Improving rainfed crop yield monitoring
5th May 2019
One of the objectives of ACCWA is to improve rainfed crop yield monitoring over the Mediterranean and Sahelian zone by better accounting for long-term and short-term changes in soil water availability. The identification of areas particularly prone to degradation in agricultural production conditions and a better understanding of the underlying drivers is increasingly important for long-term mitigation and adaptation strategies. Land degradation is mainly approximated through the study of the remotely sensed vegetation statistical trend as an indicator of changes in vegetation productivity. Among other causal factors, soil moisture (SM) is considered as an important driver of changes in vegetation productivity since it corresponds to actual water available for vegetation growth, but this has rarely been investigated as a driver of long-term changes in vegetation productivity, owing to the lack of SM data at high spatial and temporal resolution over large areas. Recently, an approach based on remote sensing, crop modelling and machine learning techniques has been proposed. We have shown that SM at high spatial resolution brings an improvement in the crop yield estimation, impacting mainly the crop water stress over the grain filling and maturation phases of the crop development. Since crop yield are mainly limited by the soil water content in the root zone, in ACCWA we propose an additional improvement by using the root zone soil moisture (RSZM).