Adoption of conservation agriculture in europe. Lesson of the KASSA project

According to KASSA findings, conservation agriculture is less adopted in Europe compared to other adopting regions and, reduced tillage is more common than no-tillage and cover crops. Currently, it is not popularised and it is less researched. It seems that the lack of knowledge on conservation agriculture systems and their management and, the absence of dynamic and effective innovation systems make it difficult and socio-economically risky for farmers to give up ploughing which is a paradigm rooted in their cultural backgrounds. In Norway and Germany the adoption of conservation agriculture has been encouraged and subsidised to mitigate soil erosion. In the other European countries the adoption process seems mainly farmers driven and the major driving force has been the cost reduction in machinery, fuel and labour saving. Soil and water conservation concerns did not appear as main drivers in the European farmers¿ decision to shift or not to conservation agriculture. The conversion of European farmers to conservation agriculture is being achieved through a step by step attitude; large scale farms are the most adopters, probably due to their ability to absorb risks. The short term socio-economic benefits that conservation agriculture provides, the need to improve farms¿ competitiveness, market globalization and the steady increase of fuel cost are likely to be sufficient to boost the ongoing slow adoption trend of conservation agriculture in Europe. Conservation agriculture is not equally suitable for all the European agroecosystems. The need of soil and water conservation in Europe requires anticipating the ongoing process in order to improve its ecological sustainability. Priority would be to define which regions in Europe are the most suitable for conservation agriculture taking into account climate and soil constraints, length of growing period, water availability and quality, erosion hazards and farming conditions. Policy and financial support favouring the use of cover crops and agronomically sound crop rotations as management strategies for weed, pest and diseases will certainly allow developing efficient and acceptable CA systems. (Résumé d'auteur

Key lessons from international experiences about conservation agriculture and considerations for its implementation in dry areas

Land scarcity and soil degradation in dry areas are increasingly recognized and being documented. Their impact on the livelihood .of people and the resilience of ecosystems is a source of growing concern. Alternative land management practices and strategies are needed to mitigate/reverse currènt negative trends. Conservation agriculture (CA) may contribute to this goal. Indeed, CA emerged historically in response to soil erosion crises and their negative economic consequences. The adaptation of CA in diverse situations, inc1uding small-scale farming, ·of rainfed and irrigated agriculture has given way to developing various CA systems spanning a wide array of practices ranging from reduced tillage (RT) to no-tillage (NT) with varying degrees and means of soil coyer. CA is perceived as a powerful tool of land management in dry areas. It allows farmers to improve their productivity and profitability especially in dry years while conserving and even improving the natural resource base and the environment. However, CA adaptation indrylands faces critical challenges linked to water scarcity and drought hazard, low biomass production and acute competition between conflicting uses inc1uding soil coyer, animal fodder, cooking/heating fuel, raw material for habitat etc. Poverty and vulnerability of many smallholders that rely more on livestock than on green production are other key factors. This paper builds on selected lessons from a wealth of international experiences with the development, fine-tuning and dissemination of CA-based systems, their known drivers, constraints and impacts, to address the potential and challenges of CA in dry areas. It suggests ways and means that may he1p in designing and shaping alternative programs, tools and strategies aimed at sustainable land management in dry areas. (Résumé d'auteur

Opportunités et limites de l'agriculture de conservation en Méditerranée. Les enseignements du projet KASSA

L'agriculture de conservation est perçue comme une alternative viable dans le contexte méditerranéen où elle pourrait constituer une réponse aux défis de la rareté et des dégradations des ressources naturelles de base et à l'instabilité des productions pluviales. Les résultats obtenus par le projet KASSA montrent que l'agriculture de conservation n'est pas également appropriée à tous les agro-écosystèmes. Le développement et la durabilité des systèmes à base d'agriculture de conservation sont hautement dépendants des conditions locales. Il ne s'agit pas d'un simple processus technique ; l'implication de l'ensemble des acteurs concernés et leur capacité à générer et à partager le savoir nécessaire pour développer, adapter, corriger et améliorer les systèmes sont fondamentales notamment dans la phase de transition où un continuel ajustement des systèmes est nécessaire. Par ailleurs, le fonctionnement des systèmes à base d'agriculture de conservation et leurs impacts à long terme ne sont pas connus ; ils méritent plus d'investigations à l'avenir. (Résumé d'auteur

