Ph.D. 1983, University of Minnesota

M.S. 1978, North Dakota State University 

B.S. 1975, University of Maine

Currently serving as an Associate Editor to Soil Science Society America Journal. Research interests include investigations of fertilizer management strategies for enhancing N recovery by crops using 15N enriched labelled fertilizers; soil emissions of greenhouse gases (nitrous oxide, methane, and carbon dioxide) as affected by cropping systems; soil carbon sequestration and characterization of dissolved organic matter in croplands; urea-fertilizer induced emissions of ammonia and mitigation with urease inhibitors; and soil acidification and aluminum toxicity of Montana soils. 

Recent Publications


  • Romero, C., R. Engel, J.D'Andrilli, C.Chen, C. Zabinski, P. Miller, and R. Wallander. 2018. Patterns of change in permanganate oxidizable soil organic matter from semiarid drylands reflected by absorbance spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry. Organic Geochem.120:19-30.
  • Miller, P.R., E.C. Glunk, J.A. Holmes, and R.E. Engel. 2018. Pea harvest timing impacts forage yield quality, and subsequent wheat. Agron. J. 110:1-9. 

  • Romero, C. M., R.E. Engel, J. D’Andrilli, C. Chen, C. Zabiniski, P.R. Miller, and R. Wallander, 2017.  Bulk optical characterization of dissolved organic matter from semiarid wheat-based cropping systems.  Geoderma 306:40-49.

  • Engel, R., Romero, C., Jones, C. and Wallander, R.  2017. Late-fall, winter and spring broadcast applications of urea to no-till winter wheat I. Ammonia loss and mitigation by NBPT.   Soil Sci. Soc. Am. J.  81 322-330. 
  • Romero, C., Engel, R., Chen, C., Wallander, R., Jones, C. 2017.  Late-fall, winter and spring broadcast applications of urea to no-till winter wheat II. Fertilizer N recovery, yield and protein as affected by NBPT.  Soil Sci. Soc. Am. J.  81:331-340. 
  • Engel, R., Miller, P., McConkey, B., Wallander, R., Holmes, J. 2017/ Soil organic C changes to increasing cropping system intensity and no-till in a semiarid climate. Soil Sci. Soc. Am. J.  81:404-413
  •  Long, D., McCallum, J., Reardon, C., Engel, R. 2017. Nitrogen requirement to change protein concentration of spring wheat in semiarid Pacific Northwest. Agron. J. 109:675-683. 
  • Engel, R., Gravens, E., Towey, B. D.  2015. Degradation of the urease inhibitor NBPT as affected by soil pH. Soil Sci. Soc. Am. J 79:1674-1683. 
  • Ehlert, K. A., Engel, R., Mangold, J. 2015. Imazapic activity in a semiarid climate at downy brome (Bromus tectorum)-infested rangeland and CRP sites. Weed Technology 29:472-479. 
  • Long, D., Whitmus, J., Engel, R., Brester, G.  2015. Net Returns from Terrain-based Variable-Rate Nitrogen Management. Agronomy Journal 107:1055-1067. 
  • Miller, P., Bekkerman, A., Jones, C., Burgess, M., Holmes, J. A., Engel, R. 2015. Pea in rotation with wheat reduced uncertainty of economic returns in southwest Montana.  Agron. J. 107:541-550.
  • Romero, C. M., Engel, R., Chen, C., Wallander, R. 2015. Microbial Immobilization of Nitrogen-15-Labeled Ammonium and Nitrate in an Agricultural Soil from Central Montana. Soil Sci. Soc. Am. J 79:595-602.



Recent Grants

  • 2017: $264,015. Engel, R., Carr, P, and Jones, C. Soil acidity management of long-term no-till fields in Montana to prevent crop failure. USDA-Western Sustainable Agricultural Research and Education Program.
  • 2017:  $18, 672. Engel, R. Evaluation of Koch Agronomic Services’ (“KSA”) experimental urease inhibitor KAS_060K001 (K32) for control of NH3 volatilization from urea fertilizers over a soil pH gradient.  Koch Agronomic Services. 
  • 2016: $12,980.  Engel, R., Carr, P., Jones, C. Understanding acidification and management of Montana soils.  Montana Fertilizer Advisory Committee. July 1, 2016-June 30, 2017. 
  • 2016: $56,275. Engel, R., Jones, C., Perry, M. Fertilizer management strategies for enhanced N recovery and reducing N losses in no-till wheat. Montana Fertilizer Advisory Committee. 
  • 2016: $9,000.  Engel, R. Pushing the limits of fertilizer N recovery in a semiarid climate with improved N management. Internal Plant Nutrition Institute. 
  • 2014:  $499,990. Menalled, F., Lehnhoff, E., Bekkerman, A.  Burrows, M., Engel, R., Gedeon, T., Glunk, E., Hatfield, P., Miller, P., Miller, Z.  Assessing the resiliency of integrated crop-livestock organic systems in water-limited environments under current and predicted climate