• B.S., University of North Carolina, Chapel Hill, 1973
• M.S., North Carolina State University, 1978
• Ph.D., North Carolina State University, Raleigh, NC , 1990

• Environmental Chemistry
• Natural Science
• Sustainability and Environmental Studies
• Agroforestry
• Quantitative Analysis CHM 341
• Advanced Lab CHM 370/371/470/471

• Smithson, P.C., B.D. McIntyre, C.S. Gold, H. Ssali and I.N. Kashaija. 2001. Nitrogen and potassium fertilizer vs. nematode and weevil effects on yield and foliar nutrient status of banana in Uganda. Nutr. Cycl. Agroecosys. 59:239-250.
• Ikerra, S.T., J.A. Maghembe, P.C. Smithson and R.J. Buresh. 2001. Dry-season sesbania fallows and their influence on nitrogen availability and maize yields in Malawi. Agrofor. Syst. 52:13-21.
• Smithson, P.C. and K.E. Giller. 2001. Appropriate farm management practices for alleviating N and P deficiencies in low-nutrient soils of the tropics. Plant Soil (in press).
• Book Chapters, Symposium Proceedings, Other
  Smithson, P.C. and P.A. Sanchez. 2001. Plant nutritional problems in marginal soils of developing countries. p. 32-68 in: N. Ae, J. Arihara, K. Okada and A. Srinivasan, eds. Plant Nutrient Acquisition: New Perspectives: Springer-Verlag, Tokyo.
• Kimiti, J.M. and P.C. Smithson. 2001. Phosphorus uptake by fallow and grain legumes from sparingly soluble P sources. Proceedings 5th Intl. Symp. Plant-Soil Interactions at Low pH, South Africa (in press).
• Murage, E.W., N.K. Karanja, P.C. Smithson and P.L. Woomer. 2000. Diagnostic indicators of soil quality in productive and non-productive smallholders’ fields of Kenya’s Central Highlands. Agric. Ecosys. Environ. 79:1-8.
• Maroko, J.B., R.J. Buresh and P.C. Smithson. 1999. Soil phosphorus fractions in unfertilized fallow-maize systems on two tropical soils. Soil Sci. Soc. Am. J. 63:320-326.
• Mutuo, P.K., P.C. Smithson, R.J. Buresh and R.J. Okalebo. 1999. Comparison of phosphate rock and triple superphosphate on a phosphorus-deficient Kenyan soil. Commun. Soil Sci. Plant Anal. 30:1091-1103.

• Ikerra, S.T., J.A. Maghembe, P.C. Smithson and R.J. Buresh. 1999. Soil nitrogen dynamics and relationships with maize yields in a gliricidia-maize intercrop in Malawi. Plant Soil 211:155-164.

• Kapkiyai, J.J., N.K. Karanja, J.N. Qureshi, P.C. Smithson and P.L. Woomer. 1999. Soil organic matter and nutrient dynamics in a Kenyan nitisol under long-term fertilizer and organic input management. Soil Biol. Biochem. 31:1773-1782.

• Rao, M.R., G. Mwasambu, M.N. Mathuva, A.A.H. Khan and P.C. Smithson. 1999. Effects of phosphorus recapitalisation and agroforestry on soil, water and nutrient conservation in phosphorus-deficient soils of western Kenya. East Afr. Agric. For. J. 65:37-53.
• Smithson, P.C. and K.E. Giller. 1999. Appropriate farm management practices for low-nutrient soils. p. 77-79 in: Food Security in Nutrient-Stressed Environments: Exploiting Plants' Genetic Capabilies. JIRCAS, ICRISAT, Patancheru, India.

• Smithson, P.C. 1999. Interactions of organic materials with phosphate rocks and triple superphosphate. Agroforestry Forum 9(4):37-40.

• Maroko, J.B., R.J. Buresh and P.C. Smithson. 1998. Soil nitrogen availability as affected by fallow-maize systems on two soils in Kenya. Biol. Fertil. Soils 26:229-234.

• Nziguheba, G., C.A. Palm, R.J. Buresh and P.C. Smithson. 1998. Soil phosphorus fractions and adsorption as affected by organic and inorganic sources. Plant Soil 198:159-168.

