THE EFFECTIVENESS OF PHOSPHOROUS FERTILIZERS WITH LONG-TERM USE IN INCREASING THE YIELD OF SPRING WHEAT GRAINS IN THE LEACHED CHERNOZEM OF THE OREL REGION

In a long-term stationary field experiment, on leached, heavy loam chernozem with a very low content of mobile phosphorus (38-47 mg/kg), the comparative effectiveness of doses and methods of applying superphosphate and phosphoric acid according to background I (N60K60) and background II (aftereffect of 24 t/ha of manure from N60K60) on the crop was studied spring wheat grains in unstable weather conditions 2009-2024. The growing seasons of 2009 and 2024 were characterized by contrasting weather conditions. In the driest year of 2010, the duration of the combined effect of drought and high temperatures was observed throughout the growing season. Precipitation was insufficiently below the annual average: in May - 21 mm, in June - 11 mm, in July - 49 mm, in August - 50 mm. In the wettest year of 2016, precipitation was higher than the annual average: in April (21 mm), May (32 mm), June (19 mm), July (52 mm) and August (162 mm). A tendency of low dependence of the yield of spring wheat grain on May precipitation was found for annual (Ps90) and reserve (Ps270) N60K60 and aftereffect of 24 t/ha from N60K60, R2=0.070 and R2=0.089, R2=0.104 and R2=0.113, in the control - R2=0.173. The assessment of the indicator "air temperature - yield according to experimental options" revealed in April a higher dependence of the yield of spring wheat grain on average daily temperatures, R2= 0.559...0.282. The use of mineral fertilizers and the aftereffect of manure fertilizers were an important factor in the stability of spring wheat crops to the effects of unstable weather conditions. The best adaptation (V=26% and V= 28%, V=27% and V= 29%) to unstable weather conditions with a more stable 16-year dynamics of the spring wheat grain harvest corresponded to the variants of the experiment using superphosphate and phosphorous flour annually (Ps90 and Pf90) and in reserve (Ps270 and Pf270) with N60K60 and the aftereffect of 24 t/ha of manure from N60K60, in control, V=40%. The largest 41% share in the increase in the yield of spring wheat grain was noted in the aftereffect of 24 t/ha of manure fertilizer and less than 16% and 37%, 35% and 24% of nitrogen - potash and applied annually (Ps90) and phosphorous flour (Pf90) and in the stock of Ps270 and Pf270 according to N60K60 The equivalent efficiency of increasing the yield of spring wheat grain from the annual and reserve methods of applying superphosphate and phosphorous flour is shown. With slightly different increments (0.69 t/ha, 0.64 t/ha and 1.27 t/ha, 1.26 t/ha; 0.45 t/ha and 1.11 t/ha and 1.08 t/ha) of spring wheat grain yields between the annual Ps90 and Pf90 and the annual Ps270 and Pf270 application superphosphate and phosphorous flour according to N60K60 and the background of the aftereffect of manure from N60K60, periodic (reserve) introduction of superphosphate and phosphorous flour into the rotation of crop rotation is justified

spring wheat (Triticumaestivum L.), methods of applying phosphorous fertilizers, superphosphate, phosphoric flour, leached chernozem