| Cite this article: | 郭晗笑,申丽霞,樊耀,等.压力水头和肥液浓度对微润灌土壤水氮运移的影响[J].灌溉排水学报,0,():-. |
| GUO Han-xiao,SHEN Li-xia,FAN Yao,et al.压力水头和肥液浓度对微润灌土壤水氮运移的影响[J].灌溉排水学报,0,():-. |
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| Effects of pressure head and nitrogen application on water and nitrogen transport in soil under moistube irrigation |
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GUO Han-xiao, SHEN Li-xia, FAN Yao, NIU Shuang, YANG Mei, SUN Xue-lan, LIU Rong-hao
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College of water conservancy and Engineering,Taiyuan University of technology
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| Abstract: |
| 【Background】Moistube irrigation is a new type irrigation technology that delivers water and fertilizer to the root area of crops through semi-permeable membrane tube in a continuous flow from line source. The water and nitrogen migration and distribution are significant bases for the design and management of micro-irrigation system. At present, there are many studies on water and nutrient transport in planting experiments, but few studies on water and nitrogen transport through indoor simulation experiments. Therefore, the promotion of moistube irrigation technology has been seriously hindered. Urea is an organic fertilizer suitable for deep application and is suitable for combination with moistube irrigation. In order to provide data support for the development of moistube irrigation, the soil water and nitrogen transport law of urea fertilizer infiltration was studied.【Objective】To explore the distribution characteristics of soil water and nitrogen under the condition of water and fertilizer integration of moistube irrigation.【Method】Through the laboratory soil simulation test, six treatments including two pressure head treatments of 1m、1.5m and three nitrogen application levels of 0mg/L、500mg/L and 1000mg/L were set in the experiment. The cumulative infiltration amount and the migration distance of the wetting front were recorded regularly. After 132h, the soil moisture content, ammonium nitrogen and nitrate nitrogen content at different locations of the wetting body were measured, and the effects of pressure head and nitrogen concentration on the distribution of water and nitrogen in the soil were studied.【Results】Urea fertilizer limited the outflow of moistube, and the cumulative infiltration amount is significantly linearly correlated with the time. The pressure water head of 1.5 m and the nitrogen application level of 0 mg/L have the largest cumulative infiltration amount, reaching 10.55 L, and the wetting front diffuses furthest. The decrease of pressure head and the increase of the concentration of infiltration led to the decrease of the wetting front advance rate. Compared with the 1 m pressure head treatment group, the soil moisture content, ammonium nitrogen content and nitrate nitrogen content in the 1.5 m pressure head treatment group all increased. There was a peak of ammonium nitrogen in the soil, and the peak occurred at different time with different treatments, which would affect the accumulation of nitrate nitrogen and ammonium nitrogen in the soil. At 132 h of infiltration, at the level of 1m pressure head, the contents of ammonium nitrogen and nitrate nitrogen in the soil were smaller when compared with that of 500 mg/L. At the level of 1.5m pressure head, the contents of ammonium nitrogen and nitrate nitrogen in the soil were larger when compared with that of 500 mg/L.【Conclusion】Increasing the pressure head significantly increased the infiltration rate, cumulative infiltration amount, the migration distance of the wetting front, soil moisture content, the contents of ammonium nitrogen and nitrate nitrogen, while the infiltration of urea fertilizer limited the micro-irrigation flow and increased the contents of ammonium nitrogen and nitrate nitrogen, excessive concentration of fertilizer will limit the decomposition and transformation of urea in soil. |
| Key words: Moistube irrigation; Liquid concentration of urea fertilizer; Pressure head; Cumulative infiltration; Soil moisture content; Ammonium nitrogen; Nitrate nitrogen; |
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