地面灌溉技术参数对氮素运移分布影响的研究进展

地面灌溉是应用最广泛的灌水方法，通过优化地面灌溉设计和管理减少水氮淋失，正在成为研究的热点问题，该文对有关成果进行了综述。由于地面灌溉的尺度较大，加之土壤水力参数和溶质运移参数的空间变异，使得地面灌溉施肥条件下溶质(N)运移分布的田间试验研究，无论在技术上还是在投入上都具有一定难度。有关沟灌、畦灌和水平畦田灌溉施肥时水氮分布的田间试验结果指出，肥料(N)分布没有入渗水深分布均匀，且与土壤初始含水率、流量、土壤入渗参数、田面糙率和施肥时机等因素密切相关。在模拟研究方面，文献中报道的模型有纯对流模型、对流-弥散模型、基于活塞流的水平衡模型和传递函数模型等。鉴于地面灌溉条件下水氮运移的复杂性，在水氮运移分布的数学模拟、灌水技术参数和施肥方式对水氮淋失的影响以及灌溉施肥质量评价指标体系等方面尚需要进一步研究。

Influence of surface irrigation technical parameter on nitrogen transport and distribution: A review

Surface irrigation regime is the most widespread irrigation regime. At present, the emerging interest in surface irrigation study is focused on reducing leaching of water and nitrogen by optimizing the design and management of surface irrigation. A literature review was conducted on the transport and distribution of solute under surface fertigation in this article. The number of field scale solute transport studies is limited due to the time and resources required, and the difficulty in isolating sources of variability in soil hydraulic and transport properties. A few of field experiments on the transport of solutes with border, furrow, and level basin irrigations showed that the solute mass demonstrated a greater nonuniformity than infiltrated water. The degree of nonuniformity for solute is affected by such factors as the initial water contents, soil surface conditions, the fertilizer application regime, and flow properties (e.g., inflow rate, infiltration characteristics, and soil hydraulic properties). Several models, including the pure advection model, the advection-diffusion model, the piston model, and the transfer function model have been reported with different complexities in the literature to simulate solute transport under surface fertigation. As surface fertigation is a complicated process, more researches on the solute transport modeling, the effects of irrigation variables and fertigation regime on leaching of fertilizers, and performance indices for surface fertigation were recommended.