Large-scale spatial variability and distribution of soil organic carbon across the entire Loess Plateau, China
Z. P. Liu A C , M. A. Shao B D and Y. Q. Wang B
+ Author Affiliations
- Author Affiliations
A State Key Laboratory of Soil Erosion and Dry-land Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences, Ministry of Water Resources, Yangling, Shaanxi 712100, PR China.
B Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, PR China.
C Graduate School of Chinese Academy of Sciences, Beijing 100049, PR China.
D Corresponding author. Email: shaoma@igsnrr.ac.cn
Soil Research 50(2) 114-124 https://doi.org/10.1071/SR11183
Submitted: 27 July 2011 Accepted: 21 February 2012 Published: 3 April 2012
Abstract
Soil organic carbon (SOC) plays an important role in soil productivity and the global carbon cycle. However, little is known about the regional distribution of SOC across the entire Loess Plateau region of China. We investigated 382 sampling sites across the region (620 000 km2) and collected 764 soil samples from the topsoil (0–20 cm) and subsoil (20–40 cm). Standard statistics were used to identify the regional SOC content and the relationships with 11 selected environmental variables. Concentrations of SOC varied within a wide range throughout the region from 0.38 to 54.03 g kg–1, with mean values of 10.34 and 6.78 g kg–1 for the topsoil and subsoil, respectively. Coefficient of variation values showed moderate variation for SOC in both soil layers. Significant correlations were detected between SOC and these environmental variables, notably with soil total nitrogen (TN), soil pH, and clay content. Multiple linear regression analysis indicated that TN, clay content, soil pH, elevation, and temperature had greatest effects on regional SOC variability among all the selected soil and site variables. Geostatistical analysis showed that the maximum autocorrelation ranges were 384 and 393 km for SOC in the topsoil and subsoil, respectively. Nugget-to-sill ratios were 0.52 and 0.50, which also indicated moderate spatial dependence. Maps of SOC distribution produced by the geostatistical method showed that the overall spatial pattern was characterised by an area of low SOC content surrounded by bands with higher values, which generally increased towards the region’s boundaries. The distribution pattern corresponded to that of the major regional landforms, which also influenced land use, whereby the sandy Ordos Plateau is surrounded by relatively fertile plains and valleys, where the human population density is highest, and the regional boundary is mountainous. The spatial data of SOC could be useful as an important initial state in regional SOC modelling and possibly be used in calibration and prediction processes in the remote sensing method to estimate SOC content for large-scale areas.
Additional keywords: geostatistics, landform, spatial heterogeneity, spatial interpolation.
References
Ardö J, Olsson L (2003) Assessment of soil organic carbon in semi-arid Sudan using GIS and the CENTURY model. Journal of Arid Environments 54, 633–651.| Assessment of soil organic carbon in semi-arid Sudan using GIS and the CENTURY model.Crossref | GoogleScholarGoogle Scholar |
Bauer A, Black AL (1994) Quantification of the effect of soil organic matter content on soil productivity. Soil Science Society of America Journal 58, 185–193.
| Quantification of the effect of soil organic matter content on soil productivity.Crossref | GoogleScholarGoogle Scholar |
Bowen GJ, Wilkinson B (2002) Spatial distribution of δ18O in meteoric precipitation. Geology 30, 315–318.
| Spatial distribution of δ18O in meteoric precipitation.Crossref | GoogleScholarGoogle Scholar |
Bremner JM, Tabatabai MA (1972) Use of an ammonia electrode for determination of ammonia in Kjeldahl. Analysis 3, 159–165.
