Mineral and water nutrition, soil cultivation technologies influence on onion yield, spatial variation and biochemical compound in the system of vegetable crop rotations of the Nizhneje Povolzhje region

To increase yields, it is necessary to improve the technologies for growing agricultural crops. Scientific research was carried out from 2016 to 2020. The optimal seeding rates per hectare, seasonal irrigation rates and doses of mineral nutrition were studied, this will reveal the levels of vegetable crop rotations adaptive intensification, its influence on soil indicators characterizing the soil formation evolutionary processes and the products quality. The objects of the study were onion hybrids of foreign selection Pandero F1, Benefit F1, Valero F1, Manas F1. The domestic zoned variety Volgodonets was taken as the standard one. As the result of the search for the optimal combination of moisture supply and mineral nutrition levels, it was established that for the Nizhneje Povolzhje region, in the conditions of the existing land use and the adopted soil preparation technologies, indicators that provide 80% of minimum water capacity are the optimal variant. For five years of observations (2016-2020) in the Astrakhan region, the Pandero F1 hybrid showed an average yield of 139.07 t/ha, Benefit F1 - 150.16 t/ha, Valero F1 - 123.73 t/ha, Manas F1 - 133.76 t/ha. In the Volgograd region, the same hybrids showed 103.10 t/ha; 129.57 t/ha; 111.6 t/ha; 104.09 t/ha, respectively. The research allows to recommend the production to include in the technological processes the soil basic preparation, namely autumn plowing, to plow not to 0.22 … 0.25 m by a conventional plow, but to plow without soil overturning by the Paraplau unit to the depth of 0.42 … 0.45 m. The authors offer to leave sowing by eight-row seeders and to change to sowing by a twelve-row seeder.