土壤中新型肥料氮素淋失特征研究

氮素淋溶是农田氮素损失的重要途径,也是造成地下水硝酸盐污染的重要原因,研究土壤氮素淋失特征对预防地下水氮素污染具有十分重要的意义。该文采用室内土柱淋溶试验的方法,研究了新型肥料在土壤中的迁移及淋溶规律,分析了氮素淋溶的地球化学响应特征,并确定了各形态氮素淋失量。研究结果表明:尿素、缓释肥料、稳定性肥料处理氮素淋溶量差异显著,分别为208.66、131.95、125.24kg·hm-2,缓释和稳定性肥料的氮素淋失率分别为32.98%和31.31%,比尿素低19.15%和20.85%,说明缓释和稳定性肥料可以显著减少氮素的淋失及对地下水的污染。硝态氮、铵态氮、有机氮分别占氮素淋失量的49.89%~75.19%、6.48%~12.77%、14.92%~31.31%,说明硝态氮是氮素淋溶的主要形态,其次是有机氮和铵态氮。

Nitrogen Leaching Characteristics of New Emerging Fertilizers in Soil

Nitrogen leaching is an important way of nitrogen loss,which makes it the dominant process accounting for nitrate pollution in groundwater. Therefore,it is of great significance to study the characteristics of nitrogen leach?ing in soil which may pave a way for groundwater nitrogen pollution prevention and control.In our study,soil column method was used to study nitrogen transport and leaching behavior of new emerging fertilizers in soil. Meanwhile ,the geochemical responses of soil to nitrogen leaching were analyzed and the leaching amounts of main nitrogen species were determined.The results showed that nitrogen leaching losses were significantly different between new emerging fertilizers and traditional nitrogen fertilizers. Nitrogen leaching losses of urea,slow-release fertilizer and stabilized fertilizer were 208.66,131.95 and 125.24 kg·hm-2,respectively.The nitrogen leaching rates of slow-release fertilizer and stabilized fertilizer(32.98%and 31.31%)were lower than that of urea(52.16%),which indicated that slow-re?lease fertilizer and stabilized fertilizer significantly reduced nitrogen losses.Nitrate ,ammonium and dissolved organic nitrogen respectively accounted for 49.89%~75.19%,6.48%~12.77%and 14.92%~31.31%of the nitrogen leach?ing amount,which demonstrated that nitrate nitrogen was the main form of nitrogen leaching,followed by dissolved organic nitrogen and ammonium nitrogen.