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James Walworth

photo of Dr. James Walworth
  

Professor and Extension Specialist

Phone: (520) 626-3364

Cell: 520-490-6895

Fax: (520) 621-1647

Office: 422 Shantz Building

Email: walworth@ag.arizona.edu.

updated 08/2011
Websites:

Soil Fertility: http://ag.arizona.edu/swes/soil_fertility/

AZDRIP, The University of Arizona Subsurface Drip Irrigation Demonstration and Research Project.: http://cals.arizona.edu/crops/irrigation/azdrip/azdripindex.html.

Areas of Focus:

  • Nutrient requirements for Arizona crops, especially pecans, turfgrass, and vegetables
  • Nutrient requirements and management in contaminated soils, concentrating on effects of nitrogen on soil water potential and microbial petroleum biodegradation
  • Irrigation water and soil salinity management in agricultural soils
  • Application of waste materials to soils, studying rates of degradation of soil-applied animal manures and environmental impacts of on-site human waste disposal systems.

Professional Development:

(a) Professional Preparation

University of Georgia                         Agronomy, Ph.D., 1985
University of Wisconsin - Madison        Soil Science, M.S.,  1980
University of Wisconsin - Madison        Soil Science, B.S.,  1976

(b) Positions

2007 to present: Professor of Soil Science and Extension Soil Specialist, Department of Soil, Water and Environmental Science, University of Arizona

1998 to 2007: Associate Professor of Soil Science and Extension Soil Specialist, Department of Soil, Water and Environmental Science, University of Arizona

1993 to 1998: Associate Professor of Soil Science, Department of Plant, Animal and Soil Sciences, University of Alaska Fairbanks

1989 to 1993: Assistant Professor of Soil Science, Department of Plant, Animal and Soil Sciences, University of Alaska Fairbanks

1985 to 1989: Assistant Professor of Soil Science, Soils and Crops Department, Rutgers University

1984 to 1985: Research Associate/Teaching Assistant, Agronomy Department, University of Georgia

1979 to 1981: Assistant Superintendent, Hancock Experiment Station, University of Wisconsin – Madison

Publications:

Book Chapters:

  1. J.L. Walworth and S. Ferguson.  2008.  Nutritional Requirements for Bioremediation.  pp. 154-169  In: D.M. Filler, D.L., Barnes, and I. Snape (Eds.). Bioremediation of Petroleum Hydrocarbons in Cold Regions.  Cambridge University Press, Cambridge, UK. 
  2. J.L. Walworth, C.M. Reynolds, I. Snape, and A. Rutter.  2008.  Land-Farming.  pp. 170-189  In: D.M. Filler, D.L., Barnes, and I. Snape (Eds.). Bioremediation of Petroleum Hydrocarbons in Cold Regions.  Cambridge University Press, Cambridge, UK. 
  3. I. Snape, C.M. Reynolds, J.L.Walworth, and S.H. Ferguson.  2008.  Treatability studies: Microcosms, Mesocosms and Field Trials. pp. 125- 153  In: D.M. Filler, D.L., Barnes, and I. Snape (Eds.). Bioremediation of Petroleum Hydrocarbons in Cold Regions.  Cambridge University Press, Cambridge, UK. 
  4. I. Snape, L. Acomb, D.L. Barnes, S. Bainbridge, R. Eno, D.M. Filler, N. Plato, J.S. Poland, T.C. Raymond, J.L. Rayner, M.J. Riddle, A.G. Rike, A. Rutter, A.N. Schafer, S.D. Siciliano, and J.L. Walworth.  2008.  Contamination, Regulation and Remediation: an Introduction to Bioremediation of Petroleum Hydrocarbons in Cold Regions.  pp. 1-37  In: D.M. Filler, D.L., Barnes, and I. Snape (Eds.). Bioremediation of Petroleum Hydrocarbons in Cold Regions.  Cambridge University Press, Cambridge, UK. 
  5. J.F. Artiola, J.L. Walworth, S. Musil, and C. Rasmussen.  2006.  Soil and Land Pollution Sources.  pp. 243-258.  In I.L. Pepper, C.P. Gerba, and M.L. Brusseau (Eds.). Environmental and Pollution Science, 2nd Edition.  Academic Press, Inc., San Diego, CA.
  6. J.L. Walworth and I.L. Pepper.  2006.  Physical Contaminants. pp. 123-131.  In I.L. Pepper, C.P. Gerba, and M.L. Brusseau (Eds.).  Environmental and Pollution Science, 2nd Edition.  Academic Press, Inc., San Diego, CA.
  7. C. Walecka-Hutchison and J.L. Walworth.  2005.  Quantification of In Situ Trichloroethane versus Biodegradation Using a Novel Chloride Concentration Method.  pp. 317-328.  In E. Lichtfouse, J. Schwarzbauer, and D. Robert (Eds.), Environmental Chemistry - Green Chemistry and Pollutants in Ecosystems.  Springer, Berlin.
  8. J.L. Walworth. I. Pepper (Eds.) Environmental Monitoring and Remediation.  Elsevier Academic Press, Burlington, MA.
  9. J.L. Walworth and M.E. Sumner.  1988.  Foliar Diagnosis - A Review.  p. 193-241.  In B.P. Tinker (ed.) Advances in Plant Nutrition, Vol. III.  Praeger Publishing, New York, NY.
  10. J.L. Walworth and M.E. Sumner.  1987.  The Diagnosis and Recommendation Integrated System (DRIS).  p. 149-188.  In B.A. Stewart (ed.) Advances in Soil Science, Vol. VI.  Springer-Verlag, New York, NY.

