Explaining yield and gross margin gaps for sustainable intensification of the wheat-based systems in a Mediterranean climate

Closing the attainable yield and gross margin gaps are important for improving food security and reducing poverty in developing world. Closing these gaps requires quantifying them, identifying major factors constraining the attainable yield and gross margins, and developing mitigation measures. Past literature predominantly focused only on quantification of yield gaps, using yields from experimental stations as the potentially attainable yields. This body of literature overlooked the gaps in gross margins, and more importantly, factors responsible for these gaps – thereby failing to provide sufficient policy guidance to increase productivity. We used a random sample of 2296 fields in 21 major wheat-growing provinces of Morocco as a case study to carry analysis of both yield and gross margin gaps. We used the random forest model to identify factors responsible for variations in yield and gross margins. Our results show that average yield in rainfed areas was 0.9 t ha−1 with yield and gross margin gaps of 41% and 75%, respectively. In irrigated areas, average yield stands at 4.0 t ha−1 with yield and gross margin gaps of 29% and 34%, respectively – indicating that there is substantial scope for increasing yields and gross margins in both environments. In the rainfed environment, tillage method was the most important variable in determining yield, followed by quantity of phosphorus and nitrogen fertilizer, seed quality, and type of preceding crop. In the irrigated environment, preceding crop was the most important variable in explaining yield gap, followed by variety, seed quality, and quantities of nitrogen and phosphorus fertilizers. Grain yield and grain price were the most important variables explaining gross margins. Top performer farmers in both environments had applied higher quantities of inputs and hence incurred higher costs but still had higher nitrogen and phosphorus use efficiencies and higher gross margins than the rest as the yield gains more-than offset the increases in costs. Policy and institutional implications of these results are: 1) The irrigated environments should be targeted with efforts and incentives to motivate wider adoption of legume-based rotations; 2) Incentive mechanisms should be created to encourage farmers in the rainfed environments to adopt no-tillage, use more phosphorus and nitrogen fertilizers, and buy certified seeds; 3) Legume-based rotations reduce need for nitrogen and enhance phosphorus use efficiency in subsequent crop, targeting rainfed environments also with rotation can be used as a strategy to enhance sustainability of the production system and reducing financial burden of higher doses of chemical inputs.