Relay Cropping of Sorghum and Legume Shrubs for Crop Yield Improvement and Striga Control in the Subsistence Agriculture Region of Tigray (Northern Ethiopia)

Striga hermonthica is a major constraint in the subsistence agriculture regions of northern Ethiopia. Low soil fertility and overall environmental degradation has contributed to the build up of the parasitic weed infestation. Improved cropping systems have to be introduced to address the interrelated problems of Striga and soil fertility decline. Thus, relay cropping of sorghum with legume shrubs was investigated at two locations representing different environments. Results showed that the output of the improved cropping system was dependent on ecological endowments. Relay cropping led to significant improvement in yield at Sheraro, at the site with relatively better weather and soil conditions. The legume shrubs resulted in significantly lower sorghum yield in a dryland location (Adibakel). Overall Striga infestation declined over the 3‐year period; however, treatment differences were not apparent. Among the two legume shrubs, Sesbania sesban was better adapted to the dryland areas. Relay cropping could provide a viable option for farmers in both types of environments that are characterized by accelerated decline in natural resource base. However, it could mean compromising the yield of non‐fertilized sorghum in the interest of long‐term benefits of low incidence of Striga and more rewarding crop enterprise in dry areas.