STUDY OF CORN AGROCENOSES IN MIXED CROPS ON GRAY FOREST SOILS OF KAMA REGION OF THE REPUBLIC OF TATARSTAN

The studies were conducted to assess the productivity of mixed crops of corn with other crops in the Republic of Tatarstan. The experiment was carried out in 2022-2023 on gray forest soil with a humus content of 2.1%, mobile phosphorus ‒ 151 mg/kg, potassium ‒ 121 mg/kg. The experimental design included the following options: nutrition background (factor A) - no fertilizers, N30P30K30, N45P45K45, N60P60K60; cropping pattern (factor B) - corn (100%), corn (50%) + peas (50%), corn (50%) + soybeans (50%), corn (50%) + vetch (50%), corn (33.3%) + vetch (33.3%) + oats (33.3%), corn (50%) + sweet clover (50%). Azofoska (15:15:15) was applied as fertilizer during pre-sowing cultivation. Before sowing, the seeds were mixed according to the experimental scheme, based on the recommended rates for pure crop sowings: corn - 80 thousand pcs./ha, peas - 1.2 million pcs./ha, soybeans - 750 thousand pcs./ha, vetch - 800 thousand pcs./ha, oats - 5 million pcs./ha, sweet clover - 6 million pcs./ha. The optimal ratio of plant heights of the studied mixtures was noted in the variants corn + pea, corn + vetch and corn + vetch + oats. The highest aboveground mass in the experiment was recorded against the background of N60P60K60 in the milky ripeness phase of corn grain in mixed crops with peas - 27.80 t/ha. The highest above-ground mass of the second crop in the mixture was formed by soybeans on the backgrounds of N60P60K60 and N45P45K45 (4.60 t/ha each). The highest yield of green mass was provided by the application of N45P45K45; further increase in the fertilizer rate is impractical. The highest yield of green mass was noted in the crops of corn + vetch + oats (25.50 t/ha) and corn + soybeans (24.80 t/ha).