Weed infestation of white clover crops on saline soils in the south of Ukraine depending on the cover crop and seeding rates

Abstract

The article reveals the influence of a cover crop and seeding rates on weed species composition and weed infestation of white sweet clover crops of the first and second years of life. The studies were conducted on chestnut alkali-affected soils of the Askania-Nova Institute of Animal Husbandry of Steppe Areas named after M.F. Ivanov in 2007-2010. We studied a cereal-legume mix for green fodder, barley for grain, oats for grain as cover crops. The following seeding rates were tested: 8; 12; 16; 20 and 24 kg/ha. The research findings show that a two-year-long cultivation of white sweet clover results is a sharp decrease in field weediness. Sowing cover crops in comparison with open sowing reduces weed infestation of white sweet clover crops almost twofold. With an increase in the seeding rate, weed infestation significantly decreases. The minimum number of weeds is registered at the highest seeding rate of 24 kg/ha. The weediness of white clover crops of the second year of life (in the period of green harvesting) decreased compared to the first year by 1.9 times under open sowing, and under the cover of early spring crops for green fodder and grain it was 2.1-2.7 times lower. On average in the experiment, there was a 2.0-2.3 time reduction in weed infestation as response to seeding rates, as compared with the first year of life. Key words: white sweet clover, open sowing, cover crop, seeding rate, weed infestation of crops, species composition of weeds.