【摘要】 甘薯田间施氮通常采用一次性基施氮肥后不再追施氮肥，因此研发和遴选符合甘薯不同生育期氮素需求的缓控释氮肥对甘薯增产、氮肥减施很重要。本研究以苏薯16为试验材料，采用盆栽试验，在等量氮、磷、钾投入下，分析不同缓控释氮肥（草酰胺、硫包衣尿素、脲甲醛、尿素结合硝化抑制剂）对甘薯不同生育期（苗期、封垄期、膨大期和收获期）生长和氮含量、氮利用效率及土壤矿质氮含量的影响。结果表明：（1）与对照相比，硫包衣尿素和草酰胺控释氮肥分别提高甘薯的块根生物量96.79%和103.59%，且显著高于脲甲醛和尿素结合硝化抑制剂处理（P<0.05）。在膨大期和收获期，硫包衣尿素处理的光合速率显著高于对照，有利于提高块根的生物量。（2）硫包衣尿素和草酰胺在甘薯苗期和封垄期氮素释放量较少，在甘薯膨大期和收获期释放量较多，铵态氮和硝态氮之和是脲甲醛和尿素结合硝化抑制剂的1.24～1.60倍，氮肥利用率提高了1.17～1.80倍。因此，硫包衣尿素和草酰胺较为符合甘薯生产上的一次性氮肥投入。本研究结果可为甘薯的养分管理和氮肥减施增效提供科学依据。更多还原

【Abstract】 Sweet potato is often base fertilized with nitrogen and no further dressing nitrogen fertilizer is needed. It is important to develop and screen slow-releasing nitrogen fertilizers that could meet the nitrogen requirements of sweet potato at different growth stages in order to promote yield and reduce nitrogen rate. A greenhouse pot experiment using variety Sushu 16 was conducted to analyze the effects of different slow-releasing nitrogen fertilizers(urea formaldehyde,sulfur-coated urea, urea formaldehyde resin, urea combined with nitrification inhibitors) on leaf photosynthesis, aboveground and underground biomass and nitrogen content, nitrogen use efficiency, and soil mineral nitrogen(nitrate nitrogen and ammonium nitrogen) content at different growth stages of sweet potato(seedling stage, vine burying stage,bulking stage, and harvest stage). Compared with the control, the sulfur-coated urea and oxamide controlled-release nitrogen fertilizers increased the biomass of sweet potato roots by 96.79% and 103.59%, respectively, significantly higher than that of the urea-formaldehyde and urea combined with nitrification inhibitor treatments(P<0.05). In addition, the photosynthesis rate of sweet potato throughout the entire growth period was significantly higher in the sulfur-coated urea treatment than that of unfertilized control, which is beneficial to improving the biomass of sweet potato roots. The nitrogen releasing of sulfur-coated urea and oxamide was less in the seedling and closure period and more in the swelling period and harvest period. The sum of ammonium nitrogen and nitrate nitrogen was 1.24-1.60 times that of urea-formaldehyde and urea combined with nitrification inhibitor, and the nitrogen fertilizer utilization rate increased by 1.17-1.80 times. In conclusion, sulfur-coated urea and urea formaldehyde are more suitable for the one-time application of nitrogen fertilizer in sweet potato production. The study results could provide scientific basis for nutrient management and nitrogen fertilizer reduction and yield enhancement in sweet potato production.更多还原