• Mathuva, M.N., M.R. Rao, P.C. Smithson and R. Coe. 1997. Improving maize (Zea mays) yields in semiarid highlands of Kenya: Agroforestry or inorganic fertilizers? Field Crops Res. 55:57-72.

• Buresh, R.J., P.C. Smithson and D.T. Hellums. 1997. Building soil phosphorus capital in Africa. p. 111-149 in: R.J. Buresh, P.A. Sanchez and F. Calhoun, eds. Replenishing Soil Fertility in Africa. SSSA Special Publ. No. 51, ASA, Madison, WI, USA.

• Motavalli, P.P., C.A. Palm, E.T. Elliot, S.D. Frey and P.C. Smithson. 1995. Nitrogen mineralization in humid tropical forest soils: Mineralogy, texture and measured nitrogen fractions. Soil Sci. Soc. Am. J. 59:1168-1175.
• Smithson, P.C. and W.P. Robarge. 1990. Short-term responses of forested soils to addition of acid or neutral salt solutions. International conference on acidic deposition, Glasgow, Scotland, 16-21 Sep. 1990.
• Theses and Dissertations
  Smithson, P.C. 1990. Aluminum chemistry of forested soils subjected to acidic inputs. Ph.D. Dissertation, N.C. State Univ. Dept. Soil Sci. 290 pp.
• Robarge, W.P., P.C. Smithson, R.I. Bruck and E.B. Cowling. 1988. Influence of acidic cloud deposition on throughfall and soil lysimeter chemistry. Acidic Deposition and Forest Decline: An International Symposium. Misc. Publ. No. 20 (ESF 88-005), State Univ. of NY, Syracuse.
• Hagan, J.M., P.C. Smithson and P.D. Doerr. 1982. Behavioral response of the American alligator to freezing weather. J. Herpetol. 17:402-404.
• Smithson, P.C. and O.T. Sanders. 1978. Exposure of bobwhite quail and cottontail rabbits to methyl parathion. Proc. Ann. Conf. S.E. Assoc. Fish and Wildl. Agencies 32:326-334.
• Smithson, P.C. 1978. Exposure of bobwhite quail and cottontail rabbits to aerially applied methyl parathion and toxaphene. M.S. Thesis, N.C. State Univ. Dept. Zool., Raleigh. 55 pp.

1993 to 2001- Senior Soil Scientist/Laboratory Manager. Int'l. Centre for Research in Agroforestry, Nairobi, Kenya (ICRAF). Conducted soil quality/fertility research on nutrients and organic matter under agroforestry management systems. Managed headquarters laboratory for worldwide agroforestry research. Training and supervision of staff, MS and PhD students and research fellows. Conducted and advised on agroforestry research in Kenya, Malawi, Zambia, Tanzania.

1991 to 1993- Self-employed environmental consultant. Consulting on contract basis for variety of needs. Examples: Oversaw renovation of and provided staff training for national agronomic/agroforestry laboratory in Brazil; provided soil classification and soil chemistry expertise in development of watershed-level nitrogen budget for eastern NC; literature review and report for national water quality policy group; endangered species survey in coastal wetlands.

1990 to 1992- Postdoctoral Research Associate. N.C. State Univ. Dept. Soil Science. Research team member for investigations of sulfur and nitrogen cycling in forest soils, mineralogical analysis and interpretation for tropical soil organic matter study

1985 to 1989- Research Assistant. N.C. State Univ. Dept. Soil Science. PhD research on soil factors involved in decline and dieback of spruce and fir trees in high elevation southern Appalachian Mtns.

1982 to 1985- Research Technician. N.C. State Univ. Dept. Soil Science. Managed laboratory and data analysis functions for tropical soils management project.

1979 to 1981- Research Technician. N.C. State Univ. Dept. Zoology. Technician and field leader of statewide alligator research project.

1975 to 1978- Research Assistant. N.C. State Univ. Dept. Zoology. MS research on pesticide exposure of bobwhite quail and cottontail rabbits in vicinity of cotton pesticide operations.

1975- Chemist. Environmental Protection Agency. Participated in study of heavy metal contamination in nationwide sample of atmospheric particulates.

1973 to 1974- Junior Chemist. Research Triangle Institute, Research Triangle Park, NC. Involved in synthesis of possible anti-fertility agents.