减少因氮肥施用而产生的N_2O对于全球N_2O的减排具有重要作用。本研究利用静态暗箱-气相色谱法,对农民习惯施肥(FP)、氮肥条施(ND)、缓控释氮肥(CRF)和一次性分层施肥(LD)4个氮肥管理措施下的华北地区夏玉米农田生态系统N_2O排放进行了...减少因氮肥施用而产生的N_2O对于全球N_2O的减排具有重要作用。本研究利用静态暗箱-气相色谱法,对农民习惯施肥(FP)、氮肥条施(ND)、缓控释氮肥(CRF)和一次性分层施肥(LD)4个氮肥管理措施下的华北地区夏玉米农田生态系统N_2O排放进行了观测,并分析不同处理下的N_2O减排效果和减排成本。结果表明,玉米季农田土壤N_2O排放峰值主要出现在施肥并灌溉后,峰值持续时间一般为3~5 d。与FP相比,ND、CRF和LD可以显著降低土壤N_2O的排放峰值,N_2O排放总量减少12.6%~18.9%,三者的减排效果依次为LD>CRF>ND。ND、CRF和LD均有N_2O减排和玉米增产的作用,但由于劳动力成本的提高,仅CRF和LD处理略有增收。与FP相比,三者的单位产量N排放强度和单位净收益N排放强度均有所降低。本试验条件下,每减排1 kg CO_2-eq,CRF可减少成本0.97元,而ND和LD的减排成本分别增加4.83和3.23元。如果生产中使用施肥机械,一次性分层施肥的减排成本可节省2元。综合来看,若无配套施肥机械,施用缓控释肥可被选为夏玉米保产减排且效益最优的氮肥管理措施;反之,也可选用一次性分层施肥。展开更多
Climate mitigation has become a global issue and most countries have promised their greenhouse gas reduction target. However, after Trump took office as president of the United States （US）, the US withdrew from the ...Climate mitigation has become a global issue and most countries have promised their greenhouse gas reduction target. However, after Trump took office as president of the United States （US）, the US withdrew from the Paris Agreement. As the biggest economy, this would have impacts on the emission space of other countries. This paper, by using the integrated model of energy, environ- ment and economy/computable general equilibrium （IMED/CGE） model, assesses the impacts of the US withdrawal from Paris Agreement on China, India in terms of carbon emission space and mitigation cost under Nationally Determined Contributions （NDCs） and 2~C scenarios due to changed emission pathway of the US. The results show that, under the condition of constant global cumulative carbon emissions and fixed burden sharing scheme among the countries, the failure of the US to honor its NDC commitment will increase its carbon emission space and decrease its mitigation cost. However, the carbon emission space of other regions, including China and India, will be reduced and their mitigation costs will be raised. In 2030, under the 2℃ target, the carbon price will increase by US$14.3 to US$45.3/t in China and by US S10.7 to US$33.9/t in India. In addition, China and India will incur additional GDP loss. Under the 2℃ target, the GDP loss of China would increase by US$23.3 to US$72.6 billion （equivalent to US$17.4 to US$54.2/capita）, and that of India would rise by US$14.2 to US$43.1 billion （equivalent to US$9.3 to US$28.2/capita）.展开更多
文摘减少因氮肥施用而产生的N_2O对于全球N_2O的减排具有重要作用。本研究利用静态暗箱-气相色谱法,对农民习惯施肥(FP)、氮肥条施(ND)、缓控释氮肥(CRF)和一次性分层施肥(LD)4个氮肥管理措施下的华北地区夏玉米农田生态系统N_2O排放进行了观测,并分析不同处理下的N_2O减排效果和减排成本。结果表明,玉米季农田土壤N_2O排放峰值主要出现在施肥并灌溉后,峰值持续时间一般为3~5 d。与FP相比,ND、CRF和LD可以显著降低土壤N_2O的排放峰值,N_2O排放总量减少12.6%~18.9%,三者的减排效果依次为LD>CRF>ND。ND、CRF和LD均有N_2O减排和玉米增产的作用,但由于劳动力成本的提高,仅CRF和LD处理略有增收。与FP相比,三者的单位产量N排放强度和单位净收益N排放强度均有所降低。本试验条件下,每减排1 kg CO_2-eq,CRF可减少成本0.97元,而ND和LD的减排成本分别增加4.83和3.23元。如果生产中使用施肥机械,一次性分层施肥的减排成本可节省2元。综合来看,若无配套施肥机械,施用缓控释肥可被选为夏玉米保产减排且效益最优的氮肥管理措施;反之,也可选用一次性分层施肥。
文摘Climate mitigation has become a global issue and most countries have promised their greenhouse gas reduction target. However, after Trump took office as president of the United States （US）, the US withdrew from the Paris Agreement. As the biggest economy, this would have impacts on the emission space of other countries. This paper, by using the integrated model of energy, environ- ment and economy/computable general equilibrium （IMED/CGE） model, assesses the impacts of the US withdrawal from Paris Agreement on China, India in terms of carbon emission space and mitigation cost under Nationally Determined Contributions （NDCs） and 2~C scenarios due to changed emission pathway of the US. The results show that, under the condition of constant global cumulative carbon emissions and fixed burden sharing scheme among the countries, the failure of the US to honor its NDC commitment will increase its carbon emission space and decrease its mitigation cost. However, the carbon emission space of other regions, including China and India, will be reduced and their mitigation costs will be raised. In 2030, under the 2℃ target, the carbon price will increase by US$14.3 to US$45.3/t in China and by US S10.7 to US$33.9/t in India. In addition, China and India will incur additional GDP loss. Under the 2℃ target, the GDP loss of China would increase by US$23.3 to US$72.6 billion （equivalent to US$17.4 to US$54.2/capita）, and that of India would rise by US$14.2 to US$43.1 billion （equivalent to US$9.3 to US$28.2/capita）.
