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William L. Pan

Bill Pan

Professor Emeritus

167 Johnson Hall
PO Box 646420
Pullman WA 99164-6420 USA
Phone 509.335.3611
FAX 509-335-8674



B.S. University of Wisconsin 1976
M.S. University of Missouri 1979
Ph.D. North Carolina State University 1983


President, Soil Science Society of America (2019)
Director of WA State Biofuel Cropping Systems Program (2007-2017)
Director of PNW Cropping Systems research for mitigating and adapting to climate change funded by USDA AFRI CAP grant, REACCH (2011-2017)
Core faculty member of NSF Graduate Training Program: NSPIRE (2010-2015)
Past Chair of Crop and Soil Sciences (2002-2008)


  • Oilseed cropping systems for fuel, food and feed
  • Soil-plant relationships in mineral nutrition, nitrogen cycling, crop root growth and development in relation to soil health
  • Computer imaging of plant roots

Related Pages

Nutrient Cycling and Rhizosphere Ecology Research
Biofuels Cropping Systems Research Project


Recent Journal and Extension Papers

Beres, B.L., J.L. Hatfield, J.A. Kirkegaard, S.D. Eigenbrode, W.L. Pan, R. P. Lollato, J.R. Hunt, S. Strydhorst, K. Porker, D. Lyon, J. Ransom, and J. Wiersma. 2020. Towards a better understanding of Genotype × Environment × Management interactions – a global Wheat Initiative agronomic research strategy. Research Topic: Exploring GxExM Synergies in World-Wide Wheat Production and the Opportunities for International Collaboration. Front. Plant. Sci. 11: article 828.

Porter, M.J., W.L. Pan, W.F. Schillinger, I.J. Madsen, K.E. Sowers, and H. Tao. 2020. Winter canola response to soil and fertilizer nitrogen. Crops & Soils 53: 38-45.

Pan, W.L., K.K. Kidwell, V.A. McCracken, R.P. Bolton, and M. Allen. 2020. Economically optimal wheat yield, protein and nitrogen use component responses to varying N supply and genotype. Front. Plant Sci. vol. 10, article 1790.

Porter, M. W.L. Pan, W. Schillinger, I. Madsen, and H. Tao. 2020. Winter canola response to soil and fertilizer nitrogen in semiarid Mediterranean conditions. Agron. J. 112: 801-814.

Breslauer, R.S., D.J. Brown, W.L. Pan, D.R. Huggins, and H. Tao. 2020. Dense subsoils limit winter wheat rooting depth and soil water depletion. Agron. J. 112: 81-91.

Pan, W.L. 2019. SSSA President’s message: “Lessons Learned from Historic Soils Meeting”. CSA News,  March 2019, 64, 18-19, 21. doi:10.2134/csa2019.64.0322.

Pan, W.L. 2019. SSSA President’s message: “Drawing Inspiration (and New Members) from Youth Activism for Climate Change, Global Health”. CSA News, 64 (11), 21-22.

Pan, W.L. 2019. SSSA President’s message: 2019: “A Momentous Year for SSSA”. CSA News, 64 (12),14. doi:10.2134/csa2019.64.1206

Pierzynski, G., E.A. Guertal, and W. Pan. 2019. Presidents’ message: “Answers to Common Questions Regarding the ACSESS–Wiley Partnership”, CSA News, 64 (12), 18-19.

Guertal, E.A., W.L. Pan, and G.M. Pierzynski. 2019. Presidents’ message: “Your Presidents Go to Washington”, CSA News 64 (8), 14-17.

Pan, W. 2019. President’s message: “Surveys Reveal What SSSA Members Are Thinking”, CSA News,  64 (7), 14-16.

Madsen, I.J. and W.L. Pan. 2019. Assessment of the relative potencies of N fertilizer sources on canola seedling root systems. Agron. J. 111:2445–2452.

Tao, H., W.L. Pan, P. Carter, and K. Wang. 2019. Addition of lignin to lime materials for expedited pH increase and improved vertical mobility of lime in no-till soils. Soil Use Manage. 35:314–322.

Tao, H., W.L. Pan, and E. Bietila. 2019. Nitrogen mineralization rates in long-term manured fields estimated using lab incubation experiment. Open Access Journal of Environmental and Soil Sciences. 12:480-484.

