Estimation of the stability of spring barley productivity under the conditions of the Central Blackearth Region

The study of the stability of productivity of the spring barley variety ‘Suzdalets’ was carried out at the FSBSI “Kursk FARC” when cultivating the crop in various crop rotations with the application of mineral fertilizers, in the conditions of the Central Blackearth Region on chernozem soils over 7 rotations of three crop rotations (from 1985 to 2010). Mineral fertilizers for barley were applied in doses of N30Р30К30 and N60Р60К60. The main tillage was plowing. The purpose of the current work was to identify the influence of factors on the stability of spring barley productivity using a comprehensive estimation of the associated data of cultivation technology, weather, and soil conditions. There has been found that the spring barley productivity variation in the trial by 44 % was because of weather conditions, the interaction of weather conditions with the application of mineral fertilizers (20 %) and the interaction of all the studied factors (12 %). The conducted correlation analysis has shown a direct dependence on the HTC (r = 0.51) and an inverse dependence with the sum of active temperatures (r = –0.66). The introduction of a double dose of mineral fertilizers has reduced the dependence of barley productivity on the amount of precipitation during the crop vegetation period. The largest productivity was established in the grain-fallow crop rotation. When fertilizing, it has increased in all crop rotations. With the introduction of grasses in the crop rotation, the stability of productivity has improved. There has been identified that spring barley productivity has a direct correlation with the content of humus and with the content of nitrate nitrogen (r = 0.56–0.69) and ammonium nitrogen (r = 0.50–0.55). There has been established that barley productivity has a direct, moderate and noticeable correlation (r = 0.33–0.63) with a mobility degree of phosphates and potassium. With the help of the obtained mathematical model, knowing the mobility degree of phosphates and potassium in soil, there will be possible to predict spring barley productivity on blackearth soils of the Central Blackearth Region.