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John Sawyer

 

publications |Extension Publications| |Publications| |Book Chapters| |Conference Papers| |Technical Articles| |Technical Abstracts|

Extension Publications:

Mallarino, A.P., and J.E. Sawyer. 2016. Take a good soil sample to help make good fertilization decisions. CROP 3108. Iowa State Univ. Ext. and Outreach, Ames.

Sawyer, J. Revised 2016. Nitrogen use in Iowa corn production. CROP 3073. Iowa State Univ. Ext. and Outreach, Ames.

Sawyer, J.E. and A.P. Mallarino. Revised 2016. Using manure nutrients for crop production. PMR 1003. Iowa State Univ. Ext., Ames, IA.

Sawyer, J. 2015. Nitrogen use in Iowa corn production. CROP 3073. Iowa State Univ. Ext. and Outreach, Ames.

Sawyer, J., B.J. Lang, and D.W. Barker. 2015. Sulfur management for Iowa crop production. CROP 3072. Iowa State Univ. Ext. and Outreach, Ames.

Sawyer, J. 2015. Nitrogen recommendations for optimizing economic return and water quality. p. 21. In 2015 Crop Advantage Series, AEP 0200. Iowa State Univ. Ext. and Outreach, Ames.

Wortmann, C.S, J. Sawyer, and S. Tonn. 2015. On-farm study researches Novozymes fermentation spent residuals. Univ. of Nebraska-Lincoln Extension and Iowa State Univ. Extension and Outreach, Lincoln, NE.

Sawyer, J.E., and A.P. Mallarino. 2014. Nutrient considerations with corn stover harvest, PM 3052C. Iowa State Univ. Ext. and Outreach, Ames.

Sawyer, J. 2014. Nitrogen fertilization and cycling in a winter rye cover crop system. p. 21. In 2014 Crop Advantage Series, AEP 0200. Iowa State Univ. Ext. and Outreach, Ames.

Sawyer, J. 2014. Corn sulfur fertilization. p. 24-25. In 2014 Crop Advantage Series, AEP 0200. Iowa State Univ. Ext. and Outreach, Ames.

Sawyer, J. 2014. Nitrogen and inhibitor use in corn production. p. 26-27. In 2014 Crop Advantage Series, AEP 0200. Iowa State Univ. Ext. and Outreach, Ames.

Barnhart, S.K., A.P. Mallarino, and J.E. Sawyer. 2013. Fertilizing pasture, PM 869. Iowa State Univ. Ext. and Outreach, Ames.

Mallarino, A.P., J.E. Sawyer, and S.K. Barnhart. 2013. A general guide for crop nutrient and limestone recommendations for Iowa, PM 1688. Iowa State Univ. Ext. and Outreach, Ames.

Mallarino, A.P., and J.E. Sawyer. 2013. Interpretation of soil test results, PM 1310. Iowa State Univ. Ext. and Outreach, Ames.

Pagani, A., J.E. Sawyer, A.P. Mallarino, L. Moody, J. Davis, and S. Phillips. 2013. Site-specific nutrient management: For nutrient management planning to improve crop production, environmental quality, and economic return. NRCS 001. A joint education project with Iowa State University Extension and Outreach, The Fertilizer Institute (TFI), Natural Resources Conservation Service (USDA-NRCS), and International Plant Nutrition Institute.

Mallarino, A.P., and J. Sawyer. 2013. Crop nutrient management for 2013. p. 6-7. In 2013 Crop Advantage Series, AEP 0200. Iowa State Univ. Ext. and Outreach, Ames.

Wortman, C., M. Al-Kaisi, M. Helmers, J. Sawyer, D. Devlin, C. Barden, P. Scharf, R. Ferguson, W. Kranz, C. Shapiro, R. Spalding, D. Tarkalson, J. Holz, D. Francis, and J. Schepers. 2013. Agricultural nitrogen management for water quality protection in the Midwest. RP189 (Revised May 2013). Univ. of Nebraska-Lincoln Ext., Lincoln, NE.

Mueller, D., R. Pope, L. Abendroth, R. Elmore, B. Hartzler, M. Helmers, E. Hodgson, C. McGrath, G. Munkvold, M. Rice, A. Robertson, J. Sawyer, K. Schaefer, A. Sisson, J. Tollefson, and G. Tylka. 2013. Corn field guide, 2nd Ed. CSI 0001. Iowa State Univ. Ext. and Outreach, Ames.

Hanna, M., J.E. Sawyer, and D. Petersen. 2012. Energy consumption for row crop production. PM 2089W.Iowa State Univ. Ext., Ames.

Sawyer, J. 2012.Nitrogen use in corn production. p. 12.In 2012 Crop Advantage Series. Iowa State Univ. Ext., Ames.

Sawyer, J. 2012. Sulfur fertilization for corn production. p. 14. In 2012 Crop Advantage Series. Iowa State Univ. Ext., Ames.

Sawyer, J.E. 2012. Soil nitrogen cycle. Publication for the USDA-NIFA Climate and Corn-Based Cropping Systems Coordinated Agricultural Project (CSCAP) 2012 annual meeting, Wooster, OH.

Sawyer, J., A.P. Mallarino, and M. Al-Kaisi. 2011. Flooded soil syndrome fact sheet. Iowa State Univ. Ext. and Univ. Nebraska-Lincoln Extension, Ames, IA and Lincoln, NE.

Rieck-Hinz, A., T. Miller, J. Sawyer. 2011. How to interpret your manure analysis. PM 3014. Iowa State Univ. Ext., Ames.

Franzen, D.W, and NCERA-103 Committee. 2011. Nitrogen extenders and additives for field crops. SF-1581. North Dakota Ext. Serv., North Dakota State Univ., Fargo.

Sawyer, J.E., M. Hanna, and D. Petersen. 2010. Energy conservation in corn nitrogen fertilization. PM 2089i. Iowa State Univ. Ext., Ames.

Sawyer, J. 2010. Nutrient deficiencies and application injuries in field crops. IPM 42. Iowa State Univ. Ext., Ames.

Buffington, B., K. Schaefer, L. Abendroth, S. Barnhart, R. Elmore, E. Hodgson, P. Pedersen, and J. Sawyer. 2009. Integrated crop management and pesticide application, field records. ICM 1. Iowa State Univ. Ext., Ames, IA.

Mueller, D., R. Pope, L. Abendroth, R. Elmore, B. Hartzler, C. McGrath, G. Munkvold, M. Rice, A. Robertson, J. Sawyer, K. Schaefer, J. Tollefson, and G. Tylka. 2009. Corn field guide. CSI 0001. Iowa State Univ. Ext., Ames, IA.

Sawyer, J.E. and A.P. Mallarino. 2008. Using manure nutrients for crop production. PMR 1003. Iowa State Univ. Ext., Ames, IA.

Sawyer, J., and A.P. Mallarino. 2008. What is meant by crop availability of manure nutrients? In Iowa Manure Manager Series, Vol. 6, Iowa State Univ. Extension, Ames, IA.

Sawyer, J. 2007. Is manure the same as fertilizer as a crop nutrient resource? In Iowa Manure Manager Series, Vol. 5, Iowa State Univ., Ames, IA.

Sawyer, J. 2007. Nitrogen fertilization for continuous and rotated corn. p. 24. In 2007 Proceedings Crop Advantage Series. AEP 0200f. Iowa State Univ., Ames, IA.

Wortman, C., M. Al-Kaisi, M. Helmers, J. Sawyer, D. Devlin, C. Barden, P. Scharf, R. Ferguson, W. Kranz, C. Shapiro, R. Spalding, D. Tarkalson, J. Holz, D. Francis, and J. Schepers. 2006. Agricultural nitrogen management for water quality protection in the Midwest. RP189. Univ. of Nebraska-Lincoln Ext., Lincoln, NE.

Sawyer, J., J. Lundvall, J. Hawkins, and D. Barker. 2006. Sensing nitrogen stress in corn. PM 2026. Iowa State Univ. Ext., Ames, IA.

Sawyer, J., E. Nafziger, G. Randall, L. Bundy, G. Rehm, and B. Joern. 2006. Concepts and Rationale for Regional Nitrogen Rate Guidelines for Corn. PM 2015. Iowa State Univ. Ext., Ames, IA.

Sawyer, J., and A. Mallarino. 2006. Applying fertilizer and lime to CRP land. CRP-5.  Iowa State Univ. Ext., Ames, IA.

Mallarino, A.P., B.M. Stewart, J.L. Baker, J.A. Downing, and J.E. Sawyer. 2005. Background and basic concepts of the Iowa phosphorus index. A support document to the USDA-NRCS field office technical note 25. Revised April 2005. USDA-NRCS, Des Moines, IA.

Sawyer, J.E. 2004. Nutrient deficiencies and application injuries in field crops. IPM-42. Revised July 2004. Iowa State University Extension, Ames, IA.

