| Cite this article: | 代智光,蔡耀辉.灌水器埋深对红壤区涌泉根灌双点源入渗水氮运移的影响[J].灌溉排水学报,2021,(1):-. |
| DAI Zhiguang,CAI Yaohui.灌水器埋深对红壤区涌泉根灌双点源入渗水氮运移的影响[J].灌溉排水学报,2021,(1):-. |
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| Effect of Emitter Depth on Water-nitrogen Transport in Duel-point Source Infiltration under Surge-root Irrigation in Red Soil Region |
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DAI Zhiguang1, CAI Yaohui2
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1.Nanchang Institute of Technology;2.Northwest A&F University
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| Abstract: |
| Red soil is mainly distributed in the hilly regions and is one of the important soil resources in China. The seasonal drought in the red soil region and the problems of acidity, stickiness and leanness severely restrict the development of local agriculture. Combined with the characteristics of red soil, it is of great significance to study the distribution of water and nitrogen transport of Surge-root irrigation (SRI) in red soil area.【Objective】 Studying the law of water and nitrogen transport and transformation in the duel-point source infiltration under SRI in the red soil area, which could provide the theoretical basis for improving the nitrogen utilization efficiency of SRI and the reasonable buried depth of the emitter under SRI.【Method】In the field, an infiltration experiment of calcium ammonium nitrate solution with 30, 45, and 60 cm burial depth of emitter was conducted to study the infiltration capacity, the soil infiltration capacity, wetting front migration, soil moisture, and the migration characteristics of ammonium nitrogen and nitrate nitrogen and the relationship model of cumulative soil infiltration volume and humid front migration distance with infiltration duration of SRI irrigation in red soil was established. 【Result】When the emitter depths were 30, 45 and 60 cm, the cumulative infiltration volume and stable infiltration rate of red soil were 18.84 L and 0.035 cm/min, 17.09 L and 0.031 cm/min and 14.37 L and 0.024 cm/min, respectively., which indicated the larger the emitter depths, the smaller the cumulative infiltration and stabilization rate of the soil, and the cumulative infiltration and the infiltration duration was in a power function relationship. When the emitter depths were 30, 45 and 60 cm, the time of intersection infiltration were 168, 187 and 197 min, respectively. The migration distance of the wet front decreased with the increase of emitter depth, and the migration distance and the infiltration duration were in a logarithmic function relationship, and the vertical downward migration distance was greater than the vertical upward. The soil moisture content (SWC) increased first and then decreased as the increase of soil layer depth. For the same soil layer, the SWC was the largest near the emitters, and the soil at a distance of 12.5 cm to the emitters was the smallest. The ammonium nitrogen and nitrate nitrogen increased first and then decreased as the depth of soil layer increased, in the horizontal direction, the closer to the emitter, the greater the concentration of ammonium nitrogen, and for nitrate nitrogen, the distribution of nitrate nitrogen was significantly different with the different emitter depths.【Conclusion】The emitter depths had significant effects on water-nitrogen transport characteristics for duel-point source intersection infiltration under SRI for red soil region, and when the emitter depth exceeds 60 cm, the risk of nitrogen leaching is greater, which not good for improving the water-nitrogen use efficiencies for crop.
Keywords：red soil; surge-root irrigation; emitter depths; water-nitrogen transport |
| Key words: red soil;surge-root irrigation;emitter depths;water-nitrogen transport |
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