Assessment of Soil Salinity and Suitability of Well Irrigation Water in Babylon, Iraq, Using Geomatics

Abstract

    Geomatics techniques provide a realistic quantitative and descriptive view of soil salinity, with the ability to spatially predict the suitability of well water for irrigation using Kriging. This procedure showed that 37.77% of the soils in the study area fall within the S0 soil class, which is not significantly affected by salinity. These are mostly agricultural soils located near surface water sources, meaning they rely on groundwater resources only during periods of severe drought and for a limited time. Additionally, the high percentage of morphologically non-saline soils (43.21%) is attributed to the presence of salt-tolerant field crop varieties within the lower limits of the S1 class. Saline areas are typically found at the edges of agricultural fields, adjacent to main and secondary drains. Soils affected by salinity and gradually transforming into slate are located in areas far from main irrigation canals and rely primarily on saline well water. This study concluded that only 42.66% of the moderately suitable water can be used in extreme necessity and during droughts, with the requirement for leaching. Soils when suitable good surface water is available. Poor and very poor ratios are a serious indicator of the possibility of salinization and degradation of the soils located above them. The unsuitability of this water for irrigation may be attributed to its higher salinity than its alkalinity due to the ionic composition of the groundwater with a high concentration of calcium and magnesium in limiting the activity of groundwater alkalinity.