Sawyer, J., A. Mallarino, and R. Killorn. 2003. Take a good sample to help make good decisions. PM 287 Revised September 2003. Iowa State University Extension, Ames, IA.

Mallarino, A., J. Sawyer, and J. Creswell. Revised 2003. Soil testing. NMEP-1 Revised September 2003. Iowa State University Extension, Ames, IA.

Sawyer, J.E., A.P. Mallarino, and R. Killorn. 2003. Interpretation of Soil Test Results. PM 1310. Iowa State University Extension, Ames, IA.

Sawyer, J.E., A.P. Mallarino, R. Killorn, and S.K. Barnhart. 2002. General Guide for Crop Nutrient Recommendations in Iowa. Pm-1688. Iowa State University Extension, Ames, IA.

Mallarino, A. J. Sawyer, and J. Creswell. 2002. Phosphorus application. NMEP-2. Iowa State University Extension, Ames, IA.

Lorimor, J., A. Mallarino, J. Sawyer, and J. Creswell. 2002. Manure resources. NMEP-3. Iowa State University Extension, Ames, IA.

DeWitt, J. M. Duffy, G. Miller, J. Sawyer, and J. Creswell. 2002. Crop rotation. NMEP-5. Iowa State University Extension, Ames, IA.

Sawyer, J. and J. Creswell. 2002. Nitrogen application. NMEP-7. Iowa State University Extension, Ames, IA.

Mallarino, A., J. Sawyer, B. Stewart, and J. Creswell. 2002. Nutrient management plan. NMEP-8. Iowa State University Extension, Ames, IA.

Sawyer, J.E., J. Creswell, R. Pope, and J. Miller. 2001. Nitrogen options, get the most from each pound of nitrogen! IPM 67. Iowa State University Extension.

Mallarino, A.P. and J.E. Sawyer. 2000. Interpreting Mehlich 3 soil test results. SP 126. 3 pp. Iowa State Univ.

Sawyer, J.E., J. Creswell, R. Pope, and J. Miller. 2000. IPM 66A. Don't go until it's 50 or below! Information Poster. Iowa State University Extension.

Publications:

Poffenbarger, H.J., D.W. Barker, M.J. Helmers, F.E. Miguez, D.C. Olk, J.E. Sawyer, J. Six, and M.J. Castellano. 2017. Maximum soil organic carbon storage in Midwest U.S. cropping systems when crops are optimally nitrogen-fertilized. PLoS ONE 12(3): e0172293.

Sawyer, J.E., D.W. Barker, and J.P. Lundvall. 2017. Impact of nitrogen timing on corn production. Fluid J. 25(2):7-10.

Woli, K.P., J.L. Pantoja, and J.E. Sawyer. 2016. Soil inorganic nitrogen with incubation of rye cover crop biomass. Commun. Soil Sci. Plant Anal. 47:2558-2572.

Puntel, L.A., J.E. Sawyer, D.W. Barker, R. Dietzel, H. Poffenbarger, M.J. Castellano, K.J. Moore, P. Thorburn, and S.V. Archontoulis. 2016. Modeling long-term corn yield response to nitrogen rate and crop rotation. Front. Plant Sci. 7:1630.

Pantoja, J.L., K.P. Woli, J.E. Sawyer, and D.W. Barker. 2016. Winter rye cover crop biomass production, degradation, and nitrogen recycling. Agron. J. 108:841-853.

Woli, K.P., M.J. Boyer, R.W. Elmore, J.E. Sawyer, L.J. Abendroth, and D.W. Barker. 2016. Corn era hybrid response to nitrogen fertilization. Agron. J. 108:473-486.

Quezada, J.C., A.W. Lenssen, K.J. Moore, J.E. Sawyer, and P. Summer. 2015. Amino acid biosynthesis byproducts are a suitable source of nitrogen for corn production. Field Crops Res. 184:123-132.

Pantoja, J.L., K.P. Woli, J.E. Sawyer, D.W. Barker. 2015. Corn nitrogen fertilization requirement and corn-soybean productivity with a rye cover crop. Soil Sci. Soc. Am. J. 79:1482-1495.

Pantoja, J.L., K.P. Woli, J.E. Sawyer, D.W. Barker, and M. Al-Kaisi. 2015. Stover harvest and tillage system effects on corn response to fertilizer nitrogen. Soil Sci. Soc. Am. J. 79:1249-1260.

Castellano, M.J., K.E. Mueller, D.C. Olk, J.E. Sawyer, and J. Six. 2015. Integrating plant litter quality, soil organic matter stabilization, and the carbon saturation concept. Global Change Biol. doi:10.1111/gcb.12982.

Woli, K.P., D.A. Ruiz-Diaz, D.E. Kaiser, A.P. Mallarino, and J.E. Sawyer. 2015. Field-scale evaluation of poultry manure as a combined nutrient resource for corn production. Agron. J. 107:1789-1800.

Iqbal, J., D.C. Mitchell, D.W. Barker, F. Miguez, J.E. Sawyer, J. Pantoja, and M.J. Castellano. 2015. Does nitrogen fertilizer application rate to corn affect nitrous oxide emissions from the rotated soybean crop? J. Eviron. Qual. 44:711-719.

Necpálová, M., R.P. Anex, M.N. Fienen, S.J. Del Grosso, M.J. Castellano, J.E. Sawyer, J.Iqbal, J.L. Pantoja, and D.W. Barker. 2015.

Understanding the DayCent model: calibration, sensitivity, and identifiability through inverse modeling. Environ. Modeling & Soft.66:110-130, doi:10.1016/j.envsoft.2014.12.011.

Daigh, A.L., M.J. Helmers, E. Kladivko, X. Zhou, R. Goeken, J. Cavdini, D. Barker, and J. Sawyer. 2014. Soil water during the drought of 2012 as affected by rye cover crops in fields in Iowa and Indiana. J. Soil Water Conserv. 69:564-573.

Kladivko, E.J., M.J. Helmers, L.J. Abendroth, D. Herzmann, R. Lal, M.J. Castellano, D.S. Mueller, J.E. Sawyer, R.P. Annex, R.W. Arritt, B. Basso, J.V. Bonta, L.C. Bowling, R.M. Cruse, N.R. Fausey, J.R. Frankenberger, P.W. Gassman, A.J. Gassmann, C.L. Kling, A. Kravchenko, J.G. Lauer, F.E. Miguez, E.D. Nafziger, N. Nkongolo, M. O’Neal, L.B. Owens, P.R. Owens, P. Scharf, M.J. Shipitalo, J.S. Strock, and M.B. Villamil. 2014. Standardized research protocols enable trasdisciplinary research of climate variation impacts in corn production systems. J. Soil Water Conserv. 69:532-542.

Necpalova, M., R.P. Anex, Jr., A.N. Kravchenko, L.J. Abendroth, S.J. Del Grosso, W.A. Dick, M.J. Helmers, D. Herzmann, J.G. Lauer, E.D. Nafziger, J.E. Sawyer, P.C. Sharf, J.S. Strock, and M.B. Villamil. 2014. What does it take to detect a change in soil carbon stock?

A regional comparison of minimum detectable difference and experiment duration in the north central United States. J. Soil Water Conserv. 69:517-531.

Woli, K.P., F.G. Fernandez, J.E. Sawyer, J.D. Stamper, D.B. Mengel, D.W. Barker, and M.H. Hanna. 2014. Agronomic comparison of anhydrous ammonia applied with a high speed-low draft opener and conventional knife injection in corn. Agron. J. 106:881-892.

Brown, K.H., E.M. Bach, R.A. Drijber, K.S. Hofmockel, E.S. Jeske, J.E. Sawyer, and M.J. Castellano. 2014. A long-term nitrogen fertilizer gradient has little effect on soil organic matter in a high-intensity maize production system. Global Change Biology, doi:10.1111/gcb.12519.

Woli, K.P., S. Rakshit, J.P. Lundvall, J.E. Sawyer, and D. Barker. 2013. Liquid swine manure application to soybean and residual-year nitrogen supply to corn. Soil Sci. Soc. Am. J. 77:1684-1695.

Barker, D.W., and J.E. Sawyer. 2013. Factors affecting active canopy sensor performance and reflectance measurements. Soil Sci. Soc. Am. J. 77:1673-1683.

Mitchell, D.C., M.J. Castellano, J.E. Sawyer, and J. Pantoja. 2013. Cover crop effects on nitrous oxide emissions: role of mineralizable carbon. Soil Sci. Soc. Am. J. 77:1765-1773.

Woli, K.P., S. Rakshit, J.P. Lundvall, J.E. Sawyer, and D.W. Barker. 2013. On-farm evaluation of liquid swine manure as a nitrogen source for corn production. Agron. J. 105:248-262.

