Effects of different tillage techniques on soil enzymes and organic carbon in semi-arid conditions

The intensive processing of agricultural lands, is one of the primary reasons for the deterioration of soil health. Accordingly, soil organic carbon, which serves as a food source for microorganisms and also influences microbial activity, diversity, and enzyme activities, decreases. The study aimed to compare the effect of traditional tillage (TT), no-tillage (NT), and straw mulching with no-tillage (SM) on changes in the content of soil organic carbon (SOC), nitrogen mineralisation (Nmin), and soil enzymes (alkaline phosphatases, β-glucosidase, and dehydrogenase). The study was conducted in a semi-arid region between 2019 and 2023 according to the randomised block trial design with four replications. Soil samples were taken and analysed in 2023. Compared to traditional tillage, straw mulching with no tillage increased organic carbon, nitrogen mineralisation, alkaline phosphatases, β-glucosidase, and dehydrogenase by 19%, 65%, 59%, 115%, and 110% respectively. Similarly, no-tillage provided an increase in organic carbon, nitrogen mineralisation, alkaline phosphatases, β-glucosidase, and dehydrogenase by 8%, 56%, 45%, 63%, and 83%, respectively, compared to the traditional tillage. Principal component analysis (PCA) showed that the nitrogen mineralisation was mostly affected by the no-tillage application and organic carbon, alkaline phosphatases, β-glucosidase, and dehydrogenase were affected by the straw mulching with no-tillage application.