种植模式对科尔沁沙地土壤微生物群落的影响

Effects of cropping patterns on soil microbial communities in Kerchin sandy land

针对科尔沁沙地土壤质量退化、花生连作障碍问题,于辽宁省农业科学院章古台试验站进行田间定位实验,设置玉米(Zea mays L)-花生(Arachis hypogaea)-玉米轮作(L1)、花生-玉米-花生轮作(L2)、玉米连作(YL)和花生连作(HL)4种种植模式,采集0-20cm土层土壤样品,采用磷脂脂肪酸法(PLFA)分析土壤微生物群落结构组成及多样性,测定土壤可培养微生物数量及土壤微生物量碳氮磷含量。结果表明:L1和L2模式下土壤微生物群落总丰度、细菌群落丰度、真菌群落丰度、放线菌群落丰度均显著高于YL和HL。主成分分析与冗余分析结果表明,L1和L2与土壤微生物量碳氮磷含量、土壤微生物各菌群丰度呈正相关;土壤可培养微生物总量与土壤总PLFA含量正相关。综上,轮作引起的土壤微生物群落丰度的变化是土壤微生物量碳氮磷累积的驱动因素。花生-玉米轮作种植能有效改善土壤微生态环境、缓解花生连作障碍。

In view of the serious degradation of soil quality and the obstacle for peanut’s continuous cropping in Horqin sandy land,field experiments were carried out at the Zhanggutai Experimental Station of the Liaoning Academy of Agricultural Sciences.Four cropping patterns including maize(Zea mays L)-peanut(Arachis hypogaea)-maize rotation(L1),peanut-corn-peanut rotation(L2),maize continuous crop(YL)and peanut continuous crop(HL)were set up.Soil samples from 0-20cm soil layers were collected.The structural composition and diversity of soil microbial communities were analyzed by phospholipid fatty acid method(PLFA),and the content of soil culturable microorganisms and soil microbial biomass carbon,nitrogen and phosphorus were measured.The results showed that the total soil microbial community abundance,bacterial community abundance,fungal community abundance,actinomycete community abundance of L1 and L2 were all significantly higher than YL and HL.The principal component analysis and redundancy analysis showed that L1 and L2 were positively correlated with soil microbiomass carbon,nitrogen and phosphorus content and the abundances of soil microbial groups.Total soil culturable microorganisms were positively correlated with total soil PLFA content.In conclusion,the changes in soil microbial community abundance caused by crop rotation are the driving factors for the accumulation of soil microbial carbon,nitrogen and phosphorus.The peanut-corn crop rotation can effectively improve the soil microbiological environment and alleviate the continuous crop barrier of peanut.