Al-Kaisi, R.W. Elmore, J.G. Guzman H.M. Hanna, C.E. Hart, M.J. Helmers, E.W. Hodgson, A.W. Lenssen, A.P. Mallarino, A.E. Robertson, and J.E. Sawyer. 2013. Drought impact on crop production and the soil environment: 2012 experiences from Iowa. J. Soil Water Conser. 68:19A-24A.

Ruiz Diaz, D.A., J.E. Sawyer, and D.W. Barker. 2012. Residual poultry manure nitrogen supply to corn the second and third years after application. Soil Sci. Soc. Am. J. 76:2289-2296.

Woli, K.P., S. Rakshit, J.P. Lundvall, J.E. Sawyer, and D.W. Barker. 2012. On-farm evaluation of liquid swine manure as a nitrogen source for corn production. Agron. J. 105:248-262.

Barker, D.W., and J.E. Sawyer. 2012. Using active canopy sensing to adjust nitrogen application rate in corn. Agron. J. 104:926-933.

Holmes, J.D., J.E. Sawyer, P. Kassel, and D. Ruiz Diaz. 2011. Using ground eggshells as a liming material in corn and soybean production. Online. Crop Management doi: 10.1094/CM-2011-1129-01-RS.

Sawyer, J.E., and D.W. Barker. 2011. An evaluation of the Illinois soil nitrogen test in Iowa corn production. Online. Crop Management doi: 10.1094/CM-2011-0630-01-RS.

Ruiz Diaz, D.A., J.E. Sawyer, and A.P. Mallarino. 2011. On-farm evaluation of poultry manure as a nitrogen source for corn. SSSAJ 75:729-737.Barker, D.W., and J.E. Sawyer. 2010. Using active canopy sensors to quantify corn nitrogen stress and nitrogen application rate. Agron. J. 102:964-971.

Barker, D.W., and J.E. Sawyer. 2010. Using active canopy sensors to quantify corn nitrogen stress and nitrogen application rate. Agron. J. 102:964-971.

Doty, D.A., and J.E. Sawyer. 2010. Process water from soybean soapstock refining as a nutrient source for corn production. Online. Crop Management doi:10.1094/CM-2010-0126-02-RS.

Sawyer, J.E., P. Pedersen, D.W. Barker, D.A. Ruiz Diaz, and K.A. Albrecht. 2010. Intercropping corn and kura clover: response to nitrogen fertilization. Agron. J. 102:568-574.

Ruiz Diaz, D.A., J.E. Sawyer, D.W. Barker, and A.P. Mallarino. 2010. Runoff nitrogen loss with simulated rainfall immediately following poultry manure application for corn production. Soil Sci. Soc. Am. J. 74:221-230.

Ruiz Diaz, D.A., P. Pedersen, and J.E. Sawyer. 2009. Soybean response to inoculation and nitrogen application following long-term grass pasture. Crop Sci. 49:1058-1062.

Barbazán, M.M., A.P. Mallarino, and J.E. Sawyer. 2009. Liquid swine manure phosphorus utilization for corn and soybean production. Soil Sci. Soc. Am. J. 73:654-662.

Ruiz Diaz, D.A., J.A. Hawkins, J.E. Sawyer, and J.P. Lundvall. 2008. Evaluation of in-season nitrogen management strategies for corn production. Agron. J. 100:1711-1719.

Ruiz Diaz, D.A., and J.E. Sawyer. 2008. Plant-available nitrogen from poultry manure as affected by time of application. Agron. J. 100:1318-1326.

Ruiz Diaz, D.A., J.E. Sawyer, and A.P. Mallarino. 2008. Poultry manure supply of potentially available nitrogen with soil incubation. Agron. J. 100:1310-1317.

Laboski, C.A.M., J.E. Sawyer, D.T. Walters, L.G. Bundy, R.G. Hoeft, G.W. Randall, and T.W. Andraski. 2008. Evaluation of the Illinois soil nitrogen test in the north central region of the United States. Agron. J. 100:1070-1076.

Al-Kaisi, M.M., M.L. Kruse, and J.E. Sawyer. 2008. Effect of nitrogen fertilizer application on growing season soil CO2 emission in a corn-soybean rotation. J. Environ. Qual. 37:325-332.

Loria, E.R., J.E. Sawyer, D.W. Barker, J.P. Lundvall, and J.C. Lorimor. 2007. Use of anaerobically digested swine manure as a nitrogen source in corn production. Agron. J. 99:1119-1129.

Hawkins, J.A., J.E. Sawyer, D.W. Barker, and J.P. Lundvall. 2007. Using relative chlorophyll meter values to determine nitrogen application rates for corn. Agron. J. 99:1034-1040.

Barker, D.W., J.E. Sawyer, and M.M. Al-Kaisi. 2006. Assessment of the amino sugar-nitrogen test on Iowa soils: I. Evaluation of soil sampling and corn management practices. Agron. J. 98:1345-1351.

Barker, D.W., J.E. Sawyer, M.M. Al-Kaisi, and J.P. Lundvall. 2006. Assessment of the amino sugar-nitrogen test on Iowa soils: II. Field correlation and calibration. Agron. J. 98:1352-1358.

Loria, E.R., and J.E. Sawyer. 2005. Extractable soil phosphorus and inorganic nitrogen following application of raw and anaerobically digested swine manure. Agron. J. 97:879-885.

Barker, D.W., and J.E. Sawyer. Nitrogen application to soybean at early reproductive development. Agron. J. 97:615-619.

Mallarino, A.P., B.M. Stewart, J.L. Baker, J.D. Downing, and J.E. Sawyer. 2002. Phosphorus indexing for cropland: Overview and basic concepts of the Iowa phosphorus index. J. Soil Water Cons. 57(6):440-447.

Sawyer, J.E., and S.A. Ebelhar. 1995. Sulfur nutrition of winter wheat varieties with till and no-till planting on highly weathered alfisol soils. Comm. Soil Sci. Plant Anal. 26(7&8):1257-1271.

Sawyer, J.E. 1994. Concept of variable rate technology with considerations for fertilizer application. J. Prod. Agric. 7:195-201.

Sawyer, J.E., and J.L. Carter. 1993. Urea-ammonium nitrate solution management techniques for winter wheat production. J. Prod. Agric. 6:62-67.

Schmitt, M.A., J.E. Sawyer, and R.G. Hoeft. 1992. Incubation of injected liquid beef manure: Effect of time and manure rate. Agron. J. 84:224-228.

Bullock, D.G., and J.E. Sawyer. 1991. Nitrogen, potassium, sulfur, and boron fertilization of canola. J. Prod. Agric. 4:550-555.

Sawyer, J.E., M.A. Schmitt, R.G. Hoeft, J.C. Siemens, and D.H. Vanderholm. 1991. Corn production associated with liquid beef manure application methods. J. Prod. Agric. 4:335-344.

Sawyer, J.E., and R.G. Hoeft. 1990. Effect of injected liquid beef manure on soil chemical properties and corn root distribution. J. Prod. Agric. 3:50-55.

Sawyer, J.E., and R.G. Hoeft. 1990. Greenhouse evaluation of simulated injected liquid beef manure. Agron. J. 82:613-618.

Sawyer, J.E., M.A. Schmitt, and R.G. Hoeft. 1990. Inorganic nitrogen distribution and soil chemical transformations associated with injected liquid beef manure. Agron. J. 82:963-969.

Vanden Heuvel, R.M., J.E. Sawyer, M.A. Schmitt, R.G. Hoeft, and G.S. Brinkman. 1989. Corn response to zinc on Illinois soils. J. Fert. Issues. 6(3):68-76.

Hoeft, R.G., J.E. Sawyer, R.M. Vanden Heuvel, M.A. Schmitt, and G.S. Brinkman. 1985. Crop response to sulfur on Illinois soils. J. Fert. Issues 2(3):95-104.

Book Chapters:

Sawyer, J.E., and G.W. Randall. 2008. Nitrogen rates, p. 59-71. In G. Laing (ed.) Final Report: Gulf Hypoxia and Local Water Quality Concerns Workshop. Upper Mississippi Sub-basin Hypoxia Nutrient Committee, Ames, IA. 26-28 Sep. 2005. ASABE, St. Joseph, MI.

Randall, G.W., and J.E. Sawyer. 2008. Nitrogen application timing, forms and additives.  p. 73-85. In G. Laing (ed.) Final Report: Gulf Hypoxia and Local Water Quality Concerns Workshop. Upper Mississippi Sub-basin Hypoxia Nutrient Committee, Ames, IA. 26-28 Sep. 2005. ASABE, St. Joseph, MI.

Conference Papers:

Pantoja, J.L., J.E. Sawyer, K.P. Woli, and D.W. Barker. 2016. Use of winter rye (Secale cereale L.) cover crop for nitrogen recycling in a corn-based cropping system. In proc. 21st Century Watershed Technology Conference and Workshop, Quito Ecuador, 3-9 Dec. 2016. ASABE, St. Joseph, MI.

