Soil salinity, irrigation, rice
Soluble salts have been shown to accumulate in Arkansas soils in sufficient quantities to impair crop plant growth. The major objective of this study was to describe the behavior of soluble chloride salt over long time periods in Sharkey clay - a major Mississippi Delta soil. Prior to flooding rice, leaching of chloride in response to rainfall was observed. The inclusion of a sandy subsoil layer reduced this effect presumably by limiting downward movement of water under unsaturated conditions. No lateral movement of the chloride salt was found during the period prior to flooding. Removal of soluble chloride salts from the top 100 cm of Sharkey soil was complete in a 1-2 year period depending on weather conditions. In a year where the rice cropping season was followed by a wet winter, losses were smaller than in a year where the rice cropping season was followed by a drier winter. These results suggested that removal of soluble salts via leaching in this soil was more efficient under less saturated soil conditions.
Gilmour, J. T.; Baser, R. E.; Scott, H. D.; and Ferguson, J. A.. 1986. The Behavior of Soluble Salt in Sharkey Clay- II. Arkansas Water Resources Center, Fayetteville, AR. PUB 123. 25