Bronson K, Zobeck T, Chua TT, Acosta-Martinez V, van Pelt RS, Booker JD (2004) Carbon and nitrogen pools of southern high plains cropland and grassland soils. Soil Science Society of America Journal 68, 1695–1704.
| Carbon and nitrogen pools of southern high plains cropland and grassland soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXns1Smt7o%3D&md5=f3f5d409f19d1194fd0587eef88f548dCAS |
Burgess TM, Webster R (1980) Optimal interpolation and isarithmic mapping of soil properties: I, The semi-variogram and punctual kriging. Soil Science 31, 315–331.
| Optimal interpolation and isarithmic mapping of soil properties: I, The semi-variogram and punctual kriging.Crossref | GoogleScholarGoogle Scholar |
Cambardella CA, Moorman TB, Novak JM, Parkin TB, Karlen DL, Turco RF, Konopka AE (1994) Field-scale variability of soil properties in Central Iowa soils. Soil Science Society of America Journal 58, 1501–1511.
| Field-scale variability of soil properties in Central Iowa soils.Crossref | GoogleScholarGoogle Scholar |
Campbell CA, Biederbeck VO, Zentner RP, LaFond GP (1991) Effect of crop rotations and cultural practices on soil organic matter, microbial biomass and respiration in a thin Black Chernozem. Canadian Journal of Soil Science 71, 363–376.
| Effect of crop rotations and cultural practices on soil organic matter, microbial biomass and respiration in a thin Black Chernozem.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK38Xlslym&md5=bac0f25c046b245a98f2c51bb110e64eCAS |
Chevallier T, Voltz M, Blanchart E, Chotte JL, Eschenbrenner V, Mahieu M, Albrecht A (2000) Spatial and temporal changes of soil C after establishment of a pasture on a long-term cultivated vertisol (Martinique). Geoderma 94, 43–58.
| Spatial and temporal changes of soil C after establishment of a pasture on a long-term cultivated vertisol (Martinique).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXmtVGrsA%3D%3D&md5=dffc04c45d620b29184751f2fd273c3cCAS |
Curtin D, Campbell CA, Jalil A (1998) Effects of acidity on mineralization: pH-dependence of organic matter mineralization in weakly acidic soils. Soil Biology & Biochemistry 30, 57–64.
| Effects of acidity on mineralization: pH-dependence of organic matter mineralization in weakly acidic soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXmtVantQ%3D%3D&md5=865d02dff6bd90a815a1baf254dcc497CAS |
Davidson EA, Janssens IA (2006) Temperature sensitivity of soil carbon decomposition and feedbacks to climate change. Nature 440, 165–173.
| Temperature sensitivity of soil carbon decomposition and feedbacks to climate change.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XitFGitLo%3D&md5=d029cffc5034e7a7953b5a87f35498ffCAS |
Duiker SW, Lal R (1999) Crop residue and tillage effects on carbon sequestration in a Luvisol in central Ohio. Soil & Tillage Research 52, 73–81.
| Crop residue and tillage effects on carbon sequestration in a Luvisol in central Ohio.Crossref | GoogleScholarGoogle Scholar |
FAO/UNESCO (1988) ‘Soil map of the world, revised legend.’ (FAO/UNESCO: Rome)
Garten CT, Kang S, Brice DJ, Schadt CW, Zhou J (2007) Variability in soil properties at different spatial scales (1 m–1 km) in a deciduous forest ecosystem. Soil Biology & Biochemistry 39, 2621–2627.
| Variability in soil properties at different spatial scales (1 m–1 km) in a deciduous forest ecosystem.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXotVagtLk%3D&md5=9f8b82c6e702dc05bc634e264dd52c5dCAS |
Goovaerts P (1992) Factorial kriging analysis: a useful tool for exploring the structure of multivariate spatial soil information. Journal of Soil Science 43, 597–619.
| Factorial kriging analysis: a useful tool for exploring the structure of multivariate spatial soil information.Crossref | GoogleScholarGoogle Scholar |
Goovaerts P (1999) Geostatistics in soil science: state-of-the-art and perspectives. Geoderma 89, 1–45.