Sawyer, J.E., D.W. Barker, and J.P. Lundvall. 2016. Impact of nitrogen application timing on corn production. p. 55-60. In Proc. Forty-Sixth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 2-3 Nov. 2016. Vol. 32. International Plant Nutrition Inst., Brookings, SD.

Clark, J., K.S. Veum, F.G. Fernandez, J.J. Camberato, P.R. Carter, R.B. Ferguson, D.W. Franzen, N.R. Kitchen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2016. The anaerobic potentially mineralizable nitrogen test as a tool for nitrogen management in the Midwest. p. 97-110. In Proc. Forty-Sixth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 2-3 Nov. 2016. Vol. 32. International Plant Nutrition Inst., Brookings, SD.

Bandura, C.J., C.A.M. Laboski, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, N.R. Kitchen, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2016. Post-harvest soil nitrate following corn production in eight Midwestern states.  p. 178. In Proc. Forty-Sixth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 2-3 Nov. 2016. Vol. 32. International Plant Nutrition Inst., Brookings, SD.

Shafer, M.E., J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, N.R. Kitchen, C.A.M. Laboski,  E.D. Nafziger, R.L. Nielsen, J.E. Sawyer, and J. Shanahan. 2016. Variation in internal N efficiency of corn and impact on yield-goal based N recommendations.  p. 209-214. In Proc. Forty-Sixth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 2-3 Nov. 2016. Vol. 32. International Plant Nutrition Inst., Brookings, SD.

Bean, G.M., N.R. Kitchen, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, C.A.M. Laboski, R. Miles, E.D. Nafziger, C.J. Ransom, J.E. Sawyer, P.C. Scharf, and J. Shanahan. 2016. Modifying the University of Missouri corn canopy sensor algorithm using soil and weather information. In Proc. 13th International Conf. on Precision Agric. 31 July-3 Aug. 2016. St. Louis, MO.

Ransom, C., G.M. Bean, N.R. Kitchen, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer and J. Shanahan. 2016. Field-scale nitrogen recommendation tools for improving a canopy reflectance sensor algorithm. In Proc. 13th International Conf. on Precision Agric. 31 July-3 Aug. 2016. St. Louis, MO.

Sawyer, J.E. 2015. Nitrogen input decisions with tight crop production margins. p. 143-148. In Proc. 27th Annual Integrated Crop Manag. Conf., Ames, IA. 2-3 Dec. 2015. Iowa State Univ., Ames.

Patel, S., J.E. Sawyer, J.P. Lundvall, and J. Hall. 2015. Root and shoot biomass and nutrient composition in a winter rye cover crop. p. 113-118. In Proc. Forty-Fifth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 4-5 Nov. 2015. Vol. 31. International Plant Nutrition Inst., Brookings, SD.

Bean, G.M., N.R. Kitchen, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2015. Integrating soil and weather information into canopy sensor algorithms for improved corn nitrogen rate recommendation. p. 213. In Proc. Forty-Fifth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 4-5 Nov. 2015. Vol. 31. International Plant Nutrition Inst., Brookings, SD.

Ransom, C., N.R. Kitchen, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, C.A.M. Laboski, E.D. Nafziger, J. Shanahan, and J.E. Sawyer. 2015. Corn nitrogen fertilization rate tools compared over eight Midwest states. p. 214. In Proc. Forty-Fifth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 4-5 Nov. 2015. Vol. 31. International Plant Nutrition Inst., Brookings, SD.

Sawyer, J.E. 2014. Corn nitrogen rate management: facts, concepts, and mother nature. p. 121-127. In Proc. 26th Annual Integrated Crop Manag. Conf., Ames, IA. 3-4 Dec. 2014. Iowa State Univ., Ames, IA.

Sawyer, J.E., J.L. Pantoja, and D.W. Barker. 2014. Corn nitrogen rate response and crop yield in a rye cover crop system. p. 59-63. In Proc. Forty-Fourth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 19-20 Nov. 2014. Vol. 30. International Plant Nutrition Inst., Brookings, SD.

Laboski, C.A.M., J.J. Camberato, and J.E. Sawyer. 2014. Evaluation of Adapt-N in the corn belt. p. 7-14. In Proc. Forty-Fourth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 19-20 Nov. 2014. Vol. 30. International Plant Nutrition Inst., Brookings, SD.

Sawyer, J.E. 2013. Update on sulfur response in Iowa field crop production. On-line. 2013 Indiana Certified Crop Adviser Conference. Indianapolis, IN. 17-18 Dec. 2013.

Sawyer, J.E. 2013. Options for in-season adjustment of nitrogen rate for corn. p. 145-151. In Proc. 25th Annual Integrated Crop Manag. Conf., Ames, IA. 4-5 Dec. 2013. Iowa State Univ., Ames, IA.

Sawyer, J.E. 2013. Comparison of the MRTN and Adapt-N derived N rates for corn. p. 60-67. In Proc. Forty-Third North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 20-21 Nov. 2013. Vol. 29. International Plant Nutrition Inst., Brookings, SD.

Pantoja, J.L., J.E. Sawyer, and D.W. Barker. 2012. Winter rye cover crop biomass production, degradation, and N recycling. p. 96-103. In Proc. Forty Second North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 14-15 Nov. 2012. Vol. 28.International Plant Nutrition Inst., Brookings, SD.

Sawyer, J.E., and A.P. Mallarino. 2012. Nutrient considerations with corn silage and stover harvest. p. 131-135. In Proc. 24th Annual Integrated Crop Manag. Conf., Ames, IA. 28-29 Nov. 2012. Iowa State Univ., Ames, IA.

Castellano, M.J., M.J. Helmers, J.E. Sawyer, D.W. Barker, and L. Christianson. 2012. Nitrogen, carbon, and phosphorus balances in Iowa cropping systems: sustaining the soil resource. p. 145-156. In Proc. 24th Annual Integrated Crop Manag. Conf., Ames, IA. 28-29 Nov. 2012. Iowa State Univ., Ames, IA.

Sawyer, J., and D. Barker. 2012. Quantifying corn N deficiency with active canopy sensors. p. 65-74. In Proc. 2012 Wisconsin Crop Manag. Conf., Vol. 51, Madison, WI. 10-12 Jan. 2012. Univ. of Wisconsin Ext. and Wisconsin Crop Prod. Assoc., Madison, WI.

Sawyer, J., B. Lang, and D. Barker. 2012. Suflur fertilization response in Iowa corn and soybean production. p. 39-48. In Proc. 2012 Wisconsin Crop Manag. Conf., Vol. 51, Madison, WI. 10-12 Jan. 2012. Univ. of Wisconsin Ext. and Wisconsin Crop Prod. Assoc., Madison, WI.

Sawyer, J., B. Lang, and D. Barker. 2011. Dealing with sulfur deficiency in Iowa crop production. 2011 CPM short course and MCPR trade show. 13-15 Dec. 2011. Univ. of Minnesota and Minnesota Crop Prod. Retailers, Minneapolis, MN.

Sawyer, J.E., J.L. Pantoja, D.W. Barker. 2011. Effect of a rye cover crop and crop residue removal on corn nitrogen fertilization. p. 115-121. In Proc. 23rd Annual Integrated Crop Manag. Conf., Ames, IA. 1 Nov-2 Dec. 2011. Iowa State Univ., Ames, IA.

Mallarino, A.P., A. Pagani, and J.E. Sawyer. 2011. Corn and soybean response to soil pH and liming. p. 93-102. In Proc. 23rd Annual Integrated Crop Manag. Conf., Ames, IA. 1 Nov-2 Dec. 2011. Iowa State Univ., Ames, IA.

Helmers, M.J., R.D. Christianson, and J. Sawyer. 2011. Nitrate loss in subsurface drainage as affected by nitrogen application rate and timing under a corn-soybean rotation. p. 123-128. In Proc. 23rd Annual Integrated Crop Manag. Conf., Ames, IA. 1 Nov-2 Dec. 2011. Iowa State Univ., Ames, IA.

Pantoja, J.L., J.E. Sawyer, D.W. Barker, and M. Al-Kaisi. 2011. Corn residue harvesting effects on yield response to N fertilization. p. 83-89. In Proc. Forty-First North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 16-17 Nov. 2011. Vol. 27. International Plant Nutrition Inst., Brookings, SD.

Pantoja, J.L., J.E. Sawyer, and D.W. Barker. 2010. Nitrogen fertilization requirement and corn-soybean productivity in a rye cover cropping system. p. 88-96. In Proc. Fortieth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 17-18 Nov. 2010. Vol. 26. International Plant Nutrition Inst., Brookings, SD.

