Redistribution of particle-size fractions in ordinary chernozem affected by long-term irrigation and chemical melioration with phosphogypsum

Abstract

The article reveals the issue of redistribution of particle-size fractions in ordinary low-humus leached chernozem on loamy loess in the condition of Northern Steppe of Ukraine affected by the irrigation with II class water and chemical melioration with phosphogypsum. Rather long use of water for irrigation from the reservoir on the Samara River in the Dniprovskyi district of the Dnipropetrovsk region deteriorated the soil properties due to salinization development in it, which led to the use of phosphogypsum. The calculated application rates of phosphogypsum 1,4 t/ha, 3 t/ha and 6 t/ha were applied along with irrigation and without it. The effect of chemical melioration and irrigation on the ecological and ameliorative condition of soil that resulted in the change of its particle-size composition, bulk density and structure was studied. 
 It is established that irrigation of the soil with an average irrigation rate of 1500 m3/ha reduces the content of physical clay by 0,12-0,06% compared to the options without irrigation. When applying phosphogypsum along with irrigation there are minor changes in the redistribution of particle-size fractions: an increase in the fractions of physical sand and a decrease in the fractions of physical clay. It was determined that the particle-size composition of soil is more resistant to the effect of phosphogypsum rather than to the effect of irrigation. 
 In non-irrigated variants when applying chemical melioration with phosphogypsum, the content of physical sand increases by 0,54-0,91% compared to the reference variant and the content of physical clay decreases by 0,87-1,13%. With increasing the rate of phosphogypsum, the content of physical sand also increases. The effect of improving the structure and loosening of the soil is observed in the variants where phosphogypsum at the rate of 6 t/ha was applied under the main tillage and at the rate of 3 t/ha under spring cultivation.

Prevention of degradation processes of soils irrigated with mineralized water through plastering

“…This causes uncontrolled irrigation both in terms of norms and quality of irrigation water. Previous experiments proved that watering with water suitable for irrigation can also have a negative effect on the physical, mechanical and other properties of soils (Makarova et al, 2020). As for water that is limited for irrigation, its influence on the salt and exchange composition of the soil is much stronger compared to irrigation with fresh water.…”

“…According to the results of scientific research conducted in the conditions of the Northern Steppe of Ukraine, the peculiarities of the degradation processes occurring in irrigated soils were established, which are determined by the quality of irrigation water, initial physical properties of soils, anti-saline buffering capacity, depth of occurrence and mineralization of groundwater (Makarova et al, 2020).…”

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“…This causes uncontrolled irrigation both in terms of norms and quality of irrigation water. Previous experiments proved that watering with water suitable for irrigation can also have a negative effect on the physical, mechanical and other properties of soils (Makarova et al, 2020). As for water that is limited for irrigation, its influence on the salt and exchange composition of the soil is much stronger compared to irrigation with fresh water.…”

“…According to the results of scientific research conducted in the conditions of the Northern Steppe of Ukraine, the peculiarities of the degradation processes occurring in irrigated soils were established, which are determined by the quality of irrigation water, initial physical properties of soils, anti-saline buffering capacity, depth of occurrence and mineralization of groundwater (Makarova et al, 2020).…”

Utilization of phosphogypsum from industrial dumps as an element of environmentally safe energy- and resource-conserving technologies

“…There are several long-range directions for its further use in various sectors of the economy. It stands to mention the effectiveness of using phosphogypsum as an ameliorant in agriculture [4][5][6] to improve the condition of the soil cover and as a bonding agent in the construction industry [7][8][9].…”