Bondar S. Reclamation of typical chernozem and improvement of agricultural crops productivity in crop rotation of the Right-Bank Forest-Steppe of Ukraine

The thesis is devoted to the reclamation of typical chernozem and to the ways of increasing productivity of oat, winter wheat, sugar beet crop rotation links as affected by fertilization practice, the phytosanitary status of sowings, nutrient status of soil under the conditions of unstable moisture in the Right Bank Forest-Steppe of Ukraine. In typical leached chernozem, the humus content in the ploughed soil layer at the application crop rotation link of 16.6 t/ha of manure + N53,3P53,3K53,3 in rotatory system stabilized at the level of 3.55 %, in hoed rotation at the level of 3.34 %, in grain-hoed crop rotation at the level of 3.45 %. In a rotatory system with incorporation of harvest residues + N53.3P53.3K53.3, the humus content was 3.24 %. Under the effect of sunflower grown in the link of hoed rotation, the yield of oat against the background of 16.6 t/ha of manure + 53.3P53.3K53.3 decreased by 7.0 t/ha compared to a rotatory system, whereas in the rotatory system and grain-hoed crop rotation the crop yield reached 47.0 and 46.2 t/ha. The yield of winter wheat in the link with oat was 4.97 t/ha in the rotatory system against the background of 8.3 t/ha manure + N43.3P43.3K43.3, while in hoed crop rotation and in grain-hoed crop rotation the yield was 5.10 and 5.10 t/ha, respectively. Incorporation of harvest residues against the background of mineral fertilization resulted in the yield value of 5.0 t/ha. In rotatory system against the background of 50 t/ha manure + N100P100K100, root yield amounted to 58.0 t/ha and sugar yield to 9.21 t/ha. When incorporating 5 t/ha straw + N100P100K100, root yield was 56.7 t/ ha and sugar yield was 9.15 t/ha. Growing sugar beet in hoed crop rotation on the fifth year after sunflower reduced root yield and sugar yield compared to the rotatory system by 4.69 and 0.41 t/ha respectively. The productivity of the link vetch oat − winter wheat − sugar beet in rotatory system against the background of 16.6 t/ha of manure + N53.3 P53.3K53.3 was 11.67 t of fodder units per hectare, in hoed crop rotation 10.5 tons of fodder units per hectare and in grain-hoed crop rotation 11.09 tons of fodder units per hectare with energy output of 106389 MJ, 97523 and 100654 MJ respectively. In the rotatory system at incorporation of harvest residues + N53.3 P53.3K53.3, the yield was 11.13 tons of fodder units per hectare and energy output 101178 MJ.