Effect of sulfur fertilizer on summer maize grain yield and soil water utilization under different irrigation patterns from anthesis to maturity

The enhanced yield of summer maize depends not only on soil water, but also on plant nutrition and fertilization with sulfur, a key element, which plays an important role in improving yield and water use. However, no research has focused on the coupling effects of sulfur application and irrigation patterns from anthesis to maturity on summer–maize grain yield and water use. We tested three irrigation patterns: no irrigation after anthesis (W0), irrigation at 15 days after anthesis (W1), and irrigation at 15 and 30 days after anthesis (W2), either combined with sulfur (S1, elemental sulfur) or without sulfur (S0) to evaluate the soil moisture content (SMC), grain yield, and water utilization of summer maize in a rainout shelter during the 2016 and 2017 growing seasons, in the North China Plain. Sulfur application reduced the SMC at 0–20 cm irrespective of irrigation pattern at harvest, but increased it at 30–120 cm while reducing evapotranspiration under W1 and W2. Compared to W0, W1 and W2 treatments significantly increased aboveground biomass (10.9% and 21.9% in 2016; 20.4% and 31.7% in 2017, respectively) and grain yield (16.1% and 26.2% in 2016; 24.6% and 35.3% in 2017, respectively). Water productivity at the grain yield level (WPy) increased with sulfur application by 6.4%, 8.8%, and 7.6% in 2016, and by 4.3%, 7.9%, and 6.4% in 2017 under W0, W1, and W2 conditions, respectively. The results indicated that sulfur application enhanced WPy, increased grain yield of summer maize. Thus, combining post-anthesis irrigation with sulfur application should be recommended for attaining high WPy and yield of summer maize in the North China Plain.