Joan Davenport

Joan Davenport

Professor Emeritus, Soil Science


Ph.D., Soil Chemistry, University of Guelph, Canada,  1985
M.S., Soil Management, Iowa State University, 1981
B.S. (Magna), Plant Science, Rutgers the State University of NJ, 1978


In the arid areas of the Pacific Northwest, soil management means knowing about water, about plants, and, of course, about soil.  Dr. Davenport’s research focuses on an array of projects designed to understand soil variability and how to manage water and nutrients for economically sustainable, environmentally friendly agricultural production.

Juice Grapes

  • Evaluation of Sidrophores, Cover Crops, and Concord Chlorosis

Wine Grapes

  • Survey of Extent of Saline and Sodic Soil Conditions in Regulated Deficit Vineyards
  • Grape Response to Polyhalite Fertilizer

Soil Fertility Evaluation

  • Development of Soil and Tissue Nutrient Standards for Blueberry
  • Corn and Dry Bean Response to Alternative P Fertilizer Sources


Stout, J.E. and J. R. Davenport. 2017. Evaluation of deficit irrigation strategies for Vitis labruscana ‘Concord’ in central Washington. Acta Hortic. 1150: 435-442 DOI: 10.17660/ActaHortic.2017.1150.60

Stout, J. E., R. T. Peters, and J. R. Davenport. 2017. Deficit Irrigation in Vitis labruscana Bailey ‘Concord’ in Central Washington. HortScience 52: 450-456. doi: 10.21273/HORTSCI11450-16

Keller, M., P. M. Shresthra, G. E. Hall, B. R. Bondada, and J. R. Davenport. 2016. Arrested sugar accumulation and altered organic acid metabolism in grape berries affected by the berry shrivel syndrome. AJEV 67: 389 – 406. DOI: 10.5344/ajev. 2016.16048

Badr, G., G. Hoogenboom, J. Davenport, and J. Smithyman. 2015. Estimating growing season length using vegetation indices based on remote sensing: A case study for vineyards in Washington state. Trans. ASABE. 58: 551-564. (doi: 10.13031/trans. 58.10845)

Bair, K. E., J. R. Davenport, and S. Burton. 2014. Speciation of phosphorus in anthropogenically acidified soils. Soil Sci. Soc. Am. J. 78:1474–1480 doi:10.2136/sssaj2013.12.0540

Yau, I-H., J. R. Davenport, M. M. Moyer. 2014. Developing a wine grape site suitability GIS for the inland Pacific Northwest. HortTechnology 24: 88-98.

Bair, K.E. and J.R. Davenport. 2013. Plant available phosphorus analysis for recently acidified soils of the Columbia Basin and Washington State. Soil Sci. Am. J. 77: 1103-1106.

Yau, I-H, J.R. Davenport, and R.A. Rupp. 2013. Characterizing Inland Pacific Northwest AVAs with geospatial data. PLoSOne 8: 1-11 e61994.

Bair, K.E., and J.R. Davenport. 2012. Influence of recent acidification on available phosphorus indices and sorption in Washington state soils. Soil Sci. Soc. Am. J. 76: 515-521.

Davenport, J.R., K.E. Bair, and R.G. Stevens. 2012. The Relationship Between Soil Temperature and N Release in Organic and Conventionally Managed Vineyards. Commun. Soil Sci Plant Anal. 43: 464-470

Davenport, J.R., J.D. Lunden and T. Winkler. 2012. Wine Grape Tissue Nutrient Concentrations in the Inland Pacific Northwest. Commun. Soil Sci Plant Anal. 43: 21-27.

Mobbs, T., R.T. Peters, J.R. Davenport, M.A. Evans, and J.Q. Wu. 2012. Effects of four soil surfactants on four soil-water properties in sand and silt loam. J. Soil Water Cons. 67: 275-283.

Peters, R.T., and J.R. Davenport. 2012. Managing irrigation water for different soil types in the same field. WSU Coop. Ext. FS086E.

Peters, R.T., and J.R. Davenport. 2012. Managing irrigation water for different soil types in the same field. WSU Coop. Ext. FS086E.

Davenport, J.R.,  R.G. Stevens, K.M. Whitley, and T. Winkler. 2011. Spatial and temporal nutrient distribution in deficit-drip irrigated wine grape vineyards using bromide as a tracer. HortScience 46: 291-295.

Pradubsuk, S., and J.R. Davenport. 2011. Seasonal Distribution of Micronutrients in Mature ‘Concord’ Grape: Boron, Iron, Manganese, Copper, and Zinc. J. Amer. Soc. Hort. Sci. 135:69-77.

Davenport, J.R., and D.A. Horneck. 2011. Sampling guide and nutrient assessments for irrigated vineyards of the inland Pacific Northwest. PNW 622.

Davenport, J.R., and D.A. Horneck. 2011. Sampling guide and nutrient assessments for irrigated vineyards of the inland Pacific Northwest.  PNW 622.

Pradubsuk, S. and J.R. Davenport. 2010. Seasonal uptake and partitioning of macronutrients in mature ‘Concord’ grape. J. Amer. Soc. Hort. Sci. 135(5):474–483. 2010.

Granatstein, D., and J. Davenport. 2010. Internal Nitrogen Supplies for Perennial Crops. Tilth Producers Quarterly 20 (2):1, 10-12.

Davenport J. Ancient Lakes AVA – petition submitted 2010, reviewed by TTB and public comment period completed 9 July 2012