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(CK);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%,内镶贴片式灌水器抗堵塞性能更好;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造成灌水器堵塞,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】施用磷酸一铵可以在一定程度上减缓灌水器堵塞。
【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,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,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 slighte
作者
杨晓奇
王珍
刘宏权
李久生
YANG Xiaoqi;WANG Zhen;LIU Hongquan;LI Jiusheng(Institute of Urban and Rural Construction,Agricultural University of Hebei,Baoding 071001,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100048,China)
出处
《灌溉排水学报》
CSCD
北大核心
2020年第7期68-76,共9页
Journal of Irrigation and Drainage
基金
国家自然科学基金项目(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)。
关键词
滴灌
灌水器
施肥
微咸水
drip irrigation
emitter
fertigation
saline water
