Assessment of nutrient uptake by sugar beet as a factor of the crop biological potential realization

Abstract

Purpose. To establish the peculiarities of the accumulation and removal of macroelements by sugar beet in the Steppe Zone of Ukraine. Methods. Field research was conducted during 2020–2022 in the Chkalov Agrocompany LLC (Kirovohrad region). The scheme of the experiment provided for the cultivation of sugar beets against the background of the use of a water-retaining agent (without hydrogel; hydrogel Aquasorb, 300 kg/ha), under different systems of the main fertilizer [without fertilizers – control; manure, 20 t/ha; N170P180K350; Leonardyt, 400 kg/ha; Parostok (brand 20), 400 kg/ha] and foliar feeding during the growing season (without foliar feeding; Humifild, SE, 2 kg/ha in the BBCH stage 30 + 39). Organic and mineral fertilizers (PK) were applied in autumn at plowing and nitrogen at cultivation in early spring. The adsorbent was applied to the soil two weeks before sowing the crop locally in the zone of the row, based on the data of the GPS tracker. The rest of the agricultural activities corresponded to the generally accepted culture cultivation technology in the research area. Results. On average, according to the experiment, sugar beet used 90.2 kg/ha of nitrogen, 15.1 kg/ha of phosphorus, and 75.6 kg/ha of potassium to form a crop. The consumption of macronutrients for the formation of humus was not calculated, since it was immediately returned to the soil during harvesting. The use of organic fertilizers of the new formulation contributed not only to the formation of a high yield of sugar beet roots, but also to a significant removal of macronutrients from the soil. In particular, when applying Leonardyt (400 kg/ha) with the crop, 94.8 kg/ha of nitrogen, 16.1 kg/ha of phosphorus and 79.9 kg/ha of potassium was removed, which is 17.1; 3.1 and 14.7 kg/ha more than on the unfertilized control. When applying Parostok (brand 20) (400 kg/ha), 101.6 kg/ha of nitrogen, 16.7 kg/ha of phosphorus and 84.2 kg/ha of potassium was removed, which exceeded the control indicators by 23.9; 3.8 and 19.1 kg/ha, respectively. Conclusions. According to the indicators of the ratio of variable to maximum fluorescence (Fv/Fm) of photosynthesis, the highest coefficient values were obtained in the case of applying Aquasorb hydrogel in the zone of the row before sowing and fertilizing with Leonardyt (0.58–0.59) and Parostok (brand 20) (0.58–0.60). Therefore, the best conditions for the growth and development of sugar beets were formed in these treatments of the experiment. Based on the obtained coefficients of the ratio of variable to maximum fluorescence (Fv/Fm) of photosynthesis, the yield of root crops can be predicted by the equation y = 88.5x + 5.1.