Antioxidant and yield responses of wheat and clover in intercropping system to late season water deficit induced by partial root-zone irrigation regime

A field experiment was conducted to evaluate the effect of planting pattern and irrigation system on antioxidant activity of wheat and Persian clover. The experiment was carried out as a two-factor factorial with three replications. The first factor was irrigation system (conventional and partial root-zone irrigation) and the second was planting pattern (sole wheat, sole Persian clover, alternate-row intercropping and within-row intercropping). Results indicated that RWC of wheat and clover leaves decreased with lowering water supply. Both crops had higher RWC in intercropping. At the stage of before irrigation, wheat and clover had lower proline in intercropping systems (15% and 9% lower for wheat and clover, respectively). SOD in wheat and Persian clover increased with the severity of water deficit. Under partial root-zone irrigation, SOD of wheat and Persian clover was increased 10% and 46% compared with conventional irrigation. The MDA content of wheat and Persian clover leaves under partial root-zone irrigation was more than that of conventional irrigation. Regarding MDA wheat experienced a higher stress under sole cropping. Grain yield of wheat and Persian clover reduced 27 and 36 percent in partial root-zone irrigation, respectively. Land equivalent ratio of intercropping in partial root-zone irrigation was significantly (P≤0.01) than that of conventional irrigation, suggesting that intercropping reduced the negative effect of lower water supply. Generally, partial root-zone irrigation induced higher antioxidant activity of wheat and Persian clover. However, partial root-zone irrigation may have a good potential for reducing water consumption in intercropping systems.