In three-year (2021–2023) studies in stationary grain-rowed five-field crop rotation on the experimental field of Bila Tserkva National Agricultural University, on unfertilized plots fertilized with 6 t/h of manure + N54P48K48, 6 t/ha of manure + N92P66K90 and 6 t/h of manure + N120P92K110, the dry mass of plant residues was 4.20; 5.90; 6.89 and 7.47 t, respectively (of which the share of roots is 73-76%), the humus balance is positive (337, 626, 554 and 604 kg/h, respectively), main product output is 2.05; 3.45; 4.32 and 4.71 t/h of dry matter, by-products – 140 Агробіологія, 2025, № 1 agrobiologiya.btsau.edu.ua 2.50; 4.35; 5.58 and 6.20 t/h of dry matter, crop rotation productivity (main + byproducts) – 4.55; 7.80; 9.90 and 10.91 t/h of dry matter. Plant residues mass of the main crops of the crop rotation exceeds the mass of the harvest weight of marketable products or close to it. With an increase in fertilizer rates, the share of non-marketable products in the total yield of main crops of the crop rotation increases, and marketable products gain is higher than plant residues. With the alienation of by-products from the fields of the crop rotation or in the absence of post-harvest white mustard sowings for green manure, the humus balance in typical medium-loamy black soil is negative. Even one field of sideral crops would be enough to obtain a positive balance, but provided that all non-marketable products are used as organic fertilizer. The most deficient balance of humus under sunflower, where its annual losses ranged from 1.3 to 3.2 t/h. In general, in the crop rotation on fertilized variants, approximately 30 % of newly formed humus enters the soil due to humification of plant residues, crop by-products and green manure, and the rest (7–9 %) – manure. When byproducts are removed from crop rotation fields or when there are no post-harvest white mustard crops for green manure, the humus balance in typical medium-loamy chernozem is negative. Even one field of green manure crops would be enough to obtain a positive balance, but with the use of all non-marketable products as organic fertilizer. The most deficient balance of humus was observed under sunflower, where annual losses ranged from 1.3 to 3.2 t/ha. In general, in crop rotation on fertilized variants, approximately 30 % of humus reenters the soil due to humification of plant residues, byproducts of crops and green manure, and the rest (7–9 %) –manure. When using post-harvest green manure in two fields of a five-field crop rotation, byproducts of agriculture as organic fertilizer on the stationary experiment plots not fertilized with mineral fertilizers and manure, the state of biological agriculture is observed; on fertilized N54P48K48 + 6 t/ha of manure and N92P66K90 + 6 t/ha of manure – the state of ecological farming; on fertilized N120P92K110 + 6 t/h of manure, biologization of the agricultural sector occurs.

Key words: soil, crop rotation, fertilization system, crop residues, humus balance, non-market products, harvest, ecologization.