Tao, H. and W.L. Pan. 2019. End-of-season corn stalk nitrate-nitrogen test for post-harvest evaluation. WSU Extension Factsheet FS336E. Washington State University, Pullman, WA.

Tao, H. and W.L. Pan. 2019. End-of-season corn stalk nitrate-nitrogen test for post-harvest evaluation-A cast study. WSU Extension Factsheet TB66E. Washington State University, Pullman, WA.

Tao, H., W.L. Pan, P. Carter, and K. Wang. Nov. 2019. A wheat straw pulping by-product mixed with lime may address soil acidification in no-till fields. WSU Extension Factsheet TB63E. Washington State University, Pullman, WA.

Waldo, S., E.S. Russell, K. Kostyanovsky, S.N. Pressley, P.T. O’Keeffe, D.R. Huggins, C.O. Stöckle, W.L. Pan, and B.K. Lamb. 2019. N2O Emissions from Two Tillage Regimes: High Spatial Variability and Long Pulses Observed Using Static Chambers and the Flux-gradient Technique. Journal of Geophysical Research: Biogeosciences 7: 1887-1904.

Nahar, K. and W. L. Pan. 2019. High resolution in situ rhizosphere imaging of root growth dynamics in oilseed castor plant (Ricinus communis L.) using digital scanners. Modeling Earth Systems and Environment, 5: 781–792.

Pan, W.L. and D. Lyon. 2018. Sustainable Straw Harvesting with Bill Pan. Small Grains Podcasts.

Maaz, T.M., J.D. Wulfhorst, V. McCracken, H. Kaur, I. Roth, D. Huggins, A. Esser, J. Kirkegaard, and W. Pan. 2018. Economic, policy, and social challenges of introducing oilseed and pulse crops into dryland wheat rotations. Agriculture, Ecosystems and Environment 253: 177-194.

Beard, T., T. Maaz, K. Borrelli, J. Harsh, and W. Pan. 2018. Nitrogen impacts wheat and canola silica accumulation, soil silica forms and crusting. J Env. Qual. 47: 1380-1388. doi:10.2134/jeq2018.01.0052

Beard, T., K. Sowers, and W. Pan. 2017. Physiology matters: adjusting wheat-based management strategies for oilseed production (Oilseed Series). WSU Extension publication FS244E.

Pan, W. L., W.F. Schillinger, F.L. Young, E.M. Kirby, G.G. Yorgey, K.A. Borrelli, E.S. Brooks, V.A. McCracken, T.M. Maaz, S. Machado, I.J. Madsen, J.L. Johnson-Maynard, L.E. Port, K. Painter, D.R. Huggins, A.D. Esser, H.P. Collins, C.O. Stockle, and S.D. Eigenbrode. 2017. Integrating historic agronomic and policy lessons with new technologies to drive farmer decisions for farm and climate: The case of inland Pacific Northwestern U.S. Frontiers in Environmental Science. doi: 10.3389/fenvs.2017.00076

Chi, J., S. Waldo, S.N. Pressley, E.S. Russell, P.T. O’Keeffe, W.L. Pan, D.R. Huggins, C.O. Stöckle, E.S. Brooks, and B.K. Lamb. 2017. Effects of climatic conditions and management practices on agricultural carbon and water budgets in the inland Pacific Northwest USA (pdf). Journal of Geophysical Research: Biogeosciences, 122, 3142–3160.

Hammac, A.H., T.M. Maaz, R.T. Koenig, I.C. Burke, and W.L. Pan. 2017. Water and temperature stresses impact canola (Brassica napus L.) fatty acid, protein, and yield over Nitrogen and Sulfur. Journal of Agriculture and Food Chemistry 65(48): 10429-10438.

Maaz, T.M., W. Schillinger, E. Brooks, S. Machado, J. Maynard-Johnson, I. Leslie, L. Port, W.L. Pan, I. Madsen, F.L. Young, A. Glover, H. Collins, and A. Esser. 2017. Impact of Climate Change Adaptation Strategies on Winter Wheat and Cropping System Performance across Precipitation Gradients in the Inland Pacific Northwest, USA. Frontiers in Environmental Science 5:23. doi: 10.3389/fenvs.2017.00023

Pan, W.L., T.M. Maaz, I.J. Madsen, M. Reese, W.A. Hammac, D. Wysocki, J.B. Davis, M. Wingerson, and J. Brown. 2017. 4R nitrogen management when integrating canola into semi-arid wheat. Crops and Soils 50: 3: 16-661. doi:10.2134/cs2017.50.0309

