Effect of Conservation Tillage on Microbial Community in Chinese Mollisol

27 Mar Effect of Conservation Tillage on Microbial Community in Chinese Mollisol

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Abstract

耕作方式通过影响土壤微生物群落而影响土壤生态系统过程。本研究以传统耕作玉米连作处理为对 照, 通过测定土壤微生物量碳及磷脂脂肪酸含量, 分析了保护性耕作(包括免耕玉米连作和免耕大豆−玉米轮 作)对黑土微生物群落的影响。结果表明, 保护性耕作可显著增加土壤表层(0~5 cm)全碳、全氮、水溶性有机 碳、碱解氮和微生物量碳(P<0.05), 为微生物代谢提供了丰富的资源。同时, 保护性耕作显著提高了土壤表层 (0~5 cm)总脂肪酸量、真菌和细菌生物量(P<0.05), 提高了土壤的真菌/细菌值, 有利于农田土壤生态系统的稳 定性。研究结果对于探讨保护性耕作的内在机制具有重要意义。

English Abstract

Tillage systems affect soil microbial communities, which in turn influence soil ecological processes. In this study, the
effects of conservation tillage (including no-tillage continuous corn and no-tillage soybean-corn rotation) on microbial community
were studied by determining the contents of soil microbial biomass carbon and phospholipid fatty acids (PLFAs) and comparing it
with conventional tillage continuous corn. Results show that implementation of conservation tillage significantly increases soil carbon and nitrogen, water soluble organic carbon, available nitrogen and microbial biomass C in the 0~5 cm soil depth (P<0.05) compared with conventional tillage. These conditions produce abundant substrate for microbial growth. Furthermore, conservation tillage practices increase total PLFAs, fungal and bacterial biomass in the surface layer, increase fungi/bacteria ratio, and thus improve soil sustainability. These findings are of great significance for understanding the internal mechanisms of conservation tillage.