Wednesday, November 7, 2007 - 9:30 AM
304-1
The Use of Gypsum to Remediate Salt Affected Soils on Cotton Production on the Southern High Plains.
The purpose of this project is to reduce the exchangeable sodium within the soil by the addition of gypsum. Even though the addition of gypsum is the standard reclamation technique used on sodic soils, the effectiveness has not been shown for cotton production on the Southern High Plains. Exchangeable sodium disperses the soil, which increases the potential for wind erosion as well as the formation of a salt-based crust. The addition of gypsum to sodic soils improves the aggregation of the soil particles. The subsequent addition of calcium improves particle to particle association, which increases water infiltration and percolation. A flocculated soil allows water to move more easily through the profile which increases the chance of leaching the sodium out of the rooting zone and decreases crusting. The accepted rate of gypsum for this study to reduce the sodium adsorption ratio and soil electrical conductivity is approximately 4.5 mega grams per hectare. Rates half and twice the needed rate were applied in a split plot design. The application of gypsum to the soil was broadcast and “in-row.” Plant emergence was taken for 14 consecutive days after planting and yield was used to measure the effectiveness of the gypsum application. Standard wind erosion measurement techniques were used to measure gypsum’s effects on reducing wind erosion. The emergence of the cotton in all treated plots was lower than the emergence of the cotton in the control plots. The yields for all rates and methods of gypsum application were also lower than the control.
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