YIELD AND PHYTOSANITARY STATE OF THE LAST CROPS OF THE CROP ROTATION OF WHEAT AND BARLEY

The article shows the analysis of the effect of long-term application (since 2006) of nonmoldboard and combined systems of main tillage in a crop rotation in comparison with annual moldboard tillage on productivity of spring wheat, yield and phytosanitary state of barley. The author studied tillage options in a cereal-grass rotation (71% cereals) with different types of fallow (clean, manured, clover and mustard) and with winter rye straw left in the field. Annual mouldboard tillage resulted in the highest yields of spring wheat and barley in the experiment – 2.90 and 2.31 t/ha. Annual nonmoldboard tillage resulted in a significant reduction in wheat yield to 2.61 t/ha and barley yield to 1.28 t/ha. The combined tillage system, alternating two mouldboard and four nonmoldboard treatments per rotation, ensured the wheat yield at the level of the mouldboard system – 2.82 t/ha, and a decrease in barley yields to 1.85 t/ha. In 2020, the limiting factor for barley yield formation in the variants with surface distribution of crop residues and straw was increased weed infestation and deterioration of the phytosanitary state of the crop. Straw had a depressive effect on the yield of the last crops in a crop rotation with pure fallow. Crop yields decreased by 0.43 and 0.26 t/ha. Wheat yield was 2.34 t/ha, barley yield was 1.41 t/ha. Green manure mustard and clover fallows leveled the depressive effect of straw. The yields of the 6th and 7th crops of the crop rotation were at the control level (2.69–2.78 t/ha of wheat and 1.70–1.81 t/ha of barley). Regardless of the tillage system and the use of by-products as organic fertilizer, the application of manure ensured the highest yields of the final crops of the rotation: 3.10 and 2.99 t/ha for spring wheat and 2.00 and 2.14 t/ha for barley.