【作者】 孙园园；

【导师】 李首成；

【作者基本信息】 四川农业大学 ， 作物栽培学与耕作学， 2007， 硕士

【摘要】 本文以四川省金堂县为研究区域，通过2005年5月～2006年5月对研究区域农户目前的作物栽培制度、管理方法、作物产出等进行调查和分析，进行土样、水样的测定，并结合当地的气象资料，利用DNDC模型模拟目前农户作物生产条件下稻田温室气体的排放情况，并和专家高产管理方法的温室气体排放进行比较。在农户调查的基础上，改变目前的生产条件中的某些影响因子，进一步研究和预测稻田温室气体的排放情况，提出减少研究区域内稻田温室气体排放的措施。主要结论如下：1研究区域农户常规栽培管理水平下CO₂、CH₄和N₂O排放情况（1）冬水田（PF），油菜—水稻田（RR）和小麦-水稻田（RW）。PF、RR和RW的CO₂年排放量分别为：4102 kg·hm^-2、7512 kg·hm^-2和8111 kg·hm^-2。PF水稻生长期和休闲期CO₂排放通量分别为25.48 kg·hm^-2·d^-1和3.36 kg·hm^-2·d^-1，前者是后者的7.58倍。RR和RW水稻生长期CO₂排放通量平均为23.32 kg·hm^-2·d^-1和25.21 kg·hm^-2·d^-1。PF、RR和RW水稻生长期CO₂排放通量差别不大。RR和RW非水稻生长期的CO₂排放通量分别为19.34 kg·hm^-2·d^-1和20.96 kg·hm^-2·d^-1，分别为PF休闲期的5.76和6.24倍。（2）PF水稻生长期CH₄排放通量为2.24 kg·hm^-2·d^-1。休闲期CH₄排放通量为0.51kg·hm^-2·d^-1。水稻生长期CH₄排放通量是休闲期的4.39倍。水稻生长期CH₄排放量为291kg·hm^-2，占全年总CH₄排放量(411 kg·hm^-2)的80.73％。PF的N₂O排放量仅为5.12kg·hm^-2·a^-1。水稻生长期和冬闲期N₂O通量分别为0.033和0.0036 kg·hm^-2·d^-1，前者是后者的9.17倍。水稻生长期N₂O排放量为4.28 kg·hm^-2，占全年总N₂O排放量的83.59％。（3）PF在采用水旱轮作制后，CH₄排放量大大降低，RR和RW全年CH₄排放量分别为146 kg·hm^-2和149 kg·hm^-2，分别为PF的35.64％和36.25％。RR和RW全年N₂O排放量分别为14.78 kg·hm^-2和17.40 kg·hm^-2，分别为PF的2.89倍和3.40倍。（4）CH₄和N₂O的排放量在水稻整个生长季节存在明显的互为消长的关系。CH₄排放多时N₂O排放少，CH₄排放少时N₂O排放多。（5）综合考虑PF、RR和RW排放CO₂、CH₄和N₂O的全球增温潜势（GWP）。PF、RR和RW由CH₄和N₂O产生的GWP：PF>>RW>RR。而由CO₂、CH₄和N₂O产生的GWP：RW>RR>PF。2作物高产管理方法和农民常规方法CO₂、CH₄和N₂O排放量的比较改用专家的管理方法后，全年PF、RR和RW的CO₂排放量分别由4111 kg·hm^-2、7512 kg·hm^-2和8111 kg·hm^-2增加到4187 kg·hm^-2、7794 kg·hm^-2和8427 kg·hm^-2，分别增加了2.07％、3.75％和3.90％；N₂O排放量分别由5.12 kg·hm^-2、14.78 kg·hm^-2和17.40kg·hm^-2增加到7.67 kg·hm^-2、15.79 kg·hm^-2和19.21 kg·hm^-2，分别增加了49.80％、6.83％和10.40％；CH₄的排放量分别由411 kg·hm^-2、146 kg·hm^-2和149 kg·hm^-2减少到319kg·hm^-2、65 kg·hm^-2和67 kg·hm^-2，分别减少了22.38％、55.62％和55.03％；全年CO₂、CH₄和N₂O的GWP，分别减少了8.47％、8.48％和6.20％。3模拟不同栽培条件的改变对温室气体排放的影响（1）在氮肥种类和用量方面：施用相同纯氮量的氮肥，就N₂O排放量而言，尿素要显著高于碳铵。氮肥施用量（折纯N）大于200 kg·hm^-2，N₂O排放量均随每百千克纯氮的投入量增加呈极显著增加。（2）有机肥种类和动物粪尿投入量方面：相同碳含量有机肥的施用条件下，CH₄排放量（p＜0.01）：农家肥>>绿肥≈稻草秸杆≈动物粪尿≈堆肥；N₂O排放量（p＜0.01）：动物粪尿>>农家肥≈绿肥＞稻草秸杆≈堆肥。随着动物粪尿施肥量的增加，CO₂、CH₄和N₂O的排放量均增加。（3）晒田和不晒田：冬水田采用专家的晒田方法，CH₄排放量减少了27.57％；N₂O和CO₂排放量都略有增加，而总的GWP下降了9.10％。（4）耕地深度：随着耕地深度的增加，CO₂的排放量逐渐增加，CH₄的排放量下降。在0～10cm范围内，N₂O排放量随着耕地深度的增加而增加，但在耕地深度达20 cm时，N₂O排放量减少，其原因还有待于进一步研究。（5）年平均气温和年降雨量变化方面：随着年平均气温的增加，各种温室气体的年排放量均呈增加趋势，存在正反馈的效应。随着年降雨量的增加，对CO₂和CH₄排放量影响不大，而N₂O的排放量逐渐减少。（6）土壤PH值、有机质含量和质地变化：土壤PH值变化对CO₂和CH₄排放量影响不大，而N₂O的排放量随PH值的变化呈“抛物线”形状；土壤PH=7左右时，N₂O的排放量最大。土壤有机质方面，随着土壤有机质含量的增加，CO₂的排放量呈极显著增加，N₂O的排放量呈显著增加，而CH₄气体的排放量增加不显著。土壤质地方面，随土壤粘性的增大，CO₂、CH₄和N₂O的排放量均减少。更多还原

【Abstract】 CO₂, CH₄ and N₂O are three important greenhouse gases. For the reason of human activities the concentration of CO₂, CH₄ and N₂O have been increasing clearly since the industrial revolution. A study indicates that rice paddy fields are one of the most important biology sources of CO₂, CH4 and N₂O.Therefore, CO₂, CH₄ and N₂O emissions from rice fields are given more attentions in the field of global climate change in recent years.Research of tillage-cropping systems on greenhouse gas （CO₂, CH₄ and N₂O） emissions from three kinds of