SOIL carbon and nitrogen in five contrasting biomes of South Africa exposed to different land uses

References

• Allsopp , N. 1999 . Effects of grazing and cultivation on soil patterns and processes in the Paulshoek area of Namaqualand . Plant Ecol. , 142 : 179 – 187 .
   Web of Science ®Google Scholar
• Birch , H. F. 1958 . The effect of soil drying on humus decomposition and nitrogen availability . Plant Soil , 10 : 9 – 31 .
   Google Scholar
• Bird , M. I. , Veenedaal , E. M. , Moyo , C. , Llyod , J. and Frost , P. 2000 . Effect of fire and soil texture on soil carbon in a sub-humid savanna (Matopos, Zimbabwe) . Geoderma , 94 : 71 – 90 .
   Web of Science ®Google Scholar
• Brye , K. R. and Kucharik , C. J. 2003 . Carbon and nitrogen sequestration in two prairie topochronosequences on contrasting soils in southern Wisconsin . Am. Midi. Nat. , 149 : 90 – 103 .
   Web of Science ®Google Scholar
• Burke , I. C. , Lauerenroth , W. K. and Parton , W. J. 1997 . Regional and temporal variation in net primary production and nitrogen mineralization in grasslands . Ecology , 78 : 1330 – 1340 .
   Web of Science ®Google Scholar
• Campbell , C. A. , Lafond , G. P. , Leyshon , A. J. , Zentner , R. P. and Janzen , H. H. 1991 . Effect of cropping practices on the initial potential rate of N mineralization in a thin Black Chernozem . Can. J. Soil Sci. , 71 : 43 – 53 .
   Web of Science ®Google Scholar
• Conover , W. J. 1980 . Practical non parametric statistics New York : John Wiley and Sons .
   Google Scholar
• Du Preez , C. C. and Snyman , H. A. 1993 . Organic matter content of a soil in a semi-arid climate with three long-standing veld conditions . Afr. J. Range For. Sci. , 10 : 108 – 110 .
   Google Scholar
• Du Toit , M. E. and Du Preez , C. C. 1995 . Effect of cultivation on the nitrogen fertility of selected dryland soils in South Africa . Soil Sci. Soc. Am. J. , 12 : 73 – 81 .
   Google Scholar
• Du Toit , M. E. , Du Preez , C. C. , Hensley , M. and Bennie , A. T. P. 1994 . Effek van bewerking op die organiese materiaalinhoud van geselekteerde droëlandgronde in Suid-Afrika . S. Afr. J. Plant Soil , 11 : 71 – 79 .
   Google Scholar
• Edwards , J. H. , Wood , C. W. , Thurlow , D. L. and Ruf , M. E. 1992 . Tillage and crop rotation effects on fertility status of a hapludult soil . Soil Sci. Soc. Am. J , 56 : 1577 – 1582 .
   Web of Science ®Google Scholar
• Fao . 1998 . World reference base for soil resources Rome : United Nations . Food and Agricultural Organisation of the
   Google Scholar
• Francis , G. S. , Tabley , F. J. and White , K. M. 2001 . Soil degradation under cropping and its influence on wheat yield on a weakly structured New Zealand silt loam . Aust. J. Soil Res. , 39 : 291 – 305 .
   Web of Science ®Google Scholar
• Greenwood , D. J. 1968 . “ Measurement of microbial metabolism in soil. ” . In The Ecology of Soil Bacteria. Liverpool Univ. Press, Liverpool. Edited by: Gray , T. R. G. and Parkinson , D.
   Google Scholar
• Haynes , R. J. , Swift , R. S. and Stephen , R. C. 1991 . Influence of mixed cropping rotations (pasture arable) on organic carbon content, water stable aggregation and clod porosity in a group of soils . Soil Till. Res. , 19 : 77 – 87 .
   Web of Science ®Google Scholar
• Knapp , A. K. , Conrad , S. L. and Blair , J. M. 1998 . Determinants of soil CO2 flux from a sub-humid grassland: effect of fire and fire history . Ecol. Appl. , 8 : 760 – 770 .
   Web of Science ®Google Scholar
• Lal , R. 2001 . “ Soils and the greenhouse effect. ” . In Soil carbon sequestration and the greenhouse effect. Soil Science Society of America, Inc., Madison, Wis. Edited by: Lai , R.
   Google Scholar
• Lechmere-Oertel , R. G. 2003 . The effects of goat browsing on ecosystem patterns and processes in succulent thicket, South Africa. Ph.D. thesis, University of Port Elizabeth.
   Google Scholar
• Lobe , I. , Amelung , W. and Du Preez , C. C. 2001 . Losses of carbon and nitrogen with prolonged arable cropping from sandy soils of the South African Highveld . Eur. J. Soil Sci. , 52 : 93 – 101 .
