单季不施氮肥对太仓水稻土的微生物功能多样性的影响

EFFECTS OF SEASONAL WITHDRAWAL OF NITROGENOUS FERTILIZER ON MICROBIAL FUNCTION DIVERSITY IN PADDY SOIL IN TAICANG

摘要:

氮肥的过量施用在浪费资源的同时也污染了环境,单季不施N肥是太仓地区探索的减少N肥施用量方法中的一种。本文通过比较短时期的单季不施N肥区和常规施肥区中土壤中微生物的数量和群落水平的功能多样性指数来研究单季不施N肥对土壤质量的影响。结果表明:细菌、真菌、放线菌的数量在两种施肥方式下没有显著差异;BIOLOG平板法获得的平均吸光度、多样性指数Shannon指数H'和Simpson指数的变型G在两种施肥方式下没有显著差异;主成分分析(PCA)在95种因子中提取的3个主成分因子,尽管主成分因子2在两种施肥方式下略有差别,主成分因子1和3却无法区分两种施肥方式。这说明短时期的单季不施N肥不会对土壤中微生物数量造成影响,对土壤微生物功能多样性也仅对细微有影响。

Abstract:

Excessive input of nitrogenous fertilizer not only wastes resources but also pollutes environment. Seasonal withdrawal of nitrogenous fertilizer is a practical method to reduce application rate of the fertilizer in Taicang. This paper compares this practice with the traditional one in soil microbe population and functional diversity index of the microbe at the community level. The results showed that no significant difference was found in populations of bacteria, fungi and actinomyce between the two fertilization modes. BIOLOG analysis indicated that no significant difference was observed either in value of Average Well Color Development (AWCD), Shannon diversity index and Simpson diversity index between the two. There were 3 principal component factors (PCF), screened out of 95 factors by Principal Component Analysis (PCA). Although PCF 2 showed some difference between the two, but PCF 1 and 3 did not. All of the above imply that short-term seasonal withdrawal of nitrogenous fertilizer has no significant effect on soil microbe in population and only a little in functional diversity.