Effects on Soil Salinty of a Dryland Winter Wheat or Cotton Rotation in Irrigated Texas Cotton.

Irrigation in semi-arid environments frequently elevates soil salinity, reducing crop production and requiring salinity management practices especially when irrigation water is high in salt species.   Traditional salinity management practices involve leaching salts below the root zone with additional or high quality irrigation water.   Leaching salts in the soil profile above the subsurface drip irrigation (SDI) tubing is not possible and SDI irrigation practices have resulted in elevated soil salinity and reduced yields in west Texas cotton production.  Salt levels are highest near the soil surface where evaporation deposits salts and causes problems with cotton seedling germination and establishment.   Soil testing in SDI irrigated cotton fields near Midkiff, Texas showed annually increasing salinity levels with annual irrigation.   A cropping system rotation of dryland cotton and winter wheat was evaluated in 2014-2016 to determine the effect on soil salinity.  Both dryland cotton and winter wheat resulted in reduced conductivity, nitrate – nitrogen, sodium, and other cations. Salt removal by wheat stover was also evaluated.