   Web of Science ®Google Scholar
• Low , A. B. and Rebelo , A. G. 1996 . Vegetation of South Africa, Lesotho and Swaziland, Department of Environmental Affairs and Tourism, Pretoria.
   Google Scholar
• Mills , A. J. 2003 . Reciprocal relationships between vegetation structure and soil properties in selected biomes of South Africa. Ph.D. thesis, University of Stellenbosch.
   Google Scholar
• Nel , P. C. , Barnard , R. O. , Steynberg , R. E. , De Beer , J. M. and Groeneveld , H. T. 1996 . Trends in maize grain yields in a long-term fertilizer trial . Field Crops Res. , 41 : 53 – 64 .
   Web of Science ®Google Scholar
• Olson , C. G. , Thompson , M. L. and Wilson , M. A. 2000 . “ Phyllosilicates. ” . In Handbook of Soil Science Edited by: Sumner , M. E. New York : CRC Press .
   Google Scholar
• Paustian , K. , Parton , W. J. and Persson , J. 1992 . Modelling soil organic matter in organic-amended and nitrogen-fertilized long term plots . Soil Sci. Soc. Am. J. , 56 : 4876 – 4882 .
   Web of Science ®Google Scholar
• Percival , H. J. , Parfitt , R. L. and Scott , N. A. 2000 . Factors controlling soil carbon levels in New Zealand grasslands: Is clay content important . Soil Sci. Soc. Am. J. , 64 : 1623 – 1630 .
   Web of Science ®Google Scholar
• Robles , M. D. and Burke , I. C. 1998 . Soil organic matter recovery on conservation reserve program fields in southeastern Wyoming . Soil Sci. Soc. Am. J. , 62 725–730
   Web of Science ®Google Scholar
• Rosenzweig , R. , Varilek , M. , Feldman , B. , Kuppallie , R. and Janssen , J. 2002 . The emerging international greenhouse gas market, Pew Center on Global Climate Change, Washington D.C.
   Google Scholar
• Russell , E. W. 1988 . Soil conditions and plant growth Harlow : Longman Scientific and Technical . UK
   Google Scholar
• Savage , M. J. and Vermeulen , K . 1983 . Microclimate modification of tall moist grasslands of Natal by spring burning . J. Range Manag. , 36 : 172 – 174 .
   Google Scholar
• Saxton , K. E. , Rawls , W. J. , Romberger , J. S. and Papendick , R. I. 1986 . Estimating generalized soil-water characteristics from texture . Soil Sci. Soc. Am. J. , 50 : 1031 – 1036 . Algorithms obtained from www.pedosphere.com
   Web of Science ®Google Scholar
• Schulze , E. D. 2000 . Carbon and nitrogen cycling in European forest ecosystems New York : Springer .
   Google Scholar
• Schulze , R. E. 1997 . South African Atlas of Agrohydrology and Climatology, Water Research Commission, Pretoria, Report TT82/96.
   Google Scholar
• SOIL CLASSIFICATION WORKING GROUP . 1991 . Soil Classification: A taxonomic system for South Africa, The Department of Agricultural Development, Pretoria.
   Google Scholar
• Sumner , M. E. 1957 . The physical and chemical properties of Tall Grass Veld soils of Natal in relation to their erodibility. M.Sc. University of Natal.
   Google Scholar
• Theron , J. J. 1951 . The influence of plants on the mineralisation of nitrogen and the maintenance of organic matter in the soil . J. Agric. Sci. , 41 : 289 – 296 .
   Web of Science ®Google Scholar
• Theron , J. J. 1963 . The mineralisation of nitrogen in soils under grass . S. Afr. J. Agric. Sci. , 6 : 155 – 164 .
   Google Scholar
• UNISTAT LIMITED . 2000 . Unistat 5.0 Users Guide. Unistat Limited, London, UK.
   Google Scholar
• Van Wyk , P. 1971 . “ Veld burning in the Kruger National Park. An interim report of some aspects of research. ” . In Proc. 11th Tall Timbers Fire Ecol. Conf Tall Timbers Research Station, Tallahassee, Florida.
   Google Scholar
• Whittaker , R. H. , Buol , S. W. , Niering , W. A. and Havens , Y. H. 1968 . Soil and vegetation pattern in the Santa Catalina Mountains, Arizona . Soil Sci. , 105 : 440 – 450 .
   Web of Science ®Google Scholar
• Zech , W. , Senesi , N. , Guggenberger , G. , Kaiser , K. , Lehmann , J. , Miano , T. M. , Miltner , A. and Schroth , G. 1997 . Factors controlling humification and mineralisation of soil organic matter in the tropics . Geoderma , 79 : 117 – 161 .
   Web of Science ®Google Scholar