Effects of Combined Organic-inorganic Fertilization on Quality and Water Use Efficiency of Spring Maize under Equal Nitrogen Fertilization

The experiment was conducted in the abandoned land of Liangjia Village, Huayin City, Shaanxi Province from April to September 2019. The experimental crop was spring maize. A total of six treatments were set up in a randomized block design. The moisture content of the top 0-60 cm soil was determined regularly, and the yield and quality indices of maize at maturity were checked. The results show that: (i) combined organic-inorganic fertilization increased the yield of spring maize by 3% ~ 8%. (ii) Compared with CK, fertilization treatments significantly improved the water use efficiency of spring maize, with an increase of 59.2%. The average water use efficiency of three combined organic-inorganic fertilization treatments was 27.81 kg/(ha • mm). Compared with CON, combined application of organic and inorganic fertilizers significantly improved the water use efficiency of spring maize, with an increase of 12.5%. (iii) The combined application of organic and inorganic fertilizers increased the moisture, total starch, crude protein and crude fat contents, and reduced crude fiber content of maize kernels. However, with the increase of the proportion of organic fertilizer, the crude protein content of maize kernels decreased. (iv) Yield of spring maize showed a significant parabolic relationship with soil water consumption. In summary, 70% inorganic fertilizer + 30% organic fertilizer is a scientific and reasonable way of fertilization.