Port, L.E., F.L. Young, and W.L. Pan. 2017. Producing high-residue no-till fallow in the low-rainfall zone of the Pacific Northwest. Crop, Forage & Turfgrass Management 3:2017-03-0024. doi:10.2134/cftm2017.03.0024

Pan, W.L., L.E. Port, Y. Xiao, A.I. Bary, and C.G. Cogger. 2017. Soil carbon and nitrogen fractionation balances during long-term biosolids applications (pdf). Soil Science Society of America Journal 81:1381–1388. Available online doi: 10.2136/sssaj2017.03.0075

Maaz, T. and W.L. Pan. 2017. Residual fertilizer, crop sequence, and water availabilty impact rotational nitrogen balances. Agron. J. 109: 6: 2839-2862 doi:10.2134/agronj2016.08.0457

Stöckle, C.S., S. Higgins, R. Nelson, J. Abatzoglou, D. Huggins, W. Pan, T. Karimi, J. Antle, S. Eigenbrode, and E. Brooks. 2017. Evaluating opportunities for an increased role of winter crops as adaptation to climate change in dryland cropping systems of the U.S. Inland Pacific Northwest. Climate Change  doi:10.1007/s10584-017-1950-z

Chi, J., F. Maureira, S. Waldo, S.N. Pressley, C.O. Stöckle, P.T. O’Keeffe, W.L. Pan, E.S. Brooks, D.R. Huggins, and B.K. Lamb. 2017. Comparison of CropSyst simulations with eddy covariance measurements. Front. Ecol. Evol. 5:50. doi: 10.3389/fevo.2017.00050

Maaz, T.M., J.D. Wulfhorst, V. McCracken, H. Kaur, I. Roth, D. Huggins, A. Esser, J. Kirkegaard, and W. Pan. 2017. Economic, policy, and social challenges of introducing oilseed and pulse crops into dryland wheat rotations. Agriculture, Ecosystems and Environment. (accepted, in press.

Pan, W.L., I.J. Madsen, L. Graves, T. Sistrunk, and R. Bolton. 2016. Ammonia/ammonium toxicity of root meristems and root hairs as influenced by inorganic and organic fertilizer sources and placement. Agronomy Journal 108:2485-2492.

Pan, W.L., T.M. Maaz, W.A. Hammac, V.A. McCracken, and R.T. Koenig. 2016. Mitscherlich-modeled, semi-arid canola nitrogen requirements influenced by soil N and water. Agronomy Journal 108:884-894.

Maaz, T., W.L. Pan, and A.H. Hammac. 2016. Influence of soil nitrogen and water supply on canola nitrogen use efficiency of canola. Agronomy Journal 108:2099-2109.

Pan, W.L., F.L. Young, S.H. Hulbert, D.R. Huggins, and T.M. Maaz. 2016. Canola Integration into Semi-Arid Wheat Cropping Systems of the inland Pacific Northwestern USA. Crop and Pasture Science 67(4) 253-265

Long, D., F. Young, W. Schillinger, C. Reardon, J. Williams, B. Allen, W. Pan, and D. Wysocki. 2016. Ongoing development of dryland oilseed production systems in northwestern region of the United States. Bionenergy Research OnLine DOI 10.1007/s12155-016-9719-1

Chi, J., S. Waldo, S.Pressley, P. O’Keeffe, D. Huggins, C. Stöckle, W.L. Pan, E. Brook, and B. Lamb. 2016. Assessing carbon and water dynamics of no-till and conventional tillage cropping systems in the inland Pacific Northwest US using the eddy covariance method. Agricultural and Forest Meteorology 218–219 (2016) 37–49

Waldo, S., J. Chi, S. Pressley, P. O’Keeffe, W.L. Pan, E. Brooks, D. Huggins, C. Stockle, and B. Lamb. 2016. Assessing carbon dynamics at high and low rainfall agricultural sites in the inland Pacific Northwest US using the eddy covariance method. Agricultural and Forest Meteorology 218–219: 25–36.

Young, F.L., A.R. Alldredge, and W.L. Pan. 2015. Comparisons of Annual No-Till Spring Cereal Cropping Systems in the Pacific Northwest Winter Wheat/Fallow Region. Crop Management. 1:1.

