灌溉水质对苜蓿生长和养分吸收的影响

采用盆栽试验研究了污水、再生水等不同灌溉水质对三次刈割期内苜蓿生长和养分元素吸收的影响。结果表明,相对于清水灌溉,再生水及污水灌溉可增加苜蓿的株高及产草量,但长期引用未经处理的污水灌溉不利于苜蓿根系的生长。第一次刈割时各灌溉处理间含钾量差异不显著,第二次刈割时污灌、再生水灌溉处理与清水灌溉相比苜蓿含钾量分别增加了33.05%和40.68%,第三次刈割时分别增加了12.90%和23.39%。污水及再生水灌溉处理苜蓿含钙量在第一次刈割时显著高于清水灌溉,但在第二、三次刈割时均低于清水灌溉。未经处理的污水不宜用作灌溉,采用混灌与轮灌方式可适当减缓其不利效应;再生水可作为苜蓿的灌溉用水,但其长期效应仍需进一步深入研究。

Effects of Irrigation Water Quality on Growth and Nutrient Intake of Alfalfa

Pot experiments were conducted to study the effects of different irrigation water treatments(sewage and reclaimed water) on Alfalfa growth and nutrient intake.The results indicated that sewage and reclaimed water increased stem length and yield comparing with the treatment of fresh water.Sewage irrigation also inhibited root growth of Alfalfa.Effect of irrigation water quality on Alfalfa K content was not remarkable at the first clipping,but sewage and reclaimed water irrigation showed higher K contents than fresh water irrigation by 33.05% and 40.68% at the second clipping,and by 12.90% and 23.39% at the third clipping.Compared with fresh water irrigation,sewage and reclaimed water irrigation significantly increased Alfalfa Ca contents at the first clipping,however at the second and third clipping,Ca content under sewage and reclaimed water irrigation treatments were lower than fresh water irrigation.Accordingly,sewage shouldn’t be used for irrigation,but after mixed or rotational with fresh water,it can properly decrease the adverse effects;reclaimed water can be used as a source of irrigation in Alfalfa growth for a short period of time and their long-term effect should be concerned.