摘要
以东北黑土区荒地土壤(H)、开垦2 a(L)、30 a(S)和100 a(Y)土壤为对象,在25℃和60%WHC水分条件下,通过7 d的室内培养试验,研究了不同开垦年限黑土温室气体N2O、CO2和CH4的排放规律.结果表明,黑土开垦后理化性质发生了显著改变,进而影响了温室气体的排放.N2O排放量随开垦年限的增加而增加,开垦30 a和100 a土壤的N2O排放量显著高于荒地土壤.净硝化量和N2O排放量与土壤水溶性有机氮和粉粒含量呈显著正相关关系,与土壤pH和砂粒含量呈显著负相关关系.CO2排放量随开垦年限的增加而逐渐降低,开垦30 a和100 a土壤与荒地土壤差异显著.土壤有机碳和水溶性有机碳含量与CO2累积排放量呈显著正相关关系.好氧条件下,荒地土壤和开垦土壤在培养前4 d表现为对CH4的微量排放,然后表现为对CH4的微量吸收,开垦土壤的CH4排放量随开垦年限的增加而增加.不同开垦年限黑土可能因土壤pH、有机碳、水溶性有机碳含量以及土壤机械组成的差异而产生CO2和CH4排放的差异.
Regularity of greenhouse gas emissions from black soil with different reclamation years in northern China was investigated by an incubation experiment. Soil samples cultivated for 2 years, 30 years, 100 years and uncultivated were collected and incubated at 25℃ and a soil moisture of 60% of the water hold capacity (WHC) for 7 days. The results indicated that the physical and chemical properties of black soil changed significantly after reclamation, which had significant influence on the greenhouse gas emissions. N2 O emission was stimulated after soil was reclaimed, the longer time of reclamation, the higher N2 O emitted from soil, and the N2 O emissions from soil cultivated for 30 and 100 years were significantly higher than that from uncultivated soil. There were significant positive correlations between N2 O emission and the content of water organic nitrogen and silt in soil, whereas significant negative correlations were found between pH, sand content and N2 O emission. CO2 emission decreased after the soil was cultivated, and CO2 emission from soil cultivated for 30 and 100 years were significantly lower than that of uncultivated soil. There were significant positive correlations between organic carbon, water organic carbon and CO2 emission. All of the soils behaved as weak sources of CH4 emission during the first 4 days of incubation, and then behaved as weak sink of atmospheric CH4 , the CH4 cumulative emission increased with reclamation years. The difference of CO2 and CH4 emissions from black soil with different reclamation years may be attributed to the difference of soil pH, organic carbon, soluble organic carbon and the contents of sand and silt.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2014年第11期4321-4328,共8页
Environmental Science
基金
国家自然科学基金项目(41301345
41101284)
江苏省高校自然科学研究计划项目(12KJB210004)
江苏省农业气象重点实验室开放基金项目(KYQ1209)
江苏省政府留学奖学金项目
江苏省高等学校大学生实践创新训练计划项目(201310300095X)