Sawyer, J.E., and D.W. Barker. 2010. Quantifying corn nitrogen deficiency and application rate with active canopy sensors. p. 97-108. In Proc. Fortieth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 17-18 Nov. 2010. Vol. 26. International Plant Nutrition Inst., Brookings, SD.

Sawyer, J.E., B. Lang, D.W. Barker, and G. Cummins. 2009. Dealing with sulfur deficiency in crop production: the Iowa experience. p. 64-73. In Proc. Thirty-Ninth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 18-19 Nov. 2009. Vol. 25. International Plant Nutrition Inst., Brookings, SD.

Sawyer, J., B. Lang, D. Barker, and G. Cummins. 2009. Dealing with sulfur deficiency in Iowa corn production. p. 117-123. In Proc. 21st Annual Integrated Crop Manag. Conf., Ames, IA. 2-3 Dec. 2009. Iowa State Univ., Ames, IA.

Sawyer, J.E., and A.P. Mallarino. 2009. Fertilization decisions in uncertain times. p. 21. In 2009 Proc. Crop Advantage Series. Iowa State Univ., Ames, IA.

Sawyer, J., B. Lang, and D. Barker. 2008. Dealing with sulfur deficiencies in crop production: the northeast Iowa experience. In 2008 Indiana Crop Adviser Conference Proc. CD. Indianapolis, IN. 16-17 Dec. 2008. Purdue Univ., West Lafayette, IN.

Sawyer, J.E. 2008. Fertilizing crops in the new price age – nitrogen. p. 253-260. In Proc. 20th Annual Integrated Crop Management Conf., Ames, IA. 10-11 Dec. 2008. Iowa State Univ., Ames.

Sawyer, J.E., J.P. Lundvall, and J.A. Hawkins. 2007. In-season nitrogen management for corn production. p. 231-240. In Proc. Nineteenth Integrated Crop Management Conf., Ames, IA. 28-29 Nov. 2007. Vol. 23. Iowa State Univ. Extension, Ames.

Sawyer, J.E., J.P. Lundvall, and J.A. Hawkins. 2007. In-season nitrogen management for corn production. p. 38-45. In Proc. Thirty-Seventh North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 14-15 Nov. 2007. Vol. 23. International Plant Nutrient Inst., Brookings, SD.

Sawyer, J.E. 2006. Managing nitrogen for high corn yields. p. 191-199. In Proc. 18th Annual Integrated Crop Manag. Conf., Ames, IA. 29-30 Nov. 2006. Iowa State Univ., Ames, IA.

Lang, B., J. Sawyer, and S. Barnhart. 2006. Dealing with sulfur deficiency in northeast Iowa alfalfa production. p. 225-235. In Proc. 18th Annual Integrated Crop Manag. Conf., Ames, IA. 29-30 Nov. 2006. Iowa State Univ., Ames, IA.

Elmore, R., L. Abendroth, J. Sawyer, M. Al-Kaisi, and M. Hanna. 2006. Management considerations for continuous corn production. p. 9-14. In Proc. 18th Annual Integrated Crop Manag. Conf., Ames, IA. 29-30 Nov. 2006. Iowa State Univ., Ames, IA.

Laboski, C.A.M., J.E. Sawyer, D.T. Walters, L.G. Bundy, R.G. Hoeft, G.W. Randall, and T.W. Andraski. 2006. Evaluation of the Illinois nitrogen test in the north central states. p. 86-93. In Proc. Thirty-Sixth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 7-8 Nov. 2006. Vol. 22. Potash & Phosphate Inst., Brookings, SD.

Sawyer, J.E., and E.D. Nafziger. 2006. Regional approach to making nitrogen fertilizer rate decisions for corn. p. 68-76. In Proc. 2006 Wisconsin Fertilizer, Aglime, and Pest Manag. Conf. Madison, WI. 17-19 Jan. 2006. Univ. of Wisconsin, Madison, WI.

Sawyer, J.E., and E.D. Nafziger. 2005. Regional approach to making nitrogen rate decisions for corn. In 2005 Indiana Crop Adviser Conference Proc. CD., Indianapolis, IN. 14-15 Dec. 2005. Purdue Univ., West Lafayette, IN.

Sawyer, J.E., and E.D. Nafziger. 2005. Regional approach to making nitrogen rate decisions for corn. p. 143-152. In Proc. 17th Annual Integrated Crop Manag. Conf., Ames, IA. 30 Nov.-1 Dec. 2005. Iowa State Univ., Ames, IA.

Ruiz Diaz, D.A, and J.E. Sawyer. 2005. Assessment of nitrogen supply from poultry manure applied to corn. p. 109-114. In Proc. Thirty-Fifth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 16-17 Nov. 2005. Vol. 21. Potash & Phosphate Inst., Brookings, SD.

Sawyer, J.E., and E.D. Nafziger. 2005. Regional approach to making nitrogen rate decisions for corn. p. 16-24. In Proc. Thirty-Fifth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 16-17 Nov. 2005. Vol. 21. Potash & Phosphate Inst., Brookings, SD.

Randall, G.W., and J.E. Sawyer. 2005. Nitrogen application timing, forms and additives.  p. 59-71. In Proc. Gulf Hypoxia abd Local Water Quality Concerns Workshop, Ames, IA. 26-28 Sep. 2005.  Upper Mississippi Sub-basin Hypoxia Nutrient Committee, Iowa State Univ., Ames, IA.

Sawyer, J.E., and G.W. Randall. 2005. Nitrogen rates, p. 59-71. InProc. Gulf Hypoxia and Local Water Quality Concerns Workshop, Ames, IA. 26-28 Sep. 2005.  Upper Mississippi Sub-basin Hypoxia Nutrient Committee, Iowa State Univ., Ames, IA.

Sawyer, J.E. 2004. With high fertilizer prices is it business as usual or should fertilization practices change? p. 163-176. In Proc. 16th Annual Integrated Crop Manag. Conf., Ames, IA. 1-2 Dec. 2004. Iowa State Univ., Ames, IA.

Nafziger, E.D., J.E. Sawyer, and R.G. Hoeft. 2004. Formulating N recommendations in the corn belt using recent data. p. 5-11. In Proc. Thirty-Fourth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 17-18 Nov. 2004. Vol. 20. Potash & Phosphate Inst., Brookings, SD.

Sawyer, J.E., D.W. Barker, and J.P. Lundvall. 2004. Using chlorophyll meter readings to determine N application rates for corn. p. 136-143. In Proc. Thirty-Fourth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 17-18 Nov. 2004. Vol. 20. Potash & Phosphate Inst., Brookings, SD.

Sawyer, J.E., D.W. Barker, J.P. Lundvall, and M. Al-Kaisi. 2004. Evaluation of the amino-sugar based soil test in Iowa corn production. Proc. Seventeenth Soil/Plant Analyst Workshop, West Des Moines, IA. 24-25 Feb. 2004, N.C. Research Committee on Soil Testing and Plant Analysis (NCR-12) and the Soil and Plant Analysis Council.

Sawyer, J.E., J.P. Lundvall, S. Rakshit, and A.P. Mallarino. 2003. Liquid swine manure nitrogen utilization for crop production. p. 95-112. In Proc. 15th Annual Integrated Crop Manag. Conf., Ames, IA. 3-4 Dec. 2003. Iowa State Univ., Ames, IA.

Sawyer, J.E., D.W. Barker, J.P. Lundvall, and M. Al-Kaisi. 2003. Evaluation of the amino-sugar based soil test in Iowa corn production. p. 125-136. In Proc. Thirty-Third North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 19-20 Nov. 2003. Potash & Phosphate Inst., Brookings, SD.

Sawyer, J.E., D.W. Barker, and M. Al-Kaisi. 2003. Iowa experience with the Illinois N test. p. 46-54. In Proc. Wisconsin Fertilizer, Aglime and Pest Manag. Conf., Madison, WI. 21-23 Jan. 2003. Univ. of Wisc., Madison, WI.

Sawyer, J.E. 2003. Developing and using the Iowa P-Index. p. 27-34. In Proc. Wisconsin Fertilizer, Aglime and Pest Manag. Conf., Madison, WI. 21-23 Jan. 2003. Univ. of Wisc., Madison, WI.

Sawyer, J.E. and D.W. Barker. 2002. Sulfur application to corn and soybean crops in Iowa. p. 13-24. In. Proc. 14th Annual Integrated Crop Manag. Conf., Ames, IA. 4-5 Dec. 2002. Iowa State Univ., Ames, IA.

Sawyer, J.E. and D.W. Barker. 2002. Corn and soybean response to sulfur application on Iowa soils. p. 157-163. In Proc. Thirty Second North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 20-21 Nov. 2002. Potash and Phosphate Inst., Brookings, SD.

Boyd, P.M., H.M. Hanna, J.L. Baker, T.S. Colvin, and J.E. Sawyer. 2002. Field corn tests to examine anhydrous ammonia manifold variability. ASAE paper number 021024. St. Joseph MI, ASAE.