| Geostatistics in soil science: state-of-the-art and perspectives.Crossref | GoogleScholarGoogle Scholar |
Hagedorn F, Spinnler D, Siegwolf R (2003) Increased N deposition retards mineralization of old soil organic matter. Soil Biology & Biochemistry 35, 1683–1692.
| Increased N deposition retards mineralization of old soil organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXosVyiur0%3D&md5=2abe10f16bc7a3028edce668b4d03f3aCAS |
Hassink J (1996) Preservation of plant residues in soils differing in unsaturated protective capacity. Soil Science Society of America Journal 60, 487–491.
| Preservation of plant residues in soils differing in unsaturated protective capacity.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28Xitleqs7Y%3D&md5=89a2877fe533cf50fa5da0e835abf6aaCAS |
Heimann M, Reichstein M (2008) Terrestrial ecosystem carbon dynamics and climate feedbacks. Nature 451, 289–292.
| Terrestrial ecosystem carbon dynamics and climate feedbacks.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXnt1CqsQ%3D%3D&md5=966848d41eef1f736084afb0d78cb6b0CAS |
Huang B, Sun WX, Zhao YC, Zhu J, Yang RQ, Zou Z, Ding F, Su JP (2007a) Temporal and spatial variability of soil organic matter and total nitrogen in an agricultural ecosystem as affected by farming practices. Geoderma 139, 336–345.
| Temporal and spatial variability of soil organic matter and total nitrogen in an agricultural ecosystem as affected by farming practices.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXkvVWls7g%3D&md5=ef141c086977dcdd0d70a31b01df4b7eCAS |
Huang XW, Senthilkumar S, Kravchenko A, Thelen K, Qi JG (2007b) Total carbon mapping in glacial till soils using near-infrared spectroscopy, Landsat imagery and topographical information. Geoderma 141, 34–42.
| Total carbon mapping in glacial till soils using near-infrared spectroscopy, Landsat imagery and topographical information.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXosVSju7s%3D&md5=d7ee7853613803e4462060f618ba1d16CAS |
IPCC (Intergovernmental Panel on Climate Change) (2001) Summary for policy makers. In ‘Climate shange 2001: The scientific basis.’ Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change. (Eds JT Houghton, Y Ding, DJ Griggs, M Noguer, PJ van der Linden, D Xiaosu) pp. 1–20. (Cambridge University Press: Cambridge, UK)
Issaks EK, Srivastava RM (1989) ‘An introduction to applied geostatistics.’ (Oxford University Press: New York)
Jenny (1941) ‘Factors of soil formation: A system of quantitative pedology.’ (McGraw-Hill: New York; Reprinted by Dover Publications: New York)
Kemmitt SJ, Wright D, Goulding KWT, Jones DL (2006) pH regulation of carbon and nitrogen dynamics in two agricultural soils. Soil Biology & Biochemistry 38, 898–911.
| pH regulation of carbon and nitrogen dynamics in two agricultural soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XjvFSisb4%3D&md5=3c0326428e59f4d4af79f6a68e816ff9CAS |
Knorr W, Prentice IC, House JI, Holland EA (2005) Long-term sensitivity of soil carbon turnover to warming. Nature 433, 298–301.
| Long-term sensitivity of soil carbon turnover to warming.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXlt1KksA%3D%3D&md5=26aa2dcae1402f1e76788c067d3ad755CAS |
Krige DG (1951) A statistical approach to some basic mine valuation problems on the Witwatersrand. Journal of the Chemical, Metallurgical and Mining Society of South Africa 52, 119–139.
