Abstract: In order to clarify the effects of different fertilization measures of sweetpotato on soil nutrient and soil microbial functional diversity，through the field positioning experiment，effects of different fertilization measures on soil nutrient content，microbial carbon source utilization capacity and functional diversity in wheat—sweetpotato rotation field were analyzed in 2020—2021. The treatments included only chemical fertilizer(T1)，straw returning without fertilization(T2)，only biological organic fertilizer(T3)，combined application of 80% chemical fertilizer and biological organic fertilizer(T4)，combined application of 80% chemical fertilizer and straw returning(T5)，combined application of 80% chemical fertilizer，biological organic fertilizer and straw returning（T6）.The results showed that，compared with the only chemical fertilizer or organic fertilizer treatments，the combined application of inorganic fertilizer and organic fertilizer increased the content of soil nutrients and changed the soil pH value.Compared with the other fertilization treatments，the contents of soil available phosphorus，available nitrogen，available potassium in T6 treatment were significantly increased by 9.27%—31.80%，5.79%—28.06%and 3. 97%—18. 54% respectively；the content of soil organic matter in T6 was significantly increased by 6.56%，11.21% and 6.86% compared with T1，T2 and T5 treatments，respectively；the average color change rate values of six treatments showed T6>T4>T5>T3>T1>T2. At 120 h of soil microorganism cultivation，compared with the other fertilization treatments，the capacities of soil microorganisms in T6 treatment to utilize the polymeric compound，carbohydrate and amino acid were significantly increased by 12.75%—74.24%，5.71%—131.25% and 20.65%—177.50% respectively；in T6 treatment，soil microbial Shannon index，McIntosh index and Richness index were the highest，while Simpson index was the lowest. The redundancy analysis showed that the utilization capacity of various carbon sources and diversity index of soil microbial community were jointly restricted by a variety of environmental factors.Among them，soil available phosphorus（contribution rate of 35.3%） and soil available nitrogen（contribution rate of 23.4%），organic matter（contribution rate of 15.7%）were the main driving factors of soil microbial carbon source utilization and functional diversity，respectively. Under the condition of straw returning，the combination of chemical fertilizer reduction and biological organic fertilizer can effectively improve the content of soil available nutrients and organic matter，and improve the utilization capacity of soil microbial carbon source.

Key words: Sweetpotato, Fertilization, Soil nutrients, Microorganism, Carbon metabolism

摘要： 为明确不同施肥措施对甘薯土壤养分变化及土壤微生物功能多样性的影响，2020—2021年通过田间定位试验，研究小麦—甘薯轮作条件下不同施肥措施［单施化肥（T1）、秸秆还田不施肥（T2）、单施生物有机肥(T3)、80%化肥+生物有机肥配施（T4）、80%化肥+秸秆还田配施（T5）、80%化肥+生物有机肥+秸秆还田配施(T6)]甘薯土壤养分含量、微生物碳源利用能力以及功能多样性的变化规律。结果表明，与单施化肥或有机肥相比，无机肥与有机肥配施能够提高土壤养分含量，改变土壤pH值。其中，T6处理土壤速效磷、速效氮、速效钾含量较其他处理分别显著提高9.27%~31.80%、5.79%~28.06%、3.97%~18.54%；土壤有机质含量较T1、T2和T5处理分别显著提高6.56%、11.21%、6.86%。土壤微生物培养120 h时，各处理平均颜色变化率表现为T6>T4>T5>T3>T1>T2；T6处理土壤微生物对多聚化合物、碳水化合物、氨基酸的利用能力较其他处理分别显著提高12.75%~74.24%、5.71%~131.25%、20.65%~177.50%；T6处理土壤微生物Shannon指数、McIntosh指数、Richness指数均最高，Simpson指数最低。冗余分析表明，土壤微生物群落对各类碳源的利用能力以及多样性指数受多种环境因子共同制约。其中，土壤速效磷（贡献率35.3%）和速效氮（贡献率23.4%）、有机质（贡献率15.7%）分别是土壤微生物碳源利用和功能多样性的主要驱动因子。秸秆还田、化肥减量与生物有机肥配施能够有效提高土壤速效养分及有机质含量，提升土壤微生物碳源利用能力。

关键词: 甘薯, 施肥, 土壤养分, 微生物, 碳代谢