| 控释尿素对黄河故道沙性潮土N2O排放的影响 |
| 摘要点击 1134 全文点击 390 投稿时间：2019-11-19 修订日期：2020-01-19 |
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| 中文关键词 控释肥 N2O排放 玉米 产量 潮土 |
| 英文关键词 controlled-release urea N2O emissions maize yield sandy loam soil |
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| 中文摘要 |
| 建立田间原位试验，采用静态箱-气相色谱法，研究了常规尿素及其与硫包膜和聚氨酯包膜控释尿素配施（比例分别为30%：70%、50%：50%和70%：30%）对黄河故道沙性潮土玉米生长季氧化亚氮（N2O）排放的影响.研究发现：常规尿素处理N2O排放量（以N计，下同）为1.78 kg·hm-2，排放系数为0.38%；与之相比，配施30%、50%和70%硫包膜尿素处理的N2O排放量分别降低了1.12%、22.5%和11.2%，排放系数下降2.63%~26.3%.相反，配施聚氨酯包膜尿素处理增加N2O排放量0.02~0.41 kg·hm-2，其中70%聚氨酯包膜尿素处理增幅最大，达到23.0%.回归分析表明，各处理N2O排放通量与10 cm处土温、土壤NH4+-N和NO3--N含量呈极显著正相关（P<0.01），而与土壤孔隙含水量和溶解性有机碳含量无显著关系.与常规尿素相比，50%常规尿素+50%硫包膜控释尿素处理玉米产量略有增加，而30%常规尿素+70%硫包膜尿素处理稍微降低了玉米产量，但不显著（P>0.05）.因此，控释肥减缓土壤N2O排放以及对作物产量的影响主要受控于包衣材料. |
| 英文摘要 |
| A field experiment was conducted in maize-cultivated sandy loam soil in the old flooded area of the Yellow River to evaluate the responses of N2O emissions to application of different type of controlled-release urea. An inorganic N fertilizer was applied at 270 kg·hm-2 during the maize season. Urea was applied alone and in combination with sulfur-coated urea (SCU) or polyurethane-coated urea (PCU) at N ratios of 30%:70%, 50%:50%, and 70%:30%, respectively. Cumulative N2O emission under urea treatment alone (CN) was 1.78 kg·hm-2 with a N2O emission factor of 0.38%. In comparison to CN, 70% urea+30% SCU, 50% urea+50% SCU, and 30% urea+70% SCU treatments reduced N2O emission by 1.12%, 22.5%, and 11.2%, respectively. In contrast, application of urea in combination with PCU (with the proportion varied from 30%-70%) increased N2O emission by 0.02-0.41 kg·hm-2 compared with the CN, while 30% urea+70% PCU treatment showed a 23.0% increase. Regression analysis showed that N2O flux was significantly (P<0.01) correlated with soil temperature at 10 cm depth and concentrations of soil NH4+-N and NO3--N in all the treatments, but not with soil moisture or dissolved organic carbon concentration. Compared with the CN, the 50% urea+50% SCU and 50% urea+50% PCU treatments slightly, but not significantly, increased the maize yield, whereas the 30% urea+70% SCU treatment showed a reduction effect. Overall, the mitigation effect of controlled-release urea on N2O emission may primarily depend on its coating material and application rate. |
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