紫色土坡耕地可溶性有机碳淋失特征
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摘要
可溶性有机碳(dissolved organic carbon,DOC)在土壤-水界面的径流迁移是土壤有机碳损失的主要形式之一,其迁移损失对土壤有机碳库的源汇功能有重要的影响。为探明紫色土坡耕地DOC的径流迁移特征,利用可测壤中流的径流小区观测壤中流DOC的迁移,结合夏玉米不同生长期土壤DOC含量动态变化分析,研究紫色土壤中流DOC淋失过程与通量。结果表明,土壤DOC含量在玉米生长期逐渐增加,到抽雄期达到最大值,收获期逐渐降至最低。2009—2011年壤中流平均径流量为264 mm,占夏季径流量的68%,表明壤中流是紫色土坡耕地径流的主要形式。壤中流径流量与降雨量呈现极显著正相关性(P<0.01),与降水强度相关性不显著。壤中流过程DOC质量浓度表现为先升后降再趋于稳定的趋势,且与径流速率呈极显著正相关关系(P<0.01)。3年内次降雨产流事件中壤中流DOC质量浓度为1.7～4.6 mg·L~(-1),平均为3.2 mg·L~(-1)。壤中流DOC迁移负荷分别为565.5、802.1和1 090.1mg·m~(-2),平均年累积迁移负荷为819.2mg·m~(-2)。DOC淋失量在玉米不同生长时期变化较为明显,主要发生在抽雄期至成熟期,淋失总量为658.4mg·m~(-2),占年平均淋失负荷的81%,与玉米生长期土壤DOC含量变化趋势基本一致。研究结果可为调控紫色土坡耕地DOC迁移淋失及评价土壤有机碳平衡提供一定的参考和依据。
Runoff is a major driver for dissolved organic carbon(DOC) diffusing into aquatic ecosystems. The transportation of DOC during storm events could have measurable impacts on the global carbon cycle. This study aimed to gain insight into the process and flux of transport of DOC in runoff as affected by rainfall characteristics. A free-drain lysimeter experiment was conducted to quantify dissolved organic carbon leaching losses(2009-2011) in sloping cropland in the purple soil area, southwestern China. Soil DOC concentrations increased distinctly from sowing to stamen stage, and then decreased to the minimum at harvest in the maize grown season. The average annual discharge of the interflows was 264 mm, accounting for 68% of total runoff in the rainy season in 2009-2011. It indicated that interflow was the main transport pathway of dissolved organic carbon in the rainy season. There was a significant positive correlation between the discharges of the interflow and rainfall. DOC concentrations increased at the initial period of a rainfall event and declined steadily, and it had a positive correlation with interflow discharge velocity. The average DOC concentrations in interflow were ranged from 1.7 to 4.6 mg·L~(-1), with an average of 3.2 mg·L~(-1). Annual loss fluxes of DOC through interflow were 565.5, 802.1 and 1 090.1 mg·m~(-2), respectively, during the experiment period, with an average of 819.2 mg·m~(-2). DOC leaching flux through the interflow showed clear seasonal patterns, and largely occurred in the stages from stamen to maturity of maize with a flux of 658.4 mg·m~(-2), about 81% of the annual total loss flux. This result responded with seasonal change of soil DOC concentrations during corn growth. The interflow discharge monitoring method used in this study proved to be useful and effective for quantifying DOC leaching losses at the field scale in hillslope cropland areas. This research will provide some basis data in regulating DOC leaching of purple soil sloping farmlands and evaluating the balance of soil organic carbon.
Runoff is a major driver for dissolved organic carbon(DOC) diffusing into aquatic ecosystems. The transportation of DOC during storm events could have measurable impacts on the global carbon cycle. This study aimed to gain insight into the process and flux of transport of DOC in runoff as affected by rainfall characteristics. A free-drain lysimeter experiment was conducted to quantify dissolved organic carbon leaching losses(2009-2011) in sloping cropland in the purple soil area, southwestern China. Soil DOC concentrations increased distinctly from sowing to stamen stage, and then decreased to the minimum at harvest in the maize grown season. The average annual discharge of the interflows was 264 mm, accounting for 68% of total runoff in the rainy season in 2009-2011. It indicated that interflow was the main transport pathway of dissolved organic carbon in the rainy season. There was a significant positive correlation between the discharges of the interflow and rainfall. DOC concentrations increased at the initial period of a rainfall event and declined steadily, and it had a positive correlation with interflow discharge velocity. The average DOC concentrations in interflow were ranged from 1.7 to 4.6 mg·L~(-1), with an average of 3.2 mg·L~(-1). Annual loss fluxes of DOC through interflow were 565.5, 802.1 and 1 090.1 mg·m~(-2), respectively, during the experiment period, with an average of 819.2 mg·m~(-2). DOC leaching flux through the interflow showed clear seasonal patterns, and largely occurred in the stages from stamen to maturity of maize with a flux of 658.4 mg·m~(-2), about 81% of the annual total loss flux. This result responded with seasonal change of soil DOC concentrations during corn growth. The interflow discharge monitoring method used in this study proved to be useful and effective for quantifying DOC leaching losses at the field scale in hillslope cropland areas. This research will provide some basis data in regulating DOC leaching of purple soil sloping farmlands and evaluating the balance of soil organic carbon.
