Impact of various organic fertilizer systems on the weediness of crops in short-term crop rotation

Abstract

Goal. To determine the patterns of formation of weediness of soybean, spring wheat, and millet crops depending on the organic fertilizer system in short-term crop rotation. Methods. The study was conducted during 2023–2025 in a stationary field experiment of the Panfily experimental station of the NSC «Institute of Agriculture of NAAS» in the subzone of unstable moistening of the Left-Bank Forest-Steppe of Ukraine on typical low-humus chornozem. In a three-field crop rotation, soybean — spring wheat — millet, they compared 4 fertilization options: by-products of the precursor, by-products of the precursor + siderate, by-products of the precursor + Bio-Gel, by-products of the precursor + siderate + Bio-Gel. Weediness was determined by quantitative and quantitative-weight methods in the phase of complete germination of crops and before harvesting. Results. The highest initial weed density was recorded in the control versions: 194 pcs./m2 in soybeans, 207 pcs./m2 in spring wheat, and 114 pcs./m2 in millet. The simultaneous use of siderate and bio-fertilizer reduced the number of weeds before harvesting to 68, 41, and 13 pcs./m2, respectively. The greatest decrease in the dry weight of weeds compared to the control was obtained in crops of millet (53.3%) and spring wheat (51.5%), which indicated an increase in the competitive ability of agrophytocenoses for complex biologization of fertilization. Conclusions. The combination of by-products of the predecessor, post-harvest siderate, and liquid biofertilizer provided the most effective suppression of the weed component in the organic short-term crop rotation, especially in the second half of the vegetation, when the main phytomass of the segetal vegetation is formed.