Biologinių preparatų ir necheminių piktžolių kontrolės būdų įtaka žieminių rapsų derlingumui ir dirvožemio savybėms ekologinėje žemdirbystėje

Abstract

The field experiment was conducted in 2014 and 2015 at the Experimental Station of Aleksandras Stulginskis University. Soil – Calc(ar)i-Endohypogleyic Luvisol. The objective of these investigations was to determine the influence of biological preparations and non-chemical weed control methods on winter oilseed rape seeds yield and soil biological properties in the organic farming system. Treatments of the experiment: factor A: 1) thermal (water steam), 2) mechanical (inter-row loosening), 3) smothering (self-regulation); factor B: biological preparations: 1) no application, 2) with application. It was established that significantly highest yield of the winter oilseed rape seeds (from 11.7 to 56.8 %) was obtained in plots where mechanical weed control method was used, compared with plots where thermal weed control method and smothering was used. The use of biological preparations, as compared to their non-use, significantly increased the yield of oilseed rape seeds in the plots where thermal (43.4%) and mechanical (25.1%) weed control was used. The yield of oilseed rape seeds depended on the crop density (r = 0.86, P < 0.05). The use of biological preparations and different non-chemical weed control methods had no significant influence on the soil enzyme urease activity. The use of biological preparations and application of the mechanical weed control method sigficinantly 7.8 % inhibited the activity of enzyme saccharase in the soil, compared with plots where smothering system was used. The use of biological preparations in the plots where smothering system was used, as compared to their non-use, significantly 14.6 % stimulated the activity of enzyme saccharase. Different non-chemical weed control methods had no significant influence on the number and mass of earthworm