Effects of liming and fertilization on the degydrogenase and catalase activities

Abstract

In this paper we provide new data about the soil enzyme activity as a biological process, which is an indicator for impacts of factorial combinations of lime and fertilizers applications. Five plots divided into fifteen subplots were sampled for determination of the enzymatic indicators of soil quality, based on the actual and potential dehydrogenase and catalase activities. The research revealed that limed soil samples, in comparison with unlimed ones, resulted in significantly higher soil enzymatic activities (p<0.05) in the upper (0-20 cm), while in the deeper (20-40 cm) layer, only catalase activity was significantly higher (at least at p<0.02). Mineral fertilization, in comparison with its farmyard manuring, led to an insignificant increase in each of the three enzymatic activities determined, excepting catalase activity which was significantly higher (0.05>p>0.02) in the 0-20 cm layer. Based on the absolute values of the enzymatic activities, the enzymatic indicators of soil quality (EISQ) were calculated. The mineral NPK-fertilization and low dose of lime in the 0-20 cm layer, and mineral NP-fertilization and low dose of lime in the 20-40 cm layer proved to be the best variants of fertilization. The enzymatic indicators of soil quality in these variants reached the highest values: EISQ=0.821 and EISQ=0.889, respectively, indicating the presence of high enzymatic activities. It should be emphasized that a balanced application of lime, mineral fertilizers and farmyard manure leads to the formation of favorable conditions for the development of microorganisms, growth of plants and for an intense and lasting enzymatic activity.