Investigating the physical and chemical properties of the soil of the main drains of the irrigation and drainage network in the Abbas plain

This research was carried out to investigate the physical and chemical properties of the soils obtained from dredging of the drainage drains in Abbas Irrigation channels in Ilam province. The area encompasses 16 thousand hectares. In this study sampling was carried out from two major branches. The drainage No. 1 with 21 km length, is flooded to the Rafahyeh river and drainage No. 2 with 5 km length is flooded to the Chikhab River. Sampling was done from drainage soil, dredged soil and the arable land around drainage. A comparison was performed between the three regions of drainage floor area, drainage agricultural land and dredged soil. Soil physico-chemical properties such as particle and bulk density, potassium, magnesium, sodium, calcium and phosphorus, carbonate and bicarbonate, sodium absorption ratio, exchangeable sodium percentage, organic matter, organic carbon, cation exchange capacity, sulfate, base saturation percentage and nitrogen. The results showed that the amount of potassium in dredged soil is more than recommended for soil. Phosphorus concentration was also higher than recommended for soil. Sodium, magnesium and calcium was lower than soil recommended levels. Due to the presence of calcareousmaterial,the amount of limein soils washigh and the amount of gypsum was high as well, due to the warm and dry climate and low rainfall. Soil pH of the region was mostly higher than 7 so they are categorized as alkaline and semi-alkaline soil. The studied soil is classified as saline soil due to high electrical conductivity.Soil texture was sandy clay loam.