Effects of chemical fertilizer reduction and application of organic manure on the yield and nutritive value of Zea mays and soil microbial activity

This study was conducted in the Guanzhong area to study the effects of chemical fertilizer reduction and application of organic manure on the yield and nutritive value of silage maize (Zea mays) and soil microbial activity. The results showed that there were no significant differences (P > 0.05) in the yields between the different treatments in the first year. The single fertilizer treatment (T₁) had the highest crude protein content, and the application of organic manure reduced the crude protein content of maize to a certain extent and increased the fiber content. The soil microbial biomass carbon, microbial biomass nitrogen, soil urease, and alkaline phosphatase activity of the T₁ treatment were the lowest. With an increase in the ratio of organic manure application, the soil microbial biomass carbon, microbial biomass nitrogen, and soil enzyme activity increased. This preliminarily indicates that the application of organic manure in the Guanzhong area can maintain the maize yield in the first year, and significantly increase the soil carbon/nitrogen reserves and enzyme activities. This study provides a theoretical basis for the development of the silage maize industry, improvement of the soil environment, and improvement of fertilizer utilization efficiency in the Guanzhong area.