THE INFLUENCE OF WINTER COVER CROPS AND THEIR INCORPORATION METHODS ON SPRING WHEAT CROP WEEDINESS AND PRODUCTIVITY

Abstract

Field experiment was conducted in 2022 and 2023 at the Experimental Station of Vytautas Magnus University Agriculture Academy. The soil of the experiment is Endocalcaric Amphistagnic Luvisol. Experimental treatments: Factor A: methods of incorporation of cover crops into the soil: 1. Deep ploughing (20 cm deep) in spring; 2. Shallow incorporation (6 cm deep) in the spring. Factor B: winter cover crops: 1. Without cover crop; 2. Crimson (incarnate) clover (10 kg ha^-1); 3. Winter vetch (50 kg ha^-1); 4. Perennial ryegrass (10 kg ha^-1); 5. Winter rye (50 kg ha^-1). In the spring wheat crop dominated Chenopodium album, Stellaria media,  Cirsium arvense and Taraxacum officinale. The lowest number of weeds was found in spring wheat fields, where winter rye was shallowly incorporated for green manure in spring. Cover crops and their incorporation methods had no significant effect on weed dry matter mass. The highest density of the spring wheat crop was formed, where winter vetch was shallowly incorporated for green manure in the spring. The 1000 grain mass of wheat was the highest when crimson clover was deeply incorporated for green manure. Significantly highest yield of wheat grain (from 1.1 to 2.1 times) was formed, where winter vetch was deeply ploughed for green manure in the spring. In the deeply ploughed fields without or with cover crops, compared to shallowly  tilled, the 1000 grain mass of wheat was significantly higher from 5.7 to 9.0%, and the grain yield was significantly higher from 24.9 to 52.8%.