William L. Pan

Bill Pan

Professor, Scientist, and Extension Specialist

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-elect, Soil Science Society of America (2017)
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

Post Graduate Associates

Tai Maaz, Post doctoral associate
Isaac Madsen, Post doctoral associate

Related Pages

Nutrient Cycling and Rhizosphere Ecology Research
Biofuels Cropping Systems Research Project


Recent Journal and Extension Papers

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. Twenty site-years of eddy covariance measurements reveal effects of climatic conditions and management practices on 3 agricultural carbon and water budgets in the inland Pacific Northwest United States. JGR-Biogeosciences (accepted for publication).

Hammac, A.H., T.M. Maaz, R.T. Koenig, I.C. Burke, and W.L. Pan. Water, temperature, and nitrogen effects on canola (Brassica napus L.) yield, protein, and oil. Journal of Agriculture and Food Chemistry (accepted, in press).

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. Changes in grain yields and fertilizer use efficiency in intensified and diversified cropping systems across the precipitation gradient of the inland Pacific Northwest. Submitted to Frontiers in Ecology and the Environment (accepted, in press).

Pan et al., 2017a: New full citation: Pan, W. L., Maaz, T. M., Madsen, I., J. Reese, M., Hammac, W. A., Wysocki, D., Davis, J. B., Wingerson, M., and Brown, J. 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. Managing high-residue no-till fallow in the low-rainfall zone of the Pacific Northwest. Crop, Forage & Turfgrass Management  (accepted, in press)

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. Soil Science Society of America Journal (in press). Available online doi: 10.2136/sssaj2017.03.0075

Maaz, T. and W.L. Pan. 2017. Residual fertilizer and crop sequence impact rotational nitrogen use efficiency. 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., 23 May 2017

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

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.

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