Combining yield gap and efficiency analysis to analyze farmers’ fields network: a case study on nitrogen in durum wheat in Tunisia

T3. Crop modeling and yield gap analysis for agricultural systems analysis and design

International audience

anglais. In most Mediterranean regions, durum wheat yield is variable with time and location, depending on several factors, primarily water and nitrogen supply (Boussen et al., 2005). Nitrogen (N) is one of the most important nutrients applied as a fertilizer and responsible to a great extent for the large yields obtained from high input agriculture (Latiri, 1998). However, the increased use of N fertilizer can affect farmers' margins, causes excessive losses to the environment and make agriculture dependent of non-renewable energy. The simultaneous increase in both yield and N-efficiency is at the core of eco-efficient agriculture which targets efficient and sustainable use of resources in agricultural production and land management (Keating et al., 2010). It adds to the concept of ecological intensification (Cassman, 1999), the hypothesis of eco-efficiency frontiers that are determined by the genetic nature or by the agrobiodiversity of the cropping systems. This study aims to analyze the efficiency of nitrogen supply on durum wheat and its drivers in different regions in Tunisia and try to identify eco-efficiency frontiers, associated with constrasting rotation sequences. We addressed the following question: Can higher yields and greater N-efficiency be expected in wheat-based cropping systems by diversifying rotation sequences?