Cereal-Based Intercropping Systems Improve Yield Advantage and Crop Yield Under Superabsorbent Application in Semiarid Conditions

Considering the yield advantage of cereal:legume intercropping in low nitrogen conditions, an experiment was laid out to examine the barley:chickpea intercropping treatments and their effects on biological yield and yield advantage of two plants under rain-fed conditions as affected by a superabsorbent polymer (0, 50, 75, and 100 kg ha⁻¹) in two cropping seasons. In both years, increasing the chickpea population increased the chickpea biological yield, total land equivalent ratio (TLER), competition index (CI), and barley and chickpea relative yields. Increasing the amount of the superabsorbent polymer to 100 kg ha⁻¹ increased the chickpea competition ratio (0.86). The highest TLER (4.00) was related to 100:100 barley:chickpea intercropping without superabsorbent polymer application. In both years, the highest CI (0.21) was attained in the 100:100 barley:chickpea intercrop system in the first year. This was followed by the 100:100 barley:chickpea intercrop ratio (0.16) in the second year. The highest barley relative yields in the first year (3.91) and second year (3.57) were related to the 100:100 barley:chickpea plant ratio, which was higher than the yields for the 100:25 (38% and 35%), 100:50 (26% and 23%), and 100:75 (12% and 10%) ratios. Based on the results, the superiority of mixed cultivation, compared with pure cultivation, in the exploitation of production resources and integration of crop plants was observed.