Lal R (2004) Soil C sequestration impacts on global climatic change and food security. Science 304, 1623–1627.
| Soil C sequestration impacts on global climatic change and food security.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXks1Cgsrk%3D&md5=45f3ff5dea490b27aadfe99c89a170b5CAS |
Leifeld J, Bassin S, Fuhrer J (2005) Carbon stocks in Swiss agricultural soils predicted by land-use, soil characteristics, and altitude. Agriculture, Ecosystems & Environment 105, 255–266.
| Carbon stocks in Swiss agricultural soils predicted by land-use, soil characteristics, and altitude.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhtVCksb%2FJ&md5=eec420663465a5ac94cda9c53c3401c5CAS |
Li YS (1995) A new awareness of the Loess Plateau. Journal of Soil and Water Conservation 2, 34–37. [in Chinese]
Li KR, Wang SQ, Cao MK (2004) Vegetation and soil carbon storage in China. Science China Ser. D 47, 49–57.
| Vegetation and soil carbon storage in China.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhsVOqsL4%3D&md5=8c249b69810966edd063422ff31ab306CAS |
Liu DW, Wang ZM, Zhang B, Song KS, Li XY, Li JP, Li F, Duan HT (2006) Spatial distribution of soil organic carbon and analysis of related factors in croplands of the black soil region, Northeast China. Agriculture, Ecosystems & Environment 113, 73–81.
| Spatial distribution of soil organic carbon and analysis of related factors in croplands of the black soil region, Northeast China.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtlCmsLY%3D&md5=72fbfd627d1c572f8469e6747b0812c8CAS |
McGrath D, Zhang CS (2003) Spatial distribution of soil organic carbon concentrations in grassland of Ireland. Applied Geochemistry 18, 1629–1639.
| Spatial distribution of soil organic carbon concentrations in grassland of Ireland.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXltF2jt7k%3D&md5=10217b04e862756410311a5b057a8011CAS |
McLean EO (1982) Soil pH and lime requirement. In ‘Methods of soil analysis. Part 2’. Agronomy Monograph, Vol. 9. 2nd edn. (Eds AL Page, RH Miller, DR Keeney) pp. 199–224. (ASA and SSSA: Madison, WI)
Meersmans J, De Ridder F, Canters F, De Baets S, Van Molle M (2008) A multiple regression approach to assess the spatial distribution of Soil Organic Carbon (SOC) at the regional scale (Flanders, Belgium). Geoderma 143, 1–13.
| A multiple regression approach to assess the spatial distribution of Soil Organic Carbon (SOC) at the regional scale (Flanders, Belgium).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhsVentrbL&md5=504defac4f491e113ccd5ccad40fa8b2CAS |
Meersmans J, Wesemael BV, Molle MV (2009) Determining soil organic carbon for agricultural soils: a comparison between the Walkley-Black and the dry combustion methods (north Belgium). Soil Use and Management 25, 346–353.
| Determining soil organic carbon for agricultural soils: a comparison between the Walkley-Black and the dry combustion methods (north Belgium).Crossref | GoogleScholarGoogle Scholar |
Mueller TG, Pierce FJ (2003) Soil carbon maps: Enhancing spatial estimates with simple terrain attributes at multiple scales. Soil Science Society of America Journal 67, 258–267.
| Soil carbon maps: Enhancing spatial estimates with simple terrain attributes at multiple scales.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXnvFShtw%3D%3D&md5=afe8ed2ad3eb7c16c668bf4927aa3e0eCAS |
Nelson DW, Sommers LE (1982) Total carbon, organic carbon and organic matter. In ‘Methods of soil analysis. Part 2’. Agronomy Monograph, Vol. 9. 2nd edn. (Eds AL Page, RH Miller, DR Keeney) pp. 534–580. (ASA and SSSA: Madison, WI)
Nielsen DR, Bouma J (1985) ‘Soil spatial variability.’ (Pudoc: Wageningen, The Netherlands)
Office for the Second National Soil Survey of China (1993) ‘Second National Soil Survey of China.’ (China Agricultural Press: Beijing)
Pan GX, Smith P, Pan WN (2009) The role of soil organic matter in maintaining the productivity and yield stability of cereals in China. Agriculture, Ecosystems & Environment 129, 344–348.
