Abstract
We investigated the soil organic carbon (SOC) associated with various aggregate size fractions in soil profiles under different land uses. Bulk soil samples were collected from incremental soil depths (0–10, 10–20, 20–40, 40–60, 60–80 and 80–100 cm) from sites with the four dominant land use types [forest, grazing land, irrigated rice in level terraces (Khet) and upland maize-millet in sloping terraces (Bari)] of the Mardi watershed (area 144 km2), Nepal. The bulk soil was separated into five aggregate size fractions and the associated SOC contents were determined. Soil physical parameters necessary for estimating the soil SOC stock such as bulk density, stone and gravel content, and SOC content, were also measured for each soil depth. The SOC stock (mean ± SE, kg C m–2) in the topsoil (0–10 cm) was higher in grazing land soil (3.4 ± 0.1) compared to forest soil (1.4 ± 0.2) and cultivated soil [Bari (2.0 ± 0.2) and Khet (1.2 ± 0.2)]. Forest and grazing lands had similar SOC contents, but the higher content of gravel and stone in forest soil resulted in a lower estimate of the SOC stock per unit area. The total SOC stock in the soil profile (to 1 m depth) over the entire watershed was estimated to be 721470 TC (tonnes of carbon). Its distribution was 52, 30, 11 and 7% in forestland, Bari, grazing land and Khet, respectively. The estimated depth wise distribution of SOC stock for 1 m soil depth in the entire watershed was 28, 22, 28 and 22% in the 0–10, 10–20, 20–40, and > 40 cm soil depths, respectively. There was a net loss of SOC stock (0–40 cm soil depth) of 29%, due to internal trading of land uses in the period from 1978 to 1996. Macro aggregates (> 1 mm) were found to be the dominant size in Bari and grazing land, whereas in forest and Khet soil micro aggregates (< 1 mm) dominated. Micro aggregates of size < 0.25 mm had a higher SOC concentration than aggregates of 0.25–0.5 mm, regardless of the depth or land uses and they may therefore contribute to soil C sequestration.
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References
Anderson J.M. and Ingram J.S.I. (eds) 1993. Total organic carbon in soil: colorimetric method. In: Tropical Soil Biology and fertility: A Handbook of Methods, 2nd edition. CAB International, Wallingford, UK, pp. 62–64.
Andrén O., Kätterer T. and Hyvönen R. 2001. Projecting soil fauna influence on long-term soil carbon balances from faunal exclusion experiments. Appl. Soil Ecol. 18: 177–186.
Awasthi K.D., Sitaula B.K., Singh B.R. and Bajracharya R.M. 2002. Land use changes and morphometric analysis using GIS for two mountain watersheds of western Nepal. Land Degrad. Develop. 13: 1–19.
Bajracharya R.M. 2001. Land preparation: an integral part of farming system in the mid-hills of Nepal. Nepal J. Sci. Technol. 3: 15–24.
Bajracharya R.M., Lal R. and Kimble J.M. 1998a. Long-term tillage effect on soil organic carbon distribution in aggregates and primary particle fractions of two Ohio soils. In: Lal R., Kimble J.M., Follett R.F. and Stewart B.A. (eds), Management of Carbon Sequestration in Soil. CRC Press, Boca Raton, Florida, USA, pp. 113–123.
Bajracharya R.M., Lal R. and Kimble J.M. 1998b. Soil organic carbon distribution in aggregates and primary particle fractions as influenced by erosion phases and landscape position. In: Lal R., Kimble J.M., Follett R.F. and Stewart B.A. (eds), Soil Processes and the Carbon Cycle. CRC Press, Boca Raton, Florida, USA, pp. 353–367.
Blake G.R. and Harte K.H. 1986. Bulk density. In: Methods of Soil Analysis part 1. Physical and Mineralogical Methods-Agronomy Monograph (2 nd edition). American Society of Agronomy–Soil Science Society of America, Madison, Wisconsin, USA, pp. 425–442.
Burton S., Shah P.B. and Schreier H. 1989. Soil degradation from converting forest land into agriculture in the Chitawan district of Nepal. Mount Res. Develop. 9: 393–404.
De Wit H.A. and Kvindesland S. 1999. Carbon stock in Norwegian forest soils and effects of forest management on carbon storage. Report fra skogforskingen-suppelement 14: 1–52.
Fernandes E.C.M., Motavalli P.P., Castilla C. and Mukurumbira L. 1997. Management control of soil organic matter dynamics in tropical land-use systems. Geoderma 79: 49–67.
Franzluebber A.J., Haney R.L., Honeycutt C.W., Arshad M.A., Schomberg H.H. and Hons F.M. 2001. Climatic influence on active fractions of soil organic matter. Soil Biol. Biochem. 33: 1103–1111.
Glaser B., Turrion M.B., Solomon D., Ni A. and Zech W. 2000. Soil organic matter quantity and quality in mountain soils of the Alay Range, Kyrgyzia, affected by land use change. Biol. Fertil. Soils 31: 407–413.