引文
BOLAN N S,ADRIANO D C,KUNHIKRISHNAN A,et al.,2011.Dissolved organic matter:biogeochemistry,dynamics,and environmental significance in soils[J].Advances in agronomy,110:1-75.
BOYER J N,DAILEY S K,GIBSON P J,et al.,2006.The role of dissolved organic matter bioavailability in promoting phytoplankton blooms in Florida Bay[J].Hydrobiologia,569(1):71-85.
DUSEK J,VOGEL T,DOHNAL M,et al.,2017.Dynamics of dissolved organic carbon in hillslope discharge:Modeling and challenges[J].Journal of Hydrology,546:309-325.
FLEMING-LEHTINEN V,KORTELAINEN P,KAUPPILA P,et al.,2015.Organic carbon concentrations in the Northern Coastal Baltic Sea between 1975 and 2011[J].Estuarine Coasts,38(2):466-481.
GAELEN N V,VERSCHOREN V,CLYMANS W,et al.,2014.Controls on dissolved organic carbon export through surface runoff from loamy agricultural soils[J].Geoderma,226:387-396.
GERKE H H,RIECKH H,SOMMER M,2016.Interactions between crop,water,and dissolved organic and inorganic carbon in a hummocky landscape with erosion-affected pedogenesis[J].Soil Tillage Research,156:230-240.
HERBRICH M,GERKE H H,BENS O,et al.,2017.Water balance and leaching of dissolved organic and inorganic carbon of eroded Luvisols using high precision weighing lysimeters[J].Soil Tillage Research,165:144-160.
HOPE D L,PALMER S M,BILLETT M F,et al.,2004.Variations in dissolved CO2 and CH4 in a first-order stream and catchment:an investigation of soil stream linkages[J].Hydrological Processes,18:3255-3275.
HORNBERGER G M,GERMANN P F,BEVEN K J,1991.Through flow and solute transport in an isolated sloping soil block in a forested catchment[J].Journal of Hydrology,124(122):81-99.
HUA K K,ZHU B,WANG X G,2014.Dissolved organic carbon loss fluxes through runoff and sediment on sloping upland of purple soil in the Sichuan Basin[J].Nutrient Cycling in Agroecosys,98(2):125-135.
LI K,XING B,TORELLO W A,2005.Effect of organic fertilizers derived dissolved organic matter on pesticide sorption and leaching[J].Environmental Pollution,134(2):187-194.
LONG G Q,JIANG Y J,SUN B,2015.Seasonal and inter-annual variation of leaching of dissolved organic carbon and nitrogen under long-term manure application in an acidic clay soil in subtropical China[J].Soil Tillage Research,146(Part B):270-278.
MARTIN H C,2003.Dissolved and water-extractable organic matter in soils:a review on the influence of land use and management practices[J].Geoderma,113(3-4):357-380.
MCDOWELL W H,2003.Dissolved organic matter in soils-future directions and unanswered questions[J].Geoderma,113(3-4):179-186.
MICHALZIK B,TIPPING E,MULDER J,et al.,2003.Modelling the production and transport of dissolved organic carbon in forest soils[J].Biogeochemistry,66(3):241-264.
NELE V G,VEERLE V,VIM C,et al.,2014.Controls on dissolved organic carbon export through surface runoff from loamy agricultural soils[J].Geoderma,226:387-396.
PACHECO F S,ROLAND F,DOWNING J A,2013.Eutrophication reverses whole-lake carbon budgets[J].Inland Waters,4(1):41-48.
PETRY J,SOULSBY C,MALCOLM I A,2002.Hydrological controls on nutrient concentrations and fluxes in agricultural catchments[J].Science of Total Environment,294(1-3):95-110.
