SOIL MOISTURE DYNAMICS AND SAFFLOWER PRODUCTIVITY IN THE CONDITIONS OF HYDROTHERMAL TENSION AND AGROTECHNICAL LAND RECLAMATION
In the conditions of hydrothermal climate tension, in order to control production processes on intensively used agrolandscapes, it is necessary to use highly profitable stress-resistant crops and agrotechnical land reclamation in crop rotation, aimed at intensive accumulation of productive moisture reserves and their loss reduction during evaporation from the soil surface. In the South-East of Russia field studies on light-chestnut saline soils were done to study the dynamics of soil moisture and responsiveness of safflower of Alexandrit variety to different depth methods of basic soil treatment and sewage sludge application as a fertilizer-meliorant. It was found that the largest productive moisture reserves in the soil layer of 0.0-0.4 m at the level of 822 and 855 m 3· ha -1 at the beginning of safflower sowing were formed in the variants with chisel dump plowing vs 722 and 776 m 3· ha -1 in the variants with moldboard plowing, as well as vs 677 and 726 m 3· ha -1 in the variants with disk plowing at comparable doses of 5 and 10 t ha -1 of soil mulching with sludge sediment. In accordance with the productive moisture reserves the valuesof safflower evapotranspiration were determined, maximum of which was in the variant with chisel dump plowing and, depending on the doses of fertilizer-meliorant, amounted to 3211-3422 m 3· ha -1 in 2016, 2647-2731 m 3· ha -1 in 2017 and 1579-1639 m 3· ha -1 in 2018. The total water consumption of the crop was lower by 4.0-5.6% and 5.2-8.0%, respectively, in the variants with moldboard and disk plowing. The evaluation of the agrotechnical land reclamation measures that provided safflower crops with available moisture, depending on the moisture content of the year, clearly demonstrates the positive impact of chisel dump plowing and doses of sludge sediment application on crop productivity. Its increase over the years of the study at different doses of sludge sediment application relative to the control variant with moldboard plowing and without fertilizer-meliorant ranged from 0.06 to 0.29 t · ha -1 (least significant difference criterion (LSD) = 0.01-0.02 t · ha -1 ) or 4.8-23.7% (LSD = 1.08-1.23%). The reliability, materiality and significance of the research results are proved by dispersion analysis.
Key words: safflower, crop yield, soil treatment, sludge sediment, productive moisture reserves, evapotranspiration, arid climate, agrotechnical land reclamation.