Socio-economic impacts of zero and reduced tillage in wheat fields of the Moroccan drylands

Abstract

Zero tillage (ZT) is recommended for dryland farming because it enhances retention of residual soil moisture. However, it is not always clear whether this translates to an economic advantage over conventional tillage, which helps in controlling weeds. Using a nationally representative sample of 1901 wheat fields in Morocco as a case study, we provide comparative analysis on different tillage intensities. Results from an endogenous switching regression model showed that fields that were not tilled gave 298.6 kg/ha (23%) higher yields, US$89/ha (27%) more income and more stable yields than those tilled once or more. Fields that were not tilled also had 87% lower yield variance with 100% and 65.6% less risk of giving yield levels below 500 and 1000 kg/ha, respectively. The highest yield losses occurred during the first and third tillage passes, but the second had negligible effect. Labor saving from avoiding tillage under ZT was undermined by higher labor needed for weeding. Along with biophysical benefits documented elsewhere, our results show that, if constraints for its wider diffusion are removed, zero or reduced tillage has the potential to sustainably improve the economic and biophysical viability of dryland agriculture in Morocco and other similar countries in North Africa andWest Asia.