Impact characteristics of reclaimed water irrigation on the growth rate, chlorophyll and cartenoids contents of lawn grasses

In order to save the clean water resources for the purpose ofexpanding the utilization of reclaimed waterand insuring good quality of lawn, the impact characteristics of reclaimed waterirrigation on the growth rate andchlorophyll contents of Poa Pratensis were studied. Seven irrigation treatmentswere conducted: proper irrigation withfresh water, proper irrigation with 1∶1 proportion of fresh and reclaimed water, full irrigation with reclaimed water,proper irrigation with reclaimed water, light water stress irrigation with reclaimed water, medium water stressirrigation with reclaimed water, severe water stress irrigation with reclaimed water. The irrigation start-points were 70%fc(field water capacity), 70%fc, 80%fc, 70%fc, 60%fc, 50%fc, 40%fc, respectively. For seven treatments,irrigation amount for an irrigation event was the same. The experimental resultsshow that the differences on the lawn grass growth rate were remarkable among the treatments under different irrigated water qualities. The growth rate of lawngrass irrigated with reclaimed water was larger than that of lawn grass irrigated with fresh water. The positive correlations were found between the reclaimedwater supply and the growth rate of lawn grass. The chlorophyll contents and thecartenoids contents of lawn grass irrigated with reclaimed water were significantly higher than those of lawn grass irrigated withfresh water. The contents of the chlorophyll and cartenoids had no significant difference among the different water supply treatments irrigated with reclaimed water.