Refereed Journal Articles:

  1. Núñez-Moreno, H., J.L. Walworth, and A.P. Pond. 2011. Field Identification and Characterization of Manganese Toxicity in ‘Western Schley’ Pecan Trees. Acta Horticulturae of the Mineral Nutrition Session (Lisboa 2010 IHC Congress)
  2. Bañuelos, J., J.L. Walworth, P.W. Brown, and D.M. Kopec. 2011. Deficit Irrigation of Seashore Paspalum and Bermudagrass. Agronomy Journal (accepted for publication).
  3. McLain, J.E.T., C.M. Rock, K. Lohse, J. Walworth. 2011. False Positive Identification of E. coli in Treated Municipal Wastewater and Wastewater-Irrigated Soils.  Canadian Journal of Microbiology.
  4. Núñez-Moreno, H., J.L. Walworth, A.P. Pond, and M.W. Kilby.  2009.  Soil Zinc Fertilization of ‘Wichita’ Pecan Trees Growing under Alkaline Soils Conditions.  HortScience 44(6):1736-1740.
  5. Núñez-Moreno, H.,  J.L. Walworth, A.P. Pond.  2009.  Manure and Soil Zinc application to ‘Wichita’ Pecan Trees Growing under Alkaline Conditions.  HortScience 44(6):1741-1745.
  6. Artiola, J.F. and J.L. Walworth.  2009.  Irrigation Water Quality Effects on Soil Carbon Fractionation and Organic Carbon Dissolution and Leaching in a Semiarid Calcareous Soil.  Soil Science 147(7): 365-371.
  7. AL-Ismaily, S.S. and J.L. Walworth.  2008.  Effects of Osmotic and Matric Potentials on Nitrogen Mineralization in Unamended and Manure-Amended Soil.  Soil Science 173(3): 203-213.
  8. J.L. Rayner, I. Snape, J.L. Walworth, P.M. Harvey and S.H. Ferguson.  2007.  Petroleum Hydrocarbon Contamination and Remediation by Microbioventing at Sub-antarctic Macquarie Island.  Cold Regions Science and Technology 48(2): 139-153.
  9. J.P. Field, K.L. Farrell-Poe, and J.L. Walworth.  2007.  Comparative Treatment Effectiveness of Conventional Trench and Seepage Pit Systems.  Water Environment Research 79(3): 310-319.
  10. D.M. Kopec, J.L. Walworth, J.J. Gilbert, G.M. Sower, and M. Pessarakli.  2007.  ‘SeaIsle 2000’ paspalum putting surface response to mowing height and nitrogen fertilizer.  Agronomy Journal 99: 133-140.
  11. J.L. Walworth, A.P. Pond, I. Snape, J.L. Rayner, and P.M. Harvey.  2007. Fine Tuning Soil Nitrogen to Maximize Petroleum Bioremediation in Contaminated Soil from Macquarie Island. Cold Regions Science and Technology 48(2): 84-91.
  12. C. Walecka-Hutchison and J.L. Walworth.  2007.  Evaluating the Effects of Gross Nitrogen Mineralization, Immobilization and Nitrification on Nitrogen Fertilizer Availability during Diesel Biodegradation.  Biodegradation 18: 133-144.
  13. A.P. Pond, J.L. Walworth, M.W. Kilby, R.D. Gibson, and R.E. Call.  2006.  Leaf Nutrient Levels for Pecan in Southern Arizona.  HortScience 41(5):1339-1341.
  14. C. Walecka-Hutchison and J.L. Walworth.  2006.  Assessment of C:N Ratios and Water Potential for Nutrient Optimization in Diesel Bioremediation..  Bioremediation Journal 10(1-2): 1-11. 
  15. A. Kusakabe, S.A. White, J. L. Walworth, G. C. Wright, and T. L. Thompson.  2006.  Response of Microsprinkler-Irrigated Navel Oranges to Fertigated Nitrogen Rate and Frequency.  Soil Science Society of America Journal 70(7):1623-1628.
  16. J.L. Walworth, A.P. Pond, G.J. Sower, and M.W. Kilby.  2006.  Fall-Applied Foliar Zinc for Pecans in the Desert Southwest.  HortScience  41(1):275-276.
