Responses of soil biochemical properties and microbial community structure to short and long‐term no‐till systems

Abstract

Abstract Tillage activities play a crucial role in impacting soil physical and chemical properties, which in turn alter soil biochemical activities and microbial community structure. In this study, responses of soil biochemical activities and microbial community structure to short‐term (NT S , <5 years) and long‐term (NT L , >10 years) no‐till (NT) systems were studied in comparison with conventional till (CT) at four different locations (Garretson, Crooks, Beresford and Mitchell) in South Dakota, USA. Data showed that the NT L resulted in increased soil labile and microbial biomass carbon (C) and nitrogen (N) compared with the CT treatment at the Garretson, Crooks and Beresford sites. At the Crooks and Beresford sites, soils under NT L and NT S had significantly increased the β‐glucosidase, urease, arylamidase, acid and alkaline phosphatase and arylsulphatase enzyme activities compared with those under CT treatment. The β‐glucosidase, urease, acid phosphatase and arylsulphatase enzyme activities showed significant correlations with the microbial biomass content of the soils. Phospholipid fatty acid (PLFA) analysis showed increased PLFA content in NT L soils compared with the CT. The content of total bacterial, actinobacterial, Gram‐positive bacterial, total fungal, arbuscular mycorrhizal fungal (AMF) and saprophyte PLFAs was consistently increased in the NT L and NT S compared with the CT soils at the Garretson site. These differences were more pronounced between NT L and CT systems than between NT S and CT systems in most of the studied sites. The findings suggest that usage of NT for a longer duration is highly beneficial to soil labile C and N pool retention and enzyme activities, and provides less disturbance to soil microbial activities and their functions, which in turn regulates nutrient transformation. Our results also suggest that converting CT soils into NT can improve some soil health indicators even over a short duration, and hence adopting NT can enhance soil microbial and plant growth. Highlights NT S and NT L systems increased soil labile C and N and microbial biomass as compared to CT Total fungi biomass was significantly enhanced under NT compared with CT Short‐term NT significantly increased β‐glucosidase activity at Crooks and Beresford sites compared to CT Compared to the CT system, NT significantly increased soil biological health