Optimal Drip Fertigation Regimes Improved Soil Micro-Environment, Root Growth and Grain Yield of Spring Maize in Arid Northwest China

Understanding the spatial distributions of soil water, temperature and nutrients as well their effects on maize growth grain yield is vital for optimizing drip fertigation regimes. In this study, a 2 year field experiment was conducted drip-fertigated spring with plastic mulching in arid northwestern China 2015 2016. Four irrigation levels were set: I60 (60% ETc; ETc crop evapotranspiration), I75 (75% ETc), I90 (90% ETc) I105 (105% 2015; I80 (80% I100 (100% I120 (120% Two fertilization rates N-P2O5-K2O F180 (180-90-90) F240 (240-120-120). The results showed that average water content deeper layer (80–120 cm) increased increase level, lowest 0–80 cm occurred under I95 level more significantly influenced at 5 than other depths. With decrease progression period, increased. nitrate nitrogen root zone decreased increasing level. largest 0–100 depth both Significant differences observed length density 0–20 various lateral locations. (60–100 layers, (2015) (2016) greater Grain yield, use efficiency (WUE) partial factor productivity (PFP) 2015, while it then I105F180 achieved maximum (18.81 t ha−1), WUE (3.32 kg m−3), PFP (52.26 kg−1) I100F180 (20.51 (3.99 (57.02 optimal regimes northwest recommended 90–100% 180-90-90 (N-P2O5-K2O) hm−2.