Full Text PDF | balance, Chernozem, crop residues, humus, N-P-K nutrients.
The balance of soil fertility in the current conditions of agriculture has a topical interest. The basic objectives of the research were to assess the possibility of obtaining a non-deficit balance of the main indicators of soil fertility (humus, nutrients) in Calcareous Chernozem using small doses of mineral fertilizers and the return of plant residues of cultivated crops. The mass balance that comprises inputs and outputs for humus, nitrogen (N), phosphorus (P) and potassium (K) from cropland of the cereal crop rotation in the 2001-2017 period in the long-term experience was analyzed. We found a deficit in N (-1.2 kg.ha-1 .yr-1) using of crop residues on experimental plot without fertilization (since 1950) and a positive balance for P and K (5.7 and 43.8 kg.ha-1.yr-1). The combined use of plant residues and mineral fertilizers in small doses (N47P46) on previously fertilized backgrounds helps maintain the positive humus and N-P-K nutrient balance.