The carbon cycle in karst area is the perfect joint combining geological process with biological process, so it is very important for accurately estimating the carbon sink effect of karstification to systemically study limestone weathering in farmlands. Taking a hydrological year as a period, corrosion experiment of the standard limestone tablets in farmland samples such as year-round flooded paddy field, seasonal rotation paddy field, vegetation plot, dry land, grassland, unutilized land and so on has been observed. Based on the lime- stone corrosion experiment, on the investigation of soil profiles and biomass of vegetation in the same farm- lands, and on the analytical experimentation of soil and the standard limestone tablets, the characteristics of corrosion of limestone in farmland ecosystems in the area and its influence factors have been analyzed. The result shows that the corrosion ratio decreases successively from seasonal rotation paddy field, to vegetation plot, to dry land and to year-round flooded paddy field. There are obvious differences, and complex changes among corrosion ratio at different soil layers of farmlands in Sanquan Town, Nanchuan City. Karstification in farmland ecosystem in the area is more intense than that in non-farmland ecosystems, and the average annual flux of CO2 absorbed by karstification in farmland ecosystems in the town is 163. 1264 × 10^5 gC/（km^2 · a）. The annual flux of CO2 absorbed by karstification in farmland ecosystems in the region is larger than that in non-farmland of other areas at the same ＂latitude. Principal component analysis shows that karstification in farmland in the region is mainly affected by the location of soil layer, the kinds of farmland, the seasonal change of farmland and the matter sources of soil in farmland ecosystem.%岩溶地区的碳循环是地质作用和生物作用最好的结合点，系统研究农田生态系统中石灰岩溶蚀作用强度对精确估算岩溶作用的碳汇效应具有重要意义。通过在重庆南川市三泉镇选择菜地、旱地、冬水田、两季田、草地、未利用地等样地类型进行以一个水文年为周期的标准溶蚀试片溶蚀试验、土壤剖面与植被样方观测以及土壤、标准溶蚀试片样品分析，探讨了农田生态系统石灰岩溶蚀的主要特征，。并进行农田生态系统岩溶作用影响因素的分析。其结果表明南川市三泉镇农田生态系统岩溶作用强度由大到小依次为两季田、旱地、菜地和冬水田。农田生态系统不同土壤剖面层次的岩溶作用强度差异明显，且变化复杂。农田生态系统岩溶作用的平均强度比非农田生态系统强。该区农田生态系统由于岩溶作用所吸收C02的平均年碳通量为163．J264×10^5g／（km^2·a），比同纬度其他地区天然生态系统高。主成分分析结果表明该区农田生态系统岩溶作用主要受土壤剖面层位、农田生态系统类型、农田生态系统季节变化以及农田生态系统土壤物质来源的影响。
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机译：喀斯特流域退耕还林项目的碳汇效应分析——以贵州省红枫湖流域为例Carbon Sink Effects in Conversion of Farmland to Forest Project in Karst Drainage Basin——A Case of Hongfenghu Drainage Basin in Guizhou Province