  17. M.M. Pessarakli and J.L. Walworth.  2005.  Growth Responses of Zoysiagrass Influenced by Different Rates of a Growth Stimulant (Soil Solution One).  Journal of Food, Agriculture and Environment.  2(3&4):287-288.
  18. X. Jia, D.S. Larson, D.C. Slack, and J.L. Walworth.  2005.  Electrokinetic Control of Nitrate Movement in Soil.  Journal of Engineering Geology. 77:273-283.
  19. Jia, X., D. L. Larson, W. S. Zimmt , and J. L. Walworth. 2005. Nitrate Pollution Control in Different Soils by Electrokinetic Technology.  Trans. of ASAE.  48(4):1343-1352.
  20. J.L. Walworth, C.R. Woolard, and K.C. Harris.  2003.  Nutrient Amendments For Contaminated Peri-Glacial Soils: Use Of An Organic Controlled Release Nutrient Source.  Cold Regions Science and Technology. 37:81-88.
  21. S. Rawahy, D.S.Larson, J.L. Walworth, and D.C. Slack.  2003.  Effect of an Electrical Input with Drip Irrigation on Nitrate Distribution in Soil.  Applied Engineering in Agriculture.  19(1):55-58.
  22. T.L. Thompson, J.L. Walworth, S. White, and G. Sower.  2003.  Fertigation Frequency in Subsurface Drip Irrigated Broccoli.  Soil Science Society of America Journal.  67:910-918.
  23. J.L. Walworth and D.E. Carling.  2002.  Tuber Initiation and Development in Irrigated and Non-irrigated Potatoes.  American Journal of Potato Research.  19:1-9.
  24. C. Walecka-Hutchison and J.L. Walworth.  2001.  Hydrocarbon Biodegradation Rates and Water Potential in Nitrogen Augmented Desert Soils.  In-Situ and On-Site Bioremediation.  Symposium: Bioremediation of Inorganic Compounds.  6(9):231-239.
  25. J.L. Walworth, J.F. Braddock, and C.R. Woolard.  2001.  Nutrient and Temperature Interactions in Bioremediation of Cryic Soils.  Cold Regions Science and Technology.  Cold Regions Science and Technology, 32 (2-3):85-91.
  26. M.W. Vandersande, E.P. Glenn, and J.L. Walworth.  2000.  Comparative Tolerances of Five Riparian Plants From The Lower Colorado River to Salinity Drought And Inundation.  Journal of Arid Environments, 49(1):147-159.
  27. C.R. Woolard, D.M. White, J.L. Walworth, and M.E. Hannah.  1999.  The Magnitude and Variability of Biogenic Interference in Cold Regions Soils.  Journal of Cold Regions Engineering 13(3)113-121.
  28. J.L. Walworth, C.R. Woolard, L. Acomb, and M. Wallace.   1999.  Nutrient and Temperature Interactions in Bioremediation of Petroleum-Contaminated Cryic Soil.  In-Situ and On-Site Bioremediation 5(3):505-510.        
  29. Bioremediation 5(3):523-527.
  30. J.F. Braddock, J.L. Walworth, and K.A. McCarthy.  1999.  Biodegradation of Aliphatic vs. Aromatic Hydrocarbons in Fertilized Arctic Soils.  Bioremediation J.  3(2):105-116.
  31. J.L. Walworth, C.R. Woolard, J.F. Braddock, and C.M. Reynolds.  1997.  Enhancement and Inhibition of Soil Petroleum Biodegradation Through the Use of Fertilizer Nitrogen: An Approach to Determining Optimum Levels.  J. Soil Contamination 6(5):465-480.
  32. J.F. Braddock, M.L. Ruth, P.H. Catterall, J.L. Walworth, and K.A. McCarthy.  1997.  Enhancement and Inhibition of Microbial Activity in Hydrocarbon-Contaminated Arctic Soils:  Implications for Nutrient-Amended Bioremediation.  Environ. Sci. Tech. 31:2078-2084.
  33. Reynolds, B.A. Koenen, J.B. Carnahan, J.L. Walworth, and P. Bhunia.  1997.  Rhizosphere and Nutrient Effects on Remediating Subarctic Soils.  In Situ and On-Site Bioremediation 4(1):297-302.
