Soil and Plant Responses from Land Application of Saline–Sodic Waters: Implications of Management

Abstract

Land application of co-produced waters from coalbed natural gas (CBNG) wells is one management option used in the Powder River Basin (PRB) of Wyoming and Montana. Unfortunately, the co-produced CBNG waters may be saline and/or sodic. The objective of this study was to examine the effects of irrigation with CBNG waters on soils and plants in the PRB. Soil properties and vegetation responses resulting from 1 to 4 yr of saline-sodic water (electrical conductivity [EC], 1.6-4.8 dS m(-1); sodium adsorption ratio [SAR], 17-57 mmol(1/2) L(-1/2)) applications were studied during 2003 and 2004 field seasons on sites (Ustic Torriorthent, Haplocambid, Haplargid, and Paleargid) representing native range grasslands, seeded grass hayfields, and alfalfa hayfields. Parameters measured from each irrigated site were compared directly with representative non-irrigated sites. Soil chemical and physical parameters, including pH, EC, SAR, exchangeable sodium percent, texture, bulk density, infiltration, and Darcy flux rates, were measured at various depth intervals to 120 cm. Multiple-year applications of saline-sodic water produced consistent trends of increased soil EC and SAR values to depths of 30 cm, reduced surface infiltration rates, and lowered Darcy flux rates to 120 cm. Significant differences (p < or = 0.05) were determined between irrigated and non-irrigated areas for EC, SAR, infiltration rates, and Darcy flux (p < or = 0.10) at most sites. Saline-sodic CBNG water applications significantly increased native perennial grass biomass production and cover on irrigated as compared with non-irrigated sites; however, overall species evenness decreased. Biological effects were variable and complex, reflecting site-specific conditions and water and soil management strategies.

Simulating the Fate and Transport of Coal Seam Gas Chemicals in Variably-Saturated Soils Using HYDRUS

“…Furthermore, SAR values greater than 13 pose a risk to the soil ecosystem [94]. Typical treatments to mitigate the effects of saline-sodic irrigation water include the addition of gypsum and elemental sulphur [21,98].…”

Effect of varying ratios of produced water and municipal water on soil characteristics, plant biomass, and secondary metabolites of Artemisia annua and Panicum virgatum

“…The continuously watered plants in both studies decreased forage yield due to water logging. Vance et al (2008) studied the soil physical parameters as well as plant diversity on range and crop land being irrigated with produced water. Sulfur burners have been used to decrease the pH of the water; however this did not decrease the amount of total dissolved solids, salts, or Na content of the water.…”

“…A recent boom in coal-bed methane production in the Powder River Basin of northeastern Wyoming has created large quantities of produced water from well sites; with total water production as of 11 February 2014 at 7.7 bcf (Wyoming Oil and Gas Conservation Commission, 2014). When used for irrigation, due to high sodicity and salinity, the water often has deleterious effects to the soil that must be managed (Vance et al, 2008). Produced water's effects on plants are less understood.…”

Land Application of Treated Industrial Wastewater on a Chihuahuan Desert Shrubland: Implications for Water Quality and Mineral Deposition

“…Vance et al (2008) suggested that a loss of grassland community diversity at Na-affected wastewater land application sites in semiarid Wyoming may limit the ultimate restorative potential of the land. Further research is needed to elucidate the edaphic changes resulting from effluent land application that may, in turn, regulate species productivity and diversity in semiarid ecosystems.…”