Sustaining conservation agriculture: Lessons learned from the EU project KASSA

The questioning of the sustainability of conventional plough-based agriculture led to the emergence of alternative concepts and practices such as conservation agriculture (CA), which is currently spreading in many places. CA-based systems are said to rely on the simultaneous use of three main components: (1) reduced tillage or no-tillage and direct seeding for less disturbance of the soil and proper crop establishment; (2) soil cover to mitigate erosion, reduce weeds, and improve soil fertility and functions; and (3) crop rotation to control pests and diseases. These systems are thought to respond to production-protection requirements; interest in their applicability and results is growing. Knowledge Assessment and Sharing on Sustainable Agriculture (KASSA) is an EU-funded project that intended to extract lessons from past research on CA. It did it through a step-by-step and iterative process that took place within four regional platforms: Asia, Europe, Latin America, and the Mediterranean. In the four platforms of KASSA, implementation of the concept of CA gave rise to many farming practices. The no-till¿based systems are the most common: in some places, they are about to replace completely the conventional plough-based systems. However, soil cover and sound crop rotation are still hardly practiced because of biophysical conditions; low biomass production; competition from livestock; lack of adapted varieties, of implements, and of knowledge; and general market conditions. The absence of these components makes the systems rely mainly on using chemicals to control weeds, pests, and diseases. The reduction in production costs CA systems provide often acts as a powerful argument for their introduction and adoption. But this argument alone is risky because (1) the development and fine-tuning of these systems is knowledge-consuming and (2) their suitability and efficiency are highly sensitive to local biophysical, social, cultural, technological, institutional, market, and policy environments. Furthermore, there are relatively few scientific data on CA systems; particularly, their long-term agronomic, environmental, and socioeconomic impacts are still not well understood. Substantial systemic and multidisciplinary research effort is needed to understand the functioning of CA systems and their socioeconomic and ecological sustainability conditions. (Résumé d'auteur

Sustainability of direct seeding versus conventional tillage

Pour analyser la durabilité du semis direct sur mulch (SDM) dans les conditions méditerranéennes, une comparaison culture traditionnelle (CT) et SDM a été réalisée sur un site expérimental à Montpellier, dans le sud de la France depuis 2000. Un blé dur a été mis en place avec différents traitements d'irrigation et d'apports d'azote en 2004. Différents paramètres du sol et de la culture ont été mesurés. En particulier, la densité du sol est légèrement accrue sous SDM et le développement racinaire, un peu moins important; le LAI et le rendement en matière sèche totale sont pratiquement équivalents à ceux de CT. Ces résultats confortent des observations antérieures sur l'efficience du SDM qui a un impact limité sur le rendement; cependant la maîtrise du semis et des adventices ont un rôle important qui doit s'appuyer sur des choix techniques adéquats et la rotation des cultures. (Résumé d'auteur

Analyse de contenu d'une carte pédologique en horizons : les formules de sol

Sur un versant schisteux, en climat méditerranéen, une cartographie d'horizons pédologiques a été réalisée à grande échelle dans un petit secteur. Les auteurs montrent ici l'intérêt de l'analyse de contenu (les formules de sol). (Résumé d'auteur

Long-term Piliostigma reticulatum intercropping in the Sahel: Impact of the density of shrub on sorghum yield

Continuous cropping of cereals and reduction of fallow periods contribute to soil degradation in Africa drylands, altering the soil functions and the systems' resilience. Alternatively, appropriate intercropping of cereals with native evergreen woody shrubs is proposed as a way to restore degraded lands and, ultimately, positively impact crop yields (Lahmar et al., 2012; Bright et al., 2017). The effect of the density of shrubs (Piliostigma reticulatum) was tested on a continuous sorghum crop (Sorghum bicolor). The experimentation is located in the 2iE Campus – Kamboinsé, Burkina Faso (12°28.031'N; 1°32.929'W) including randomized block design with four replicates. Shrubs were installed in August 2012 with different shrub densities: 0, 488, 976 and 1953 shrub ha-1; Sorghum was cultivated using the Zaï technique (traditional planting pits) since 2013 season. Fertilizers were provided on the sorghum crop only in the first 2 years. Each year, the shrubs were coppiced before the start of the rainy season in June, and during the cropping season (starting from 2016). All the shrub biomass was used as soil cover. After sorghum grain yield was harvested, the remaining sorghum biomass was also left on the soil surface. Piliostigma aboveground dry matter have increased during the 4 years of monitoring (from 2015 to 2018), reaching in 2018 a production of 6160 kg ha-1 (dry matter) for both the highest shrub densities (976 and 1953 shrub ha-1), and 3890 kg ha-1 for the lowest density (488 shrub ha-1). Sorghum grain yields declined progressively since 2014 when we stopped using fertilizers, and for all treatments. Our results over a 5-years trial support the fact that Piliostigma intercropping alone do not significantly increase sorghum yield. Piliostigma is a non-nitrogen-fixing legume shrub that allows the stabilization of soil carbon content but not of soil nutriment nitrogen and phosphorus (Félix et al., 2018). Further researches combining Piliostigma with other sources of nutrient would need to be tested. For example in 2018 we started to study the effect of adding cowpea (Vigna unguiculata L. Walp, nitrogen-fixing legume) to the intercropping of shrub with sorghum. Another consideration is the time required to achieve measurable benefits. It was observed that it took more than 4 years to obtain consistently increased yields of sorghum when shifting to an optimized Piliostigma system (Bright et al., 2017). This experiment is the support for various studies on hydrology of soil and on nutrient cycling (CGIAR Research Program “Grain Legumes and Dryland Cereals”, LeapAgri “Ramses II” project, MacKnight “3F” project)