温室水肥滴灌系统迷宫式灌水器堵塞试验

为探明温室滴灌灌水器堵塞的影响因素及机理,研究了灌水量和施肥量对灌水器堵塞的影响,并利用场发射扫描电镜分析了灌水器内的堵塞物质。结果表明,灌水器平均流量随着灌水量和施肥量的增加呈下降趋势,下降幅度在1.51%~14.16%之间。方差分析表明施肥量对灌水器平均流量的影响达到极显著水平(P0.01)。解剖灌水器后发现堵塞物质多沉积在流道前部。堵塞物质主要由生料带残渣、微小沙粒和白色粉末状化学沉淀物组成,其中白色粉末主要由钙、镁、碳、氧、磷元素等组成。说明本试验中灌水器堵塞主要是由物理堵塞和化学堵塞共同作用引起的。

Clogging of Labyrinth Emitters in Greenhouse Fertigation

Emitter clogging caused by simultaneous irrigation and fertilization (fertigation) has negative influence on the normal operation of drip irrigation systems. This study was carried out to determine the effects of fertigation amount and irrigation amount on labyrinth emitter clogging. Additionally, sediments in the labyrinth passage were analyzed by field emission scanning electron microscope (FESEM) to determine their composition. Results indicated that average discharge of the emitters decreased between 1.51% and 14.16% with the increase of the irrigation or fertigation amount after operating the drip irrigation system for 21 weeks. Statistical analysis showed that fertigation amount significantly affected emitter average discharge (P<0.01). Dissection of the clogged emitters revealed that the sediments located in the front labyrinth passage comprised primarily of sealing tape, insoluble fertilizer particles, and white powdery chemical precipitation. The chemical precipitation was found to be constituted of carbon, oxygen, phosphorus, calcium, magnesium, and other minerals. Consequently, emitter clogging was mainly caused by the combined effect of physical and chemical clogging.