To investigate the effect of maize/soybean intercropping on rhizosphere soil microbial communities and phosphorus (P) bioavailability, we examined the changes of soil bioavailable P fractions and microbial community characteristics in the monoculture and intercropping systems based on high-throughput sequencing. The results showed that maize/soybean intercropping increased the contents of rhizosphere soil organic matter (SOM), available phosphorus (AP), microbial biomass phosphorus (MBP), and aboveground biomass. The increase of AP was mainly related to the increasing enzyme extracted phosphorus (Enzyme-P) and hydrochloric acid extracted phosphorus (HCl-P) contents. The dominant bacterial phyla under each treatment were Proteobacteria, Actinobacteria, Acidobacteria and Chloroflexi, while the dominant bacterial genera were Nocardioides, Solirubacter, Sphingomonas and Arthrobacter, with Proteobacteria and Sphingomonas having the highest relative abundance. The relative abundance of Proteobacteria and Sphingomonas in intercropping maize rhizosphere soil was significantly higher than that in monoculture, and that of Proteobacteria in intercropping soybean rhizosphere soil was significantly higher than monoculture. Soil properties and P fractions were closely related to the rhizosphere soil microbial composition. In all, maize/soybean intercropping could affect the rhizosphere soil P bioavailability by altering the structure of rhizosphere microbial communities.
为了探究玉米/大豆间作对根际土壤微生物群落和磷素生物有效性的影响,本研究基于高通量测序技术研究玉米和大豆单作与间作模式中土壤磷组分和微生物群落结构特征。结果表明:与单作相比,玉米/大豆间作能够提高根际土壤有机质、速效磷、微生物生物量磷和地上部生物量,其中速效磷的提高主要与酶浸提磷和盐酸浸提磷含量的提高有关。各处理根际土壤的优势菌门均为变形菌门、放线菌门、酸杆菌门和绿弯菌门,优势菌属均为类诺卡氏属、红杆菌属、鞘氨醇单胞菌属和节杆菌属,其中变形菌门和鞘氨醇单胞菌属的相对丰度最高;间作玉米根际土壤变形菌门和鞘氨醇单胞菌属的相对丰度均显著高于单作,间作大豆根际土壤变形菌门的相对丰度较单作显著增加。土壤理化指标和有效性磷组分与根际土壤微生物组成关系密切。表明玉米/大豆间作能通过改变根际微生物群落结构来影响根际土壤磷的生物有效性。.
Keywords: P bioavailability; maize and soybean intercropping; microbial community.; rhizosphere soil.