Shchapova L.N., Purtova L.N., Kiseleva I.V.
Regional problems 2019; 22(3): 38-44
Changes in the number and composition of microflora of agro dark humus bleached soil in the cultivation of various phytomeliorants in the conditions of short-term field experiments are established (1 и 3 years) are established. On the variants with the sowing of phytomeliorants, there is a pronounced tendency for an increase in the content and reserves of humus as compared with the control. Changes in the indicators of the humus state and microbiological activity of the soils were traced. Under the conditions of one-year experience, the highest number of ammonifying microorganisms showed the variant with buckwheat. This led to increased activity of polyphenol oxidases and more intensive accumulation of humus. The mineralization ratio decreased markedly. The mobility of humic acids increased as compared with the control; the humus system was in an unstable state. In the variant with sowing of clover, the mineralization processes were most pronounced due to the decrease in the share of ammonifiсators, but due to the low activity of peroxidase, the humus accumulation coefficient had average values. The composition of humus dominated by the fraction associated with calcium. Humus on all variants, under the conditions of one-year experience, had a fulvate-humate composition. In three-years phytomeliorative experience, a high intensity of mineralization processes was observed in the soil under crops of the timothy grass + clover. The type of humus formation changed to humate-fulvate.The mobility of humic acids increased. The activity enzymes and coefficient of humus accumulation in this variant was low. The most favorable ratio of the processes of mineralization and accumulation of humus was established on the variant under the alfalfa in the three-years phytomeliorative experience, which was characterized by higher humus reserves and the humate type of humus formation, high polyphenol oxidase activity and humus accumulation coefficient. High polyphenol oxidase activity and humus accumulation coefficient are characteristic of the process. The proportion of the 2nd fraction of humic acids increased to high values, indicating a more stable state of the soil humus system.
