摘要
采用小区试验 ,大田试验研究湿地稻 -鸭复合生态系统甲烷排放规律。稻鸭复合生态系统中甲烷排放随季节变化 ,在早稻 -晚稻耕作制度条件下 ,6月上旬和 7月底分别有 2个高峰。早稻与晚稻的排放规律也各异 ,早稻甲烷排放峰值出现在水稻幼穗分化期 ,最高值为 1 3 .6 93 mg/(m2 .h) ,晚稻峰值出现在分蘖盛期 ,可达 2 3 .1 45～ 1 0 5 .5 95 mg/(m2 .h)。养鸭处理与常规栽培甲烷排放差异达极显著水平。稻田养鸭的早稻生育期间甲烷排放总量为 5 .5 1 7g/m2 ,传统栽培为 9.89g/m2 。稻田养鸭的晚稻生育期间排放总量为 1 0 .1 1 3 g/m2 ,传统栽培为 1 7.0 5 4 g/m2 。稻田养鸭与传统栽培比较 ,土壤氧化还原电位增加 1 5 .3 m V,还原物质总量、活性还原物质总量、活性有机还原物质总量分别降低 0 .3 6 5 cmol/kg、0 .2 4 2 cmol/kg和 0 .1 80 cmol/kg。土壤氧化还原特性影响甲烷排放通量 ,土壤还原物质总量、活性还原物质及活性有机还原物质数量与甲烷排放通量的相关系数分别为 0 .80 5、0 .791、0 .76 9。
The pattern of methane emission in wetland rice-duck complex ecosystems was studied in block experiment and field production. The results showed that methane emission displayed clear seasonal variation in rice-duck complex ecosystems. In the case of the early rice-late rice cropping system,methane emission peaked in the first part of June and the end of July respectively.Methane emission also varied by the growth course,For early rice, 2 methane emission peak of 13^693mg/(m 2·h) appeared in the young panicle differentiation stage, and for late rice in the full tiller stage with 23^145～105^595 mg/(m 2·h). The difference in total methane emission between rice-duck complex ecosystems and conventional culture was the most obvious by statistics. For the total course of early rice,methane emission in rice-duck complex systems was 5^517g/m 2 and in conventional culture was 9^891g/m 2. For the total course of late rice,methane emission in rice-duck complex systems was 10^113g/m 2 and in conventional culture was 17^054g/m 2. Comparing rice-duck complex ecosystems to conventional culture,redox status increased by 15^3 mV; reducing matter,active reducing matter and active organic reducing matter decreased by 0^365 cmol/kg, 0^242 cmol/kg and 0^180 cmol/kg respectively. Soil oxidation-reduction characteristics affected the fluxes of methane emission. The correlation between the total reducing matter, active reducing matter, active organic reducing matter and fluxes of methane emission were 0^805+*, 0^791+* and 0^769+* respectively. The improvement in soil oxidation-reduction status of wetland rice-duck complex ecosystem was one of the contributing factors to the reduction of methane emission.
出处
《生态学报》
CAS
CSCD
北大核心
2003年第5期929-934,共6页
Acta Ecologica Sinica
基金
国家 8 63资助项目 (863 -3 0 6-ZD0 5 -3 -E)
国家自然科学基金资助项目 (3 9670 1 4 2 )
湖南省科技厅资助项目(OONKY1 0 0 1 )~~