RIECKH H,GERKE,H H,SOMMER M,2014.Water and dissolved carbon fluxes in an eroding soil landscape depending on terrain position[J].Vadose Zone Journal,13(7):124-129.
SINGH S,GHOSHAL N,SINGH K P,2007.Variations in soil microbial biomass and crop roots due to differing resource quality inputs in a tropical dryland agroecosystem[J].Soil Biology&Biochemistry,39:76-86.
SONG K S,WEN Z D,SHANG Y X,et al.,2018.Quantification of dissolved organic carbon(DOC)storage in lakes and reservoirs of mainland China[J].Science of Total Environment,217:391-402.
SOULSBY C,PETRYA C,BREWERB M J,2003.Identifying and assessing uncertainty in hydrological pathways:a novel approach to end member mixing in a Scottish agriculture catchment[J].Journal of Hydrology,274(1-4):109-128.
TRANVIK L J,DOWNING J A,COTNER J B,et al.,2009.Lakes and reservoirs as regulators of carbon cycling and climate[J].Limnology&Oceanography,54(6):2298-2314.
TRANVIK L J,JANSSON,2002.Climate change:terrestrial export of organic carbon[J].Nature,415(6874):861-862.
VEUM K S,GOYNE K W,MOTAVALLI P P,2009.Runoff and dissolved organic carbon loss from a paired-watershed study of three adjacent agricultural Watersheds[J].Agriculture,Ecosystem&Environment,130(3-4):115-122.
ZHU B,WANG T,KUANG F H,2009.Measurements of nitrate leaching from a hill slope cropland in the central Sichuan Basin,China[J].Soil Science Society of America Journal,73:1419-1426.
郭太龙,谢金波,孔朝晖,等,2015.华南典型侵蚀区土壤有机碳流失机制模拟研究[J].生态环境学报,24(8):1266-1273.
花可可,朱波,王小国,等,2013.紫色土坡耕地可溶性有机碳径流迁移特征[J].农业工程学报,29(5):81-88.
李太魁,郭战玲,寇长林,等,2017.提取方法对土壤可溶性有机碳测定结果的影响[J].生态环境学报,26(11):1878-1884.
李仲明,张先婉,何毓蓉,1991.中国紫色土[M].北京:科学出版社.
汪涛,2007.紫色土坡地硝态氮淋失过程研究[D].成都:中国科学院成都山地灾害与环境研究所:61-63.
杨玉盛,郭剑芬,陈光水,等,2003.森林生态系统DOM的来源、特性与流动[J].生态学报,23(3):547-558.
张永领,高全洲,黄夏坤,等,2007.西江溶解有机碳的输送对典型洪水过程的响应[J].环境科学学报,27(1):143-150.
朱波,汪涛,况福虹,等,2008.紫色土坡耕地硝酸盐淋失特征[J].环境科学学报,28(3):525-533.
BOYER J N,DAILEY S K,GIBSON P J,et al.,2006.The role of dissolved organic matter bioavailability in promoting phytoplankton blooms in Florida Bay[J].Hydrobiologia,569(1):71-85.
DUSEK J,VOGEL T,DOHNAL M,et al.,2017.Dynamics of dissolved organic carbon in hillslope discharge:Modeling and challenges[J].Journal of Hydrology,546:309-325.
FLEMING-LEHTINEN V,KORTELAINEN P,KAUPPILA P,et al.,2015.Organic carbon concentrations in the Northern Coastal Baltic Sea between 1975 and 2011[J].Estuarine Coasts,38(2):466-481.
GAELEN N V,VERSCHOREN V,CLYMANS W,et al.,2014.Controls on dissolved organic carbon export through surface runoff from loamy agricultural soils[J].Geoderma,226:387-396.
GERKE H H,RIECKH H,SOMMER M,2016.Interactions between crop,water,and dissolved organic and inorganic carbon in a hummocky landscape with erosion-affected pedogenesis[J].Soil Tillage Research,156:230-240.
HERBRICH M,GERKE H H,BENS O,et al.,2017.Water balance and leaching of dissolved organic and inorganic carbon of eroded Luvisols using high precision weighing lysimeters[J].Soil Tillage Research,165:144-160.
HOPE D L,PALMER S M,BILLETT M F,et al.,2004.Variations in dissolved CO2 and CH4 in a first-order stream and catchment:an investigation of soil stream linkages[J].Hydrological Processes,18:3255-3275.
HORNBERGER G M,GERMANN P F,BEVEN K J,1991.Through flow and solute transport in an isolated sloping soil block in a forested catchment[J].Journal of Hydrology,124(122):81-99.
