Influence of reclaimed water and tap water mixed irrigation and a water-retaining agent on yield and quality of feed sweet sorghum

Reclaimed and tap water mixed irrigation experiments on feed sweet sorghum (Sorghum dochna) were conducted in the Ordos region. The effect of using a water-retaining agent (30 kg·ha-1) under 75% and 50% of the normal irrigation amount were studied, and the yield, crude protein, neutral detergent fiber, acid detergent fiber, and soluble sugar contents were compared to determine the most efficient ratio of reclaimed and tap water irrigation. The result showed that under 75% normal irrigation (+PAM), the yield of sweet sorghum (26.89 t·ha-1) was 39.68% higher than that under the ratio of reclaimed and tap water and pure tap water irrigation of 2∶1. Compared with the 1∶1 irrigation ratio of reclaimed and tap water with only tap water irrigation, the CP and SS contents increased by 9.7% and 12.9%, respectively, whereas the NDF and ADF contents decreased by 4.8% and 7.3%, respectively.