Chemical Properties and Enzyme Activity of Soil as Affected by Tillage System and Previous Crop

The objective of this study was to evaluate the effect of tillage system and previously cultivated crop on the chemical properties and enzyme activity of soil. The first-order experimental factor was the tillage system, i.e., (1) conventional tillage (CT) and (2) reduced tillage (RT), whereas the second-order experimental factor was the previously cultivated crop, i.e., (a) pea and (b) durum wheat. Samples of soil were analyzed for the contents of organic C, total N, available forms of P, K, and Mg, as well as soil pH, total sorption capacity, and activity of soil enzymes (dehydrogenases, phosphatases, ureases, and proteases). The study demonstrated that the contents of organic C, total N, and available forms of K and Mg as well as soil pH were higher in soil subjected to RT than in that subjected to CT. In plots after pea cultivation, higher values were determined for the contents of total N and Mg, whereas in plots after durum wheat cultivation, the contents of organic C, P, and K and the soil pH were higher. Higher activities of dehydrogenases and phosphatases in soil were noted in soils subjected to the CT system than in those subjected to the RT system, whereas the activities of ureases and proteases were higher in soils subjected to RT. In addition, higher activities of dehydrogenases, phosphatases, and proteases were determined in the soil after pea cultivation than after durum wheat cultivation, whereas a higher activity of ureases was found in the soil after durum wheat cultivation. The C/N ratio was more beneficial after CT than after RT, as well as in the soil from plots after pea cultivation than after durum wheat cultivation.