Effect of intercropping on water use efficiency, yield quantity and quality of millet and soybean in irrigation regimes

To investigate the effects of intercropping on yield quantity and quality of soybean (Glycine max (L.) Merr.) and millet (Panicum miliaceum L.) in irrigation regimes, the experiment was carried out as a split-plot based on a randomized complete block design with three replications at the Research Station of Agricultural Faculty of Bu-Ali Sina University, 2015. The main factor included three levels of irrigation regimes (irrigation after 60, 90 and 120 mm cumulative evaporation from pan class A) and five levels of replacement intercropping consisted of monoculture of soybean, monoculture of millet, 67 % soybean+ 33 % millet (67Soybean:33Millet), 50 % soybean+ 50 % millet (50Soybean:50Millet) and 33 % soybean+ 67 % millet (33Soybean:67Millet) as subplot. The results showed that the highest grain phosphorus concentration of millet (0.35 percent) was obtained from (50Soybean:50Millet) ratio in irrigation regimes after 60 mm evaporation, and the lowest one (0.12 percent) was observed in monoculture of millet in irrigation regimes after 120 mm evaporation. The highest grain phosphorus concentration (0.27 percent) of soybean was observed in (50Soybean:50Millet) ratio, that was 14.4 percent, higher than monoculture of soybean. Grain phosphorus and oil content reduced in irrigation regimes after 120 mm evaporation were about 40.7 and 34.8 percent, respectively, compared to irrigation regimes after 60 mm evaporation. Intercropping increased protein content of millet. Intercropping increased the water use efficiency of soybean and millet. Maximum value of LER (1.14) was achieved in (50Soybean:50Millet) intercropping in irrigation regimes after 120 mm evaporation.