玉米—大豆轮作体系对黑土土壤固氮菌群落结构及其质量的影响

Effects of corn-soybean rotation system on soil nitrogen-fixing bacteria community structure and quality in black soil

以大豆连作(CS)、玉米连作(CM)、玉米—大豆轮作(MS)、玉米—玉米—大豆(MMS)和玉米—大豆—大豆(MSS)为研究对象,利用荧光定量PCR和高通量测序分析种植制度对土壤固氮菌丰度和群落结构的影响。结果表明:轮作中土壤有机质(SOM)、全磷(TP)、有效氮(AN)和有效磷(AP)的含量显著高于连作;轮作固氮菌丰度显著高于CM,显著低于CS;MMS与MSS固氮菌多样性显著高于CM;轮作和连作土壤固氮菌群落结构差异明显,全氮(TN)是固氮菌群落结构变化的主要驱动因子,种植制度通过土壤化学性质间接影响固氮菌丰度和多样性。这说明,在吉林省西部半干旱区,MSS与MMS更有利于土壤固氮菌繁殖,可以从微生物学的角度为合理种植和氮素调控提供科学依据。

The effects of soybean continuous cropping(CS), maize continuous cropping(CM),corn-soybean rotation(MS), corn-corn-soybean(MMS) and corn-soy-soybean(MSS) on soil nitrogen fixing bacteria abundance and community structure were analyzed by fluorescence quantitative PCR and high-throughput sequencing. The results showed that soil organic matter(SOM), total phosphorus(TP), available nitrogen(AN) and available phosphorus(AP) contents in rotation were significantly higher than those in continuous cropping. The abundance of nitrogen-fixing bacteria in rotation was significantly higher than that in CM and significantly lower than that in CS. The diversity of NITR Ogen-fixing bacteria in MMS and MSS was significantly higher than that in CM. Total nitrogen(TN) was the main driving factor for the change of nitrogen-fixing bacteria community structure. Planting system indirectly affected the abundance and diversity of nitrogen-fixing bacteria through soil chemical properties. These results indicate that MSS and MMS are more conducive to the propagation of soil nitrogenfixing bacteria in the semi-arid area of Western Jilin province, which can provide scientific basis for rational planting and nitrogen regulation from the perspective of microbiology.