Gurung N.R. 2000. Forest degradation/regeneration in the hills of Nepal, a study at watershed level. M.Sc. Thesis. Noragric, Agricultural University of Norway, Ås, Norway.
Hao X., Chang C. and Lindewall C.W. 2001. Tillage and crop sequence effect on organic carbon and total nitrogen content in an irrigated Alberta soil. Soil Till. Res. 62: 167–169.
use/ (Date: 01.07.2001)
Islam K.R. and Well R.R. 2000. Land use effect on soil quality in a tropical forest ecosystem of Bangladesh. Agric. Ecosyst. Environ. 79: 9–16.
Kanchikerimath M. and Singh D. 2001. Soil organic matter and biological properties after 26 years of maize-wheat-cowpea cropping as affected by manure and fertilization in a Cambisol in semiarid region of India. Agric. Ecosyst. Environ. 86: 155–162.
Ketterings Q.M., Blair J.M. and Marinissen J.C.Y. 1997. Effects of earthworms on soil aggregate stability and carbon and nitrogen storage in a legume cover crop agro ecosystem. Soil Biol. Biochem. 29: 401–408.
Lal R. 2002. Soil carbon dynamics in cropland and rangeland. Environ. Pollut. 116: 353–362.
Lal R., Kimble J. and Follett R. 1998. Land use and C pools in terrestrial ecosystems. In: Lal R., Kimble J.M., Follett R.F. and Stewart B.A. (eds), Management of Carbon Sequestration in Soil. CRC Press, Boca Raton, Florida, USA, pp. 1–10.
Lal R., Kimble J. and Stewart B.A. 1995. World soils as a source or sink for radiatively-active gases. In: Lal R. and Stewart B.A. (eds), Soil Management and Greenhouse Effect. Lewis Publishers, Boca Raton, Florida, USA, pp. 1–8.
Manjaiah K.M., Voroney R.P. and Sen U. 2000. Soil organic Carbon stocks, storage profile and microbial biomass under different crop management systems in a tropical agricultural ecosystem. Biol. Fertil. Soils 31: 273–278.
Martin A., Mariotti A., Balesdent J., Lavelle P. and Vuattoux R. 1990. Estimates of the organic matter turnover rate in a savanna by the 13 C natural abudance. Soil. Biol. Biochem. 22: 517–523.
McLean E.O. 1982. Soil pH and lime requirement. In: Page A.L. (ed.), Methods of Soil Analysis Part 2. Chemical and Microbiological Properties, 2nd Ed. American Society of Agronomy Monograph No. 9. ASA-SSSA Inc., Madison, Wisconsin, USA, pp. 199–224.
Neupane R.P. and Thapa G.B. 2001. Impact of agroforestry intervention on soil fertility and farm income under the subsistence farming system of the middle hills, Nepal. Agric. Ecosyst. Environ. 84: 157–167.
Pilbeam C.J., Tripathi B.P., Sherchan D.P., Gregory P.J. and Gaunt J. 2000. Nitrogen balances for households in the mid-hills of Nepal. Agric. Ecosyst. Environ. 79: 61–72.
Post W.M. and Kwon K.C. 2000. Soil carbon sequestration and land use change: processes and potential. Global Change Biol. 6: 317–327.
Poudel G.S. and Thapa G.B. 2001. Changing farmer's land management practices in the hills of Nepal. Environ. Manage. 28: 789–803.
Lal R. 2000. Mulching effects on soil physical quality of an alfisol in western Nigeria. Land Degrad. Dev. 11: 383–392.
SAS Institute 2000. SAS/Procedures Guide, Release 8 edition. SAS, Cary, North Carolina, USA.
Singh B.R. and Lal R. 2004. The potential of soil carbon sequestration through improved management practices in Norway. Environ. Develop. Sustainabil. (in press)
Sombroek W., Nachtergaele F. and Hebel A. 1993. Amounts, dynamics and sequestering of carbon in tropical and subtropical soils. Ambio 22: 417–426.
Thapa G.B. 1996. Land use an land management and environment in a subsistence mountain economy in Nepal. Agric. Ecosyst. Environ. 57: 57–71.
Tisdall J.M. and Oades J.M. 1982. Organic matter and water stable aggregates in soils. J. Soil Sci. 33: 141–163.
Trujilo W., Amezquita E., Fisher M.J. and Lal R. 1997. Soil organic carbon dynamics and land use in the Colombian Savannas I. Aggregate size distribution. In: Lal R., Kimble J.M., Follett R.F. and Stewart B.A. (eds), Soil Processes and the Carbon Cycle. CRC Press, Boca Raton, Florida, USA, pp. 267–280.
Unger P.W. 1997. Aggregate and organic carbon concentration interrelationships of a Torrertic Paleustioll. Soil Till. Res. 42: 95–113.
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Shrestha, B., Sitaula, B., Singh, B. et al. Soil organic carbon stocks in soil aggregates under different land use systems in Nepal. Nutrient Cycling in Agroecosystems 70, 201–213 (2004). https://doi.org/10.1023/B:FRES.0000048472.25373.7e
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DOI: https://doi.org/10.1023/B:FRES.0000048472.25373.7e