  34. J.L. Walworth, C.R. Woolard, and K.C. Harris.  1997.  Bioremediation of Petroleum-Contaminated Soil Using Fish Bonemeal in Cold Climates.  Agroborealis 29(1): 31-34.
  35. E.H. Willson, E.V. Hogan, C.R. Woolard, and J.L. Walworth.  1997.  Nitrous Oxide Consumption in Contaminated Soil.  In Situ and On-Site Bioremediation 4(1):397-401.
  36. J.L. Walworth, C.R. Woolard, J.F. Braddock, and C.M. Reynolds.  1997.  The Role of Soil Nitrogen Concentration in Bioremediation.  In Situ and On-Site Bioremediation 4(4):283-288.
  37. C.M. Reynolds, C.A. Beyrouty, D.C. Wolf, and J.L. Walworth.  1995.  Rhizosphere Enhanced Bioremediation for Cold Regions:  Contaminant Effects on Root Distribution.  Proceedings of a Joint US/Canada Military and Civilian Workshop, Technologies and Techniques for Hydrocarbon Remediation in Cold and Arctic Climates, June 6-7, 1995, Royal Military College, Kingston, Ontario.
  38. J.L. Walworth and C.M. Reynolds.  1995.  Remediation of a Petroleum Contaminated Cryic Soil:  Effects of Phosphorus, Nitrogen, and Temperature.  J. Soil Contamination 4: 299-310.
  39. R.G. Gavlak, W.L. Campbell, J.L. Walworth, C.L. Johnson, J.E. Muniz, and T.A. Tindall.  Nitrogen Fertilization of Irrigated Russet Potatoes in Southcentral Alaska.  American Potato Journal 70: 571-578.
  40. J.L. Walworth and J.E. Muniz.  A Compendium of Tissue Nutrient Concentrations for Field-Grown Potatoes.  American Potato Journal 70: 579-597.
  41. J.L. Walworth, R.G. Gavlak, and M.T. Panciera.  1992.  Mehlich 3 Extractant for Determination of Available B, Cu, Fe, Mn, and Zn in Cryic Alaskan Soils.  Canadian Journal of Soil Science 72: 517-526.
  42. J.L. Walworth.  1992.  Soil Drying and Rewetting, or Freezing and Thawing, Affects Soil Solution Composition.  Soil Science Society of America Journal 56:433-437.
  43. J.L. Walworth, D.E. Carling, and G.J. Michaelson.  1992.  Nitrogen Sources and Rates for Direct-Seeded and Transplanted Head Lettuce.  HortScience 27:228-230.
  44. J.L. Walworth and S. Ceccotti.  1990.  A Re-examination of Optimum Foliar Magnesium Levels in Corn.  Communications in Soil Science and Plant Analysis 21:1457-1473.J.L.
  45. Walworth and M.E. Sumner.  1990.  Alfalfa Response to Lime, Phosphorus, Potassium, Magnesium, and Molybdenum on Acid Ultisols.  Fertilizer Research 24:167-172.
  46. J.L. Walworth, H.J. Woodard, and M.E. Sumner.  1988.  Generation of Corn Tissue Norms from a Small, High-Yield Data Base.  Communications in Soil Science and Plant Analysis 19:563-577.
  47. W.B. Hallmark, J.L. Walworth, M.E. Sumner, C.J. deMooy, J. Pesek, and K.P. Shao.  1987.  Separating Limiting from Non-Limiting Nutrients.  Journal of Plant Nutrition 10:1381-1390.
  48. J.L. Walworth, M.E. Sumner, and W.S. Letzsch.  1986.  Effectiveness of Topdressed Phosphorus Applied to Established Alfalfa.  Proceedings of the 1986 Forage and Grassland Conference pp. 235-240.
  49. J.L. Walworth, W.S. Letzsch, and M.E. Sumner.  1986.  Use of Boundary Lines in Establishing Diagnostic Norms.  Soil Science Society of America Journal 50:123-128.
  50. J.L. Walworth, M.E. Sumner, R.A. Isaac, and C.O. Plank.  1986.  Preliminary DRIS Norms for Alfalfa in the Southeastern United States and a Comparison with Midwestern Norms.  Agronomy Journal 78:1046-1052.