Sawyer, J.E. and D. Barker. 2001. In-season nitrogen fertilization of soybean. p. 158-161. In Proc. Thirty First North Central
Extension-Industry Soil Fertility Conf., Des Moines, IA. 14-15 Nov. 2001. Potash and Phosphate Inst., Brookings, SD.

Sawyer, J.E. 2001. Nitrogen fertilizer and swine manure application to soybean. p. 33-44. In. Proc. 13th Annual Integrated Crop Manag. Conf., Ames, IA. 5-6 Dec. Iowa State Univ., Ames, IA.

Mallarino, A.P., B. M. Stewart, J.L. Baker, J.A. Downing, and J. Sawyer. 2001. Background and basic concepts of the Iowa phosphorus index. p. 63-71. In Proc. Agriculture and the Environment: State and Federal Water Initiatives conference, Ames, IA. 5-7 March. Iowa State Univ., Ames, IA.

Sawyer, J.E. 2000. Methods to Determine Risk of Phosphorus Loss From Farm Fields. p. 197-201. In Proc. Integrated Crop Manag. Conf., Ames, IA. 29-29 Nov. Iowa State Univ., Ames, IA.

Kassel, P., J.E. Sawyer, D. Haden, D. Barker. 2000. Soil pH and corn-soybean rotation yield responses to limestone application and tillage. p. 193. In Proc. Thirtieth North Central Extension-Industry Soil Fertility Conf., St. Louis, MO. 15-16 Nov. Potash and Phosphate Inst., Brookings, SD.

Sawyer, J.E. 2000. Nutrient Management - What's Doable. p. 15-24. In Proc. Iowa State University Agriculture and the Environment: A Wake-Up Call for Iowans, Ames, IA. 7-8 March. Iowa State Univ., Ames, IA.

Sawyer, J.E. and A.P. Mallarino. 1999. Differentiating and Understanding the Mehlich, Bray, and Olsen Soil Phosphorus Tests. p. 75-80. In Proc. University of Minnesota Crop Pest Management Short Course Program, St. Paul, MN. 22-23 Nov. Univ. of Minnesota, Minneapolis, MN.

Sawyer, J.E. 1999. Making Every Fertilizer Dollar Pay. p. 63-78. In Proc. Integrated Crop Manag. Conf., Ames, IA. 1-2 Dec. Iowa State Univ., Ames, IA.

Sawyer, J.E. 1998. Managing Crop Nutrients and Limestone with Reduced Financial Resources. p. 33-36. In Proc. Integrated Crop Manag. Conf., Ames, IA. 17-18 Nov. Iowa State Univ., Ames, IA.

Sawyer, J.E. 1998. Managing Crop Nutrients and Limestone - Reducing Production Costs. In Farm Economy Issues Paper.  Iowa State Univ. Extension, Ames, IA.

Sawyer, J.E. 1997. Nightmare on yield street. p. 9-19. In Proc. 1997 Fert., Aglime and Pest Manag. Conf., Middleton, WI. 20-22 Jan. 1997. Univ. Wisconsin, Madison, WI.

Sawyer, J.E. 1977. The CCA Program: What's Right, What's Wrong, What's in Our Future. p. 126-133. In Proc. 1997 Illinois Agricultural Pesticides Conf., Urbana, IL. 8-9 Jan. 1997. Univ. of Illinois, Urbana, IL.

Sawyer, J.E. 1996. Should yield maps correlate to soil tests and nightmare on yield street. 1996 Information Agriculture Conf., Urbana, IL. 30 July-Aug. 1. Potash and Phosphate Institute, Atlanta, GA.

Sawyer, J.E, and R. Milby. 1994. Realities of providing site-specific services to customers. p. 81-89. In Proc. Integrated Crop Manag. Conf., Ames, IA. 30 Nov.-1 Dec. Iowa State Univ., Ames, IA.

Sawyer, J.E. 1994. Grid sampling: the worth of information. p.148-151. In Proc. 24th North Cent. Ext.-Ind. Soil Fert. Workshop, St. Louis, MO. 26-27 Oct. Potash and Phosphate Inst., Manhattan KS.

Sawyer, J.E. 1993. How you may fit into the certified crop adviser (CCA) program. p. 143-147. In Proc. 1993 Fert., Aglime and Pest Manag. Conf. Middleton, WI. 19-21 Jan. 1993. Univ. Wisconsin-Extension, Madison, WI.

Technical Articles:

Sawyer, J., S. Patel, and J. Lundvall. 2016. Enhancing corn yield in a rye cover cropping system. Final project report to the Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation and Water Quality, State Soil Conservation Committee Research and Demonstration grant.

Woli, K.P., M.J. Boyer, R.W. Elmore, J.E. Sawyer, L.J. Abendroth, and D.W. Barker. 2016. Corn hybrid response to N fertilization over five decades. P. 11. CSA News. ASA, CSSA, SSSA, Madison, WI. doi:10.2134/csa2016-61-4-3.

Pantoja, J.L., J.E. Sawyer, K.P. Woli, and D.W. Barker. 2016. Use of winter rye (Secale cereale L.) cover crop for nitrogen recycling in a corn-based cropping system. In proc. 21st Century Watershed Technology Conference and Workshop, Quito Ecuador, 3-9 Dec. 2016. ASABE, St. Joseph, MI.

Wright Morton, L., L. Abendroth, R. Anex, J. Arbuckle, R. Arritt, M. Castellano, R. Cruse, J. Frankenberger, M. Helmers, E. Kladivko, M. O’Neal, P. Scharf, B. Basso, L. Bowling, W. Dick, N. Fausey, A. Gassmann, D. Herzmann, P. Gassman, C. Kling, A. Kravchenko, R. Lal, J. Lauer, F. Miguez, D. Mueller, E. Nafziger, N. Nkongolo, P. Owens, J. Sawyer, J. Strock, J. Tyndall, and M. Villamil. 2016. Climate and Managing Corn-Soybean Agroecosystems I: Findings, Implications and Recommendations. Technical Report Series: Findings and Recommendations of the USDA-NIFA funded Climate and Corn-based Cropping Systems Coordinated Agricultural Project. Iowa State University, Ames. Vol 1 of 5. Pub. No. CSCAP-0195-2016.

Al-Kaisi, R.W. Elmore, J.G. Guzman H.M. Hanna, C.E. Hart, M.J. Helmers, E.W. Hodgson, A.W. Lenssen, A.P. Mallarino, A.E. Robertson, and J.E. Sawyer. 2013. Drought impact on crop production and the soil environment: 2012 experiences from Iowa. J. Soil Water Conser. 68:19A-24A. doi:10.2489/jswc.68.1.19A.

Mitchell, D.C., M.J. Castellano, J.E. Sawyer, and J. Pantoja. 2013. Cover crop effects on nitrous oxide emissions: Role of mineralizable carbon. p. 14. CSA News. ASA, CSSA, SSSA. Madison, WI. Doi:10.2134/csa2013-58-9-5.

Sawyer, J., J. Pantoja, and D. Barker. 2012. Nitrogen fertilization of corn grown with a cover crop. Final project report, Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation Integrated Farm/Livestock Management Demonstration Program.

Iowa State University Science Team. 2012. Iowa science assessment of nonpoint source practices to reduce nitrogen and phosphorus transport in the Mississippi River basin. 159 p. Iowa State Univ., Ames. http://www.nutrientstrategy.iastate.edu/documents.

Sawyer, J., B. Lang, and D. Barker. 2011. Sulfur emerges as a nutritional issue in Iowa alfalfa production. p. 6-7. Better Crops, Vol. 95 (No.2). International Plant Nutrition Institute (IPNI), Norcross, GA.

Sawyer, J., B. Lang, and D. Barker. 2011. Sulfur fertilization response in Iowa corn production. p. 8-10. Better Crops, Vol. 95 (No.2). International Plant Nutrition Institute (IPNI), Norcross, GA.

Sawyer, J., and D. Barker. 2011. Evaluation of combination phosphorus - sulfur fertilizer products for corn production. Iowa State Univ., Ames, IA.

Sawyer, J., D. Barker, and B. Lang. 2010. Summary of sulfur strip trials conducted in central and northeast Iowa. Preliminary 2009 results. Iowa State Univ., Ames, IA.

Sawyer, J., D. Barker, and M. Hanna. 2010. Crop response to shallow placement of anhydrous ammonia in corn. Final project report. Iowa State Univ., Ames, IA.

Sawyer, J., B. Lang, and D. Barker. 2008. Evaluation of corn response to sulfur fertilization in northeast Iowa. Project report for 2006 and 2007 research. Iowa State Univ., Dept. of Agronomy, Ames, IA.

