Data collection of soil organic carbon(SOC) of 154 soil series of Jiangsu, China from the second provincial soil survey and of recent changes in SOC from a number of field pilot experiments across the province were co...Data collection of soil organic carbon(SOC) of 154 soil series of Jiangsu, China from the second provincial soil survey and of recent changes in SOC from a number of field pilot experiments across the province were collected. Statistical analysis of SOC contents and soil properties related to organic carbon storage were performed. The provincial total topsoil SOC stock was estimated to be 0 1 Pg with an extended pool of 0 4 Pg taking soil depth of 1 m, being relatively small compared to its total land area of 101700 km 2 One quarter of this topsoil stock was found in the soils of the Taihu Lake region that occupied 1/6 of the provincial arable area. Paddy soils accounted for over 50% of this stock in terms of SOC distribution among the soil types in the province. Experimental data from experimental farms widely distributed in the province showed that SOC storage increased consistently over the last 20 years despite a previously reported decreasing tendency during the period between 1950—1970 The evidence indicated that agricultural management practices such as irrigation, straw return and rotation of upland crops with rice or wheat crops contributed significantly to the increase in SOC storage. The annual carbon sequestration rate in the soils was in the range of 0 3—3 5 tC/(hm 2·a), depending on cropping systems and other agricultural practices. Thus, the agricultural production in the province, despite the high input, could serve as one of the practical methods to mitigate the increasing air CO 2展开更多
农田土壤碳库对缓解气候变化、保证粮食安全具有重要作用。日益加剧的气候变化对农田土壤有机碳库演变的潜在影响受到广泛关注。全球气候变化所带来的温度、降雨和大气二氧化碳(CO2)浓度的改变,会通过影响净初级生产力(NPP)、外源碳投...农田土壤碳库对缓解气候变化、保证粮食安全具有重要作用。日益加剧的气候变化对农田土壤有机碳库演变的潜在影响受到广泛关注。全球气候变化所带来的温度、降雨和大气二氧化碳(CO2)浓度的改变,会通过影响净初级生产力(NPP)、外源碳投入和有机碳分解速率等因素改变生态系统碳循环过程。另外,气候变化也会通过改变土地利用方式和种植制度等农业措施改变生态系统碳循环。综述国内外农田土壤碳库演变对气候变化影响的研究成果表明,到21世纪末,中国气温将会升高3.9—6.0℃,降水有望增加9%—11%。至2050年,气温和降水的变化会造成中国农田系统碳投入相比1980年降低2.3%—10%(小麦、玉米和水稻平均值)。相反,在综合考虑CO2浓度升高的协同作用后,2050年中国农田系统碳投入相比1990年前将会增加13%—22%(平均年增长率0.2%—0.4%)。模型预测显示,至2020、2050和2080年,中国旱地0—30 cm土层有机碳在CO2低排放情景下分别会损失2.7、6.0和7.8 t C·hm-2,在CO2高排放情景下分别会损失2.9、6.8和8.2 t C·hm-2,大概占1980年农田土壤碳的4.5%、10.5%和12.7%。综合碳投入和排放对农田土壤碳库的整体影响来看,21世纪末期中国农田土壤有机碳库含量较1980年会下降10%左右,但如果采取相应的管理措施,可有效抑制农田土壤碳库的降低甚至提高,如农田系统碳投入以每年1%的速度增加时,土壤碳库会在21世纪末增加两倍。目前的研究结果显示,气候变化是否会强烈影响农田土壤碳库依然有很大的不确定因素,其对固碳效应正面和负面影响相互抵消后成为碳源还是碳汇说法不一。因此,在采取缓解气候变化、增加农田土壤固碳的措施的同时,还需加强农田土壤碳库未来变化趋势的研究和探索,为中国政策框架的决定以及未来气候变化谈判提供可靠的科学依据。展开更多
Soil carbon content is an important ecosystem property, especially under the ongoing climate change. The stability of soil organic matter (SOM) is controlled by environmental and biological factors including anthropog...Soil carbon content is an important ecosystem property, especially under the ongoing climate change. The stability of soil organic matter (SOM) is controlled by environmental and biological factors including anthropogenic-induced agricultural management change. However, understanding the effects of anthropogenic activities (e.g., intensive agricultural