尿素对浑水水肥一体化滴灌滴头堵塞的影响

为确定水肥一体化灌溉过程中,尿素对滴头堵塞的影响,分别配置了3种泥沙浓度(1.0、1.5 g·L~(-1)和2.0 g·L~(-1)),3种肥料质量浓度(1%、2%和3%),进行了间歇灌水堵塞试验,分析了滴头流量和排出泥沙量。结果表明:施加尿素对浑水滴灌具有缓解滴头堵塞的作用,在一定的尿素浓度范围内,施肥浓度越大,减缓作用越明显;施肥浓度对滴头的堵塞形式和主要堵塞物淤积位置的影响很小。滴头出流泥沙含量随灌水次数的增加呈现先快速增加,后逐渐变缓并趋于下降的趋势。施加尿素提高了滴头泥沙输送能力,施肥浓度越大,滴头输送泥沙的能力越大,泥沙排出率越大。浑水中施加尿素具有减缓滴头堵塞,延长滴头有效灌水次数的作用,当含沙量为2.0g·L~(-1)时,尿素浓度为1%,2%和3%的水肥一体化滴灌有效灌水次数比未添加尿素的可分别提高11%,89%和100%。可尝试通过尿素水肥一体化滴灌,缓解黄河水滴灌滴头堵塞危险,提高滴灌系统使用效率。

Influence of urea on emitter clogging with muddy water fertigation

Three kinds of sediment concentrations (1.0, 1.5 g·L^-1 and 2.0 g·L^-1) and three concentrations of the fertilizers (1% , 2% and 3%) were set up to determine the effect of urea on the clogging of the drip in the process of fertigation, and intermittent irrigation clogging test was conducted. The amount of discharge sediment and deposits sediment in the capillary was analyzed. The results showed that the application of urea to muddy water drip irrigation had the effect of relieving drip clogging. The effect of fertilization on the clogging of the emitter and the location of the main clogging was small. After apply urea to muddy water, the number of completely clogged emitters had declined, while the number of partially clogged drippers had increased. The sediment content in the drip flow increased with the increase of irrigation times, then gradually slows down and tends to decrease. Application of urea to muddy water improved the drip sediment transport capacity, the greater the concentration of fertilization, the greater the capacity of the drip sediment transport, the greater the discharge sediment rate. The application of urea in the water had the effect of slowing the clogging of the drip and prolonging the effective irrigation times of the dripper. When the sediment concentration was 2.0 g·L^-1, the number of effective irrigation with the urea concentration of 1%, 2%, and 3% was 11%, 89% and 100% higher than that of urea without adding urea. After application of urea to muddy water, changing the nature of the electrochemical properties and sediment particle surface of muddy water, muddy water stable aggregates sediment flocculation difficult to form, the ability to carry muddy sediment particles applied urea increased, thus play a role in slowing the emitter clogging. The current study can provide a way to alleviate the risk of drip clogging which using the Yellow River water and improve drip irrigation system efficiency.