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通过原位采集淹水和排水状态下土壤剖面4个层次的气体,研究氧化亚氮(N2O)在水旱轮作体系稻田土壤剖面中的动态分布特征.试验设置小麦-单季稻和油菜-双季稻两种轮作体系,包括施N和不施N两种施肥方式.结果表明:施用N肥极显著促进了土壤剖面N2O的产生(P<0.01),不同层次间N2O浓度相关性极显著(P<0.01),小麦、油菜生长期施N和无N处理下层30cm和50cm处N2O浓度均高于表层7cm和15cm处;早稻无N处理则为表层7cm和15cm处高于下层30cm和50cm处(P<0.05),其他水稻处理各层次间无显著差异.无N处理土壤N2O峰值出现在旱作向水稻的转变期,施N处理则出现在旱作第2次追肥后,季节转变期也有较高的N2O浓度.
The dynamic distribution characteristics of N2O in paddy soil profile of a rotation-flowering farming system were studied by in situ collection of four layers of soil profiles in submerged and drained soil profiles.The experiment set up wheat-single cropping rice and rape-double cropping rice The results showed that applying N fertilizer significantly promoted the production of N2O in soil profile (P <0.01), and the correlation between N2O concentrations in different layers was significant (P < 0.01). The N2O concentrations at 30 cm and 50 cm in wheat and rapeseed were lower than those at 7 cm and 15 cm in the lower layer of N and N treatments, while those at 7 cm and 15 cm in early rice were higher than those at 30 cm and 50 cm <0.05), there was no significant difference in the other rice treatments.The peak N2O in the soil without N appeared in the transitional period from the dryland to the paddy, while the N treatment appeared after the second topdressing in the dry land, and the season transitional period was also higher Of N2O concentration.