Remediation of Salt Affected Cotton Soils Using Gypsum on the Southern High Plains.
Quint Chemnitz, Texas Tech Univ, 1914 80th St, Lubbock, TX 79423, Wayne Hudnall, Plant & Soil Science, Lubbock, TX 79409, United States of America, and Richard Zartman, Texas Tech Univ-Plant & Soil Sciences Dept, PO Box 42122, Lubbock, TX 79409-2122.
The objectives of this study are to reduce exchangeable sodium (Na+) within the soil, increase germination rate, and increase cotton yield by the addition of gypsum. The addition of gypsum is the standard reclamation technique used on sodic soils, but its effects have not been shown in cotton production on the Southern High Plains (SHP). Exchangeable sodium disperses the soil, which increases the potential for wind erosion. The addition of gypsum to sodic soils is intended to improve the aggregation of the soil particles. The addition of Ca+2 will improve particle to particle association, which increases water infiltration and percolation. The rate most commonly used to reduce the sodium adsorption ratio (SAR) and soil electrical conductivity (EC) is approximately 2 to 3 tons per acre (http://waterquality.montana.edu/docs/methane/oster.pdf). Application rates of one, two, and four tons per acre were applied in a split plot design using broadcast and in-row application methods. Emergence at 14 days after planting and yield were used to measure the effectiveness of the gypsum application. The use of gypsum is being compared to a control (no conservation treatment) and a cover crop. Preliminary results indicate no significant benefit to plant emergence with the addition of gypsum. The control group performed as well, if not better, than the plots treated with gypsum. The study is on-going and the final results will not be available until yields have been analyzed.