Intercropping Chickpea with Durum Wheat Enhances Nutrient Uptake and Grain Yield Under Low Phosphorus Availability

Intercropping is a traditional farming system that increases crop diversity to strengthen agroecosystem functions while decreasing chemical inputs and minimizing negative environmental effects of crop production. However, the effect of intercropping legume-cereal in enhancing nutrient uptake and use efficiency under low phosphorus (P) soils is poorly understood. Growth, nodulation, P uptake and use efficiency, and changes in inorganic P availability in the rhizosphere of intercropped species were thus investigated in a field experiment with durum wheat and chickpea either grown alone or intercropped. The results showed that both plant biomass and grain yield, and consequently, the amount of P uptake by intercropped durum wheat increased significantly (30%, 12%, and 46%, respectively) compared with sole cropping during the two seasons. P availability increased in the rhizosphere of the two species, either grown as sole crops or as intercrops, and was enhanced by intercropping. Moreover, total biomass, grain yield, and P uptake were significantly improved, as indicated by higher land equivalent ratio (LER > 1) in intercropping over sole cropping treatments. The increased biomass and grain yield for intercropped durum wheat were associated with the stimulation of P absorption and use efficiency. Furthermore, intercropped wheat was more competitive than their respective chickpea over two growing seasons. The results of this study suggest that changes in the intercropped chickpea rhizosphere may enhance plant growth, P uptake, and use efficiency of the intercropped wheat under low-P soils.