【摘要】 通过控释尿素（CRU）替代普通尿素（CU）,是实现农业生产化肥"减施增效"及其使用量零增长目标的有效途径之一。选取环洞庭湖典型双季稻（Oriza sativa L.）连作区,设置100%氮CU（农民习惯施肥方式,CU）、100%氮CRU（1.0CRU）、减氮10%CRU（0.9CRU）、减氮20%CRU（0.8CRU）和减氮30%CRU（0.7CRU）共5个处理,通过静态暗箱采气、气相色谱法检测,研究CRU减氮施用对双季稻田CH₄、N₂O排放及稻作经济效益的影响。结果表明:减氮10%—30%CRU处理早稻的CH₄、N₂O排放总量和全球增温潜势（GWP）比CU处理分别减排18.8%—28.7%、15.7%—28.6%、18.4%—28.7%,晚稻的分别减排27.1%—39.5、17.5%—25.0%、25.5%—37.1%;与CU处理相比,0.8CRU和0.7CRU处理显著减少双季稻田CH₄排放总量的23.1%、33.5%和N₂O排放总量的21.9%、26.9%,0.9CRU、0.8CRU和0.7CRU处理分别有效降低GWP的21.7%、22.9%、32.5%和温室气体排放强度的33.0%、29.5%、36.4%;1.0CRU、0.9CRU处理连续4年显著增产（3.75%—18.05%）,年均增产幅度分别为12.03%和11.20%;CRU处理双季稻生长季平均增加经济收益2 124.1yuan·hm^-2,且以0.9CRU处理最高。综合考虑控释尿素施用后的环境及经济效益,减氮20%CRU是一种适宜在环洞庭湖典型双季稻区推广的氮肥有效管理模式。更多还原

【Abstract】 For reducing chemical fertilizer application with increasing fertilizer efficiency and the zero growth of fertilizer usage, it could be an effective way to replace ordinary urea（CU） by controlled-release urea（CRU）. In this study, a field experiment was conducted in the representative double cropping paddy fields of Dongtinghu lake area, with six treatments including CU, 100% nitrogen（N） of controlled release urea（1.0 CRU）, N reduction 10% of controlled release urea（0.9 CRU）, N reduction 20% of controlled release urea（0.8 CRU）, and N reduction 30% of controlled release（0.7 CRU）. Through static chamber sampling and gas chromatograph analysis method, the effects of CRU on CH₄ and N₂O emission reduction and its economic benefits were explored. Results showed that the total CH₄, N₂O and GWP emissions of early-season rice stage for treatments of 0.9 CRU, 0.8 CRU and 0.7 CRU were reduced by 18.8%–28.7%, 15.7%–28.6%, 18.4%–28.7%, respectively, while those of late-season rice stage were reduced by 27.1%–39.5%, 17.5%–25.0% and 25.5%–37.1%, respectively, compared to CU treatment. Meanwhile, 0.8 CRU and 0.7 CRU treatments significantly decreased the total CH₄ and N₂O emissions by 23.1%, 33.5% and 21.9%, 26.7% in double-cropping rice（Oriza sativa L.） fields, respectively; 0.9 CRU, 0.8 CRU, and 0.7 CRU treatments significantly reduced the potentials of global warming and the intensity of greenhouse gas by 21.7%, 22.9%, 32.5% and 33.0%, 29.5%, 36.4%, respectively. The treatments of 1.0 CRU and 0.9 CRU were found to significantly enhance rice yield by 3.75%–18.05% in a four year field experiment, with an average annual increase rate of 12.03% and 11.20%, respectively. In addition, CRU treatments obtained the average economic benefits of 2 124.18 yuan·m^-2 for double-cropping rice production, and that maximum value was under 0.9 CRU treatment. Considering both economic and environmental benefits of CRU application, it is suggested that the application of N reduction 20% of controlled release urea is a suitable and effective N management mode in the typical double-cropping rice areas around Dongting Lake.更多还原