Nitrate leaching from potato (Solanum tuberosum L.) production is of great concern because of its potential effects on water resources. Suction lysimeters were used in combination with a one‐dimensional flow model to quantify NO₃–N leaching under irrigated potato produced on sandy soils near Québec City, QC, Canada. The 3‐yr (2010−2012) study compared a single application of polymer‐coated urea (PCU) and split‐applied soluble N fertilizers (ammonium nitrate, AN; ammonium sulfate, AS) at three N rates (120, 200, and 280 kg N ha⁻¹) in addition to an unfertilized control. Fertilizer N application increased total seasonal NO₃–N leaching. A single application of PCU increased total seasonal NO₃–N leaching in 2011 compared with AN and AS, which was attributed to a greater soil NO₃–N concentration under the PCU treatment in combination with increased rainfall during the tuber bulking phase (60−90 d after planting). Total seasonal NO₃–N leaching in 2012 was reduced with PCU and AS compared with AN, which was attributed to reduced soil NO₃–N concentrations between planting and hilling when rainfall was high. Regardless of the fertilizer N source, NO₃–N leaching was primarily driven by precipitation, as leaching occurred when elevated soil NO₃–N concentrations coincided with excess water in the soil. The results suggest that a single application of PCU is an effective strategy for reducing NO₃–N leaching in years when there is significant rainfall during the period between planting and hilling.

中文翻译：

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灌溉马铃薯生产中受氮管理影响的生长季硝酸盐淋失

从马铃薯（Solanum tuberosum L.）生产中浸出的硝酸盐由于对水资源的潜在影响而备受关注。吸气式测力计与一维流动模型结合使用，定量了在加拿大魁北克省魁北克市附近的沙质土壤上生产的灌溉马铃薯中NO ₃ -N的淋溶。3年（2010-2012年）研究比较了三种氮肥浓度（120、200和200）分别施用聚合物包膜尿素（PCU）和分批施用的可溶性氮肥（硝酸铵，AN；硫酸铵，AS）。除了未受精的对照外，还具有280 kg N ha ^-1）。施氮肥增加了总的季节性NO ₃ -N淋溶。一次施用PCU会增加季节性总NO ₃与AN和AS相比，2011年–N淋溶，这归因于在PCU处理下土壤NO ₃ –N浓度更高，并且在块茎膨大阶段（种植后60-90 d）降雨增加。与AN相比，PCU和AS减少了2012年季节性NO ₃ -N总淋失，这是由于降雨多时种植和耕种之间土壤NO ₃ -N浓度降低所致。不管肥料中的氮源如何，NO ₃ -N的淋溶主要是由降水驱动的，因为当土壤中NO ₃ -N的浓度升高与土壤中的水分过多时，就会发生淋溶。结果表明，一次应用PCU是减少NO的有效策略在种植和耕种之间有大量降雨的年份，₃ –N淋洗。