Stover return and nitrogen application affect soil organic carbon and nitrogen in a double-season maize field

Cultivation techniques have an important influence on grain yield of maize. This experiment investigated the effect of stover return (SR) and different nitrogen (N) application rate on soil organic carbon (SOC) composition, soil nutrient and maize yield. Different nitrogen application rate 100 (N100), 150 (N150), 200 (N200), 250 (N250) or 300 (N300) kg ha^-1 applied to the maize field with stover return and without stover return traditional planting (TP) method. Nitrogen application rate and stover return affected the SOC, labile organic carbon (LOC), microbial biomass (MBC), NO₃ ^- -N, NH₄ ⁺ -N and maize yield. Soil N, soil carbon content and maize yield of SR were all higher than TP. The SOC content of SR and TP were 9.67 and 9.19 g kg^-1 , respectively. Nitrogen application was significantly and positively correlated with soil MBC, LOC, SOC, NO₃ ^- -N, NH₄ ⁺ -N and yield. The maximum values of SOC composition, soil nutrients and maize yield were reached at SR with 250 kg ha^-1 . Stover return with application of N 250 kg ha^-1 significantly increased the growth attribute and maize yield in subtropical region compared with traditional planting.