefits on soil quality in organic production system including spring cash crop such as soybean. However, CCNT remains poorly practiced by organic farmers due the challenges to manage weeds and cover crops without neither soil tillage nor herbicide. This paper aims to investigate the effect of a mix of cereal grains as cover crop compared to pure species to reduce weed pressure and the effect on soybean in organic CCNT system. Trials were conducted at four locations in France to compare three cover crops: rye, triticale and mix of rye/triticale. The cover crops are rolled and soybean is directly planting into the mulch. The mix of rye/triticale cover crop conducted to an intermediate weed control between the pure species from the soybean planting to the harvest. The mix of rye/triticale as rolled cover crop provided similar soybean yield than with pure rye (2.5 t.ha-1) which is superior to the soybean yield obtained with triticale cover crop (2.0 t.ha-1)

Carbon Sequestration By Organic Conservation Tillage – A Comprehensive Sampling Campaign In Nine European Long-Term Trials

Conservation tillage is suggested to sequester carbon although a stratification of soil organic carbon rather than a total increase is mostly observed. It is not clear whether conservation tillage in combination with organic farming practices has a higher potential. Beyond, many datasets are biased in terms of sampling depth. A joint sampling campaign in nine European long-term trials considered soil organic carbon stocks until 100 cm soil depth comparing reduced tillage with ploughing under organic farming conditions. First results show a significant increase of carbon stocks in 0-30 cm and also in 0-100 cm depth with the conversion to reduced tillage

Cover crop-based no tillage without herbicide : technical itinary design, experimentation and evaluation between farmers and researchers

Le semis direct sous couvert végétal (SDSC) apparaît comme une solution innovante pour gérer les adventices tout en limitant les dégradations des sols et en répondant aux enjeux économiques, sociologiques et agroécologiques du XXIème siècle (Mäeder et Berner, 2012). Cette technique culturale sans labour consiste à implanter une culture, sans travail du sol, soit sous un couvert végétal vivant soit sous un couvert détruit mécaniquement à partir d’un rouleau cranteur (Mirsky et al., 2012). Cette innovation se développe en Amérique du Nord et commence à émerger en France. Elle suscite en effet beaucoup d’intérêts auprès des agriculteurs qui souhaitent améliorer la fertilité des sols, réduire la consommation de carburant et d’herbicides ou encore limiter le temps de travail (Soane et al., 2012 ; Casagrande et al., 2015). Cette technique constitue un enjeu majeur à la fois en agriculture biologique et en agriculture conventionnelle pour diminuer le recours au travail du sol et limiter ou remplacer l’utilisation du glyphosate à l’origine de nombreux débats en Europe (Johnsen et al., 2016). Toutefois, d’importantes difficultés sont souvent relevées lors de l’adoption du SDSC (maîtrise du couvert et des adventices, disponibilité de l’azote etc.) et une reconsidération de l’ensemble du système serait nécessaire pour les limiter. De plus, peu de références existent sur cette thématique et la majorité des études a été menée dans un contexte nord-américain (Moyer, 2011). Ainsi, des questions persistent sur les moyens de mise en œuvre de cette innovation dans les exploitations agricoles actuelles (machinisme, compétences, connaissances, choix techniques et organisationnels etc.) ainsi que sur les performances économiques et agronomiques du SDSC. Cette thèse s’axe donc autour de ces trois grandes problématiques et propose de développer des solutions viables chez les agriculteurs pour intégrer cette technique dans un contexte européen. Ce projet vise notamment à prendre en compte les objectifs et les contraintes des producteurs à plusieurs niveaux d’organisation (parcelle, systèmes de culture, exploitation agricole) en alliant une approche à la fois systémique et analytique.Cover crop-based no-tillage (NT) techniques appear as an innovative solution to manage weeds while limiting soil disturbance and facing economic, sociologic and agro ecologic challenges of the 21st century (Mäeder et Berner, 2012). This technic consists of sowing a cash crop without tillage either under living or terminated cover crop with a roller crimper (Mirsky et al., 2012). This innovation has been developed in North America and NT is emerging in France. Especially, farmers are motivated by NT adoption to improve soil fertility, reduce fuel and herbicides consumption and decrease labor (Soane et al., 2012 ; Casagrande et al., 2015). Cover crop-based NT practice represents a major challenge both in organic farming and conventional farming to reduce tillage and limit and/or replace the use of the Glyphosate causing discussions in Europe (Johnsen et al., 2016). However, high number of difficulties are often reported (cover crop control, weeds management, nitrogen availability etc.) and a system rethinking is required to limit them. In addition, only few references are available on this subject and most of the studies have been conducted in North America (Moyer, 2011). Consequently, concerns reminds on means to adopt the innovation in current farms (equipment, skills, knowledge, technical and organizational choices etc.) and on economic and agronomic benefits provided by cover crop-based NT techniques. This thesis relies on these three major issues and proposes to design viable solutions in current farms integrating cover crop-based NT techniques under European conditions. This thesis project aims especially to consider the farmer’s objectives and constraints at three organizational level (plot, cropping systems, farm) combining both a systemic and an analytic approach

