Moisture consumption by grain sorghum varieties depending on seeding rates and sowing methods in the southern part of the Rostov region

The current work was carried out on the experimental plot of the research crop rotation of the laboratory for cultivation technology of row crops of the FSBSI Agricultural Research Center “Donskoy”. The soil is represented by ordinary calcareous heavy loamy chernozem with such agrochemical parameters in the soil layer of 0–30 cm as 7.1 pH, 3.3 % of humus content, 18–20 mg/kg of P2O5; 340–370 mg/kg of K2O. The trials were carried out on the early-maturing grain sorghum varieties ‘Zernogradskoye 88’ and ‘Ataman’. The purpose of the current research was to identify the moisture consumption of new grain sorghum varieties, depending on the sowing norms and methods in the southern part of the Rostov region. The year 2018 was arid with 93.4 mm of rainfall. In 2019 there was also a shortage of precipitation, which amounted to 66.9 mm to the long-term average. The weather conditions of 2020 were characterized by the highest amount of precipitation (223.2 mm). The reserves of productive moisture on average over the years of study at the beginning of plant development in terms of sowing rates and methods in a meter-long soil layer were at the level of 111.2–113.9 mm, which is enough to obtain thick seedlings. The smallest amount of moisture was noted by the dead-rape stage and ranged from 6.5 to 20.5 mm for the studied varieties. On average, over the years of study, for all variants of the trial, the variety ‘Ataman’ was more productive, its productivity varied within 3.75–4.83 t/ha. At the same time, this variety formed the highest yield indicators (727 tons) with a row spacing of 0.45 m and a seeding rate of 0.4 million germinating seeds per ha, with the lowest moisture consumption per 1 ton of grain. As for the variety ‘Zernogradskoe 88’, the lowest moisture consumption was 823 tons at a seeding rate of 0.6 million germinating seeds per ha with a row spacing of 0.45 m.