长期偏施氮肥对桑树根际土壤微生物碳源利用能力的影响

采用Biolog微生态技术,研究长期(4年-4Y,17年-17Y,32年-32Y)偏施氮肥桑树根际土壤微生物碳源利用能力变化。结果表明,不同施肥年限及不同取样时期桑树根际土壤微生物利用单一碳源能力不同,4Y土壤微生物活性(AWCD)、Shannon多样性指数及对糖类、氨基酸类、胺类碳源的利用能力均高于其他处理土壤,且与32Y土壤均达显著差异水平(P0.05);主成分分析表明,4Y土壤和17Y土壤与32Y土壤间微生物碳代谢功能差异较大;逐步回归分析表明,碳源利用Shannon多样性指数与土壤有机质含量、p H及速效氮含量有一定相关关系。

Effects of Long-term Partial Application of Nitrogen Fertilizer on Soil Carbon Source Utilization Ability in Mulberry Rhizosphere

Changes in soil microbial carbon source utilization ability of mulberry rhizosphere in long-term partial application of nitrogen fertilizer were investigated by using Biolog micro ecological technology. The results showed that the carbon utiliza-tion ability in different fertilization years and sampling date was different. The AWCD, Shannon diversity index and the uti-lization ability of carbohydrates, amino acids, amines in 4Y soils were higher than in other treatment soils, and had signifi-cant difference compared with 32Y soils ﹙P<0.05﹚. The principle components analysis indicated that there was significant dif-ference between 4Y, 17Y soils and 32Y soils. Stepwise regression analysis indicated that there was certain ﹙P<0.01﹚ correla-tions among Shannon diversity index and organic matter content, pH, and available nitrogen content.