Influence of tillage and fertilizers on the weed infestation of field crop rotation link in the Northern Steppe of Ukraine

Topicality. In the current conditions in Ukraine, the issues of weed control in crops do not lose their relevance due to the negative processes caused by the aggravation of the economic situation, the rapid soaring prices on mineral fertilizers, machinery, fuels and lubricants, plant protection products, the replacement of energy-intensive traditional tillage systems with moldboardless and other resource-saving ones. Purpose. To study the influence of tillage and fertilizers on the weed infestation of agricultural crops in the link of the field grain-fallow-row crop rotation: winter wheat after maize (milk-wax ripeness) – grain peas – winter wheat in the Northern Steppe of Ukraine. Materials and Methods. Methods of tillage with applying mineral fertilizers under the primary tillage were tested. The field and statistical-mathematical methods were used in experimental studies. The number of weeds in crops was determined by the quantitative-weight method using square frames. Results. It was established that moldboardless tillage in the crop rotation link against the background of plowing under maize and harrowing with light harrows during the growing season leads in comparison with moldboard tillage to the following increase in weed infestation – on average for years of research: annual weeds during the growing season: in peas crops – by 40.6 (without fertilizers), 44.2 (with recommended dose) and 51.6 (with calculated dose) pcs/m2; before harvesting: by 22.7, 24.4 and 36.4 pcs/m2, respectively; in winter wheat crops after peas – by 0.5, 11.9 and 19.4 pcs/m2; 5.8, 8.4 and 6.7 pcs./m2, respectively; perennials in winter wheat crops after peas during the growing season: by 10.4, 9.1 and 10.9 pcs/m2; before harvesting: by 19.1, 18.3 and 20.0 pcs/m2, respectively. The application of mineral fertilizers increases germination of annual weed seeds. This was most clearly observed in winter wheat crops after maize of milk-wax ripeness. A tendency towards an increase in the air-dry weight of weeds under fertilization was revealed for all crops in the crop rotation link. Conclusions. Moldboardless tillage increases the number of weeds, but does not increase their air-dry weight, and decreases grain yield and quality. Mineral fertilizers applied in the experiment increase the air-dry weight of weeds and the number of their annual species. The species composition of weeds in the crops did not depend on the method of tillage. Key words: weeds, tillage, mineral fertilizers, winter wheat, peas