References

General Soil Characteristics:

“Brazil.” Microsoft Encarta Encyclopedia 2002. (1993-2001). Microsoft Corporation.

Soil Map of the World. (1971).Food and Agriculture Organization of the United Nations, Paris.

Tan, Kim H. (2000). Envrionmental Soil Science, (2nd Edition). Marcel Dekker Inc., New York, NY.

www.soils.org

www.runet.edu/~swoodwar/CLASSES/GEOG235/biomes/main.html

Maps:

http://www.nrcs.usda.gov/technical/worldsoils/mapindx/order.html

http://www.ibge.gov.br

Nitrogen Cycle:

“Nitrogen Cycle.” Microsoft Encarta Encyclopedia 2002. (1993-2001). Microsoft Corporation.

Soils of the Humid Tropics. (1972). Committee on Tropical Soils, Agricultural Board, National Research Council. National Academy of Sciences, Washington D.C.

Numerical Data:

Mendonca, Eduardo S. & Rowell, David L. (1996). "Mineral and Organic Fractions of Two Oxisols and Their Influence on Effective Cation-Exchange Capacity". Soil Science Society of America Journal, 60(6).

Monitoring:

Benton Jones, J., (2001). Laboratory Guide for Conducting Soil Tests and Plant Analysis, CRC Press

Mycorrhizae/Soil microorganisms:

Harley, J.L., Smith, S.E. (1983). Mycorrhizae Symbiosis. Academic Press, London

www.theguardians.com/Microbiology/gm_mbr_10.htm

http://www.treemail.nl/eurobio/inform/Mycorrhi.htm