Enzymological and Physicochemical Evaluation of the Effects of Soil Management Practices

Abstract

Soil enzymes activities have been considered as sensitive indicators of alteration soil quality by management. In order to obtain new data on the soil enzymological effects of soil management practices, we have determined some enzymatic activities in a preluvosoil submitted to a complex tillage and crop rotation experiment at the Agricultural Research and Development Station in Oradea (Bihor County). Actual and potential dehydrogenase, acid phosphatase and catalase activities were investigated in a split plot experiment where tillage (no-till and conventional tillage) was the main plot and crop rotation (Wheat/Maize, W/M; Soybean/Maize, S/M; Oats-Clover/maize, O-C/M) was the subplot. Soil samples were taken at 0-20, 20-40 and 40-60 cm. Each activity in both non-tilled and conventionally tilled soil under maize crop decreased with increasing sampling depth. It was found that no-till, in comparison with conventional tillage, resulted in insignificantly higher (p]0.10) soil enzymatic activities in the 0-20 cm layer and insignificantly (at least at p]0.10) lower activities in the deeper layers, excepting actual and potential dehydrogenase activities in the 40-60 cm layer, in which these activities were significantly lower(0.02]p]0.01). Based on the absolute values of the enzymatic activities, the enzymatic indicator of soil quality (EISQ) was calculated. The EISQ values ranged between 0.201 and 0.974 indicating the presence of high enzymatic activities in the upper layer and a moderate intensity of the enzymatic activities in the deeper layers. A significant correlation between soil enzyme activities and physical and chemical indicators was established.