Influence of systematic fertilizer on biological activity of gray forest soil

The article presents the results of research on the biological activity of gray forest soil depending on the systematic use of organic and mineral fertilizers. It is established that effective reproduction of humus in gray forest soil is provided by organo-mineral (12 t of manure together with N80P60K80 application per 1 ha of crop rotation area) and organic (24 t/ha of manure), respectively 36,5 t/ha, and 35,6 t/ha. The application of only mineral fertilizers in the norm of N80P60K80 per 1 ha of crop rotation area resulted in a decrease in humus reserves by 9 % relative to the initial level (32,4 t/ha). The highest degree of humification of organic matter provided the option of applying organic fertilizers (60 t/ha) both separately – 36,0% and compatible with mineral – (60 t/ha manure + N80P60K80) – 34 %. Prolonged use of organic and mineral fertilizers in crop rotation significantly increased the total number of microorganisms in the soil. The result was increased decomposition of organic matter and increased release of CO2 from the soil. The areas with the highest biological activity and CO2 intensity were characterized by areas where the soil was systematically enriched with fresh organic matter. The intensity of biological processes in the organo-mineral system increased by 67 % relative to the variant without fertilizers and by 30 % relative to the variant with only N80P60K80. The use of organic and mineral fertilizers in one system stimulated the process of decomposition of fiber – at the level of 78,5 %, which in percentage terms exceeded the value of the indicators obtained for a purely mineral fertilizer system.