Effects of Equivalent Substitution of Chemical Nitrogen Fertilizer with Straw-Derived Nitrogen on Water Consumption Characteristics of Maize Stages

This investigation examines the effects of straw-based nitrogen fertilization on soil hydrological properties and biomass partitioning in maize under arid zone conditions. A biennial field investigation was conducted during the 2016–2017 cropping seasons, with an equal nitrogen content of 225 kg ha⁻¹, and a total of 5 treatments, 100% fertilizer nitrogen (CK), 25% straw nitrogen + 75% fertilizer nitrogen (S25), 50% straw nitrogen + 50% fertilizer nitrogen (S50), 75% straw nitrogen + 25% fertilizer nitrogen (S75), 100% straw nitrogen (S100). The data demonstrated that in 2017, in comparison with CK, the soil water storage in the 0–60 cm soil layer of S25 and S50 in the large trumpet stage (V12) increased significantly by 23.32% and 25.14% (<i>p</i> < 0.05), respectively. In the two-year experiment, stratified moisture reserves (0–200 cm) in different treatment groups exhibited a fluctuating pattern characterized by successive increase-decrease-increase transitions along the soil profile, and overall S25 and S50 were larger than CK. In 2016, the biomass accumulation of the S50 treatment at the maturity stage (R6) was the highest, which increased by 18.11% and 19.49% compared with the CK and S75 (<i>p</i> < 0.05), respectively. There was statistical parity in water use efficiency between treatments. Soil moisture retention capacity of 180–200 cm soil was positively correlated with yield at the jointing (V6) and maturity (R6) stages, and soil water storage of 160–180 cm soil was positively correlated with yield at the tasselling stage (VT). Water consumption during the presowing–to–jointing phase demonstrated the strongest correlation with final grain yield. In summary, the S25 treatment in this experiment significantly enhanced the optimization of soil hydrological properties, increasing soil moisture storage, fully utilizing soil moisture, increasing dry matter accumulation in each growth period of maize, and replacing chemical nitrogen fertilizer with 25% of straw equivalent N fertilizers was beneficial to soil moisture storage.