paddy-rice fields in a central Sichuan hilly area of southwest china from May 2005 to May 2006—in case of jintang in Sichuan province in this dissertation. Have a detailed farmer investigate ,include crop type , tillage ,fertilizer, manure type, irrigation ,output and so on. Mensurate soil pH, N concentration in rainfall, bulk density and so on.Simulate the CO₂, CH₄ and N₂O fluxs from paddy-rice fields by peasants.Research the variations in CO₂, CH₄ and N₂O emissions from rice paddy fields between peasants and experts.Research CO₂, CH₄ and N₂O fluxs from permanently floodedpaddy-rice fields by chang one of the factors in DNDC model.Put forward ways and means to reduce greenhouse gas emissions.The results show that:（1） Research the CO₂, CH₄ and N₂O fluxs from paddy-rice fields by peasants.①CO₂ fluxs from three kinds of paddy-rice fields during the growth period of paddy-rice are similar.CO₂ emissions in not the growth period of paddy-rice were increased after conducting rapeseed-paddy rice fields （RR） and winter wheat-paddy rice fields （RW） systems, which were 5.76 and 6.24 times larger than those of permanently flooded paddy fields （PF）. CO₂ emissions in fallow period were 7.58 times larger than the growth period in permanently flooded paddy fields.②The average CH₄ fluxes from a permanently flooded rice field with a single middle rice crop and flooded with PF were 2.24 kg·hm^-2·d^-1 and 0.512 kg·hm^-2·d^-1 during rice-growing and non-rice growing periods, respectively. The annual CH₄ emission was mainly occurred in the rice growing period, being only 29.27% of the total annual CH₄ flux emitted from the non-rice growing period, though the latter occupied two thirds of a year. The annual average flux of nitrous oxide was 0.014 kg·hm^-2·d^-1 and the N₂O emission also intensive in the rice growing period. However, being only 16.41% of total annual N₂O flux emitted from the non-rice growing period.③After implementing the rice oil-seed rape rotation （RR） and rice-wheat rotation （RW）, the CH₄ emissions were reduced substantially, only 35.64 % and 36.25 % of those of PF, respectively. However, the N₂O emissions were increased after conducting RR and RW systems, which were 2.89 and 3.40 times larger than those of PF.④There was a clear trade-off between CH4 and N₂O emission in paddy fields during the growth period of paddy-rice.⑤The global warming potentials （GWPs） of the CO₂, CH₄ and N₂O emissions under the three tillage-cropping systems were assessed in an integrated way. The results show that the integrated GWPs of the CH₄ and N₂O emissions are in the following sequence: PF＞＞RW＞RR. After introducing rice-wheat or rice oil-seed rape rotation systems into the permanently flooded rice fields, the integrated GWPs of the CH₄ and N₂O emissions were decreased largely. But the results show that the integrated GWPs of the CO₂, CH₄ and N₂O emissions are in the following sequence: RW＞RR＞PF.