Differentiated application of fertilizers on seed crops of buckwheat in the steppe zone of the Central Chernozem region

For wide economic introduction of crested wheatgrass, it is necessary to permanently breed new adaptive varieties and develop effective agrotechnical methods of their cultivation in relation to certain zonal soil and climatic conditions. One of the most effective methods of increasing the yield of wheatgrass seeds is a scientifically based system of using mineral fertilizers, primarily nitrogen-containing ones. The purpose of the work is to conduct a comparative assessment and identify the optimal timing and rates of application of mineral nitrogen fertilizer on seed crops of comb-wheatgrass 1-2-go g.p. of the new variety Nenarokovskiy in the steppe zone of the Central Black Earth Region. It was established that on leached chernozem soils with an average supply of mobile forms of phosphorus and increased exchangeable potassium, the use of P60K30 contributed to an increase in seed yield by 19 % relative to the control. Against the background of P60K30, autumn or spring application of mineral nitrogen in doses from N30 to N90 resulted in an increase in seed yield by 27–77 %. The maximum seed yield of 362–375 kg/ha, or 77-84% more than in the control, was obtained with fractional autumn-spring application of mineral nitrogen at the rate of N75 (N30+45) and a single spring dose of N60. With fractional application of the N60 rate (N30+30), the seed yield was 342 kg/ha, which exceeded the control by 68 %. Along with this, a high yield of 322 kg/ha, or 58 % higher than in the control, was obtained with a single spring application of N45. Autumn use of N45 and N60 was less effective, but also provided a reliable increase in seed yield of 28 and 43 %. According to the change in the indicators of individual components of the structure of the seed grass stand of the 2nd year of production, the value of the level of actual collection of comb-wheatgrass seeds, the transition between the doses, rates and timing of application of nitrogen and phosphorus-potassium fertilizers was statistically significant.