粉垄耕作对耕地土壤酶活性、微生物群落结构和功能多样性的影响

Effects of deep vertical rotary tillage on soil enzyme activity, microbial community structure and functional diversity of cultivated land

粉垄耕作是中国的一种新型耕作技术,对耕地质量和作物增产有重要影响。设置传统耕作深度20 cm(CK)、粉垄耕作深度35 cm(FL1)和粉垄耕作深度50 cm(FL2)对玉米耕地进行处理,重点研究了粉垄耕作技术对土壤微生态的影响,并阐明土壤微生物群落组成及功能对粉垄耕作的响应。结果表明,FL1、FL2和CK处理玉米产量分别为8.58、8.38和6.22 t/hm^(2),FL1和FL2处理增产率分别为34.7%—37.9%。在0—20、20—40 cm土层中,粉垄耕作两个处理的土壤酶活性、微生物群落多样性和功能多样性均显著高于CK处理。通过结构方程模型发现,粉垄耕作直接提高了土壤酶活性、细菌参与养分循环的功能基团和细菌的群落结构,并通过细菌群落间接影响了真菌群落,增加了真菌参与养分循环的功能基团和真菌群落多样性,使土壤微生物碳源利用的能力和功能多样性指数得到提升,以FL1效果更佳。总之,研究从微生物的角度解释了粉垄耕作对土壤微生态的影响机制,为粉垄耕作提升土壤耕地质量提供了理论依据。

Deep vertical rotary tillage is a new tillage technique in China, which has an important effect on the quality of cultivated land and crop yield. In this study, corn cultivated land was treated with conventional tillage depth of 20 cm(CK), deep vertical rotary tillage depth of 35 cm(FL1), and deep vertical rotary tillage of 50 cm(FL2). The effect of deep vertical rotary tillage technology on soil microecology is studied. Responses of soil microbial community composition and function to ridge tillage are illustrated. The specific results are shown as follows. The maize yield of FL1, FL2 and CK treatments was 8.58, 8.38 and 6.22 t/hm~2, respectively. The yield increases of FL1 and FL2 treatments were 34.7%—37.9%. The soil enzyme activities, microbial community diversity and functional diversity of the two treatments in deep vertical rotary tillage were significantly higher than those in the 0—20 and 20—40 cm layers of CK treatment. The structural equation model analysis showed that the activities of soil enzymes, the functional groups of bacteria involved in nutrient cycling and the community structure of bacteria were directly increased by deep vertical rotary tillage. The fungal community was indirectly affected by bacterial community, which increased the functional groups of fungi involved in nutrient cycling and the diversity of fungal community. This improved the utilization capacity and functional diversity index of soil microbial carbon sources, which contributed to improve the effect of FL1. In conclusion, the study explains the mechanism of the effects of silt ridge tillage on soil microecology from the perspective of microorganisms and provides a theoretical basis for improving the quality of soil cultivated land by deep vertical rotary tillage.