（2） Variations in CO₂, CH₄ and N₂O emissions from rice paddy fields between peasants and expertsCO₂ fluxs from permanently flooded paddy-rice fields increased 2.08%～3.90 % byuse experts’ theoretics. N₂O fluxs from permanently flooded paddy-rice fields increased 49.80 %, 6.83 % and 10.40 % in permanently flooded paddy fields, rapeseed-paddy rice fields and winter wheat-paddy rice fields. CH₄ fluxs from permanently flooded paddy-rice fields reduced 22.38 %, 55.62 % and 55.03 % in permanently flooded paddy fields, rapeseed-paddy rice fields and winter wheat-paddy rice fields.（3） CO₂, CH₄ and N₂O fluxs from permanently flooded paddy-rice fields by chang one of the factors in DNDC model.①The amounts of N₂O flux from permanently flooded paddy-rice fields with the same quantity N account between Urea and ammonium: Urea＞ammonium. There is a linear relationship between N₂O fluxs of Urea and ammonium.N₂O flux from permanently flooded paddy-rice fields increasing with the increase of the N account increased in 100 kg. There is a linear relationship between N₂O fluxs and the amount of nitrogenous fertilizer.②The Amounts of CH₄ flux from permanently flooded paddy-rice fields with the same quantity C account during different organic manures: farmyard＞＞green≈starw≈liquid animal≈compostThe Amounts of N₂O flux from permanently flooded paddy-rice fields with the same quantity C account during different organic manures: liquid animal＞＞farmyard≈green＞starw≈compost CO₂, CH₄ and N₂O fluxs from permanently flooded paddy-rice fields are increasing with the enhance of the dosage of liquid animal manure.③CH₄ flux from permanently flooded paddy-rice fields were reduced of 27.57 % because the paddy-fields were basked by the method of experts. And the GWP were reduced of 9.10 %.④CO₂ flux from rice field increasing with the depths of tillage. But CH₄ flux from rice field reducing with the depths of tillage. In the range of 0～10cm under the different depths of tillage, N₂O flux from rice field increasing with the different depths of tillage, there is a linear relationship between N₂O flux and the different depths of tillage. But when the depth of tillage goes to 20cm, N₂O flux from rice field reduced.⑤CO₂, CH₄ and N₂O fluxs from rice field increasing with the increase of temperature, there is a linear relationship between CO₂, CH₄ and N₂O fluxs and temperatures.⑥In the range of pH 5-7, N₂O flux from rice field increasing with the soil pH, there is a linear relationship between N₂O flux and pH of soil. In the range of pH 7-9, N₂O flux from rice field reducing with the soil pH, there is a linear relationship between N₂O flux and pH of soil.CO₂ and N₂O fluxs from rice field increasing with the different soil organic C contents, there is a linear relationship between CO₂, N₂O flux and the different soil organic C contents. CO₂, CH₄ and N₂O fluxs from rice field reducing with the soil glutinosity, there is a linear relationship between CO₂, CH4 and N₂O fluxs and soil glutinosity.更多还原