Book Description

Coal bed methane is a highly used natural gas extracted from coal seams. Its production has greatly increased in the last 25 years. The U.S. is the top producer of coal bed methane in the entire world, and produced around 41.51 billion m3 in the year 2013. Coal bed methane production also releases large volumes of co-produced water or coal bed methane water (CBMW) to the surface. Due to its chemical properties this water is sometimes considered disadvantageous for soil and environment but if properly managed and used CBMW also have some beneficial effects. There are a number of research studies that show a positive impact of CBMW on crop production especially in Wyoming. Properties of CBMW vary greatly. CBMW produced in Wyoming’s Powder River basin is considered better for irrigation compared to CBMW produce in other states, but still most of the CBMW produced in this area is either re-injected back or discharged to the surface. Using CBMW produced in Wyoming for irrigation of various crops would address the problem of fresh water scarcity, leading to increases in production and also contributing towards beneficial disposal of this water. Hence the objective of this thesis was to conduct field and greenhouse studies on various crops to determine short and long term impact of CBMW on various bio-fuels, forage, and medicinal crops. Three separate research studies were conducted to meet the desired objectives. Two studies were conducted in the greenhouse and one in the field. The first greenhouse study was to determine the effect of different doses of CBMW on plant biomass, essential oil yield and essential oil content of dill and wyoming big sagebrush. Treatments consisted of 0% CBMW (tap water only), 25% CBMW (25% CBMW, 75% tap water), 50% CBMW (50% CBMW, 50% tap water), 75% CBMW (75% CBMW, 25% tap water) and 100% CBMW. The experiment was carried out as completely randomized design with 6 replications. After the study, plant biomass was determined for both crops. Distillation was carried out only for dill as sagebrush did not yield sufficient biomass. Soil sampling was also carried out. Results revealed, plant biomass and essential oil content of dill to be statistically similar in all the treatments, but there were changes seen in some of the constituents of essential oil. For sagebrush fresh plant biomass and plant height was maximum at 0% CBMW treatment and reduced significantly on 25% CBMW treatment, but did not reduced further on 50%, 75% and 100% CBMW treatments. The second greenhouse research was to determine forage yield and quality of oat and alfalfa grown on various concentrations of CBMW. Treatments consisted of different doses of CBMW, as done previously. A similar experimental design was followed. Yield of forages were compared using regression, and forage quality was compared using fisher least significant difference. After the study fresh and dry biomass was determined for both crops. Forage analysis was also carried out for forage quality. Results demonstrated, a gradual decrease (21-33% for alfalfa and 10–16% for oat) in fresh biomass for both crops with increasing concentration of CBMW treatments but their forage quality remained unchanged. A field study was conducted to determine long term possibility of growing wormwood, switchgrass, native spearmint, japanese cornmint, alfalfa, and brome grass receiving CBMW as irrigation. Selected field plots had been receiving CBMW treatment for two consecutive years and similar treatment was applied in the third year. Experimental design was randomized complete block design (split plot in space) with 4 replications and 2 factors (water treatment and crops). Crops were harvested at various times and their fresh and dry weight was determined. Oil crops were distilled and forage quality analysis was carried out for forage crops. Results demonstrated that CBMW did not have any impact on crop biomass, oil yield or forage quality, which was confirmed by p-value from the ANOVA table. The above studies demonstrate the possibility of using CBMW for irrigation of various crops. However, various soil qualities (e.g. pH, electrical conductivity etc.) in both field and greenhouse research were significantly affected by the application of CBMW and therefore need to be considered before application.