保护性耕作模式对黑钙土农田养分含量、细菌群落结构及多样性的影响

Effects of Conservation Tillage on Nutrient Content,Bacterial Community Structure and Diversity in Chernozem of Cropland

为验证轮耕制度下的保护性耕作长期效应,并快速推广秸秆原位还田,基于土壤化学分析和Illumina高通量测序技术,比对了保护性与传统耕作模式下土壤养分指标和细菌群落组成的差异,探究保护性耕作模式对黑钙土农田养分含量和细菌群落结构及多样性的影响。结果表明,保护性耕作模式下的碱解氮、有效磷、速效钾和有机质含量较传统模式显著提高17.75%、10.98%、7.62%和12.89%;细菌群落多样性和均匀度显著提高;保护性耕作模式优化了细菌群落结构,富集了具有促进氮素转化、提高作物抗旱、抗逆作用的变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、芽单胞菌门(Gemmatimonadetes)、拟杆菌门(Bacteroidetes)、硝化螺菌门(Nitrospirae)、Rokubacteria和浮霉菌门(Planctomycetes),以及在植物固氮和营养转化方面具有重要作用的慢生根瘤菌属(Bradyrhizobium)、Rhodanobacteria、KD4-96、红色杆菌属(Rubrobacter)和中慢生根瘤菌属(Mesorhizobium),这些优势类群与环境因子和玉米产量显著正相关,可以提高土壤肥力,进而增产。

In order to investigate the effects of conservation tillage on nutrient content,bacterial community structure and diversity in black calcareous soil farmland,based on soil chemical analysis and Illumina high-throughput sequencing technology,differences in soil nutrient indicators and bacterial community composition between conservation and traditional tillage modes were compared.The results showed that compared to the traditional mode,the alkaline nitrogen,available phosphorus,available potassium,and organic matter content under the protective tillage mode were significantly increased by 17.75%,10.98%,7.62%and 12.89%.The diversity and evenness of bacterial communities significantly improved.The conservation tillage model optimized the bacterial community structure,enriched Proteobacteria,Acidobacteria,Gemmatimonadetes,Bacteroidetes,Nitrospirae,Rokubacteria,and Planctomycotes that promotes nitrogen transformation,improve crop drought resistance,and stress resistance.And enriched Bradyrhizobium,Rhodanobacteria,KD4-96,Rubrobacter and Mesorhizobium which played important roles in plant nitrogen fixation and nutrient transformation.These dominant groups were significantly positively correlated with environmental factors and maize yield,thereby improving soil fertility and promoting yield increase.