Managing Saline-Sodic Cotton Soils Using S Burner Treated Irrigation Water.

Cotton is a major crop in the El Paso County located in west Texas. El Paso County is a part of the Chihuahua desert and has an extremely arid climate. Agriculture is highly dependent on irrigation and major sources of irrigation water are the Rio Grande River and the groundwater. Both the river water and the groundwater have elevated salinity and soils in cropped area are fine textured with smectitic clay. Long term irrigation with saline water on fine textured soil has resulted in elevated salinity and sodicity in the root zone. Although cotton is considered as a salt tolerant crop, the salinity levels in the root-zone are above its threshold, which has resulted in reduction in yield levels. Leaching of salts is problematic because of sodium hazard that has reduced the permeability of soil profile. However, these cotton soils contain up to 10% of calcite (CaCO₃) by weight in the upper 1 m depth. Thus it may be possible to utilize native Ca sources to improve soil permeability and reduce soil salinity. This study evaluated the effectiveness of S burner treated water to manage root zone salinity in a cotton field. Changes in spatial distribution of salinity and sodicity in the effective root-zone (upper 75 cm) were examined using the electromagnetic induction (EMI) technique. Results indicated that the pre-study EC_e and SAR in upper 75 cm at the study site ranged from <1 to 13 dS m^-1 and 12-21, respectively. After one year of irrigation with S burner treated water both EC_e and SAR values declined but the values in remained above the threshold in worst affected parts of the field. Results of this study indicated that S burner technique has the potential to reduce sodicity and salinity of cotton fields over long term