Impact of Vermicompost as Component of Growing Medium on Phytomass Formation of Radish (Raphanus Sativus L.)

In Slovakia more than a half of the landfill‘s waste consist of the biodegradable waste (BDW). Therefore the BDW composting can decrease significantly the production of the landfill gas as well as the financial and space requirements for landfills. However, the composts production have to be solved comprehensively, including their rational usage. In Slovakia the use of composts is ineffective if the location of their production is farther than 50 km, because of the high tranportation costs. The objective of the experiments was to determine the ratio of vermicompost in the soil growing medium in order not to decrease the yield quantity and quality of radish - the most commonly grown vegetable in the gardens in Slovakia. Five shares of vermicompost were tested in the soil substrate (0%, 10%, 20%, 25% and 50%). The results show that 50% share of vermicompost in the soil substrate, i.e. the ratio of vermicompost to soil 1:1, was not the optimal solution of the vermicompost usage. However, even this quantity of vermicompost did not have a negative impact on the weight of the aboveground and underground phytomass in comparison with the treatment without vermicompost. 50% share of vermicompost in the growing medium had the negative impact on the qualitative parameters of radish. It decreased the content of vitamin C and increased the content of nitrates in radish roots and leaves. Along with the higher share of vermicompost in the growing medium, the content of vitamin C was decreased in radish roots and leaves, and the content of nitrates in radish roots was increased. The roots of the biggest diameter, and consequently the highest yield of radish roots and leaves was formed in the treatment where the soil substrate consisted of four portions of soil and one p ortion of vermicompost (20% proportion of vermicompost).