| The role of soil organic matter in maintaining the productivity and yield stability of cereals in China.Crossref | GoogleScholarGoogle Scholar |
Paterson E, Midwood AJ, Millard P (2009) Through the eye of the needle: a review of isotope approaches to quantify microbial processes mediating soil carbon balance. New Phytologist 184, 19–33.
| Through the eye of the needle: a review of isotope approaches to quantify microbial processes mediating soil carbon balance.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXht1KitLfK&md5=a34ec900d62643be169f0c76ddfad70fCAS |
Reeder JD, Schumman GE, Bowman RA (1998) Soil C and N changes on conservation reserve program lands in the Central Great Plains. Soil & Tillage Research 47, 339–349.
| Soil C and N changes on conservation reserve program lands in the Central Great Plains.Crossref | GoogleScholarGoogle Scholar |
Reeves DW (1997) The role of soil organic matter in maintaining soil quality in continuous cropping systems. Soil & Tillage Research 43, 131–167.
| The role of soil organic matter in maintaining soil quality in continuous cropping systems.Crossref | GoogleScholarGoogle Scholar |
Reichstein M, Beer C (2008) Soil respiration across scales: The importance of a model-data integration framework for data interpretation. Journal of Plant Nutrition and Soil Science 171, 344–354.
| Soil respiration across scales: The importance of a model-data integration framework for data interpretation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXot1aqu7k%3D&md5=bae5d4a4b06126930d66f9923f21c1d3CAS |
Rossi J, Govaerts A, De Vos B, Verbist B, Vervoort A, Poesen J, Muys B, Deckers J (2009) Spatial structures of soil organic carbon in tropical forests—A case study of Southeastern Tanzania. Catena 77, 19–27.
| Spatial structures of soil organic carbon in tropical forests—A case study of Southeastern Tanzania.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXit1ersL8%3D&md5=5328f214bbb993db1547f5385ed4c38aCAS |
Sainju UM, Good RE (1993) Vertical root distribution in relation to soil properties in New Jersey Pinelands forest. Plant and Soil 150, 87–97.
| Vertical root distribution in relation to soil properties in New Jersey Pinelands forest.Crossref | GoogleScholarGoogle Scholar |
Saxton KE, Rawls WJ (2006) Soil water characteristic estimates by texture and organic matter for hydrologic solutions. Soil Science Society of America Journal 70, 1569–1578.
| Soil water characteristic estimates by texture and organic matter for hydrologic solutions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xpsl2lsL4%3D&md5=048d004e65571ccf58e1953650b4d7d2CAS |
Shepherd TG, Saggar S, Newman RH, Ross CW, Dando JL (2001) Tillage induced changes to soil structure and soil organic carbon fractions in New Zealand soils. Australian Journal of Soil Research 39, 465–489.
| Tillage induced changes to soil structure and soil organic carbon fractions in New Zealand soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXks1KqtL4%3D&md5=558e904b09db1db6ab42c1c8bc8ffcf7CAS |
Shi H, Shao MA (2000) Soil and water loss from the Loess Plateau in China. Journal of Arid Environments 45, 9–20.
| Soil and water loss from the Loess Plateau in China.Crossref | GoogleScholarGoogle Scholar |
Stenberg B (2010) Effects of soil sample pretreatments and standardised rewetting as interacted with sand classes on Vis-NIR predictions of clay and soil organic carbon. Geoderma 158, 15–22.
| Effects of soil sample pretreatments and standardised rewetting as interacted with sand classes on Vis-NIR predictions of clay and soil organic carbon.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXnvFWhsr8%3D&md5=9af54dd889102543d8deda9b35416e37CAS |
Tan ZX, Lal R (2005) Carbon sequestration potential estimates with changes in land use and tillage practice in Ohio, USA. Agriculture, Ecosystems & Environment 111, 140–152.
