Agroecological estimation of the effect of crop rotation and mineral fertilizers on productivity and quality of spring barley grain in the Central Blackearth region of Russia

The purpose of the current study was to determine the effect of crop rotations and doses of mineral fertilizers on productivity, grain quality of spring barley and fertility of typical chernozem in the Central Сhernozem Region (CBR). The study was conducted in a multifactorial trial located on the watershed plateau of the research and production department No. 2 of the Federal Agricultural Kursk Research Center in 2018 and 2022. The soil of the experimental plot was typical medium-loamy chernozem, with 5.9 % of humus. There have been studied such factors as grain-fallow-row and grain-grass-row crop rotations; with fertilizer doses and no fertilizers, N 30 Р 30 К 30 , N 60 Р 60 К 60 . The highest biological productivity of spring barley up to 5.99 t/ha was identified in the grain-fallow-row crop rotation with the dose of N 60 Р 60 К 60 . However, the presence of perennial leguminous grasses in the grain-grass-row crop rotation contributed to a smaller decrease in humus, the maximum loss of which in it was 0.14 %, which was 0.02 % lower than in the grain-fallow-row crop rotation. The trends of agroecological effect of crop rotations and mineral fertilizers on the indicators of spring barley grain production were estimated with a digital method, namely the Harrington desirability function. There has been established an “acceptable, satisfactory” effect of crop rotations and mineral fertilizers on the studied indicators ( d i = 0.50), but in relation to individual indicators of grain production, the level of effect of crop rotations varies significantly from d i = 0.12 “completely unacceptable” to d i = 0.83 “most acceptable”. The ecological properties of crop rotation are manifested in the estimation of its effect on the humus content in the soil: “acceptable, satisfactory” ( d i = 0.38–0.52). The comprehensive estimation of the effect of mineral fertilizers for most indicators has increased proportionally to their dose, reaching d i = 0.49–0.65, which indicates their “acceptable, satisfactory” effect.