NFLUENCE OF MINERAL FERTILIZERS ON THE HUMIS STATE OF LEACHED CHERNOZES NOVOSIBIRSKY PROB’YA IN AGROCENOZ

Abstract

In small-scale and field experiments, it was found that the content and reserves of humus in the 0-20 cm layer of leached Chernozem used for 20 and 50 years in arable land were average. Nitrogen-phosphorus and full mineral fertilizers, applied randomly, in rows and locally in the soil, supported them in the arable and sub-arable soil layer. Wheat cultivation without fertilizers did not affect the amount of total organic carbon (C,%) and humic acids (ha) in the humus of Chernozem used for 50 years in arable land. Mineral fertilizers, on the one hand, supported the content of organic carbon in the humus; on the other hand, they changed its quality: they reduced the content of ha, and in their composition, first of all, the fractions of GK1 and GK3, and did not affect the content of GK2. The greatest changes in these indicators occurred during local fertilization. When growing wheat without fertilizers in the arable soil layer, the proportion of fulvic acids (FC) increased, mainly due to the fractions of FC 3. Fertilizers with all methods of application to the soil, except local, did not affect the content of FC and the fraction of FC 1A in their composition and significantly increased FC 1. Localization of fertilizers in the soil to a depth of 10-12 cm significantly reduced the number of FC and all their fractions, except FC 1. The use of Chernozem in arable land without the use offertilizers led to a 26 % reduction in the composition of humus of its most stable part - humins. Mineral fertilizers, depending on the method of application, increased the stability of humus by increasing its composition by 18; 24 and 80 % of humins compared to the control. Cultivation of grain crops without the use of fertilizers reduced the ratio of SGC: SFKfrom 1.7 to 1.4, increasing the mobility of humus. Fertilizers maintained the quality of humus in comparison with the control, and their local application increased the ratio of SGC: The use of leached Chernozem in arable land for more than 50 years contributed to a greater accumulation of microbial carbon in the control than in 20-year-old arable land, and when applying mineral fertilizers to rows - the opposite. Mineral fertilizers showed the greatest efficiency when applied in a row in doses of N43P43K43 in 50-year-old arable land and P20 against the background of N60P20 in 20-year-old arable land, allowing you to get an increase in the yield of spring wheat to the control of 26 and 54 % in action and 20 % of oats in aftereffect.