Effects of subsoiling before winter wheat on water consumption characteristics and yield of summer maize on the North China Plain

As an important industry for national development, summer maize production occupies a key position in China and globally. However, agricultural water consumption is becoming increasingly problematic, and global climate change and long-term traditional rotary tillage have negative effects on the soil surface layer. Subsoiling has been an effective measure to improve soil surface-layer structure and increase yield. In the present study, field experiments were conducted to compare the effects of subsoiling and rotary tillage in winter wheat and summer maize double cropping systems. Subsoiling treatments at a depth of 40 cm (S40) and 35 cm (S35), and rotary tillage at a depth of 15 cm (R15) before winter wheat planting were used, and the effects of tillage methods on soil stable infiltration rate, soil water consumption, evapotranspiration, grain yield, and crop water productivity (CWP) in summer maize growing seasons were determined. The results showed that subsoiling significantly improved soil infiltration rate. Water consumption in the subsoiling treatments increased significantly, and especially promoted the crops to utilize soil water at depths below 60 cm in the soil profile. As a result, compared with R15, kernel numbers per row and 1000–grain weight in S35 were significantly increased; therefore, both grain yield and CWP were significantly improved. Our results indicate that the S35 treatment is a reasonable subsoiling measure on the North China Plain, which can increase both summer maize grain yield and CWP in double cropping systems.