The microbial network in naturally fertile paddy soil possibly facilitates functional recruitment in the rice mature stage

摘要

How agriculture practice, especially the nitrogen fertilization, influences different paddy soil microbial ecosystems remains unclear. The bacterial communities in two paddy fields, which were distinguished by the natural fertility level, were utilized in this study. Each field held two control plots and two nitrogen-fertilized ones. The microbial communities mainly differed in their relative abundances of Proteobacteria and Chloroflexi between the two fields. However, they were very similar in the alpha-diversity and enzymatic functions, as well as their resistances indexes in response to the nitrogen fertilizers. Redundancy analysis indicated that phosphorus, nitrogen and potassium contents significantly explained the variability of the communities in the two fields total potassium (TK) plus nitrogen level and TK alone significantly explained the variation of the microbial communities in the high yield field and the low yield, respectively. Network analysis data showed that the microbial community in the high-yield field possessed a higher connectivity, which might facilitate recruiting more microbes that were predicted to drive organic matter decomposition, sulfate/iron reduction, nitrogen retention, and methane oxidation at the mature stage. The use of nitrogen fertilizer in the low yield field would help to recruit microbial functions similar to those in the high-yield at the stage. This ecological process possibly stimulated nutrient availability for rice production in the present case.