INFLUENCE OF PREDECESSORS ON WATER CONSUMPTION AND PRODUCTIVITY OF WINTER WHEAT IN THE ZONE OF THE LEFT-BANK FOREST-STEPPE OF UKRAINE

Abstract

Winter wheat (Triticum aestivum L.) is a strategic grain crop, which ensures food security of the state. Constantly growing demand for winter wheat encourages the search for ways to increase its yield and im-prove quality indicators while reducing the cost of a unit of marketable products. Possible measures to stabi-lize winter wheat production include its place in scientifically substantiated crop rotation system. The aim of the study was to determine the effect of different predecessors, fertilization levels on water consumption of winter wheat plants and its productivity. The studies were conducted at Poltava State Agricultural Research Station named after M. I. Vavilov during 2019–2020. It has been found out that the most available moisture in the 1.5-meter soil layer at the time of resuming spring vegetation was accumulated at sowing winter wheat on black fallow of 250.9 mm. Sainfoin, as a fallow land wheat predecessor, was only 2.9 % inferior to black fallow in terms of moisture reserves. Sufficient reserves of available moisture were accumulated at sowing winter wheat after pea for grain in crop rotation, but they were lower than fallow predecessors by 6.8–13.8 mm or 2.8–5.6 %. The worst conditions for moisture accumulation in the soil were formed during sow-ing winter wheat after winter wheat. It has been found out that pea for grain was the best predecessor of winter wheat, the yield made 4.52 t/ha at applying N50 P50 K50 under the crop. Sainfoin per mowing was al-most equal predecessor for wheat. Grain yield was by only 1.2% lower as compared with post-pea for grain cultivation. Sowing winter wheat on black fallow was effective only in dry years. In favorable years as to moistening, a decrease in the yield of winter wheat on black fallow was registered as a result of early and intensive lodging of crops. It has been determined that cultivating winter wheat after winter wheat in crop rotation is undesirable because it leads to yield decrease by 28.0–34.5 % in comparison with better predecessors.