CAJ | 학술논문

土壤的有机碳蓄积量及其动态变化,不仅是维持农业生产可持续发展的重要因素,而且在全球变化碳循环研究中具有重要地位。本文基于GIS技术和DNDC模型,以江西省余江县为例,模拟研究了典型红壤丘陵区不同土地利用方式下的土壤有机碳储量及其变化。结果表明：余江县表层土壤有机碳储量为3.52×109kg,平均土壤有机碳密度为4.24 kg m-2。不同利用方式中,灌溉水田的土壤有机碳密度最高,其次是望天田、园地、林地和菜地,旱地的较低,草地的最低。该县土壤有机碳库的年度变化量为8.63×107kg,变化率为＋2.45%。土壤有机碳密度下降的地区多位于农田区内,特别是旱地,部分灌溉水田的碳密度略有增加,林地、园地、草地的土壤有机碳密度是增加的,其中园地的增幅最大。在不考虑土壤流失的情况下,自然植被覆盖下的土壤碳截留能力强于农业植被下的土壤,但是灌溉、施肥、种植绿肥等保护性农业措施可以减少土壤碳的损失,甚至增加有机碳的储量。
토양적유궤탄축적량급기동태변화,불부시유지농업생산가지속발전적중요인소,이차재전구변화탄순배연구중구유중요지위。본문기우GIS기술화DNDC모형,이강서성여강현위례,모의연구료전형홍양구릉구불동토지이용방식하적토양유궤탄저량급기변화。결과표명：여강현표층토양유궤탄저량위3.52×109kg,평균토양유궤탄밀도위4.24 kg m-2。불동이용방식중,관개수전적토양유궤탄밀도최고,기차시망천전、완지、임지화채지,한지적교저,초지적최저。해현토양유궤탄고적년도변화량위8.63×107kg,변화솔위＋2.45%。토양유궤탄밀도하강적지구다위우농전구내,특별시한지,부분관개수전적탄밀도략유증가,임지、완지、초지적토양유궤탄밀도시증가적,기중완지적증폭최대。재불고필토양류실적정황하,자연식피복개하적토양탄절류능력강우농업식피하적토양,단시관개、시비、충식록비등보호성농업조시가이감소토양탄적손실,심지증가유궤탄적저량。
Soil organic carbon（SOC） storage and its dynamic change are not only important factors to maintain agricultural sustainable development,but also play an important role in global carbon cycle.Based on geographical information system（GIS） and soil organic carbon model—denitrification-decomposition model（DNDC）,the SOC storage under different land use types and its annual change in a typical red soil hilly area,Yujiang County in Jiangxi Province,was simulated and analyzed.According to the simulation,the SOC storage in the surface soil horizons of Yujiang County were estimated to be 3.52×109 kg,and the average SOC density was 4.24 kg m-2.The sequence of the SOC densities of different land use types is： irrigated paddy-rice upland-rice orchard forests vegetable land cropland grassland.The annual variation of the SOC storage of Yujiang County was ＋8.63×107kg with an increase of 2.45% without consideration of soil erosion.On the average cropland and vegetable land lost 0.04 kg m-2 and 0.01 kg m-2 respectively,whereas orchard,grassland and forests gained 0.54 kg m-2,0.21 kg m-2,and 0.17 kg m-2 respectively.Land use types and soil management have important influence on soil carbon sequestration.Our results demonstrated that the performance of soil carbon sequestration under natural vegetation is generally higher than that under agricultural vegetation despite soil erosion.For farmland,the source/sink effect of SOC is highly related to the agronomic practices.Conservation managements,such as irrigation,fertilization,and green manure planting,can maintain the storage of SOC.