 

Electronic Publications:

  1. J.L. Walworth.  2006.  Soil Structure: The Roles of Sodium and Salts.  The University of Arizona Cooperative Extension Publication AZ1414, University of Arizona, Tucson, AZ.  http://cals.arizona.edu/pubs/crops/az1414.ppt (peer reviewed)
  2. J.L. Walworth, A.P. Pond, and M.W. Kilby.  2006.  Leaf Sampling Guide with Interpretation for Arizona Pecan Orchards.  The University of Arizona Cooperative Extension Publication AZ1410, University of Arizona, Tucson, AZ.  http://cals.arizona.edu/pubs/diseases/az1410.pdf (peer reviewed)
  3. J.L. Walworth.  2006.  Using Gypsum in Southwestern Soils.  The University of Arizona Cooperative Extension Publication AZ1413, University of Arizona, Tucson, AZ.  http://cals.arizona.edu/pubs/garden/az1413.pdf (peer reviewed)
  4. J.L. Walworth.  2006.  Soil Sampling and Analysis.  The University of Arizona Cooperative Extension Publication AZ1412, University of Arizona, Tucson, AZ.  http://cals.arizona.edu/pubs/crops/az1412.pdf (peer reviewed)
  5. J.L. Walworth.  2006.  Recognizing and Treating Iron Deficiency in the Home Yard.  The University of Arizona Cooperative Extension Publication AZ1415, University of Arizona, Tucson, AZ.  http://cals.arizona.edu/pubs/garden/az1415.pdf (peer reviewed)
  6. T.L. Thompson and J.L. Walworth.  2006.  Salinity Management and Soil Amendments for Southwestern Pecan Orchards.  University of Arizona Cooperative Extension Publication AZ1411, University of Arizona, Tucson, AZ.  http://cals.arizona.edu/pubs/diseases/az1411.pdf (peer reviewed)
  7. D.M. Kopec, J.L., Walworth, J.J. Gilbert, G. Sower, and M. Pessarakli.  2005.  Ball Roll Distance of Sea Isle 2000 in Response to Mowing and Fertility. USGA Turfgrass and Environmental Research Online 4(7):1-6. http://usgatero.msu.edu/v04/n07.pdf  (not peer reviewed).
  8. D.M. Kopec, J.L. Walworth, J.J., Gilbert, G. Sower, M. Pessarakli, D. Kerr and J. Spence.  2004.  Response of Sea Isle I Paspalum To Fertilization and Mowing for Tee and Fairway Turf. 2004 Turfgrass Landscape and Urban IPM Research Summary. AZ 1359 Series P-141. University of Arizona, Tucson, AZ. http://cals.arizona.edu/pubs/crops/az1359/az13593c10.pdf  (not peer reviewed).
  9. D.M. Kopec, J.J. Gilbert, J.L. Walworth, M.Pessarakli, D. Kerr, and J. Spence.  2004.  Best Management Practices for Sea Isle 2000 Surface Conditions as a Putting Green Turf Under Desert Conditions.  2004 Turfgrass Landscape and Urban IPM Research Summary. AZ 1359 Series P-141. University of Arizona, Tucson, AZ. http://cals.arizona.edu/pubs/crops/az1359/az13593c6.pdf (not peer reviewed).
  10. Kopec, D.M., J.L. Walworth, J.J. Gilbert, G.M. Sower and M.Pessarakli.  2004.  Response of Sea Isle 2000 Paspalum to Mowing Height and Nitrogen Fertility as a Putting Surface Under Semi-Arid Conditions. Two Year Report. 2004 Turfgrass Landscape and Urban IPM Research Summary. AZ 1359 Series P-141. University of Arizona, Tucson, AZ. http://cals.arizona.edu/pubs/crops/az1359/az13593c9.pdf (not peer reviewed).
  11. J.L. Walworth and D. Kopec.  2004.  Response and Nutrient Uptake in Bermudagrass Treated with Aquatrols Surfactant ACA 1848 in the Desert Southwest.  2004 Turfgrass Landscape and Urban IPM Research Summary. AZ 1359 Series P-141.  University of Arizona, Tucson, AZ.  http://cals.arizona.edu/pubs/crops/az1359/az13593c2.pdf (not peer reviewed).
  12. J.L. Walworth and D.M. Kopec.  2004.  Aquatrols Surfactant Study on Turfgrass Nutrient Uptake.  2004 Turfgrass Landscape and Urban IPM Research Summary. AZ 1359 Series P-141.  University of Arizona, Tucson, AZ. http://cals.arizona.edu/pubs/crops/az1359/az13593c5.pdf (not peer reviewed).
  13. T.L. Thompson, S.A. White, J.L. Walworth.  2003.  Development of Best Management Practices for Fertigation of Young Citrus Trees.  2003 Citrus Research Report.  University of Arizona, Tucson, AZ  http://ag.arizona.edu/pubs/crops/az1331/az1331-8.pdf (not peer reviewed).
  14. J.L. Walworth and M. Kilby.  2002.  Pecan Leaf Tissue Nutrient Concentrations: Temporal Relationships and Preliminary Standards.  2002 Citrus and Deciduous Fruit and Nut Research Report.  University of Arizona, Tucson, AZ.  http://ag.arizona.edu/pubs/crops/az1303/az1303-16.pdf (not peer reviewed).
  15. T.L. Thompson, S.A. White, J.L. Walworth, and G. Sower.  2002.  Development of Best Management Practices for Fertigation of Young Citrus Trees.  2002 Citrus and Deciduous Fruit and Nut Research Report.  University of Arizona, Tucson, AZ  http://ag.arizona.edu/pubs/crops/az1303/az1303-2.pdf (not peer reviewed).
  16. T.L. Thompson, S.A. White, J.L. Walworth, and G.J. Sower.  2002.  Optimum Fertigation Frequency for Subsurface Drip-Irrigated Broccoli on Medium-Textured Soils.  http://www.back-to-basics.com (peer reviewed).

