|Ulery, A. - U.C. RIVERSIDE|
|Ernst, F. - U.C. RIVERSIDE|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 29, 1996
Publication Date: N/A
Interpretive Summary: A field experiment was conducted to determine if undiluted saline wastewater from the cooling towers of an electrical power generation plant could be used to grow sorghum. The plants were sprinkled with saline water at three stages of growth to determine the best management strategy for utilizing wastewater while maintaining relatively high grain yields. The highest yields were obtained from the plots that received pure water throughout the growing season, or at least in the germination to reproductive growth stages. Thus plants that were irrigated with the salty wastewater late in the season, after booting, had fairly high yields. Plant height was an early indicator of salt stress and was noticeably shorter in the saline plots. Soil salinity resulted in both plant height and grain yield decreases. We showed that with the proper management in hot, dry regions with sandy soils and deep groundwater tables, saline wastewater could be used to grow crops instead of being stored in evaporation ponds or disposed of in rivers.
Technical Abstract: Saline wastewater from industrial or agricultural sources may be an alternative irrigation supply in arid regions if effective crop and water management strategies for their use are developed. A field experiment was conducted to determine if grain yields of sorghum [Sorghum bicolor (L.) Moench] irrigated with undiluted saline wastewater from cooling towers of an electrical power generation plant can be significantly increased by applying nonsaline water at a critical growth stage. The wastewater had an average EC of 0.67 S m-1 and was high in CaSO4. Plot studies were conducted for four years using conventional cultural practices and sprinkler irrigation on a mixed, thermic Typic Xeropsamment classified as Tujunga loamy sand and Hanford fine sandy loam. Highest grain yields were obtained from the nonsaline control plots and from treatments that received nonsaline water during either the vegetative or reproductive growth stages. Plant height decreased in response to salinity and differences between treatments were apparent by 27 days after planting. Plant height, grain yield, and soil salinity were all correlated by the third year of the experiment.