Assessing drainage water reuse options in Bojili Irrigation District, Shandong

Abstract

AbstractFor assessing the potential and need to reuse surface drainage and groundwater for sustainable crop production in the Shandong province of the Yellow River basin, inventories were made on the quality of alternative sources of irrigation and on the yields achieved by farmers using those waters for irrigation. Drainage and groundwater quality (EC < 2 dS m−1) in most parts of Huimin and Yangxin counties favors their use for irrigation but there can be some limitations in Wudy as the salinity increases towards the sea. Yield–soil salinity functions were developed for both maize and wheat; for the latter, functions depend upon the number of irrigations applied. Simulations using the SWAP model showed that yields of wheat and maize could be sustained with the reuse of drainage water having a salt content up to 4 mg cm−3. There is a clear benefit from using drainage water for the last two wheat irrigations relative to deficit irrigation despite water salinity. Monsoon rainfall should help to maintain a favorable salt balance, thus to avoid salt build‐up along the soil profile. Results indicate that the reuse of drainage waters offers opportunities for improving irrigation water management in wheat for areas facing water shortage. Copyright © 2006 John Wiley & Sons, Ltd.