Semis direct sous couvert végétal sans herbicide : conception, expérimentation et évaluation conjointes d’itinéraires techniques entre praticiens et chercheurs

Cover crop-based no-tillage (NT) techniques appear as an innovative solution to manage weeds while limiting soil disturbance and facing economic, sociologic and agro ecologic challenges of the 21st century (Mäeder et Berner, 2012). This technic consists of sowing a cash crop without tillage either under living or terminated cover crop with a roller crimper (Mirsky et al., 2012). This innovation has been developed in North America and NT is emerging in France. Especially, farmers are motivated by NT adoption to improve soil fertility, reduce fuel and herbicides consumption and decrease labor (Soane et al., 2012 ; Casagrande et al., 2015). Cover crop-based NT practice represents a major challenge both in organic farming and conventional farming to reduce tillage and limit and/or replace the use of the Glyphosate causing discussions in Europe (Johnsen et al., 2016). However, high number of difficulties are often reported (cover crop control, weeds management, nitrogen availability etc.) and a system rethinking is required to limit them. In addition, only few references are available on this subject and most of the studies have been conducted in North America (Moyer, 2011). Consequently, concerns reminds on means to adopt the innovation in current farms (equipment, skills, knowledge, technical and organizational choices etc.) and on economic and agronomic benefits provided by cover crop-based NT techniques. This thesis relies on these three major issues and proposes to design viable solutions in current farms integrating cover crop-based NT techniques under European conditions. This thesis project aims especially to consider the farmer’s objectives and constraints at three organizational level (plot, cropping systems, farm) combining both a systemic and an analytic approach.Le semis direct sous couvert végétal (SDSC) apparaît comme une solution innovante pour gérer les adventices tout en limitant les dégradations des sols et en répondant aux enjeux économiques, sociologiques et agroécologiques du XXIème siècle (Mäeder et Berner, 2012). Cette technique culturale sans labour consiste à implanter une culture, sans travail du sol, soit sous un couvert végétal vivant soit sous un couvert détruit mécaniquement à partir d’un rouleau cranteur (Mirsky et al., 2012). Cette innovation se développe en Amérique du Nord et commence à émerger en France. Elle suscite en effet beaucoup d’intérêts auprès des agriculteurs qui souhaitent améliorer la fertilité des sols, réduire la consommation de carburant et d’herbicides ou encore limiter le temps de travail (Soane et al., 2012 ; Casagrande et al., 2015). Cette technique constitue un enjeu majeur à la fois en agriculture biologique et en agriculture conventionnelle pour diminuer le recours au travail du sol et limiter ou remplacer l’utilisation du glyphosate à l’origine de nombreux débats en Europe (Johnsen et al., 2016). Toutefois, d’importantes difficultés sont souvent relevées lors de l’adoption du SDSC (maîtrise du couvert et des adventices, disponibilité de l’azote etc.) et une reconsidération de l’ensemble du système serait nécessaire pour les limiter. De plus, peu de références existent sur cette thématique et la majorité des études a été menée dans un contexte nord-américain (Moyer, 2011). Ainsi, des questions persistent sur les moyens de mise en œuvre de cette innovation dans les exploitations agricoles actuelles (machinisme, compétences, connaissances, choix techniques et organisationnels etc.) ainsi que sur les performances économiques et agronomiques du SDSC. Cette thèse s’axe donc autour de ces trois grandes problématiques et propose de développer des solutions viables chez les agriculteurs pour intégrer cette technique dans un contexte européen. Ce projet vise notamment à prendre en compte les objectifs et les contraintes des producteurs à plusieurs niveaux d’organisation (parcelle, systèmes de culture, exploitation agricole) en alliant une approche à la fois systémique et analytique

