Salt Regime of the Manych Valley Chestnut-Solonetz Soil Complexes

Indicators of optimal soils conditions for crop growing and preserving soil fertility in Rostov region and North Caucasus under irrigation conditions

“…Developing an optimal soil fertility management system, first of all requirements of the objective law of continuous, increasing soil fertility should be taken into account, as well as the laws of nutrient return to soil; the interaction of plant growth and development factors; minimum, etc. Only a comprehensive requirements consideration of these basic laws allows to develop an optimal soil fertility management system aimed at their fertility reproduction and constantly increasing agricultural productivity [5,11].…”

“…Due to unfavorable water-physical and physicalchemical parameters, it is within rather narrow limits: on neutral salt licks from about 20 to 25, on soda 16-21%. The upper limit of the sodium content in the soil absorption complex, providing optimal conditions for the development of crops is in a range of 5-10% [5,9]. Signs of soil salinity are enhanced when magnesium prevails over calcium more than twice and the sodium content exceeds 5% of the absorption capacity Soils of salsuginous complexes in relation to the predominance of the alkaline reaction of the soil solution in them, they differ in the unsatisfactory structural state of the arable and subsurface horizons.…”

“…With a content of 0.1-0.2% HCO 3 and at pH of 9.5-10.0, crop plants usually die. With chloride salinization, noticeable inhibition begins when the chlorine ion content is 0.04-0.08% [5,9].…”

“…Under irrigation conditions, these soils caused the secondary soils salinization. Due to the salts redistribution by irrigation groundwater, they underwent secondary alkalization (soda salinization) and salinization [5,12].…”

“…In relation to agricultural plants, the optimal soils properties should be considered such a combination of their quantitative and qualitative indicators that can maximize the use of all vital factors for plants and maximize the crops potential in their highest quality harvest [1,5].…”