【作者】 白东升；

【导师】 杨治平；

【作者基本信息】 山西大学 ， 水土保持与荒漠化防治， 2009， 硕士

【摘要】 N₂O是一种相当重要的温室效应气体,它的存在也严重地破坏了大气中的臭氧层。本研究采用田间试验,通过采集气样,分析了在不同施肥管理方式下,华北平原潮褐土区夏玉米农田N₂O的排放量。试验结果表明,不同施肥处理对农田N₂O排放量影响不同,农田N₂O排放量随着土壤中氮素含量的增加而升高;农田土壤含水量和土壤温度也影响了农田N₂O的排放。通过本次试验,得出主要结论如下:1)华北潮褐土区冬小麦-夏玉米体系下夏玉米地N₂O的排放主要是与农田施氮量有关。农田N₂O排放量随施肥量（施N量）的增加而增加,二者之间达到了极显著正相关关系。2)农田N₂O的排放量与土壤湿度有关。当土壤湿度（土壤含水量）小于田间持水量时,农田N₂O排放量随土壤含水量的增大而增加,起先硝化作用是产生N₂O的主要机理,当土壤含水量达到一定程度时,反硝化作用是N₂O产生的主要机理,此时是表土硝化作用、底土反硝化作用占主要地位;土壤湿度（土壤含水量）等于田间持水量时,农田N₂O排放量的稳定程度达到最大;当土壤含水量大于田间持水量时,农田N₂O排放量随土壤含水量的增大而逐渐变小。3)农田N₂O的排放量与土壤温度有关。在土壤温度达到30摄氏度时,农田N₂O排放量最大。在土壤温度低于30摄氏度时,农田N₂O排放量随着土壤温度的升高而增大;当土壤温度高于30摄氏度时,农田N₂O排放量随着土壤温度的升高而降低。4)经过各项指标的对比,DMPP管理模式更可取。尽管优化配置管理方式（180N）处理夏玉米的产量稍高于120N处理与DMPP处理管理模式下夏玉米产量,但是180N处理农田N₂O的排放量要比120N处理与DMPP处理排放量高的多,而且180N处理的施用氮肥量要比120N处理和DMPP处理施用氮肥量高;结合DMPP处理夏玉米的产量稍高于120N处理的产量,而且其农田N₂O的排放量要远远低于120N处理的排放量,所以DMPP处理管理模式优于120N处理模式与180N处理模式。通过本次试验,确定了华北潮褐土区夏玉米最佳施肥管理方式,从而达到指导农民合理施肥,同时实现温室气体减排的目的。更多还原

【Abstract】 N₂O is one kind of important green-house gases;its existence also severely destroyed the atmospheric ozone layer.This paper makes a study of the emission amount of N₂O under the different administration mode in the process of applying a fertilizer on the basis of the field test of the summer maize in the meadow-cinnamon soil area and the types of gathering gas.The result proves that the amount of N₂O emission would increase with the nitrogen input and seasonal variation of N₂O emission flux is significantly determined by water situation and soil temperature of maize fields. Throughout this study,the following points can be listed:1) Under the system of winter wheat-summer maize of Cinnamon tidal zone in North China,the amount of N₂O emissions are mainly related with the nitrogen application amount of farmland.The amount of N₂O emissions of agricultural land increase with applying amount of the fertilizer（N-volume） and the two reaches a very significant positive correlation.2) The amount of N₂O emissions of farmland relates with soil moisture.When soil moisture（water content in soil） is less than field capacity,the amount of N₂O emissions increase with soil moisture.At the very beginning nitrification is the main mechanism of N₂O producing,as the soil moisture content up to a certain extent,denitrification is the main mechanism of N₂O producing,and this moment the topsoil nitrification and subsoil denitrification dominate the main role.As soil moisture equals to field capacity,the amount of N₂O emissions of farmland maintain at the stable maximum index,as soil moisture content is more than field capacity,the amount of N₂O emissions become smaller phasing with the increase of soil moisture.3) The amount of N₂O emissions of farmland connect with soil temperature.As the soil temperature reaches at 30 degrees Celsius,the amount of N₂O emissions of farmland is the maximum.As the soil temperature below 30 degrees Celsius,the amount of N₂O emissions of farmland will increase with temperature;when the soil temperature is above 30 degrees Celsius,the amount of N₂O emissions of farmland will decrease with temperature.4) Concerning of comparison the various index,DMPP is the preferred management model.Although the output of summer corn is slightly higher in the mode of the optimal allocation of management（180N） than in the mode of the 120N and DMPP,the amount of N₂O emissions of farmland is much higher as well as the amount of the nitrogen fertilizer application.Furthermore,The output of summer corn is higher in the mode of DMPP than that of 120N, taking all the previous comparison index into account,the DMPP mode is the best choice.Throughout this test,this paper identifies the best management mode of the summer maize in the meadow-cinnamon soil so as to provide the guide for the farmer and to realize the aim of the green-house gas cut.更多还原