Phytomelioration as a factor of increasing fertility, productivity of crop rotation and improving soil moisture dynamics of southern black soil

Abstract

A new farming system has been proposed, which combines phytomelioration and minimization of primary tillage for saving the water-physical factors of southern black soil fertility and productivity of spring crops of early grain crops cultivated in field crop rotation. During the research, it has been found that minimization of tillage during a crop rotation that includes 3 years of using the alfalfa phytomeliorant contributed to longer preservation of soil fertility. It has been experimentally found that plowing on a layer of alfalfa increased air permeability by 53 %, and disk plowing by 171 %. The greatest permeability in the variant with minimal tillage was noted in case of soil overturning, which amounted to 112 mm/hour. During the first year after plowing into the phytomeliorant, the moisture content in the one meter thick soil layer increased by 0.8 % after plowing, and by 1.3 % after disk plowing. The highest increase in the soil moisture was noted in the third year - 1.3 - 1.5 %, which amounted to 18.2 - 21.0 mm of moisture. The yield of grain crops in case of minimal tillage in a crop rotation with the phytomeliorant exceeded the reference by 6.0 - 73.2 % in the first year, by 16.9 - 60.9 % in the second year, by 24.6 - 56.7 % in the third year after harrowing the soil after alfalfa, by 11.0 - 57.5 % in the fourth year, and by 10.9 - 44.0 % in the fifth year. In the plowed variants in field crop rotation, the after-effect of phytomelioration ended by the fifth year. The yield data for barley and oats were within the error of the experiment, compared to the reference variant (with the use of lentil instead of alfalfa). In the variants with minimal tillage, the productivity of barley increased by 16.3 %, and that of oats increased by 10.9 % in the fifth field of crop rotation, compared to the reference. In the sixth field, after tillage of an alfalfa field in the variant with the use of conventional dump tillage in crop rotation, the productivity of spring cereals was lower by 7.1 - 16.1 %, compared to the reference. The combination of phytomelioration and minimum tillage, the grain yield was the same as in the reference.