The effect of biological preparations on the indicators of biological activity of typical slightly eroded chernozem

Abstract

Abstract. The purpose is to study the effect of biological preparations based on Trichoderma viride and Pseudomonas aureofacieens, nitrogen fertilizers (N10 kg a. v. per 1 t of straw) on the surface incorporation of crushed by-products into the soil on the indicators of biological activity of typical slightly eroded chernozem. Methods. The studies were carried out in 2018-2020 in field experiments with biological preparations of FGBNU “Kursk FANTS” (Kursk region, Medvensky district, Panino village) on typical poorly eroded chernozem in the grain (barley – buckwheat – fodder beans) and grain-tilled (sunflower – barley – soybean) crop rotation. The indices of biological activity (C-CO2 production by soil, cellulolytic activity of typical chernozem) are presented for the vegetation period of 2020 in soybean and fodder bean crops. Results. It was found that the use of biopreparations based on Trichoderma viride and Pseudomonas aureofacieens, provided an increase in carbon dioxide emissions on average for the growing season of soybean by 43 % and by 65 % for forage beans in relation to the control. It was revealed that the highest activity of microorganisms participating in mineralization of by-products was observed in soybean during shoots: when nitrogen fertilizers were applied by 7.5 kg/h/ha and when they were mixed with biopreparations by 4.6 kg/h/ha relative to the control. For forage beans, the process of soil C–CO2 emission was more intense in the variant with the application of biopreparations by 3.8 kg/h/ha and their combined use with nitrogen fertilizers by 4.7 kg/h/ha compared to the control. It was shown that a significant proportion of the contribution to the variation of cellulolytic activity in soybeans belonged to nitrogen fertilizers – 80.6 %. For forage beans the main share of participation in variation of cellulosic decomposition intensity was determined by biopreparations, which was 3 times higher in relation to nitrogen fertilizers.