METHODOLOGICAL AND ENVIRONMENTAL ASPECTS OF AGRICULTURAL CULTURES WATER REGIMES CALCULATION IMPROVEMENT

Abstract

Deficit of water resource in the country requires a careful approach to the use of irrigation water, adjusting the timing and rates of irrigation.Special place in solving these problems takes the issue ofsubstantiation of water consumption norms of crops and irrigationrates. When determining the irrigation rate of any crop, the mostsignificant factors are the wetting depth and the soil moisture limits that must be maintained. Traditionally, irrigation rates are determined by the lowest moisture capacity and the minimum of allowable water supply for plants. The article proved that irrigation norms of crops should be linked to the conditions of natural formation of soils and determined their value by the difference of rainfall during the growing season for very wet (probability <15%) and very dry (probability > 85%) years under the conditions of natural water supply. It is necessary to take into account the productive soil’s moisture at the beginning of the growing season. Therefore, irrigation rates should be determined not by the lowest moisture capacity and minimum of allowable water supply for plants, but by the optimal humidity of the soil with permissible marginal deviations of 5… 10% of the optimum value (for soil porosity). Using the proposed method for determining irrigation rates of crops will allow more efficient use of irrigation water within the field and maintain a satisfactory ecological and ameliorative state.