Sawyer, J., and D. Barker. 2008. Illinois soil nitrogen test evaluation, 2006-2007 final project report. Final report to the Iowa State University, College of Agriculture Corn and Soybean Initiative.

Pedersen, P., J. Sawyer, D. Barker, D. Ruiz Diaz, and J. Stuart. 2008. Educating growers about living mulch systems for grain crop production. Final project report to the Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation, IFLM program.

Mallarino, A.P., J.E. Sawyer, D. Kaiser, D. Ruiz-Diaz, B. Allen, D. Barker, and D. Wittry. 2007. Demonstration of Agronomic and Environmentally Sound Utilization of Nitrogen and Phosphorus in Poultry Manure. Final project report to the Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation, IFLM program.

Sawyer, J., J. Lundvall, and J. Hawkins. 2007. Demonstration of in-season nitrogen management strategies for corn production. Final project report to the Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation, IFLM program.

Sawyer, J.E., and M. Al-Kaisi. 2005. Soil nitrogen and carbon management project. Final project report to the Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation, IFLM program.

Sawyer, J., J. Lundvall, and J. Hawkins. 2005. Demonstration of in-season nitrogen management strategies for corn production. Crop year 2004 project report to the Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation, IFLM program.

Sawyer, J., A. Mallarino, and J. Lundvall. 2005. Swine manure nutrient utilization project. Final project report to the Iowa Department of Agriculture and Land Stewardship, Division of Soil Conservation, IFLM program.

Lorimor, J, and J.E. Sawyer. 2004. Swine USA anaerobic digester performance analysis. Part 1. 12 p. Final project report, Iowa NRCS, Des Moines, IA.

Loria, E.R., J.E. Sawyer, and J.C. Lorimor. 2004. Use of anaerobically digested swine manure in corn production. Part 2. 32 p. Final project report, Iowa NRCS, Des Moines, IA.

Sawyer, J.E., and D. Barker. 2003. Soil nitrogen and carbon management project. In Research Farm annual reports, Iowa State University, Ames, IA.

Kanwar, R., C. Pederson, A. Mallarino, J. Baker, J. Sawyer, and K. Pecinovsky. 2003. Fertilizer and swine manure management systems. 1. Impacts on crop production and nitrate-nitrogen leaching with subsurface drainage. In Northeast Research Farm annual report. Iowa State University, Ames, IA.

Mallarino, A.P., R. Kanwar, K. Pecinovsky, C. Pederson, J. Klatt, J. Baker, and J. Sawyer. 2003. Fertilizer and swine manure management systems. 2. Impacts on agronomic and environmental soil phosphorus tests and on phosphorus loss with subsurface drainage. In Northeast Research Farm annual report. Iowa State University, Ames, IA.

Sawyer, J.E. and D. Barker. 2000-2003. Seasonal and rotation influences on corn nitrogen requirements. In Research Farm annual reports, Iowa State University, Ames, IA.

Sawyer, J.E. and D. Barker. 2001-2002. Sulfur fertilizer application to corn and soybean. In Research Farm annual reports, Iowa State University, Ames, IA.

Sawyer, J.E. and D. Barker. 2000. Mid-season nitrogen fertilization of soybeans. In Research Farm annual reports, Iowa State University, Ames, IA.

Sawyer, J.E., and S.A. Ebelhar. 1993. Wheat response to sulfur fertilization in southern Illinois. p. 51-75. In R.G. Hoeft (ed.) Illinois Fert. Conf. Proc., Springfield, IL. 25-27 Jan. 1993. Univ. of Illinois, Urbana, IL.

Clark, K.N., T.R. Peck, and J.E. Sawyer. 1993. Comparison of plow-layer distributed and surface applied limestone for no-till crop production. p. 127-136. In R.G. Hoeft (ed.) Illinois Fert. Conf. Proc., Springfield, IL.25-27 Jan. 1993. Univ. of Illinois, Urbana, IL.

Sawyer, J.E., and R.G. Hoeft. 1989. The manure challenge. Dealer Progress. 20:34-35.

Hoeft, R.G., and J.E. Sawyer. 1987. Maximize benefits or minimize risks when using livestock wastes. p. 7-12. In Livestock Waste Manag. Conf., Champaign, IL. 24 March 1987. Univ. of Illinois, Urbana, IL.

Technical Abstracts:

Sawyer, J.E. 2017. Evaluation of the Soltita/Haney soil health test response across historical nitrogen rates and crop rotations. In meetings abstract (on-line), NCERA-13 North Central Soil and Plant Analyst’s Workshop, Iowa City, IA.

Patel, S., J.E. Sawyer, and J.P. Lundvall. 2016. Root and shoot biomass and nutrient composition in a winter rye cover crop. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Shafer, M.E., J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, N.R. Kitchen, C.A.M. Laboski,  E.D. Nafziger, R.L. Nielsen, J.E. Sawyer, and J. Shanahan. 2016. Variation in internal N efficiency N fertilizer recommendations. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Clark, J., K.S. Veum, F.G. Fernandez, J.J. Camberato, P.R. Carter, R.B. Ferguson, D.W. Franzen, N.R. Kitchen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2016. Can the anaerobic potentially mineralizable nitrogen test improve predictions of fertilizer nitrogen rates in the Cornbelt? In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Bandura, C.J., C.A.M. Laboski, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, N.R. Kitchen, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2016. Post-harvest soil nitrate following corn production in eight Midwestern states. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Mac Bean, G., N.R. Kitchen, R.B. Ferguson, J.J. Camberato, C.A.M. Laboski, J.E. Sawyer, F.G. Fernandez, D. Franzen, E.D. Nafziger, P.R. Carter, and J. Shanahan. 2016. Fusing regional soil and weather variability with site-specific canopy reflectance for improved in-season nitrogen fertilizer recommendation. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Ransom, C., N.R. Kitchen, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2016. Corn nitrogen fertilization rate tools compared over eight Midwestern states. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Iqbal, J., M.J. Castellano, M. Nelpalova, S.V. Archontoulis, J.E. Sawyer, D. Herzman, and R.P. Anex. 2016. Extreme precipitation years impact soil N loss in Mid-West corn-soybean cropping systems. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Kladivko, E.J., A. Kravchenko, M.J. Helmers, D. Herzman, L.J. Abendroth, W. Dick, N.V. Nkongolo, J.E. Sawyer, and P.C. Scharf. 2016.

Evaluation of a winter cereal rye cover crop at ten sites across the US Cornbelt. In Annual Meetings Abstract (on-line), ASA, Madison, WI.Patel, S., J.E. Sawyer, and J.P. Lundvall. 2015. Enhancing corn yield in a winter cover crop system. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Poffenbarger, H.J., D.W. Barker, M.J. Helmers, F.E. Miguez, J.E. Sawyer, M. Six, and M.J. Castellano. 2015. Nitrogen fertilizer rate effects on soil organic carbon in Iowa continuous corn and corn-soybean systems. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Kitchen, N.R., J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2015. Public-private partnering for improving performance of corn nitrogen fertilization tools. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Ransom, C., N.R. Kitchen, G.M. Bean, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2015. Corn nitrogen fertilization rate tools compared over eight Midwest states. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Bean, G.M., N.R. Kitchen, J.J. Camberato, P.R. Carter, R.B. Ferguson, F.G. Fernandez, D.W. Franzen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2015. Integrating soil and weather information into canopy sensor algorithms for improved corn nitrogen rate recommendation. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Clark, J.D., F.G. Fernandez, J.J. Camberato, P.R. Carter, R.B. Ferguson, D.W. Franzen, N.R. Kitchen, C.A.M. Laboski, E.D. Nafziger, J.E. Sawyer, and J. Shanahan. 2015. What plant and soil testing from 16 sites in eight Midwestern states tells us about split nitrogen applications. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Barker, D.W., and J.E. Sawyer. 2014. Active sensor strategies for in-season application of urea in corn. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Castellano, M.J., M. Liebman, W.R. Osterholz, J.E. Sawyer, and F. Miguez. 2014. Nitrogen conservation in high-input low diversity and low-input high diversity agroecosystems. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Iqbal, J., D.C. Mitchell, D.W. Barker, F. Miguez, J.E. Sawyer, J. Pantoja, and M.J. Castellano. 2014. Nitrogen fertilizer rate to corn can affect N2O emission from the following soybean crop in a corn-soybean rotation. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Sassman, A.M., J.E. Sawyer, and D.W. Barker. 2013. Evaluation of Instinct nitrification inhibitor with spring applied urea-ammonium nitrate solution. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Woli, K.P., S. Rakshit, J.P. Lundvall, J.E. Sawyer, and D.W. Barker. 2013. Residual-year corn response to liquid swine manure nitrogen applied to soybean. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Pagani, A., J.E. Sawyer, A.P. Mallarino, L. Moody, J.R. Davis, and S. Phillips. 2013. Cooperative industry-agency-university site-specific nutrient management education project. In Annual Meetings Abstract (on-line), ASA, Madison, WI.

