WATER CONSUMPTION BY AGROECOSYSTEMS OF LEGUMINOUS PERENNIAL GRASSES DEPENDING ON VEGETATION YEARS
Authors: Tkachuk Oleksandr , Vdovenko Sergiy 
Published: January 2022

At the end of the growing season of the first year of life of perennial legumes, the highest soil moisture - 27.45% was observed in the agroecosystem of alfalfa, and the lowest - 24.14% - in the agroecosystem of the horned lily. The coefficient of water use by agroecosystems of legumes of perennial grasses in the first year of their growing season was 455.1-1738.0. The smallest coefficient of water use was in the agroecosystem of the white melilot, and the highest in the eastern goat's rue.
At the end of the growing season of perennial legumes of the second year of life, soil moisture in agroecosystems was 11.67-17.00%. It was the largest in the agroecosystem of white melilot, which forms only one cut in the middle of summer in the second year of its life and then dies off, and the smallest in the agroecosystem of sandy sainfoin. The coefficient of water use by agroecosystems of perennial legumes in the second year of vegetation was 429.2-696.7. It was the smallest in the agroecosystem of white melilot, and in perennial legumes that grow by autumn - in the agroecosystem of sandy sainfoin, and the highest was in horned beetle. By the end of the third year of the growing season of perennial legumes, soil moisture had been 18.00-23.11%. It was the largest in the agroecosystem of sandy sainfoin, and the smallest in the horned sainfoin. The coefficient of water use by agroecosystems of leguminous perennial grasses for the third year of growing season was 484.0-619.6. The smallest was in the agroecosystem of the sandy sainfoin, and the largest was the horned sainfoin. At the end of the fourth year of the growing season of perennial legumes, soil moisture was valued in 22.60-25.07%. It was the largest in the agroecosystem of sandy sainfoin, and the smallest in alfalfa. The coefficient of water use by agroecosystems of perennial legumes in the fourth year of their growing season was 489.3-1130.7. Less moisture is used for the formation of a unit of dry matter by the agroecosystems of sainfoin, the coefficient of water use of the agroecosystem of alfalfa is higher by 13.4%. The agroecosystem of Lyadvenets horned had the highest coefficient of water use - 2.3 times more than in the agroecosystem of sainfoin. In conditions of the greenhouse effect, in particular, with an increase in air temperature, an increase in moisture evaporation from the soil and a decrease in the amount of atmospheric precipitation, it is necessary to grow herbs that consume moisture most economically and have the lowest water consumption coefficient: the first year of growing season - white melilot - 455.1; second year - white sweet clover - 429.2 and sandy sainfoin - 472.1; the third year - sandy sainfoin - 484.0 and alfalfa - 510.3; the fourth year - sandy sainfoin - 489.3.
When using perennial legumes as precursors of winter crops, it is necessary to use those species that leave behind the largest reserve of moisture in the soil: in the second year of growing season - white sweet clover - 57.6 mm in a 30-cm soil layer; the third year - sandy sainfoin - 81.1 mm; the fourth year - sandy sainfoin - 88.7 mm in a 30-cm soil layer and eastern goat's rue - 84.8 mm.