No-tillage agriculture in West Asia North Africa: Paradigms, Trade-offs and Perspectives

摘要

West Asia North Africa (WANA) agriculture is now at the crossroad. Serious problems of land degradation, reduced soil fertility (quality) and declining agricultural production levels are occurring. Past agricultural research has strongly focused on designing and testing cropping systems and crop management options in conventional tillage. Changes in the global environment have led researchers to question whether the role of conventional soil management in economic development is still relevant to WANA today. In fact, most of soils need skilled management systems to ensure sustainable agricultural production, among them no-tillage (NT) systems. More than 105 million hectares of land are under no-tillage systems worldwide. This means that no-till and other conservation tillage systems can work in a wide range of climates, cropping scenarios, soils and geographic areas. This paper reviews the research conducted on NT in WANA dryland regions, and discusses the problems faced with the introduction and application of conservation agriculture (CA) practices. In the last 25 years, there are evidences from examples throughout the region of sustainable production systems that can be achieved when the principles of conservation farming are applied. In WANA, where water scarcity is becoming endemic, NT could rehabilitate productivity of soils and crops as well as farmer’s returns. Production of cereals and other crops under no-tillage was found to have economic and edaphic benefits over conventional tillage systems, although in some years it can result in lower yields, which are essentially due to mis-management of weeds. Nevertheless, for a proper dissemination of NT in WANA, there should a greater attention to production and economics along with environmental and social factors by institutions.