JOURNAL OF FOOD AGRICULTURE & ENVIRONMENT, cilt.9, sa.1, ss.648-652, 2011 (SCI-Expanded)
This work was carried out in Akarsu Irrigation District (AID) of 9495 hectares, having irrigation and drainage networks for about 50 years in Lower Seyhan Plain (LSP). The farmers in the district use the traditional surface irrigation systems of low irrigation efficiency. Drainage and groundwater salinity problems developed due to mismanaged irrigation systems, low irrigation efficiency, heavy soil texture, inadequate drainage systems and other likely problems which all cause reduced agricultural production. The undertaken work investigated interrelations between the existing irrigation practice with groundwater depths and salinity, using groundwater observation wells. With additionally installed drainage observation wells, a total of 107 wells were under survey in 2006. The groundwater depths were measured in May, July and September, and samples were collected concurrently for measuring electrical conductivity (EC, dS m(-1)). The groundwater depths in May showed that there was no drainage problem in the area. However, drainage problem (groundwater depth < 1 m) was evident during high irrigation season in July. Mean groundwater salinity in May, July and September was respectively 4.3 +/- 10.1, 2.8 +/- 4.3 and 3.4 +/- 5.0 dS m(-1). The area with high threshold groundwater salinity (EC > 5 dS m(-1)) in May, July and September was respectively 24%, 14% and 21% of the total area. Field irrigation efficiency and irrigation water use efficiency, assessed during the mentioned periods, were respectively 20% and 29%. The high groundwater salinity observed during the peak irrigation season in July was attributed to wide spread practice of excess irrigation resulting in both low field irrigation efficiency and low irrigation water use efficiency. Improvement of existing irrigation management is required for solving the mentioned problems observed in the study area.