practices) on carbon stability of soil profiles remains a challenge. The objective of this study was to determine the changes in carbon stocks through soil profiles following agricultural management change from grain fields to greenhouse vegetable fields. The sampling sites were located in an intensive vegetable production area in northernChina. A total of 20 pairs of grain fields (GF) and adjacent vegetable fields (VF) within a distance of50 mwere selected. The results showed that soil organic carbon (SOC) storage increased by 10.6 mg C ha-1 in upper soil layers but decreased by 5.3 mg C hm2 indeeper soil layers due to large input of organic manure and chemical fertilizer following the conversion from GF to VF. Conversion to VF also led to increased dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) concentrations. Extremely higher input of chemical N fertilizer in the VF led to the soil C:N ratio decreased by 2.02 times and the -N leached to deeper soils increased by 3.7 times compared to that in the GF. The pH value and microbial biomass carbon (MBC) content were lower in the VF than in the GF. These results indicate that excessive nitrogen application as fertilizers might lead to deeper soil carbon depletion. Reducing nitrogen addition in intensive agricultural systems is thus necessary to reduce soil carbon loss and to maintain a relatively sustainable soil system.展开更多
玄武岩加强风化是在土壤中添加玄武岩粉末来增强岩石风化作用,形成碳酸盐储存于海洋和土壤中的一种新兴的CO_(2)封存方法.但是加强风化技术的CO_(2)封存量仍有不确定性,中国的不同区域开展加强风化的潜力未知.并且玄武岩的储量分布是否...玄武岩加强风化是在土壤中添加玄武岩粉末来增强岩石风化作用,形成碳酸盐储存于海洋和土壤中的一种新兴的CO_(2)封存方法.但是加强风化技术的CO_(2)封存量仍有不确定性,中国的不同区域开展加强风化的潜力未知.并且玄武岩的储量分布是否满足加强风化的需求,加强风化技术的成本是否优于已有固碳方式,均有待研究.综合温度、降雨和土壤酸碱度构建加强风化速率公式,基于气温、降雨量、土壤酸碱度、土地坡度、土地利用和玄武岩采矿点的空间分布数据,分析了中国不同区域开展加强风化的适宜性和固碳潜力,比较了加强风化与其他固碳方式的经济成本,分析了加强风化技术的影响.结果表明,中国适宜进行加强风化的地区主要集中在长江中下游和黄淮海平原地区,通过在中国适宜地区开展玄武岩加强风化,每十年的固碳量约为0.576~2.83 Gt,封存1 t CO_(2)的成本约为2152￥.与已有的固碳方式相比,其成本低于直接从空气捕集与封存CO_(2)的方法,高于植树造林和生物炭固碳等封存方法.展开更多
文摘Data collection of soil organic carbon(SOC) of 154 soil series of Jiangsu, China from the second provincial soil survey and of recent changes in SOC from a number of field pilot experiments across the province were collected. Statistical analysis of SOC contents and soil properties related to organic carbon storage were performed. The provincial total topsoil SOC stock was estimated to be 0 1 Pg with an extended pool of 0 4 Pg taking soil depth of 1 m, being relatively small compared to its total land area of 101700 km 2 One quarter of this topsoil stock was found in the soils of the Taihu Lake region that occupied 1/6 of the provincial arable area. Paddy soils accounted for over 50% of this stock in terms of SOC distribution among the soil types in the province. Experimental data from experimental farms widely distributed in the province showed that SOC storage increased consistently over the last 20 years despite a previously reported decreasing tendency during the period between 1950—1970 The evidence indicated that agricultural management practices such as irrigation, straw return and rotation of upland crops with rice or wheat crops contributed significantly to the increase in SOC storage. The annual carbon sequestration rate in the soils was in the range of 0 3—3 5 tC/(hm 2·a), depending on cropping systems and other agricultural practices. Thus, the agricultural production in the province, despite the high input, could serve as one of the practical methods to mitigate the increasing air CO 2
