持续施用生物有机肥对花生产量和根际细菌群落的影响

为了揭示集约化经营制度下施用生物有机肥对花生连作障碍的调控,采集旱地红壤进行了连续5 a的盆栽试验,试验处理包括:花生–玉米轮作、施用化肥的花生连作和施用生物有机肥的花生连作,探究持续施用生物有机肥防控花生连作障碍的根际微生态机制。结果显示,相比于轮作,施用化肥的连作花生产量显著降低;相比于连作花生施用化肥,持续施用生物有机肥可以显著缓解连作花生产量降低的问题,施用有机肥第5季荚果干重提高27%。与施用化肥的连作处理相比,持续施用生物有机肥显著增加了花生根际细菌多样性和丰富度,与轮作花生处理无显著差异;持续施用生物有机肥显著提高了连作花生根际变形菌门和拟杆菌门的相对丰度,降低了厚壁菌门的相对丰度;属水平上,花生根际促生菌Rhizobium,Mesorhizobium和Bradyrhizobium的相对丰度较化肥处理分别提高了295%、89%和40%,而Leifsonia和Burkholderia的相对丰度分别降低了67%和47%。冗余分析进一步发现,土壤有机质和p H是根际细菌群落结构改善的重要理化因素。这表明持续施用生物有机肥可以改良红壤理化环境(如p H和有机质含量),进而优化连作...

Effect of Persistent Application of Bioorganic Fertilizer on Peanut Yield and Rhizosphere Bacterial Community

To reveal the regulating effect of bioorganic fertilizer on peanut continuous cropping obstacle under intensive management system, a 5-year pot experiment was conducted with chemical fertilizers and bioorganic fertilizer (organic fertilizer inoculated with Bacillus pumilus WXX-2) applied under peanut continuous monoculture and peanut/maize rotation in order to explore the microbial mechanism in the rhizosphere of bioorganic fertilizer application to relieve the continuous cropping obstacle of peanut. Compared to rotated peanuts, pod yield of mono-cropped peanuts applied with chemical fertilizers significantly decreased; Compared with chemical fertilization of mono-cropped peanuts, persistent bioorganic fertilization significantly mitigated the severity of yield reduction, with pod yield increased by 27% on the fifth year of fertilization. Compared to mono-cropped peanuts applied with chemical fertilizers, persistent application of bioorganic fertilizer significantly increased rhizosphere bacterial diversity and richness, with no significant difference with those of rotated peanuts. Persistent application of bioorganic fertilizer significantly increased the relative abundances of Proteobacteria and Bacteroides, and decreased that of Firmicutes in peanut rhizosphere. At the genus level, the relative abundances of Rhizobium, Mesorhizobium and Bradyrhizobium, which are important plant growth-promoting rhizobacteria, increased by 295%, 89% and 40%, respectively, and those of Leifsonia and Burkholderia decreased by 67% and 47% under five-year bioorganic fertilization. Redundancy analysis further revealed that the increase of soil pH and organic matter may be responsible for the optimization of rhizosphere bacterial community structure. This indicated that persistent application of bioorganic fertilizer can improve physicochemical properties of red soil, optimize the microbial structure and enhance peanut resistance to diseases in the rhizosphere subsequently, thus can stably promote crop yield.