Sawyer, J.E., C. Laboski, and E. Nafziger. 2012. Maximum return to nitrogen (MRTN) method for nitrogen recommendations for corn. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Mitchell, D.C., M.J. Castellano, J.E. Sawyer, F. Miguez, and J.L. Pantoja. 2012 Do cover crops and historical fertilizer rate affect nitrous oxide emissions from soybean as well as maize? In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Mitchell, D.C., M.J. Castellano, J.E. Sawyer, J.L. Pantoja, and F. Miguez. 2012 Mineralizable C and nitrate limitation on nitrous oxide from an intensive maize system: interaction between cover crop and fertilizer rate. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Pantoja, J.L., J.E. Sawyer, and D.W. Barker. 2012. Aboveground Biomass Yield and Carbon and Nitrogen Accumulation in a Continuous Corn Stover Harvesting System. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Pantoja, J.L., J.E. Sawyer, and D.W. Barker. 2012. Winter rye cover crop biomass production, degradation, and N re-cycling. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Pantoja, J.L., J.E. Sawyer, D.W. Barker, and M. Al-Kaisi. 2011. Corn residue harvesting effects on yield response to N fertilization. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Pantoja, J.L., J.E. Sawyer, and D.W. Barker. 2011. Corn nitrogen fertilization in a rye cover cropping system. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Mitchell, D.C., M.J. Castellano, F. Miguez, J.E. Sawyer, and J.L. Pantoja. 2011. Cover crop and nitrogen fertilizer effects on nitrous oxide flux from a corn-soybean rotation. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Sawyer, J., and E. Nafziger. 2010. Experiences developing and using a regional corn nitrogen response trial database.  In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Fernandez F., J.E. Sawyer, D.B. Mengel, and J. Stamper. 2010. No-till corn response to shallow placement of anhydrous ammonia. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Barker, D.W., and J.E. Sawyer. 2009. Optimizing nitrogen fertilizer application in corn using green technology. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Ruiz Diaz, D.A., and J.E. Sawyer. 2008. Nitrogen surface runoff from poultry manure with simulated rainfall. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Nafziger, E.D., and J.E. Sawyer. 2008. Economic optimization using input response data. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Sawyer, J.E., and E. Nafziger. 2007. Changes in nitrogen guidelines for corn in the Midwest. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Nafziger, E.D., and J.E. Sawyer. 2007. A new approach to formulating N rate guidelines for corn. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Pedersen, P., J. Sawyer, J. Stuart, and D. Barker. 2007. Educating growers about kura clover living mulch systems for grain crop production. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Hendrickson, L., G. Ostermeier, and J. Sawyer. 2007. Use of aerial imagery in making effective nitrogen recommendations. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Barker, D.W., and J.E. Sawyer. 2007. Evaluation of crop canopy sensors for in-season N rate management in corn. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Kaiser, D.E., A.P. Mallarino, D.J. Wittry, B.L. Allen, and J.E. Sawyer. 2007. Availability of poultry manure phosphorus for corn and application impacts on soil phosphorus. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Ruiz Diaz, D.A., J.E. Sawyer, D.W. Barker, and A.P. Mallarino. 2006. Assessment of nitrogen supply from poultry manure applied to corn. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Holmes, J.D., P.A. Kassel, J.E. Sawyer, and D.A. Ruiz Diaz. 2006. Evaluation of ground eggshells as a liming material. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Hawkins, J.A., J.E. Sawyer, and J.P. Lundvall. 2005. Demonstration of in-season nitrogen management for corn production. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Sawyer, J.E., D.W. Barker, and J.P. Lundvall. 2004. Using chlorophyll meter readings to determine N application rates for corn. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Lundvall, J.P., J.E. Sawyer, S. Rakshit, A.P. Mallarino, and D.W. Barker. 2003. Liquid swine manure impact on first-year soybean and residual year corn. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Sawyer, J.E., D.W. Barker, and M. Al-Kaisi. 2003. Evaluation of the Illinois N soil test on Iowa soils. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Kruse, M., M. Al-Kaisi, and J.E. Sawyer. 2003. Nitrogen management effect on soil carbon change and carbon dioxide release under a corn-soybean rotation. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Kruse, M.L., M. Al-Kaisi, and J.E. Sawyer. 2003. Nitrogen management effect on soil carbon dioxide emission. Iowa Academy of Sciences Annual Meeting, April 25-26, 2003, Des Moines, IA. Iowa Academy of Sciences, Cedar Falls, IA.

Kruse, M.L., M. Al-Kaisi, and J.E. Sawyer. 2003. Nitrogen management effects on soil carbon dioxide emission. Fourth annual North Central Region Symposium on Natural Organic Matter in Soils and Water. March 21-22, 2003, Ames, IA. Iowa State Univ., Ames, IA.

Rakshit, S., J.E. Sawyer, J.P. Lundvall, D.W. Barker, and A.P. Mallarino. 2002. Liquid swine manure nitrogen utilization project. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI. Sawyer, J.E., E.R. Loria, D.W. Barker, and J.C. Lorimor. 2002. Use of anaerobic digested swine manure in corn production. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Loria, E.R., J.E. Sawyer, and J.C. Lorimor. 2002. Comparison of phosphorus and nitrogen from raw and anaerobic digested swine manure. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Barbazan, M., A. Mallarino, and J. Sawyer. 2002. Liquid swine manure phosphorus utilization in corn-soybean production. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Barbazan, M.M., A.P. Mallarino, A. Atia, and J.E. Sawyer. 2001. Evaluation of phosphorus availability in manured soils by soil testing and plant analysis. In Annual Meetings Abstract CD-ROM, ASA, Madison, WI.

Mallarino, A.P., B.M Stewart, J.L. Baker, J.A Downing, T.E. Fenton, J.E. Sawyer, G.A. Miller, J.L. Kovar, T.J. Sauer, R.D. Voss. 2001. Phosphorus Indexing in Cropland: The Iowa P Index. Soil Water Cons. Soc. 2001 Annual Meeting.

Sawyer, J.E. and D.W. Barker. 2000. In-season nitrogen fertilization of soybean. p. 286. In Agronomy abstracts, ASA, Madison, WI.

Mallarino, A.P., J.L. Baker, J.A. Downing, T.E. Fenton, G.A. Miller, J.E. Sawyer, B.M. Stewart, J.L. Kovar. 2000. Development of a phosphorus assessment tool for Iowa. p. 328. In Agronomy abstracts, ASA, Madison, WI.

Kassel, P., J.E. Sawyer, D. Haden, S. Parker. 1999. Soil pH and corn-soybean rotation yield responses to limestone application and tillage. p. 260. In Agronomy abstracts, ASA, Madison, WI.

Sawyer, J.E., and R.M. Vanden Heuvel. 1995. Preplant anhydrous ammonia knife spacing for corn production. p. 315. In Agronomy Abstracts, ASA, Madison, WI.

Clark, K.N., T.R. Peck, and J.E. Sawyer. 1994. A comparison of plow layer distributed versus surface applied limestone in no-till crop production. p. 321. In Agronomy abstracts, ASA, Madison, WI.

Sawyer, J.E., and R.G. Hoeft. 1992. Effect of injected liquid beef manure on soil chemical properties and corn root distribution. p. 279. In Roots of Plant Nutrition Conf., Champaign, IL. 8-10 July 1992. Potash and Phosphate Institute, Atlanta GA.

Ebelhar, S.A., and J.E. Sawyer. 1992. Wheat response to sulfur fertilization in southern Illinois. p. 276. In Agronomy abstracts, ASA, Madison, WI.

Sawyer, J.E., L.E. Paul, S.A. Ebelhar, and R.G. Hoeft. 1991. Sidedress anhydrous ammonia knife spacing for corn production. p. 300. In Agronomy abstracts, ASA, Madison, WI.

Sawyer, J.E., R.G. Hoeft, and L.V. Boone. 1989. Effect of lime quality on soil pH. p. 251. In Agronomy abstracts, ASA, Madison, WI.

Bicki, T.J., L.V. Boone, W.H. Brink, J.W. Hummel, M.J. Mainz, G.A. Raines, J.E. Sawyer, S.K. Sipp, and J.C. Siemens. 1989. Summary of corn, soybean, and sorghum yields for different tillage systems in Illinois. p. 275. In Agronomy abstracts, ASA, Madison, WI.

Sawyer, J.E., and R.G. Hoeft. 1987. Knife injected liquid manure interrelationship with corn row placement and soil chemical transformations. p. 216. In Agronomy abstracts, ASA, Madison, WI.

Sawyer, J.E., M.A. Schmitt, and R.G. Hoeft. 1986. Effect of liquid manure application on soil chemical properties. p. 214-215. In Agronomy abstracts, ASA, Madison, WI.

 

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