文摘农田土壤碳库对缓解气候变化、保证粮食安全具有重要作用。日益加剧的气候变化对农田土壤有机碳库演变的潜在影响受到广泛关注。全球气候变化所带来的温度、降雨和大气二氧化碳(CO2)浓度的改变,会通过影响净初级生产力(NPP)、外源碳投入和有机碳分解速率等因素改变生态系统碳循环过程。另外,气候变化也会通过改变土地利用方式和种植制度等农业措施改变生态系统碳循环。综述国内外农田土壤碳库演变对气候变化影响的研究成果表明,到21世纪末,中国气温将会升高3.9—6.0℃,降水有望增加9%—11%。至2050年,气温和降水的变化会造成中国农田系统碳投入相比1980年降低2.3%—10%(小麦、玉米和水稻平均值)。相反,在综合考虑CO2浓度升高的协同作用后,2050年中国农田系统碳投入相比1990年前将会增加13%—22%(平均年增长率0.2%—0.4%)。模型预测显示,至2020、2050和2080年,中国旱地0—30 cm土层有机碳在CO2低排放情景下分别会损失2.7、6.0和7.8 t C·hm-2,在CO2高排放情景下分别会损失2.9、6.8和8.2 t C·hm-2,大概占1980年农田土壤碳的4.5%、10.5%和12.7%。综合碳投入和排放对农田土壤碳库的整体影响来看,21世纪末期中国农田土壤有机碳库含量较1980年会下降10%左右,但如果采取相应的管理措施,可有效抑制农田土壤碳库的降低甚至提高,如农田系统碳投入以每年1%的速度增加时,土壤碳库会在21世纪末增加两倍。目前的研究结果显示,气候变化是否会强烈影响农田土壤碳库依然有很大的不确定因素,其对固碳效应正面和负面影响相互抵消后成为碳源还是碳汇说法不一。因此,在采取缓解气候变化、增加农田土壤固碳的措施的同时,还需加强农田土壤碳库未来变化趋势的研究和探索,为中国政策框架的决定以及未来气候变化谈判提供可靠的科学依据。
文摘Soil carbon content is an important ecosystem property, especially under the ongoing climate change. The stability of soil organic matter (SOM) is controlled by environmental and biological factors including anthropogenic-induced agricultural management change. However, understanding the effects of anthropogenic activities (e.g., intensive agricultural practices) on carbon stability of soil profiles remains a challenge. The objective of this study was to determine the changes in carbon stocks through soil profiles following agricultural management change from grain fields to greenhouse vegetable fields. The sampling sites were located in an intensive vegetable production area in northernChina. A total of 20 pairs of grain fields (GF) and adjacent vegetable fields (VF) within a distance of50 mwere selected. The results showed that soil organic carbon (SOC) storage increased by 10.6 mg C ha-1 in upper soil layers but decreased by 5.3 mg C hm2 indeeper soil layers due to large input of organic manure and chemical fertilizer following the conversion from GF to VF. Conversion to VF also led to increased dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) concentrations. Extremely higher input of chemical N fertilizer in the VF led to the soil C:N ratio decreased by 2.02 times and the -N leached to deeper soils increased by 3.7 times compared to that in the GF. The pH value and microbial biomass carbon (MBC) content were lower in the VF than in the GF. These results indicate that excessive nitrogen application as fertilizers might lead to deeper soil carbon depletion. Reducing nitrogen addition in intensive agricultural systems is thus necessary to reduce soil carbon loss and to maintain a relatively sustainable soil system.
文摘玄武岩加强风化是在土壤中添加玄武岩粉末来增强岩石风化作用,形成碳酸盐储存于海洋和土壤中的一种新兴的CO_(2)封存方法.但是加强风化技术的CO_(2)封存量仍有不确定性,中国的不同区域开展加强风化的潜力未知.并且玄武岩的储量分布是否满足加强风化的需求,加强风化技术的成本是否优于已有固碳方式,均有待研究.综合温度、降雨和土壤酸碱度构建加强风化速率公式,基于气温、降雨量、土壤酸碱度、土地坡度、土地利用和玄武岩采矿点的空间分布数据,分析了中国不同区域开展加强风化的适宜性和固碳潜力,比较了加强风化与其他固碳方式的经济成本,分析了加强风化技术的影响.结果表明,中国适宜进行加强风化的地区主要集中在长江中下游和黄淮海平原地区,通过在中国适宜地区开展玄武岩加强风化,每十年的固碳量约为0.576~2.83 Gt,封存1 t CO_(2)的成本约为2152￥.与已有的固碳方式相比,其成本低于直接从空气捕集与封存CO_(2)的方法,高于植树造林和生物炭固碳等封存方法.
