Reclamation of Calcareous Saline Sodic Soil Properties and Improvement of Wheat Growth Using Different Industrial Byproducts, Chemical, and Organic Amendments.

A greenhouse experiment was conducted to investigate the comparative efficacy of different chemical, industrial byproducts and organic soil amendments in calcareous saline sodic soil reclamation. Soil amendments used included gypsum (G), sulfur (S), ferrous sulphate (FS), pyrite (P), and langbeinite (L) (soluble potassium-magnesium sulphate mineral). Industrial byproducts used were water treatment residual (WTR) (by-products from the production of potable water), spent lime (SL) (byproduct from sugar purification process), and thinstillage (TS) (byproduct from alcohol distilleries). The amendments were added to calcareous saline sodic soil collected from Wamsutter, WY (CaCO₃ = 6.7 %, electrical conductivity (EC) = 12.2 dSm⁻¹, exchangeable sodium percentage (ESP) = 31.7 %, and soil pH = 8.5). All amendments were applied alone or in a combination with compost (C). Gypsum, sulfur, ferrous sulphate, and pyrite were applied at equivalent rates of gypsum requirements for treating sodic soil. Whereas, application rates of water treatment residuals, spent lime, langbeinite and thinstillage were evaluated using a batch study experiment. Compost application rates were calculated to increase soil organic matter by 1%. In three replicates, treatments were applied to the soil, filled in soil pots, and then incubated in the field capacity moisture and a constant temperature at 25 C^o for one month. After incubation period, 15 wheat plants per pot were seeded, and watered weekly with distilled water. After 5 weeks of sowing, the wheat was harvested by cutting it at soil level and the biomass yield was recorded. The results demonstrated that the yield biomass of TS and TS+C significantly increased compare to the control; the increased was 6.5 times more than control, and 2.3 times more than gypsum. The yield of all treatments followed the order: TS>TS+C>SL>P+C>S>S+C=WTR>SL+C>G+C=P>C>FS+C>G>WTR+C>FS>L+C>L>Ctrl.