摘要
摘要:NH₃挥发是稻田氮素损失的重要途径之一, 基于基肥期尿素氮肥深施、追肥期用缓释肥替代尿素和配施脲酶抑制剂对太湖地区水稻生长季NH₃挥发影响少有报道。为此, 本研究共设置了7个原位试验处理: 1)空白处理, 不施氮肥(CK); 2)当地常规氮肥表施处理, 施氮量300 kg?hm^?2 (SN300); 3)减氮10%, 氮肥表施处理, 施氮量为270 kg?hm^?2 (SN270); 4)减氮10%+基肥氮深施+追肥表施尿素处理(DN270); 5)减氮10%+基肥氮深施+追肥表施尿素+脲酶抑制剂(DN270+UI); 6)减氮10%+基肥氮深施+追肥表施缓释肥(DN270+SR); 7)减氮10%+基肥深施+追肥表施缓释肥+脲酶抑制剂(DN270+SR+UI)。与常规尿素表施SN300处理NH₃累积排放量相比, 采用基肥深施可降低78.2%~85.2%的基肥期NH₃排放量, 基肥减氮深施且追肥期配施脲酶抑制剂(DN270+UI处理)可降低30.4%的分蘖肥期NH₃排放量和25.3%的穗肥期NH₃排放量, 基肥减氮深施且水稻追肥期用缓释肥替代尿素(DN270+SR处理)可降低36.4%的分蘖肥期NH₃排放量和28.1%的穗肥期NH₃排放量。整个水稻生长季NH₃累积排放量大小为SN300>SN270>DN270>DN270+UI>DN270+SR>DN270+SR+UI, 其中DN270+SR+UI处理下NH₃排放量最小, 与SN300处理相比, 可显著降低50.9%的NH₃累积排放量(P<0.05)。除CK外, 各处理间水稻产量差异不显著, 单位水稻产量NH₃排放强度以DN270+SR+UI处理下最小, 与SN300处理相比, 可显著降低52.5%单位水稻产量氨排放强度(P<0.05)。综合考虑经济生态环境效益, 在南方典型稻田中采用基肥期尿素深施可有效地降低氨挥发量, 是一种值得推广的稻田氨减排模式, 在追肥期用缓释肥替代尿素同时配施脲酶抑制剂可进一步提高NH₃减排效果。
关键词:稻田/
NH₃挥发/
深施肥/
脲酶抑制剂/
缓释肥/
NH₃排放强度/
水稻产量
Abstract:.Ammonia (NH₃) volatilization is an important nitrogen (N) loss pathway in paddy fields. However, the effects of N fertilizer deep placement, slow-release N fertilizers, and urea inhibitors on NH₃ volatilization reduction during the entire rice-growing season remain uncertain. To fill this knowledge gap, we conducted a field experiment with seven treatments: (1) no N application, (2) local broadcasting application of urea at a rate of 300 kg(N)?hm^?2 (SN300), (3) 10% reduction of N from SN300 (SN270), (4) deep placement of basal urea together with the broadcasting of topdressing of urea at tiller and panicle stages of rice, at a total a rate of 270 kg(N)?hm^?2 (DN270), (5) application of urea inhibitor for DN270 (DN270+UI), (6) 10% nitrogen reduction, deep application of basal urea together with the surface application of slow-release N fertilizer (DN270+SR), and (7) application of urease inhibitors for DN270+SR (DN270+SR+UI). Compared with the SN300 treatment, deep placement of basal N fertilizer reduced the cumulative NH₃ emissions by 78.2%?85.2% in the basal fertilization period. The combined application of the urease inhibitors in the rice topdressing periods (DN270+UI treatment) reduced the NH₃ emissions by 30.4% at the tillering stage and 25.3% at the panicle stage in comparison with the SN300 treatment. Replacing urea with a slow-release N fertilizer (DN270+SR treatment) in the rice topdressing periods reduced NH₃ volatilization by 36.4% at the tillering stage and 28.1% at the panicle stage. The cumulative NH₃ volatilization changed in the following order: SN300 > SN270 > DN270 > DN270+UI > DN270+SR > DN270+SR+UI. Compared to the local treatment (SN300), DN270+SR+UI significantly reduced NH₃ volatilization by 50.9%. There was no significant difference in rice yield among the N fertilizer treatments. NH₃ emission intensity per unit rice yield was lowest for the DN270+SR+UI treatment, 52.5% lower than the SN300 treatment. Overall, simultaneous N fertilizer deep placement with slow-release N and urease inhibitors produced more grains with lower environmental costs associated with NH₃ emissions. This represents a promising and sustainable management strategy for paddy fields in the Taihu Lake region of China.
Key words:Paddy field/
NH₃ volatilization/
Deep placement of N fertilizer/
Urease inhibitor/
Slow-release fertilizer/
NH₃ emission intensity/
Rice yield



PDF全文下载地址:

http://www.ecoagri.ac.cn/article/exportPdf?id=1678f410-51fc-4f66-ad86-76149a5973a8