关键词: 土壤; 施肥组合; 有机碳; 易氧化有机碳; 碳库管理指数; 产量

Abstract: 【Objective】 To find out the effects of different fertilization combinations on soil organic carbon and soybean yield and screen out best fertilization combinations in the hope of providing important theoretical basis for annual fertilization in Ili Valley.【Method】In this experiment, the split zone experiment design was adopted, and the main area was fertilization in wheat season, four treatments were set up: CK(non- fertilizer), A(nitrogen fertilizer), B(organic fertilizer), C(organic fertilizer+ nitrogen fertilizer). The sub-area was soybean season fertilization. On the basis A, B and C three treatments, the two levels of nitrogen application were applied as follows: no topdressing nitrogen fertilizer and topdressing nitrogen 150 kg/hm², thus studying the effects of different fertilizer combinations on the soil organic carbon (SOC), oxidizing organic carbon (EOC), carbon pool management index (CPMI) and yield.【Results】The results showed that under different fertilizer combinations in 2017 and 2018, with the increase of the depth of soil layer (0-100 cm), the SOC, EOC of each treatment increased at first and then decreased, but the effect of each treatment on CPMI was not obvious. The content of SOC and EOC by A1, A2, B1 and B2 treatments reached the highest value when the depth of soil layer was 20-30 cm but there was no significant difference among the treatments. The content of SOC and EOC by C1 and C2 treatments reached the highest value when the depth of soil layer was 30-40 cm, arriving at a significant level with each treatment (P<0.05). In terms of the mean value of CPMI in each soil layer of 0-100 cm in two years, the average value was the highest in C1 treatment (the combination of organic fertilizer and nitrogen fertilizer). (C1) compared with the annual nitrogen application treatment (A2) and the control (CK), the treatment was 8.3% and 50.62% higher than those of the annual nitrogen treatment (A2) and the control, respectively. The yield of C1 treatment (organic fertilizer and nitrogen fertilizer in wheat season in combination with Non-fertilizer treatment ) was 8.3% and 50.62% higher than those of A2 treatment (annual nitrogen application) and the control (CK), respectively. There was a significant correlation between yield and soil SOC, EOC and CPMI.【Conclusion】The C1 treatment not only improved soil quality, increased soil carbon sequestration, but also increased crop yield. This study screened out the most favorable combination of annual fertilization under drip irrigation, and provided an important theoretical basis for the annual fertilization in wheat-soybean rotation system in Ili River Valley

Key words: soil; fertilizing combination; organic carbon; oxidizing organic carbon; carbon pool management index; yield