摘要
在内蒙古农牧交错带,选择4个邻近、不同开垦年限（5、10和50 a）的农田,分别记为C5、C10和C50,以及天然草地作为研究样地;利用静态箱法,在2008—2010年作物生长季（4—10月）进行野外原位试验,研究了土地利用变化对N2O排放量的影响.结果表明：草地与C5、C10、C50农田土壤的N2O排放量在2008—2010年作物生长季均存在显著差异,F分别为53.8、17.3和153.0（P均小于0.001）,草地N2O排放量分别为87.6、91.8和211.0 mg/m^2.在2008—2010年作物生长季,C5和C10农田土壤N2O排放量比草地低10%-50%;随着开垦年限的增加,N2O累积排放量增加,C50在作物生长季的N2O排放量比草地高10%-30%.草地和不同开垦年限的农田土壤在作物生长季内N2O排放量的58.1%受土壤w（NH4＋-N）和含水量的综合影响（R2=0.58,P〈0.01）.
Four adjacent sites with different land-use histories were selected in the agro-grassland ecotone of Inner Mongolia over three growing seasons from 2008-2010. The sites included grassland and cropland eultivated for 5, 10 and 50 years after their conversions. N20 flux measurements were obtained using the closed-chamber method and performed continuously from April to October in 2008, 2009 and 2010, respectively. The results indicated significant differences of NaO emissions between crop/and and grassland in 2008 （ F = 53.8, P〈0.001）, 2009 （F=17.3, P〈0.001） and 2010 （F=153.0, P〈0.001）. Seasonal cumulative N20 emissions were 87.6, 91.8, and 211.0 mg/m2 during seven months for the growing seasons in 2008, 2009 and 2010. From 2008-2010, the cumulative seasonal N20 emissions of the cropland soils that were 5 and 10 years old were 10% -50% less than those of the grasslands, and the seasonal N20 emissions from 50 year-old cropland soil were 10%-30% greater than those of the grasslands. Thus, N20 emissions increased with the growth of the cropland age from 5 to 50 years. The cumulative seasonal N20 emissions of the grassland and cropland soils could be quantitatively predicted from the soil NH4 ^＋-N and moisture concentrations （R2 =0.58, P 〈0.01 ）.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2015年第1期16-22,共7页
Research of Environmental Sciences
基金
国家自然科学基金项目(41165010
41375144)
2013内蒙古高等学校"青年科技英才"支持计划(NJYT-13-B06)
