摘要
【目的】提高水肥一体化条件下水肥利用率。【方法】通过不同流量膜下滴灌水肥入渗试验,研究了滴灌结束时及再分布后的土壤含水率、电导率运移规律,并测定氮素在土壤中的动态分布特性。【结果】(1)滴灌结束时,各滴头流量下土壤含水率随着离滴头距离的增大而减小,流量为2 L/h的土壤含水率、电导率在垂直方向运移距离大于流量为3、4 L/h的;再分布后,不同滴头流量下土壤含水率的分布差异不大,流量2 L/h与流量为3、4 L/h的土壤电导率集中分布在不同区域,流量为3、4 L/h的土壤电导率在土体内主要分布区域相近。(2)不同滴头流量下土壤铵态氮质量分数随时间的延长逐渐减小,土壤硝态氮质量分数则表现为相反的变化趋势;土壤铵态氮质量分数在径向和垂向上随着离滴头距离的增大而减小。24 h土壤硝态氮质量分数在径向和垂向上随着离滴头距离增大而增大,72 h后呈减小的趋势。【结论】滴灌后不同流量下土壤电导率集中分布区域不同,土壤氮素随时间呈动态变化,可根据作物生长特点选择合适的滴头流量,制定合理的施肥时间。
[Objective] Improve the utilization of water and fertilizer under the integration of drip irrigation and fertilization. [Method] The rules of soil moisture, EC migration during the drip irrigation and redistribution and characteristic dynamic distribution of available nitrogen were researched by the different flow of water-fertilizer infiltration experiments. [Result] （1）At the end of drip irrigation, the soil moisture decreased with the increase of the distance from the dripper. The migration distances of soil moisture and EC with flow of 2 L/h were more farther than the flow 3, 4 L/h in the vertical. After redistribution, the distribution of soil moisture was not significantly influenced by emitter discharge; the main distribution region of soil EC with flow rate 2 L/h was different from flow rate 3, 4 L/h; The main distribution region of soil EC with the flow 4 L/h was similar to that of flow 3 L/h. （2） Under the different dripper discharge, the ammonium nitrogen decreased gradually with time, but nitrate nitrogen had an opposite changing trend to that of ammonium nitrogen; The ammonium nitrogen decreased along with the increase of distance from dripper in the radial and vertical directions. The nitrate nitrogen increased gradually as the distance of emitter increased in 24 h, but it decreased after 72 h. [Conclusion] The main distribution region of soil EC under different flow rates was inconsistent and the available nitrogen in soil was changed dynamically with time after drip irrigation. So, according to the characteristics of crop growth, the appropriate drip discharge could be selected and reasonable fertilization time was established.
出处
《灌溉排水学报》
CSCD
北大核心
2018年第3期51-57,共7页
Journal of Irrigation and Drainage
基金
公益性行业(农业)科研专项项目(201503125)
"十三五"国家重点研发计划项目(2016YFC0400200)