Overview of Organic Cover Crop-Based No-Tillage Technique in Europe: Farmers’ Practices and Research Challenges

Cover crop mulch–based no-tillage (MBNT) production is emerging as an innovative alternative production practice in organic farming (OF) to reduce intensive soil tillage. Although European organic farmers are motivated to implement MBNT to improve soil fertility and achieve further management benefits (e.g., labor and costs savings), low MBNT practice is reported in Europe. Thus, this paper aims to understand the challenges of both farmers and researchers limiting the further adoption of MBNT in organic farming in temperate climates. The primary no-tillage (NT) practices of organic European farmers and findings of organic MBNT studies conducted in Europe are reviewed, focusing on living or mulch cover crop-based NT (LBNT or MBNT) for arable crop production. Major conclusions drawn from this review indicate consistent weed control and an establishment of best practices for cover crop management as the two main overarching challenges limiting adoption. In view of substantial gaps of knowledge on these issues, additional research should focus on cover crop selection and management (species, date of sowing) to increase cover crop biomass, particularly in warmer climates. Lastly, further research is needed to optimize cover crop termination to prevent competition for water and nutrients with cash crops, particularly in wetter northern conditions which promote vigorous cover crop growth

Reduced tillage in organic farming affects soil organic carbon stocks in temperate Europe

For decades, conservation tillage has been promoted as a measure to increase carbon stocks in arable soils. Since organic farming improves soil quality and soil carbon storage, reduced tillage under organic farming conditions may further enhance this potential. Therefore, we assessed soil organic carbon (SOC) stocks of reduced tillage compared with mouldboard ploughing in nine organic farming field trials in France, Germany, the Netherlands, and Switzerland with the same sampling and analytical protocol. We sampled soil cores until a depth of 100 cm to determine soil carbon stocks that are relevant for climate change mitigation but are often overlooked in tillage studies with shallow sampling depths. The studied field experiments were between 8 and 21 years old and comprised different soil types with clay contents ranging from 10% to 50%. SOC stocks increased with increasing clay-to-silt ratio, precipitation and organic fertiliser input. Across sites, reduced tillage in comparison with ploughing increased SOC stocks in the surface layer (0–10/15 cm) by 20.8% or 3.8 Mg ha-1, depleted SOC stocks in the intermediate soil layers to 50 cm soil depth with a maximum depletion of 6.6% or 1.6 Mg ha-1 in 15/ 20–30 cm and increased SOC stocks in the deepest (70–100 cm) soil layer by 14.4% or 2.5 Mg ha-1. The subsoil SOC stock increase may be linked to the inherent soil heterogeneity. Cumulative SOC stocks increased by 1.7% or 1.5 Mg ha-1 (0–50 cm, n = 9) and 3.6% or 4.0 Mg ha-1 (0–100 cm, n = 7) by reduced tillage compared with ploughing with estimated mean C sequestration rates of 0.09 and 0.27 Mg ha-1 yr-1, respectively. There was no effect of field trial duration on tillage induced cumulative SOC stocks differences. Under reduced tillage, biomass production was 8% lower resulting in a decrease of crop C input by 6%. However, this reduction may have been outbalanced by increased C inputs from weed biomass resulting from a higher weed incidence in reduced tillage, which warrants further research. Thus, reduced tillage in organic farming has the potential to increase total SOC stocks, while crop management has to be improved to increase productivity