TY JOUR TI CHANGES IN AGRO-CHERNOZEM HUMUS STATE UNDER FERTILIZERS INFLUENCE KW agrochernozem KW humus carbon KW alkali-hydrolyzed carbon KW water-soluble carbon KW humus reserves KW ammonium nitrate KW humic fertilizers JO Bulletin of KSAU AU Kazyulin, L.F. AU Kurachenko, N.L. PY 2025 IS 0 PB Krasnoyarsk State Agrarian University