College of Water Resources and Civil Engineering, China Agricultural University, Beijing, 100083, China.
Department of Chemical and Agricultural Engineering and Technology, University of Girona, Girona, 17003, Spain.
J Environ Manage. 2020 Jun 1;263:110366. doi: 10.1016/j.jenvman.2020.110366. Epub 2020 Mar 12.
Phosphorous (P) fertigation with high salinity water (HSW) drip irrigation would be an effective measure to relieve soil and water pollution caused by the excessive application of P fertilizer, and achieve synergistic saving of both limited fresh water and non-renewable P resources. However, the emitter clogging issues of drip fertigation systems seriously restricts the utilization of this technology. This study proposes an approach to reduce emitter clogging in HSW drip fertigation systems by choosing the appropriate type and concentration of P fertilizer. The effects of two new types of P fertilizers (ammonium polyphosphate, APP; urea phosphate, UP), and a traditional P fertilizer (monopotassium phosphate, MKP), were assessed at three fertilization concentrations (0, 0.15, and 0.30 g/L) on the clogging behavior of four types flat emitters. The results indicated that the application of MKP aggravated the clogging of emitters in comparison with non-fertilization. While the addition of two new types of P fertilizers (APP and UP) effectively alleviated emitters clogging (the irrigation uniformity of systems increased by 26.2%-74.6%) by inhibiting the formation of carbonate, although precipitation of phosphate, silicate, and quartz increased. Moreover, under the equal application amount of P fertilizer, UP and APP were more effective in relieving clogged when applied at a low-concentration with long-term running and high-concentration with short-term running mode. The results could pave a way for reducing the pollution in agricultural production and conserving freshwater and non-renewable P resources.
高盐度水（HSW）滴灌条件下磷（P）施肥可能是缓解过量施用磷肥造成的土壤和水污染、实现有限淡水资源和不可再生磷资源协同节约的有效措施。然而，滴灌施肥系统的滴头堵塞问题严重限制了该技术的利用。本研究提出了一种通过选择合适的 P 肥类型和浓度来减少 HSW 滴灌施肥系统滴头堵塞的方法。评估了两种新型 P 肥（聚磷酸铵，APP；磷酸脲，UP）和一种传统 P 肥（磷酸一钾，MKP）在三种施肥浓度（0、0.15 和 0.30 g/L）下对四种类型扁平滴头堵塞行为的影响。结果表明，与不施肥相比，MKP 的应用加剧了滴头的堵塞。而两种新型 P 肥（APP 和 UP）的添加通过抑制碳酸盐的形成，有效地缓解了滴头堵塞（系统的灌溉均匀度提高了 26.2%-74.6%），尽管磷酸盐、硅酸盐和石英的沉淀增加了。此外，在等量施用 P 肥的情况下，UP 和 APP 在长期低浓度运行和短期高浓度运行模式下更有效地缓解堵塞。研究结果可为减少农业生产中的污染和节约淡水资源及不可再生磷资源铺平道路。
