Effects of produced water on soil characteristics, plant biomass, and secondary metabolites

Authors: BURKHARDT, ANDY - University Of Wyoming; GAWDE, ARCHANA - University Of Mississippi; Cantrell, Charles; BAXTER, HOLLY - University Of Tennessee; JOYCE, BLAKE - University Of Tennessee; STEWART, JR., C. - University Of Tennessee; ZHELJAZKOV, VALTCHO - University Of Wyoming

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2015
Publication Date: 11/6/2015
Publication URL: http://handle.nal.usda.gov/10113/62573
Citation: Burkhardt, A., Gawde, A., Cantrell, C.L., Baxter, H.L., Joyce, B.L., Stewart, Jr., C.N., Zheljazkov, V.D. 2015. Effects of produced water on soil characteristics, plant biomass, and secondary metabolites. Journal of Environmental Quality. 44:1938-1947.

Interpretive Summary: The Powder River Basin in Wyoming and Montana contains the United States’ largest coal reserve. The area produces large amounts of natural gas through extraction from water-saturated coalbeds. Determining the impacts of coalbed natural gas-produced efflux water on crops is important when considering its potential use as supplemental irrigation water. We hypothesized that coalbed natural gas water, because of its high salinity and sodicity, would affect essential oils and growth. A 2-yr field study was conducted in Wyoming to investigate the effects of produced water on two traditional bioenergy feedstocks—corn and switchgrass and four novel biofuel feedstock species—spearmint, Japanese cornmint, lemongrass, and common wormwood. The four nontraditional feedstock species were chosen because they contain high-value plant chemicals that can offset production costs. Essential oil content was significantly affected by coalbed natural gas water in lemongrass and spearmint. Oil content differences between two spearmint harvests in the same year indicated that there were significant changes between the growth stage of the plant and essential oil content. Results indicated that produced water can be used for short-period (2 yr) irrigation of crops. However, prolonged use of untreated produced water for irrigation would likely have deleterious long-term effects on the soil and plants unless the water was treated or diluted (mixed) with good water.

Technical Abstract: The Powder River Basin in Wyoming and Montana contains the United States’ largest coal reserve. The area produces large amounts of natural gas through extraction from water-saturated coalbeds. Determining the impacts of coalbed natural gas-produced efflux water on crops is important when considering its potential use as supplemental irrigation water. We hypothesized that coalbed natural gas water, because of its high salinity and sodicity, would affect plant secondary metabolism (essential oils) and biomass accumulation. A 2-yr field study was conducted in Wyoming to investigate the effects of produced water on two traditional bioenergy feedstocks—corn (Zea mays L.) and switchgrass (Panicum virgatum L.)—and four novel biofuel feedstock species—spearmint (Mentha spicata L.), Japanese cornmint (Mentha canadensis L.), lemongrass [Cymbopogon flexuosus (Nees ex Steud.) J.F. Watson], and common wormwood (Artemisia vulgaris L.). The four nontraditional feedstock species were chosen because they contain high-value plant chemicals that can offset production costs. Essential oil content was significantly affected by coalbed natural gas water in lemongrass and spearmint. Oil content differences between two spearmint harvests in the same year indicated that there were significant changes between the growth stage of the plant and essential oil content; the first harvest averaged 0.42 g of oil per 100 g biomass while the second harvest (harvested before flowering) yielded only 0.19 g oil per 100 g dry biomass. Results indicated that produced water can be used for short-period (2 yr) irrigation of crops. However, prolonged use of untreated produced water for irrigation would likely have deleterious long-term effects on the soil and plants unless the water was treated or diluted (mixed) with good water.