Professional Pamphlets, Popular Press Articles, Newsletters

  1. J.L. Walworth.  2009.  Soil Degradation.  In D.R. Molina and J. Elliot (eds.) Soil: A Teacher Reference Unit.  Department of Agricultural Education, the University of Arizona, Tucson, AZ. 
  2. J.L. Walworth.  2009.  Fertilizers and Soil Amendments.  In D.R. Molina and J. Elliot (eds.) Soil: A Teacher Reference Unit.  Department of Agricultural Education, the University of Arizona, Tucson, AZ. 
  3. J.L. Walworth.  2009.  Soil Sampling and Testing.  In D.R. Molina and J. Elliot (eds.) Soil: A Teacher Reference Unit.  Department of Agricultural Education, the University of Arizona, Tucson, AZ. 
  4. J.L. Walworth and A.P. Pond.  2006.  Zinc Nutrition of Pecans Growing in Alkaline Soils.  Pecan South 39(5):14-22.
  5. D.M. Kopec, J.L. Walworth, J.J. Gilbert, G.M. Sower, and M. Pessarakli.  2005.  Sea Isle 2000 on Desert Greens. Mowing Height and Nitrogen Fertility. Golf Course Management. Research Section.  November 2005, pp. 84-87. 
  6. D.M. Kopec, J.J. Gilbert, J.L. Walworth, M. Pessarakli, D. Kerr, and J. Spence. 2005.  Effects of Surface Cultural Practices on Sea Isle 2000 Greens. Golf Course Management. Research Section. December 2005, pp. 81-84.
  7. J.P. Field and J.L. Walworth.  2003.  Impacts of Biosolids on Agricultural Lands.  Pima Natural Resource Conservation District Newsletter.
  8. J.P. Field and J.L. Walworth.  2003.  Guidelines for the Application of Biosolids to Agricultural Lands.  Pima Natural Resource Conservation District Newsletter.
  9. J.P. Field and J.L. Walworth.  2003.  Beneficial Effects of Biosolids on Soil Properties.  Pima Natural Resource Conservation District Newsletter.
  10. J.L. Walworth and J. Kelly.  2002.  Managing Caliche in the Home Yard.  The University of Arizona Cooperative Extension Publication AZ1281.  The University of Arizona, Tucson, AZ.
  11. D. Thelander, W. Accomazzo, S.R. Jones, A. Lopez, K.G. Rogers, W. Rousseau, E.G. Sander, J.E. Schafer, M. Somerville, and J.L. Walworth.  2001.  Guide to Agricultural PM10 Best Management Practices.  15 pp.   Arizona Department of Environmental Quality.