HUA K K,ZHU B,WANG X G,2014.Dissolved organic carbon loss fluxes through runoff and sediment on sloping upland of purple soil in the Sichuan Basin[J].Nutrient Cycling in Agroecosys,98(2):125-135.
LI K,XING B,TORELLO W A,2005.Effect of organic fertilizers derived dissolved organic matter on pesticide sorption and leaching[J].Environmental Pollution,134(2):187-194.
LONG G Q,JIANG Y J,SUN B,2015.Seasonal and inter-annual variation of leaching of dissolved organic carbon and nitrogen under long-term manure application in an acidic clay soil in subtropical China[J].Soil Tillage Research,146(Part B):270-278.
MARTIN H C,2003.Dissolved and water-extractable organic matter in soils:a review on the influence of land use and management practices[J].Geoderma,113(3-4):357-380.
MCDOWELL W H,2003.Dissolved organic matter in soils-future directions and unanswered questions[J].Geoderma,113(3-4):179-186.
MICHALZIK B,TIPPING E,MULDER J,et al.,2003.Modelling the production and transport of dissolved organic carbon in forest soils[J].Biogeochemistry,66(3):241-264.
NELE V G,VEERLE V,VIM C,et al.,2014.Controls on dissolved organic carbon export through surface runoff from loamy agricultural soils[J].Geoderma,226:387-396.
PACHECO F S,ROLAND F,DOWNING J A,2013.Eutrophication reverses whole-lake carbon budgets[J].Inland Waters,4(1):41-48.
PETRY J,SOULSBY C,MALCOLM I A,2002.Hydrological controls on nutrient concentrations and fluxes in agricultural catchments[J].Science of Total Environment,294(1-3):95-110.
RIECKH H,GERKE,H H,SOMMER M,2014.Water and dissolved carbon fluxes in an eroding soil landscape depending on terrain position[J].Vadose Zone Journal,13(7):124-129.
SINGH S,GHOSHAL N,SINGH K P,2007.Variations in soil microbial biomass and crop roots due to differing resource quality inputs in a tropical dryland agroecosystem[J].Soil Biology&Biochemistry,39:76-86.
SONG K S,WEN Z D,SHANG Y X,et al.,2018.Quantification of dissolved organic carbon(DOC)storage in lakes and reservoirs of mainland China[J].Science of Total Environment,217:391-402.
SOULSBY C,PETRYA C,BREWERB M J,2003.Identifying and assessing uncertainty in hydrological pathways:a novel approach to end member mixing in a Scottish agriculture catchment[J].Journal of Hydrology,274(1-4):109-128.
TRANVIK L J,DOWNING J A,COTNER J B,et al.,2009.Lakes and reservoirs as regulators of carbon cycling and climate[J].Limnology&Oceanography,54(6):2298-2314.
TRANVIK L J,JANSSON,2002.Climate change:terrestrial export of organic carbon[J].Nature,415(6874):861-862.
VEUM K S,GOYNE K W,MOTAVALLI P P,2009.Runoff and dissolved organic carbon loss from a paired-watershed study of three adjacent agricultural Watersheds[J].Agriculture,Ecosystem&Environment,130(3-4):115-122.
ZHU B,WANG T,KUANG F H,2009.Measurements of nitrate leaching from a hill slope cropland in the central Sichuan Basin,China[J].Soil Science Society of America Journal,73:1419-1426.
郭太龙,谢金波,孔朝晖,等,2015.华南典型侵蚀区土壤有机碳流失机制模拟研究[J].生态环境学报,24(8):1266-1273.
花可可,朱波,王小国,等,2013.紫色土坡耕地可溶性有机碳径流迁移特征[J].农业工程学报,29(5):81-88.
李太魁,郭战玲,寇长林,等,2017.提取方法对土壤可溶性有机碳测定结果的影响[J].生态环境学报,26(11):1878-1884.
李仲明,张先婉,何毓蓉,1991.中国紫色土[M].北京:科学出版社.
汪涛,2007.紫色土坡地硝态氮淋失过程研究[D].成都:中国科学院成都山地灾害与环境研究所:61-63.
杨玉盛,郭剑芬,陈光水,等,2003.森林生态系统DOM的来源、特性与流动[J].生态学报,23(3):547-558.
张永领,高全洲,黄夏坤,等,2007.西江溶解有机碳的输送对典型洪水过程的响应[J].环境科学学报,27(1):143-150.
朱波,汪涛,况福虹,等,2008.紫色土坡耕地硝酸盐淋失特征[J].环境科学学报,28(3):525-533.