Landry, E.J., J.E. Lafferty, C.J. Coyne, W.L. Pan, and J. Hu. 2015. Registration of four winter-hardy faba bean germplasm lines for use in winter pulse and cover crop development. Journal of Plant Registrations 9(3):367-370.

Nahar, K., and W.L. Pan. 2015. Urea Fertilization: Effects on growth, nutrient uptake and root development of the biodiesel plant, castor bean (Ricinus communis L). American Journal of Experimental Agriculture 5(4): 320-335.

Evans, M.A., D.Z. Skinner, R.T. Koenig, S.H. Hulbert, and W.L. Pan. 2015. Effect of phosphorus, potassium and chloride on cold tolerance of winter canola (Brassica napus L.). J. Plant Nutr. DOI:10.1080/01904167.2014.990095.

Young, F.L., D.K. Whaley, W.L. Pan, D. Roe, and J.R. Alldredge. 2014. Introducing winter canola to the winter wheat-fallow region of the Pacific Northwest. Crop Management. DOI: 10.2134/CM-2013-0023-RS.

Bass, R., M. Garcia-Perez, D. Horneck, M. Lewis, B. Pan, T. Peters, B. Stevens, and D. Wysocki. 2014. Carbon implications of converting a coal-fired power plant to combustion of torrefied Arundo Donax. Applied Bioenergy 1:30-43.

Cherian, G., A. Orr, I.C. Burke, and W. Pan. 2013. Feeding Artemisia annua alters digesta pH and muscle lipid oxidation products in broiler chickens. Poultry Science 92:1085–1090.

Gollany, H.T., A.M. Fortuna, M.K. Samuel, F.L. Young, W.L. Pan, and M. Pecharko. 2013. Estimated soil organic carbon accretion vs. sequestration using chemical and physical fractionation and the CQESTR model. Soil Sci. Soc. Am. J. 77:618–629.

Sowers, K.E., R.D. Roe, and W.L. Pan. 2012. Oilseed Production Case Studies in the Eastern Washington Low-to-Intermediate Rainfall Zone. Washington State University Extension Manual EM048E.

Koenig, R.T., W.A. Hammac, and W. L. Pan. 2011. Canola growth, development and fertility. WSU Extension Fact Sheet FS045E.

Sowers, K.E., R.D. Roe, and W.L. Pan. 2011. Oilseed Production Case Studies in the Eastern Washington High Rainfall Zone. Washington State University Extension Manual EM037E.

Hulbert, S., S. Guy, B. Pan, T. Paulitz, B. Schillinger, D. Wysocki, and K. Sowers. 2011. Camelina production in the dryland Pacific Northwest. WSU Extension Fact Sheet.

Kincaid, R., K. Johnson, J. Michal, S. Hulbert, W. Pan, J. Barbano, and A. Huisman. 2011. Biennial canola for forage and ecosystem improvement in dryland cropping systems. Advances in Animal Biosciences 2(2):457.

Hammac, A., W.L. Pan, R.P. Bolton, and R.T. Koenig. 2011. In-Situ imaging to assess oilseed species’ root hair responses to water stress. Plant Soil 339: 125-135.

Abi-Ghanem, R., L. Carpenter-Boggs, R. Koenig, C. Pannkuk, W. Pan, and R. Parker. 2009. Extension education for dryland cropping systems in Iraq. JNRLSE 38:133-139.

Xiao, C., M. Fauci, D.F. Bezdicek, W.T. McKean, and W.L. Pan. 2008. Soil aggregation and microbial responses to straw pulping byproducts. Soil Sci. Soc. Am. J 72: 1471-1477.

Young, F.A., L.S. Bewick, and W.L. Pan. 2008. Systems Approach to Crop Rotation Research: Guidelines and Challenges. In Y.U. Berklian, ed. Crop Rotation. Nova Science Publishers, Inc.

Pan, W., W. Schillinger, D. Huggins, R. Koenig, and J. Burns. 2007. Fifty years of predicting wheat nitrogen requirements based on soil water, yield, protein and nitrogen efficiencies. In Managing Crop Nitrogen for Weather. International Plant Nutrition Institute, Norcross, GA.

Cerny-Koenig, T., C.A. Perillo, C.H. Pearson-Mims, K.M. Williams, G. Brown, A. Morozov, W.L. Pan, and W. Hendrix. 2007. Piloting a program-level learning assessment plan in plant and soil science. NACTA Sept.: 26-33.

