Relationship between groundwater table depth, groundwater quality, soil salinity and crop production

Abstract

This technical report presents the first results of the study that looks at how intensive irrigation and rising groundwater tables have increased soil salinity. It assesses the current state of groundwater levels, groundwater and soil salinity, irrigation and drainage practices and their combined impact on crop production and soil salinization. Salinity problems are most observed in central and southern Iraq where the alluvial plain has become a discharge area for saline ground water. While large scale salt accumulation is the result of soil evaporation, salinity may have been caused by intensive irrigation and rising groundwater table due to high seepage losses from canals and irrigated fields. The slight slope of the river plains and the low rainfall limit natural drainage. As a result, salts from the irrigation water of some millennia have accumulated in the topsoil. To this end, cropping patterns and selected yields were examined; soil properties and quality of irrigation and ground water quality in Mussaiab and Dujailah were also analyzed.