Influence of the sowing time and mineral fertilizers on the productivity of annual grass mixtures

Abstract

The productivity of annual feed grass mixtures (vetch + oats, Sudan grass + white mustard, Sudan grass + oilseed radish), sown after the winter rye harvesting during the “shooting” phase (the 1st time of sowing), during the “heading” phase (the 2nd time of sowing), and during the phase of complete ripeness (the 3d time of sowing), was studied in the conditions of forest-steppe soils of the Volga Region (the Republic of Mordovia). The experiment was carried out in 2018-2020 on heavy loamy soils against the background of three doses of mineral fertilizers use (without fertilizers, N16P16K16 + N30, N16P16K16 + N60). It has been established that the duration of vegetation of feed mixtures according to the time of sowing when harvesting for green mass was: at the first the time of sowing - 63-85 days, at the second - 63-76 days, at the third - 56-62 days. The highest height of the plant was at the first time of sowing with the use of fertilizers at a dose of N16P16K16 + N60, the lowest - at the third time of sowing. The highest growth was achieved by Sudan grass (48-116 cm), the lowest - by the mixture of vetch and oats (18-67 cm). The highest yield of green mass (14.0 t/ha) was observed when cultivating Sudan grass mixed with oilseed radish on the background of N16P16K16 + N60 at the first time of sowing. For mixture of Sudan grass with white mustard, the yield was 2-7 % lower, and for vetch + oats mixture - 32-45 % lower. The same was observed according to the yield of dry matter and feed units. As to the protein content, mixtures of Sudan grass with cruciferous crops exceeded the vetch + oats mixture by 7-26 %. The fiber content in the grass mixtures was decreasing from the first time of sowing to the last. The greatest amount of fiber (28.11-28.72 %) was observed during the second time of sowing. The economic assessment showed that the cultivation of annual grass mixtures after winter rye without mineral fertilizers was the most cost-effective (29-208 %). The highest efficiency (202-208 %) was provided by the mixture of Sudan grass with oilseed radish and white mustard.