Effect of irrigation regime on water consumption pattern and grain yield of seed maize under partial root zone irrigation

Alternate partial zone irrigation (APRI) has been widely practiced worldwide and has been proven that it has a great potential of water saving in arid and semi-arid areas, but information on different irrigation regimes on water consumption pattern under APRI receives limited attention, especially for seed maize. To better use and development of APRI in arid area, we carried out a field experiment to investigate the effect of different irrigation regimes on water consumption pattern and grain yield of seed maize (Zay mays, Gold northwestern 22) under APRI at Wuwei, northwest China in 2014 using ridge planting-furrow irrigation technology. The irrigation regimes included only moderate water deficit at seeding stage (T1), only severe water deficit at seeding stage (T2), only moderate water deficit at heading stage (T3), only severe water deficit at heading stage (T4), only moderate water deficit at flowering and kernel stage (T5), only severe water deficit at flowering and kernel stage (T6) and full irrigation during whole growth period of seed maize (CK). Weather data during the seed maize growth season, water consumption amount of the different growth stages (planting to jointing, jointing to bell, bell to tasseling, tasseling to silking, silking to filling, filling to milk and milk to maturity) and grain yield at the maturity of seed maize were determined. The intensity of water consumption and crop coefficient at the different growth stages, water use efficiency (WUE) and irrigation water use efficiency (IWUE) were calculated. The results showed that, the CK resulted in the greatest water consumption amount and the average crop coefficient during the whole growth period of seed maize as well as the grain yield, and the corresponding values were 494 mm, 0.86 and 6478 kg/hm2, respectively. Compared to CK, the average intensity of water consumption during the seed maize grown season were decreased in any water deficit treatment, and the average intensity of water consumption in the T6 treatment was significantly smaller than that in the T5 treatment. The crop coefficient in any water deficit period of seed maize was also decreased by all the water deficit treatments. Compared to CK, the T2, T3, T4, T5 and T6 treatments significantly decreased grain yield of seed maize by 13.29%,15.48%, 28.13%, 14.06% and19.87% (P<0.05), respectively. However, the grain yield of the T1 treatment was comparable to that of the CK. At the same time, the T1 treatment significantly decreased the water consumption during the whole growth period of seed maize by 20.44% if compared to CK. As a result, the T1 treatment achieved the greatest WUE (1.55 kg/hm2) and IWUE (2.54 kg/hm2). These results suggested alternate partial root zone irrigation with the irrigation regime of moderate water deficit at the seeding stage and full irrigation at the other growth stages could maintain the grain yield and obviously reduce the water consumption amount during the whole growth period of seed maize, and thereby improving water use efficiency. The results could provide guidance to irrigation management in the field for seed maize in the Hexi Corridor area of northwest China. © 2019, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.