摘要
通过设置四个不同的氮肥管理措施,即氮肥施用量300kgN/ha(N300)和250kgN/ha(N250)、改进的施肥模式(Optimized)以及施用缓释肥(SRU),研究华北平原夏玉米生长季土壤与大气之间CH4和N2O的交换通量及相应措施的减排潜力.结果表明,在2008年整个夏玉米生长季,土壤都是大气CH4的净吸收库和N2O的排放源.夏玉米生长季土壤氧化吸收的CH4总量从大到小依次为Optimized>N250>SRU>N300,对应的吸收总量依次为624.16、590.07、487.89以及316.02gCH4-C/ha,各处理间氧化吸收的CH4总量无显著差异.与N300和N250这两个处理相比,依据夏玉米对氮肥的需肥规律以及玉米根层土壤速效氮的供给能力而确定氮肥施用量,同时再平衡施用磷肥和钾肥的改进施肥模式能够显著降低夏玉米生长季N2O的排放.施用聚乙烯包膜的尿素也能够显著降低夏玉米季N2O的排放.夏玉米生长季土壤排放的N2O总量从大到小依次为N300>N250>Optimized>SRU,对应的排放总量依次为3462.18、2340.07、1680.00以及911.91gN2O-N/ha,相应的N2O排放系数分别为1.15%、0.94%、0.91%以及0.30%.
CH4 and N2O fluxes from summer maize soil in North China Plain were measured in 2008 using a close chamber method. Four different nitrogen management levels were used： nitrogen application at the rate of 300 kg N/ha （N300）, nitrogen application at the rate of 250 kg N/ha （N250）, improved nitrogen management methods （Optimized）, and the application of slow-release urea （SRU）. The summer maize soil was a net sink of CH4 and an emission source of N2O during the whole growing season. The accumulative CH4 oxidation rate of Optimized, N250, SRU, and N300 was 624.16, 590.07, 487.89, and 316.02 g CH4-C/ha, respectively. The difference of accumulative CH4 oxidation rate between four treatments was not significant （t-test, P 〈 0.05）. The Optimized treatment, which applied nitrogen according to maize demand and mineral nitrogen （Nmin） content in the soil of maize root layer, and balance phosphorus and potassium fertilizer application rate, could reduce N20 emission obviously compared to N300 and N250. The application of SRU could also reduce N2O emission significantly. The accumulative N2O emissions of N300, N250, Optimized and SRU were 3462.18, 2340.07, 1680.00, and 911.91 g N20-N/ha, respectively, and the fertilizer-induced N：O emission factors were 1.15, 0.94, 0.91, and 0.30%, respectively.
出处
《中国科学：化学》
CAS
CSCD
北大核心
2011年第1期117-128,共12页
SCIENTIA SINICA Chimica
基金
国家自然科学基金项目(40975079 & 40771098)
国家科技支撑计划(2006BAD17B01)
国家重大基础研究项目(2009CB11860)
国家基金创新群体(30821003)
中德合作项目(GK1070)支持
关键词
CH4
N2O
尿素
缓释肥
玉米
CH4, N2O, urea, slow release urea, summer maize
