Tuesday, July 31, 2012
Grand Ballroom
Wyoming is a major producer of coal bed methane. In the methane production process, large amount of waste water, also known as coal bed methane water (CBMW), is pumped out and need to be disposed of. The CBMW quality varies across the state; however, the major issues are its high salt content and high sodium adsorption ratio (SAR). The objective of this controlled environment pot experiment was to evaluate the effect of different rates of CBMW on productivity, essential oil yield, composition, and bioactivity of Japanese mint (Mentha canadensis L. = M. arvensis L.), grown on two different soil types (lowland and upland). The CBM water treatments were 0 (control), 25%, 50%, 75%, and 100%, the rest of the water was tap water. Overall, increasing rates of CBMW treatments increased soil pH, soil EC, SAR, and S. The application of CBMW increased significantly the accumulation of S and Na in plant tissue, and reduced fresh yields in the lowland but not in the upland soil. The essential oil content within a soil type was not affected by the CBMW treatments. However, the essential oil content was greater in the 75 and 100% CBMW treatments in the upland soil compared to the 75% CBMW lowland soil type. Menthol concentration in the oil was reduced at 50% CBMW treatment relative to the control and at the 100% CBMW. The soil type also affected menthol concentration of the essential oil. Results indicate that CBMW can be used for irrigation of Japanese mint in Wyoming. However, yield reduction may occur in some soils if CBMW application exceeds 50% of the crop water needs.