Irrigation effects of cooling tower effluent on soil chemistry and alfalfa in the Rio Grande river basin

Abstract

Development of alternative sources through wastewater reuse is important to meet water demands in arid regions. However, effects of wastewater irrigation on soil properties and crop performance must be evaluated before advocating its widespread use. Objectives of this study were to evaluate: (i) effects of prior evaporative disposal of saline-sodic blowdown water (BW) on soil (fine-loamy, mixed, and thermic Typic Calciorthods) properties in the disposal area, and (ii) effects of flood irrigation with three water qualities (control, BW 1X, and BW 2X) on soil salinity and alfalfa performance using a greenhouse soil column study (soil collected from same study area as objective (i)). Results indicated that although prior land disposal of BW had increased salinity and sodicity of soil, they were within the tolerance limits of the intended crop, alfalfa. Mass balance calculations indicated measured (15Á6 Mg ha À1 ) and calculated (13Á2 Mg ha À1) salt accumulation at the test site used for evaporative disposal were similar. Alfalfa grown using BW under greenhouse conditions produced prime quality hay and biomass yield similar to the control treatment (8Á3 g column À1 vs. 10Á5 g column À1 in control). Although 3Á6 years equivalent of flood irrigation with BW 1X did not result in saline soil (BW 1X irrigated soils EC ranged from 2Á2 to 3Á5 dS m À1 ), BW 2X irrigation resulted in saline soils. Sodicities of irrigated soils were greater in fine textured deep soils than coarse textured surface soils (e.g., SAR of 6Á1 at 0-5 cm vs. 19Á5 mmol 1/2 L À1/2 at 30-60 cm in BW 1X), indicating the need for high solubility Ca amendments for long-term irrigation with BW on fine texture soils within the soil profile.

Soil Property Changes Following Irrigation With Coalbed Natural Gas Water: Role of Water Treatments, Soil Amendments and Land Suitability

“…CBNG(GSB)+GS had a significantly greater infiltration rate (33·5 cm h −1 ) than that of all CBNG-water and soil amendment combinations. Greater infiltration rates of the CBNG(GSB)+GS treatment could be due to better soil permeability as a result of greater Ca 2+ availability because of solubilization of in-situ calcite/ applied gypsum, and acidification of CBNG water that reduced Ca 2+ precipitation as CaCO 3 (Bauder and Brock, 1992;Hillel, 2000;Lebron et al, 2002;Ganjegunte et al, 2010).…”

Soil Salinity and Sodicity Appraisal by Electromagnetic Induction in Soils Irrigated to Grow Cotton

“…Most of the irrigated area is located in the valley and has fine-textured soils within the effective crop root zone. Long-term irrigation with saline water has led to serious soil salinity problems in many irrigated regions (Wittler et al, 2006;Eldeiry and Garcia, 2008;Ganjegunte et al, 2011aGanjegunte et al, , 2011b. Soil salinity reduces the availability of water, selected plant nutrients, and increases the toxicity of certain ions, whereas soil sodicity decreases the permeability of soils (Ganjegunte and Vance, 2006;Ganjegunte et al, 2008;Vance et al, 2008).…”

Salinity Management Using an Anionic Polymer in a Pecan Field with Calcareous-Sodic Soil

“…Study site soils contained appreciable amounts of native Ca in the form of gypsum and calcite, which could have contributed to increased Ca in soil solution. We hypothesize that improved hydraulic conductivity as a result of PAM application helped in solubilizing some of the native Ca minerals, which in turn resulted in increased Ca concentrations in the soil solution (Ganjegunte et al, 2010). Increased Ca in soil solutions will result in greater penetration of irrigation water deeper into the soil profile and this in turn will reduce soil SAR values at different depths.…”