Xiao, C., R. Stevens, M. Fauci, R. Bolton, M. Lewis, W.T. McKean, D.F. Bezdicek, and W.L. Pan. 2007. Soil microbial activity, aggregation and nutrient responses to straw pulping liquor in corn.  Biol. Fert.Soils 43:709-719.

Xiao, C, R. Bolton, and W.L. Pan. 2007. Lignin from rice straw kraft pulping: effects on soil aggregation and chemical properties. Bioresource Technology 98:1482-1488.

Camberato, J.J., B. Gagnon, 0.A. Angers, and W.L. Pan. 2006. Pulp and paper mill byproducts as plant nutrient sources and soil amendments. Can. J. Soil Sci. 86: 641-653.

Book Chapters

Kirby, EM, Pan, WL, Huggins, DR, Painter, KM, and P. Bista. 2017. Rotational diversification and intensification strategies. In Yorgey, G. and C. Kruger, eds. Advances in Sustainable Dryland Farming in the Inland Pacific Northwest, Washington State University Extension Publication EM108, Pullman, WA.

Yorgey, G.G., W.L. Pan, R. Awale, S. Machado, and A. Bary. 2017. Soil Amendments Research in Dryland Systems of the Inland Pacific Northwest. In Yorgey, G. and C. Kruger, eds. Advances in Sustainable Dryland Farming in the Inland Pacific Northwest, Washington State University Extension Publication EM108, Pullman, WA.

Borrelli, K., T. Maaz, W. Pan, P. Carter, H. Tao. 2017. Soil Fertility Management. In Yorgey, G. and C. Kruger, eds. Advances in Sustainable Dryland Farming in the Inland Pacific Northwest, Washington State University Extension Publication EM108, Pullman, WA.

Pan, W.L. 2011. Nutrient Interactions in Soil Fertility and Plant Nutrition. In Huang, P.M., Li.Y., and Sumner, M.E., eds., Soil Science Handbook, CRC Press, Boca Raton, Fl.

Young, F.A., L.S. Bewick, and W.L. Pan. 2008. Systems Approach to Crop Rotation Research: Guidelines and Challenges. In Y.U. Berklian, ed. Crop Rotation. Nova Science Publishers, Inc.

Pan, W.L., R.G. Stevens, and K.L. Labno. 2004. Cadmium accumulation in wheat and potato from P and waste-derived Zn fertilizers. In W.L. Hall and W.P. Robarge, Environmental Impacts of Fertilziers on Soil, Air, and Water, American Chemical Society, Washington, D.C.

Huggins, D.R. and W.L. Pan. 2003. Key indicators for assessing nitrogen use efficiency in cereal-based agroecosystems. In Cropping Systems: Trends and Advances Part I & II, A. Shrestha (ed.), Haworth Press, Binghamton, NY.

Camberato, J.J. and W.L. Pan. 1999. Bioavailability of calcium,magnesium, and sulfur. In M. E. Sumner (ed.), Handbook of Soil Science, CRC Press, Boca Raton, FL.

William Pan, Collaborative Soil Scientist and Mentor, Looks Back on 36 Years at WSU

William Pan, a soil scientist, research leader, instructor and mentor who helped develop sustainable Pacific Northwest farming practices and crops, retired this winter after a 36-year career at Washington State University.

Trained and educated at land-grant universities, Pan throughout his career has sought out projects that crossed disciplines and benefited farmers, the economy, and the environment.

“You have to work holistically to make progress,” he said. “There’s a whole range of things I never thought I would grasp, from crop insurance to transportation, but that’s what ended up happening. And that’s what led to success.”


Roots of Soil Fertility

Dr. Pan was honored to deliver the 2016 Leo M. Walsh Soil Fertility Distinguished Lectureship at the Soil Science Society of America meetings in Minneapolis, MN on November 17, 2015. He reflected on his 40 year academic career as student and faculty, following a land-grant institutional trail that began at University of Wisconsin-Madison and ended at Washington State University-Pullman. He took the locational opportunity to reflect on his own family roots in Minnesota, and on key pivot points that lead him to devote his research, teaching and extension career focused on the essence of the life-death-soil fertility cycle. Basic laws of nutrient cycling and mass conservation, and models of soil-plant interactions at micro and macro scales shaped his research inquiries to connect nutrient dynamics and management to the current issues of the day from water and soil quality to biofuels and climate change.

William L. Pan and students