Land degradation
The territory of Marksovsky district is located in the zone prone to land degradation and which after FAO classification is a zone of very high land degradation. After Kust, 2002 research of land degradation indicators and processes mapping in South region of Russia in this zone, the main degradation process is soil alkalinisation at used space scale.
From a scientificpoint of view a major land degradation problem in this area is caused mainly by long time irrigation system used since their construction from 1960th which provoked a ground water table rising originated by overdoses of water application for irrigation. By consequences the ground water rising provokes (1) water logging of irrigated and surrounding of irrigated areas causing change of soil water regime from semi-arid to semi-humid, (2) a secondary soil salinization due to dissolution of salt crystals stoked in the ground layers of vadose zone and lifting them to the upper root zone creating toxic conditions for plants and augmenting a soil water osmotic pressure leading to diminishing of interval of available for plants water in soil, (3) soil organic matter content diminishing due to soil layer washing, which leads to soil compaction, damage of soil structure, worsens hydraulic conductivity and water retention capacity and other soil parameters.
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Sprinkler installations |
Irrigation Channel |
From the land users' point of view a high groundwater level, not uniform pattern of soil fertility and extensive weed growth are consequences of extended irrigation of former time that in some areas are still maintained. Thus, the main degradation type of irrigated fields and surrounding territories are chemical soil deterioration, i.e. salinization: a net increase of the soluble salt content at the plant root zone leading to a productivity decline.