| Carbon sequestration potential estimates with changes in land use and tillage practice in Ohio, USA.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXhtVyntr7P&md5=70812bdc2a0dbc33c9818097e3ef18c7CAS |
Tang KL (1991) ‘Soil erosion on the Loess Plateau: Its regional distribution and control.’ (China Sciences and Technology Press: Beijing)
Tiessen H, Cuevas E, Chacon P (1994) The role of soil organic matter in sustaining soil fertility. Nature 371, 783–785.
| The role of soil organic matter in sustaining soil fertility.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXmvF2qtrw%3D&md5=573c70e8dc2f00b76cae6b004c6397feCAS |
Trangmar BB, Yost RS, Uehara G (1986) Application of geostatistics to spatial studies of soil properties. Advances in Agronomy 38, 45–94.
| Application of geostatistics to spatial studies of soil properties.Crossref | GoogleScholarGoogle Scholar |
Wang J, Fu BJ, Qiu Y, Chen LD (2003) Analysis on soil nutrient characteristics for sustainable land use in Danangou catchment of the Loess Plateau, China. Catena 54, 17–29.
| Analysis on soil nutrient characteristics for sustainable land use in Danangou catchment of the Loess Plateau, China.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXptlensLs%3D&md5=a99049c3e1cd014ad51269c8bc3b8165CAS |
Wang L, Okin GS, Caylor KK, Macko SA (2009a) Spatial heterogeneity and sources of soil carbon in southern African savannas. Geoderma 149, 402–408.
| Spatial heterogeneity and sources of soil carbon in southern African savannas.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXitlGhu7o%3D&md5=b414a9bf285e965550cc3a0cbe74136eCAS |
Wang YQ, Zhang XC, Huang CQ (2009b) Spatial variability of soil total nitrogen and soil total phosphorus under different land uses in a small watershed on the Loess Plateau, China. Geoderma 150, 141–149.
| Spatial variability of soil total nitrogen and soil total phosphorus under different land uses in a small watershed on the Loess Plateau, China.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXjt1Kis7g%3D&md5=cc4325e40f3e05ca12a12c560d607cb4CAS |
Wang YF, Fu BJ, Lv YH, Song CJ, Luan Y (2010) Local-scale spatial variability of soil organic carbon and its stock in the hilly area of the Loess Plateau, China. Quaternary Research 73, 70–76.
| Local-scale spatial variability of soil organic carbon and its stock in the hilly area of the Loess Plateau, China.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhsFarsLzE&md5=b3d7fa4ad946b4d35fb5d3bfe633b217CAS |
Wang YQ, Shao MA, Zhu YJ, Liu ZP (2011) Impacts of land use and plant characteristics on dried soil layers in different climatic regions on the Loess Plateau of China. Agricultural and Forest Meteorology 151, 437–448.
| Impacts of land use and plant characteristics on dried soil layers in different climatic regions on the Loess Plateau of China.Crossref | GoogleScholarGoogle Scholar |
Yang WZ, Shao MA (2000) ‘Soil water research on the Loess Plateau.’ (Science Press: Beijing)
Zhang XY, Sui YY, Zhang XD, Meng K, Herbert SJ (2007) Spatial variability of nutrient properties in black soil of northeast China. Pedosphere 17, 19–29.
| Spatial variability of nutrient properties in black soil of northeast China.Crossref | GoogleScholarGoogle Scholar |
Zhao JB, Huang CC, Zhu XM (1999) Formation and development of Loess Plateau. Journal of Desert Research 19, 333–337. [in Chinese with English abstract]
Zhao LP, Sun YJ, Zhang XP, Yang XM, Drury CF (2006) Soil organic carbon in clay and silt sized particles in Chinese mollisols: Relationship to the predicted capacity. Geoderma 132, 315–323.
| Soil organic carbon in clay and silt sized particles in Chinese mollisols: Relationship to the predicted capacity.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XksFaqsb0%3D&md5=c3d330e0c0d525b6e0618710de30f296CAS |
