The influence of predecessors and means of chemicalization on the formation of the efficiency summer wheats in the conditions of the steppe zone of the Republic of Тuvа

The research objective was to study the influence of predecessors and mineral fertilizers on the productivity and the qualities of grain of spring-sown wheat. The research problems were to study the influence of predecessors and mineral fertilizers on the dynamics of the content of nitrate nitrogen in the soil; to estimate the influence of various predecessors and mineral fertilizers on productivity of spring-sown wheat, quality indicators of grain. The experiments were made in a steppe zone of the Republic of Tyva in 2019-2020, on dark-chestnut, medium loamy soils, in a three-field crop rotation with short rotation (fallow-wheat-wheat; fallow - perennial herbs wheat; fallow - oats - wheat, permanent wheat), on two backgrounds of chemicalixation: without use of mineral fertilizers (control, background 0), with use of mineral fertilizers (background 1). The influence of predecessors and funds of chemicalixation on the level of nitric food of plants, productivity and protein content in grain of spring-sown wheat was shown. It was revealed that the best conditions of nitric food in the soil had been noted at the placement of spring-sown wheat after perennial herbs. Introduction of mineral fertilizers promoted the growth of the content of nitrate nitrogen in the soil to a phase of shoots for 8.3-38.0 %, bushing and harvesting - by 1.2-1.7 times, depending on various predecessors. It was shown that the content of nitrate nitrogen in the soil was reflected in corresponding way in protein content in grain of spring-sown wheat. The best indicators on productivity and quality of grain of spring-sown wheat are noted after perennial herbs, on average by experience the highest productivity of spring-sown wheat - 1.63 t/hectare and high wheat grain protein content - 16.6 % was received here. Further as decrease in the efficiency bare fallow (1.44 t/hectare, 13.8 %), wheat (1.37 t/hectare, 14.9 %), and oats (1.04 t/hectare, 15.4 %) followed. It was established that application of means of chemicalixation reduced the influence of predecessors. At introduction of mineral fertilizers the productivity of spring-sown wheat increased on average by the experiment by 34.2 %.