不同施肥处理对玉米-小麦轮作土壤微生物群落功能多样性的影响

土壤微生物多样性能反应土壤的肥力,不同的施肥措施对土壤微生物的种群和功能多样性也会产生重要的影响。以山东德州连续两年小麦季和玉米季收获后土壤为研究对象,利用Biolog技术研究了6种不同施肥处理对土壤微生物群落功能多样性的影响。结果表明:其中各个施肥处理的平均颜色变化率(average well color development,AWCD)差异显著,常规氮磷钾肥+全量秸秆还田+秸秆腐熟剂(FS)处理代谢活性最高;物种丰富度指数(H)和均匀度指数(E)也表明各施肥方式均能够维持微生物种群的多样性,其中FS和30%猪粪+70%常规氮磷钾肥(OF)处理物种丰富度指数(H)和均匀度指数(E)最高;PCA及RDA分析显示,OF和FS处理微生物功能多样性相似,且其微生物功能多样性与有机质(Soil organic matter,SOM)、全氮(Total N,TN)、速效磷(Available P,AP)和速效钾(Available K,AK)密切相关。猪粪堆肥有机无机复合肥3 600 kg/hm2(OI2)处理与猪粪堆肥有机无机复合肥1 800 kg/hm2(OI1)处理相似,其功能多样性比常规施肥(CF)处理稍高。综上所述,OF处理和FS处理的土壤微生物群落功能多样性程度高于其他处理,说明秸秆还田+秸秆腐熟剂和有机肥部分替代氮磷钾肥能够显著提高土壤微生物功能多样性,有利于保护土壤微生态。

Effects of Different Fertilization on Soil Microbial Community and Functional Diversity in Maize-Wheat Crop Rotation

The diversity of soil microbes can reflect the soil fertility and different fertilization also works importantly on soil microbial population and diversity. In this study, soil after the harvest of two year in succession of maize season and wheat season in Dezhou field ecosystem station run by CAAS was taken as the research object to study the influence of different fertilization on microbial community functional diversity with six different fertilization treatments using Biolog technique. The results showed that each of six fertilization treatments had significant differences in AWCD (average well color development), and each of them were all significantly higher than that of the control without fertilization (CK). Soil microbial communities richness index (H) and evenness index (E) of fertilization treatments FS (conventional NPK+ straw + straw decomposing inoculants) and OF (70% conventional NPK + 30% swine excrement) were higher than others''. PCA (principal component analysis) and RDA (redundancy analysis) showed that OF and FS had similar functional diversity of microbial communities, and they had high level relativity with SOM (soil organic matter), TN (total N), AP (available P), and AK (available K). The treatment of swine excrement compost + organic + inorganic compound fertilizer 1 800 kg/hm₂ (OI1) and the treatment of swine excrement compost + organic + inorganic compound fertilizer 3 600 kg/hm₂(OI2) were treated similarly, their functional diversity were lower than FS and OF, and higher than CF. To sum up the above mentioned, the degree of soil microbial community and functional diversity of OF treatment and FS treatment was higher than those other treatments, indicated that straw field returning plus straw decomposing preparation and organic fertilizer to replace part of NPK fertilizer could improve soil microbial community and functional diversity, and conduce to protect soil microbial ecology.