有机物料还田对稻田土壤DOM碳源代谢能力的影响

以成都平原典型稻麦轮作长期定位施肥试验土壤为研究对象，设置常规施肥(T1)、猪粪替代50%氮肥(T2)和猪粪替代50%氮肥+秸秆全量还田(T3)这3种处理，采用Biolog-ECO方法，研究长期有机物料还田下土壤和土壤可溶性有机质(DOM)的碳源代谢能力.结果表明，T3处理较T1和T2处理显著增加了土壤的碳源代谢能力，平均颜色变化率(AWCD)分别增长16%和48%;同时T3处理提高了土壤DOM的碳源代谢能力，其AWCD值为0.43.从微生物碳代谢功能多样性指数来看，土壤和土壤DOM中微生物的碳代谢功能多样性指数均以T3处理最高，其中土壤DOM中微生物的Shannon、 Simpson和McIntosh指数分别为2.73、 0.91和3.75.主成分分析和富集分析结果显示，不同施肥处理下土壤和土壤DOM的主要利用碳源类型存在差异，对于DOM而言，T1和T2处理的DOM主要利用碳源仅为糖类，而T3处理增加了对氨基酸类、羧酸类、聚合物类和胺类的利用.土壤pH和质地的改变是引起土壤DOM碳源代谢能力差异的主要因素.综上，猪粪配合秸秆施用显著增加了土壤和土壤DOM的微生物群落多样性和碳源代谢能...

Effects of Agricultural Organic Waste Incorporation on the Metabolic Capacity of Microbial Carbon Sources of Dissolved Organic Matter in Paddy Soil

A long-term fertilization experiment with a system of rice-wheat rotation was conducted in Chengdu Plain. Three fertilization treatments including conventional fertilization (T1), pig manure substituting for 50% nitrogen fertilizer (T2), and T2 plus straw (T3) were set up to study the characteristics of microbial carbon source utilization of soil and dissolved organic matter (DOM). The results showed that T3 improved the soil microbial carbon source metabolism in comparison with those of the T1 and T2 treatments; the average color change rate (AWCD) increased by 16% and 48%, respectively. Meanwhile, T3 improved the soil DOM microbial carbon source metabolism, and the AWCD value was 0.43. The highest Shannon, Simpson, and McIntosh indexes of soil and DOM were all found in the T3 treatment, and the Shannon, Simpson, and McIntosh indexes of DOM were 2.73, 0.91, and 3.75, respectively. The results of principal component analysis and enrichment analysis showed that the main carbon sources used by microorganisms of soil and DOM were different under different fertilization treatments. For DOM, the main carbon source used by microorganisms in the T1 and T2 treatments was sugar, whereas T3 increased the utilization of amino acids, carboxylic acids, polymers, and amines. The changes in soil pH and texture were the main factors that caused the difference in soil DOM microbial carbon source metabolism. In conclusion, the application of organic fertilizer (pig manure plus straw) significantly increased the microbial community diversity and carbon source metabolic capacity of soil and DOM and promoted the diversification of microbial carbon source preference.