Soil water regime in the fields of corn fields under different tillage practices

Abstract

The results of ecological tests of corn hybrids of Ukrainian selection under different methods of main tillage (moldboard ploughing to a depth of 25‒27 cm, minimal tillage (disc and sweep), to a depth of 14‒16 cm, no-till) are presented. The research was conducted in the experimental field of the Department of Arable farming of the Institute of Agriculture of the North-East of Ukraine on chernozem typical silt loam on loess (content of humus by Tyurin 4,1‒4,7 % рНKCl 6,0, рНH2O 7,9). 2018‒2020 years of research were significantly warmer than the average long-term indexes during May-September. It was found that the weather conditions of the growing season of corn on average for 2018‒2019 were characterized as very arid (hydrothermal coefficient HTC = 0.57) with ranging from very arid in 2018 and 2019 (HTC = 0.45‒0.46) to arid in 2020 (HTC = 0.80). It was determined that the value of total water consumption did not depend on the methods of tillage and, under other equal factors, determined by the total precipitation and ranged from 245.4–252.2 mm with precipitation of 110.4 mm to 319.1–321, 4 mm at 230 mm.
 It is established that the influence of precipitation in the structure of total water consumption depends on their amounts and if it were about 44.2‒45.0 % at precipitation of 110.4 mm, with 230.0 mm would be 71.6–73.1 %. On that account, a portion of the total water consumption from 0‒50 cm soil layer did not depend on precipitation and in the average was 0.77–0.79.
 In 2018‒2020, corn hybrids of Ukrainian selection with N100P45K45-ferilizers formed quite high yields (9.40–7.78 t/ha) with a significant dependence on FAO. The yield of hybrid Donor (FAO 310) did not depend on tillage, while hybrids Zoryany (FAO 190) and Leleka (FAO 260) gave the highest yields on ploughing plots without significant responce to other methods of basic tillage. The Donor hybrid formed a statistically equal yield on all variants in all years of research.