The effect of different doses application of dry granulated vermicompost on yield parameters of maize and potatoes

Abstract

Both pilot experiments were carried out in the district of Veľký Krtíš. The experiment with maize was realized on loamy Luvisol (cadastre Opatovská Nová Ves), characterized by a medium N_an, conforming P, good K content and neutral pH. The experiment with potatoes was realized on loamy Fluvisol (cadastre Malá Čalomija) characterized by a medium N_an, very low P, good K content and neutral pH. The experimental site has a warm climate, with the warm and dry subarea and with mild winters.

In the experiment with maize grown for grain were 4 treatments established – a control treatment and three treatments with dose increasing of granulated vermicompost (4.6; 9.2; 11.6 t.ha^-1, respectively), which supplied 57, 114 and 142 kg.ha^-1 total nitrogen to the soil, respectively. The experiment was not irrigated.

The experiment with potatoes included 7 treatments of fertilization. The first treatment was a control treatment, i.e., without the appliance of dry granulated vermicompost. In treatment 2 to 6 increasing doses of vermicompost (3.3; 6.6; 9.9; 13.2 and 19.8 t.ha^-1, respectively) were applied. Through the following doses of granulated vermicompost were applied to the soil 40, 80, 120, 160, 240 kg.ha^-1 N. Not only was the granular vermicompost applied in treatment 7, but also the industrial NPK fertilizer (150 kg urea + 200 kg.ha^-1 NPK 15-15-15).

The pre-sowing application of granulated vermicompost was significantly influenced the grain yield of maize, starch content in the grain, a thousand kernel weight and content of five observed macroelements (N, P, K, Ca, Mg). The grain yield was increased with the dose increasing of vermicompost. A thousand kernel weight, starch content and magnesium content parameters with the increasing dose of vermicompost were reduced. A dose of 4.6 t.ha^-1 vermicompost seems like the most appropriate for the parameters of a thousand kernel weight, starch and magnesium content.

The increasing doses of vermicompost significantly increased the yield of potato tubers, starch content and dry matter content in tubers. The application of granulated vermicompost reduced vitamin C content in potato tubers. The use of fertilizers resulted to increasing the nitrate content in potato tubers however the application of granulated vermicompost has increased the contents of nitrates to a lesser extent than the joint application of NPK fertilizer and granulated vermicompost.