| 引用本文: | 杨晓奇,王珍,刘宏权,等.微咸水滴灌条件下氮磷肥协同施入对灌水器堵塞的影响[J].灌溉排水学报,2020,(5):-. |
| Yang Xiaoqi,Wang Zhen,Liu Hongquan,et al.微咸水滴灌条件下氮磷肥协同施入对灌水器堵塞的影响[J].灌溉排水学报,2020,(5):-. |
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| 摘要: |
| 微咸水滴灌条件下水肥一体化过程可能加剧灌水器堵塞的发生。【目的】评估氮磷肥协同施入对微咸水滴灌系统灌水器堵塞的影响。【方法】以灌水器类型、灌溉水电导率和氮磷肥协同施入模式为研究对象，灌水器类型选取内镶贴片式灌水器（E1）和单翼迷宫式灌水器（E2）；灌溉水质按照电导率设置3个水平，分别为2（S2）、4（S4）和6 dS/m（S6），另外设置地下水（G）（电导率约0.5 dS/m）作为对照；氮磷协同施入模式设置磷酸一铵-尿素（MU）、磷酸一铵-硫酸铵（MA）、磷酸二铵-尿素（DU）、磷酸二铵-硫酸铵（DA）4种，测定了灌水器流量、灌水器堵塞物质干质量及堵塞物质成分。【结果】滴灌氮磷协同施入条件，系统运行96 h时内镶贴片式灌水器平均相对流量均值较单翼迷宫式灌水器高19%，内镶贴片式灌水器表现出更好的抗堵塞性能；灌水器堵塞随灌溉水电导率升高明显增加，当灌溉水电导率>4 dS/m时，氮磷肥协同施入会导致滴灌系统的快速堵塞，磷酸盐类沉淀是主要堵塞诱因，占比超过85%；施用磷酸二铵较磷酸一铵更易形成灌水器堵塞，地下水和2 dS/m灌溉水条件施用磷酸一铵处理灌水器堵塞物质干质量均值分别较施用磷酸二铵处理低76%和41%。【结论】施用呈弱酸性的氮磷肥可以在一定程度上减缓灌水器堵塞。 |
| 关键词: 滴灌；灌水器堵塞；氮磷协同施肥；微咸水 |
| DOI： |
| 分类号:S275.6 |
| 基金项目:国家自然科学(51790531)、国家重点研发计划课题(2016YFC0403103)、流域水循环模拟与调控国家重点实验室自由探索课题(SKL2018TS06) |
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| Effect of phosphorus and nitrogen fertigation on clogging in drip emitters applying saline water |
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Yang Xiaoqi1, Wang Zhen2, Liu Hongquan1, Li Jiusheng2
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1.Institute of Urban and Rural Construction,Agricultural University of Hebei;2.State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing
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| Abstract: |
| 【Objective】Drip irrigation has been regarded as one of the most effective ways to apply saline water to crops as the water could be irrigated at a high frequency and low discharge rate, resulting in relatively low salinity levels in the soil due to leaching. However, the diverse ionic composition (Na+, Ca2+, Mg2+, HCO3-, SO42-, etc.) in saline water may accelerate the formation of clogging sediments, thus obstructing the emitters, which has been considered as a major problem in drip irrigation systems. Besides, emitter clogging risk might be increased by the fertigation practice for the drip irrigation system applying saline water. The objective of this paper was to evaluate the clogging process and mechanisms in drip emitters during the application of saline water with combined P and N fertigation. 【Method】On-site drip irrigation experiments applying saline water were conducted using a plain channel emitter (E1) and a labyrinth emitter (E2) to investigate the effect of the phosphorus and nitrogen fertigation and the water salinity on emitter clogging. In the test, four combined phosphorus and nitrogen fertigation practice were produced by integrating one typical phosphorus fertilizer (Monoammonium Phosphate (MAP) or Diammonium phosphate (DAP) ) with one typical nitrogen fertilizer (Urea (U) or Ammonium Sulphate (AS) ). Besides, three saline water qualities with electricity conductivity of 2 (S2), 4 (S4), and 6 (S6) dS m-1, respectively, were tested with the groundwater (G) that was considered as the control. The discharge rates of emitters were measured followed by each fertigation event. Several representative emitters were sampled to measure the dry weight (DW) and the chemical constituents of the clogging substances in the emitters at the end of the experiments. 【Result】 The mean discharge ratio (Dra) averaged over the E1 treatments with an operation of 96 h was 19% higher than that for the E2 treatments. The plain emitters demonstrated significantly better anti-clogging performance than the labyrinth emitters. Under groundwater irrigation, a relatively slighter decrease of Dra with time were observed for the G treatments while emitter clogging increased obviously with water electricity conductivity. A greater DW represents more severe clogging in emitters while a significantly negative correlation was found between the DW and the Dra. Phosphorus and nitrogen fertigation produced rapid clogging of emitters in the drip irrigation system applying saline water with electricity conductivity larger than 4 dS m-1. Phosphate sediments account for more than 85% of DW for the S4 and S6 treatments. The emitter clogging occurred more easily for treatments with DAP fertigated than those for the treatments with MAP fertigated. The averaged DW of the clogging substances over the treatments with MAP applied were 76% and 41% lower than those for the treatments with DAP applied under groundwater and saline water (S2) application, respectively. 【Conclusion】The phosphorus-coupled nitrogen drip fertigation should be applied with cautious applying saline water with electrical conductivity higher than 4 dS m-1. Using acid phosphate and nitrogen mixture fertilizer is a promising way to alleviate the emitter clogging caused by iron components in saline water. |
| Key words: drip irrigation; emitter clogging; nitrogen and phosphorus fertigation; saline water |
