The possibility of planning winter wheat grain productivity in the southern part of the Rostov region

The current paper has presented the results of study conducted at the Agricultural Research Center “Donskoy” in 2019–2021. The winter bread wheat variety ‘Lidiya’ was taken as the object of study. The forecrop was sunflower. In the variants where it was planned to yield 5.0; 6.0 and 7.0 t/ha, there were used mineral fertilizers (ammonium nitrate, ammophos and potassium salt) in doses (mean through the years) of N66P66K43, N79P79K52 and N92P92K61, respectively. In the control variant, there were used on fertilizers. The purpose of the study was to find out the possibility obtaining the planned winter wheat grain productivity in the southern part of the Rostov region under the use of mineral fertilizers. The amount of precipitation during the agricultural year and a vegetation period of winter wheat was 520.3 and 431.6 mm, while the norm was 582.4 and 446.3 mm, respectively. Depending on the hydrothermal conditions, the sum of air humidity deficits from September to June varied from 1034.1 to 1278.2 mm over the years, and water need for plants ranged from 672.2 to 830.8 mm. The coefficients of precipitation and moisture availability for winter wheat were in the range of 0.53–0.67 over the years. The hydrothermal conditions during the years of study determined win­ter wheat moisture supply during a vegetation period and contributed to obtaining grain productivity of different levels. Under the prevailing hydrothermal conditions, it was not possible to obtain the planned productivity of the winter bread wheat variety ‘Lidiya’. However, all applied doses of mineral fertilizers were cost-effective and there were obtained a significant yield increase of 1.28–2.03 t/ha (the yield on the control was 3.52 t/ha). There has been recommended to take into account the conditions of moisture supply in the cultivation zone when planning productivity and effective use of mineral fertilizers.