Coal‐Bed Methane Water Effects on Dill and Its Essential Oils

• Published in: Journal of environmental quality 2016-03, Vol.45 (2), p.728-733
• Main Authors: Poudyal, Shital, Zheljazkov, Valtcho D., Cantrell, Charles L., Kelleners, Thijs
• Format: Article
• Language: English
• Subjects: Agricultural Irrigation; Anethum graveolens; Coal; Methane; Oils, Volatile; Soil
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2015.05.0215

Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic method of methane extraction. The water that is pumped out is known as “coal‐bed methane water” (CBMW), which is high in sodium and other salts. In the past 25 yr, the United States has seen a 16‐fold increase in the production of coal bed methane gas, and trillions of cubic meters are yet to be extracted. There is no sustainable disposal method for CBMW, and there are very few studies investigating the effects of this water on plants and their secondary metabolites and on soil properties. This study was conducted to determine the effects of CBMW on soil chemical properties and on the biomass and essential oil yield and composition of dill (Anethum graveolens L.). This crop was grown in a greenhouse and was subjected to different levels of CBMW treatment: tap water only; 25% CBMW, 75% tap water; 50% CBMW, 50% tap water; 75% CBMW, 25% tap water; and 100% CBMW. The major dill oil constituents, limonene and α‐phellandrene, were not affected by the treatments; however, the concentration of dill ether increased with increasing CBMW levels, whereas the concentration of carvone decreased. In soil, sodium level significantly increased with increasing level of treatment, but pH and cation exchange capacity were not much affected. Coal bed methane water could be used for irrigation of dill for one growing season, but longer‐term studies may be needed to clarify the long‐term effects on soil and plant. Core Ideas Coal‐bed methane production results in coproduced waste water, also called CBMW. Sustainable disposal of CBMW is a challenge. We determined the effect CBMW on soil and on the biomass and essential oil composition of dill. CBMW increased dill ether but reduced carvone in the oil; biomass and oil yields were not affected. CBMW increased electrical conductivity and Na but not pH or cation exchange capacity.