Effect of biological preparations and mineral fertilizers on productivity of natural grasslands of the Sysola river floodplain
In the first time under conditions of Republic of Komi study was conducted on the influence of biologically active substances ("Verva", "Appin") and concentrated organoleptic fertilizer "potassium humate/sodium with microelements" in pure form and on the background of mineral fertilizers on productivity of natural grassland of the Sysola River floodplains, as well as evaluation of hay quality in the period from 2011 to 2015. The results of investigations shown that application of preparations in pure form does not lead to significant increase in productivity but a positive trend of its increasing always exists. In addition the positive effect of growth stimulators on the quality of the products was obtained. Gathering of the exchange energy, fodder units and crude protein increased in all variants with use of preparations in pure form and on the background of mineral fertilizers. Input of the preparation "Verva" on the N<sub>30</sub>P<sub>45</sub>K<sub>45</sub> background allows to obtain the best result. So productivity grew by 49.0 % (+0.29 t/ha), the yield of exchange energy by 49.1 % (+3.9 GJ/ha); 1.5 thousand fodder units/ha (+66.6 %) was obtained and the content of crude protein in absolute dry matter was 10.3 %.