Mineral nutrition of wheat, chickpea and lentil as affected by mixed cropping and soil moisture

Interspecific complementary and competitive interactions on yield and N, P, K, Fe, Zn and Mn nutrition of mixed wheat/chickpea and wheat/lentil grown in a glasshouse under normal and drought conditions, and intercropping of wheat/chickpea in the field under rainfed conditions were investigated. The results of the experiments confirmed that drought significantly decreased the growth and mineral nutrition of all plant species. Individual plant dry weights of wheat, chickpea and lentil in the glasshouse experiment, and vegetative shoot dry weight of intercropped wheat in the field experiment were significantly increased by the associated plant species as compared with their monoculture. Even though there were increases in vegetative shoot dry weight of wheat, biological and seed yield of intercropped wheat and chickpea were decreased due to the lower row number in intercropping. However, the calculated LER (Land Equivalent Ratio) was found to be higher than 1.0 for biological and seed yields, showing that intercropping of wheat and chickpea has an advantage over monoculture. In many cases, the drought x cropping system interaction on the nutrient concentrations of plant species was not significant. Results of the glasshouse study showed that P nutrition of wheat was improved by chickpea and lentil, which might result from increases in leaf acid phosphatase in mixed cropping. The release of Fe(III)-complexing compounds from the roots was higher in the sole wheat and mixed culture than that of monocultured chickpea and lentil. This improves Fe nutrition of wheat and chickpea, but those improvements were not significant. However, Zn and Mn concentrations of mixed cropped chickpea were also increased. Under the field conditions, shoot concentration of P, K, Fe, Zn and Mn in wheat were increased by intercropping. Furthermore, the concentrations of Zn and Mn in chickpea were increased by intercropping while N, P and K concentrations were decreased. In addition, the concentrations of N, P, K and Fe for wheat seeds and of Zn and Mn for chickpea were improved by intercropping. It is concluded that interspecific interaction was complementary and generally facilitated the mineral nutrition of wheat and chickpea species grown in mixed culture. Besides giving a yield advantage, intercropping of chickpea and wheat also had a positive effect on seed mineral composition.