Effect of microbiological products on soil properties in the conditions of replant disease

Abstract

The phenomenon of soil fatigue, causing replant disease, can occur in the conditions of monocultural cultivation. This evokes a decrease in the soil productive value because of the deterioration of biological soil properties. In the present work, an attempt has been made to improve the biological activity of a replanted soil by the use of three micro-biological preparations: EM-5, Bacto Fill 10B and Humobak PG. The biological activity of soil was estimated using two parameters: the activity of soil enzymes, dehydrogenase and protease as well as the respiratory activity. The application of microbiological preparations significantly increased the activity of dehydrogenase in the soil. The effect of two among the three applied preparations exerted a smaller influence on the protease activity. An exception was the Humobak PG preparation whose application distinctly increased the activity of protease in the replanted soil. On the other hand, the vegetation period was found to exert a significant effect both on soil enzymatic and respiratory activity. In the autumn period, the activity of both enzymes in the soil was higher, in comparison with the spring period, while the respiratory activity was higher in the spring. The functioning of soil microorganisms depends on some physico-chemical properties of soil. In our work, the studied preparations did not have any significant effect on the changes in the pH values. However, the effect was more perceivable on the content of organic carbon in the soil. The application of microbiological preparations in replanted soil caused a change in the plant growth and fruiting. Among others, an increase in the average leaf area of strawberry, the average fruit mass and the content of juice extract in fruits was observed.