G. Philip Robertson

G. Philip Robertson

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University Distinguished Professor
Department of Plant, Soil and Microbial Sciences



B.A., Hampshire College
PhD, Indiana University, Biology

Overview of current program:

We study the sustainability of field crop ecosystems with a focus on ecosystem services related to their productivity and biogeochemistry. We study food crops (primarily corn, soybean, and wheat) as well as cellulosic biofuel crops (including switchgrass, miscanthus, and restored prairie), and consider both conventional and alternative management strategies, including reduced input and organic. We are particularly interested in questions of nitrogen availability  and loss, soil carbon dynamics, and fluxes of the greenhouse gases CO2, nitrous oxide, and methane.  Our studies range in scale from the microbial to landscapes and regions. We ask fundamental questions of topical importance: our research informs the design of resource-efficient high-yielding cropping systems, strategies to reduce nitrogen pollution from agricultural landscapes, and national greenhouse gas mitigation policies.

Web Links:

Recent Publications:

(Full list of publications)


  1. Bowles, T. M., M. Mooshammer, Y. Socolar, F. Calderón, M. A. Cavigelli, S. W. Culman, W. Deen, C. F. Drury, A. Garcia Y Garcia, A. C. M. Gaudin, W. S. Harkrom, R. M. Lehman, S. L. Osborne, G. P. Robertson, J. Salerno, M. R. Schmer, J. Strock, and A. S. Grandy. 2020. Long-term evidence shows crop rotation diversification increases agricultural resilience to adverse growing conditions in North America. One Earth 2:284-293. [PDF]
  2. Cusser, S., C. A. Bahlai, S. M. Swinton, G. P. Robertson, and N. M. Haddad. 2020. Long-term research avoids spurious trends in sustainability attributes of no-till. Global Change Biology https://doi.org/10.1111/gcb.15080. [PDF]
  3. Gelfand, I., S. K. Hamilton, A. N. Kravchenko, R. D. Jackson, K. D. Thelen, and G. P. Robertson. 2020. Empirical evidence for the potential climate benefits of decarbonizing light vehicle transport in the U.S. with bioenergy from purpose-grown biomass with and without BECCS. Environmental Science & Technology 54:2961-2974. [PDF]
  4. Hess, L., E. S. Hinckley, G. P. Robertson, and P. A. Matson. 2020. Rainfall intensification increases nitrate leaching from tilled but not no-till cropping systems of the U.S. Midwest. Agriculture, Ecosystems and Environment 290:106747. [PDF]
  5. Hussain, M. Z., G. P. Robertson, B. Basso, and S. K. Hamilton. 2020. Leaching losses of dissolved organic carbon and nitrogen from agricultural soils in the upper US Midwest. Science of the Total Environment 734:139379. [PDF]
  6. Reed, D., J. Chen, M. Abraha, G. P. Robertson, and K. Dahlin. 2020. The shifting role of mRUE for regulating ecosystem production. Ecosystems 23:359-369. [PDF]
  7. Sciusco, P., J. Chen, M. Abraha, C. Lei, G. P. Robertson, R. Lafortezza, G. Shirkey, Z. Ouyang, R. Zhang, and R. John. 2020. Spatiotemporal variations of albedo in managed agricultural landscapes: Inferences to global warming impacts (GWI). Landscape Ecology https://doi.org/10.1007/s10980-020-01022-8. [PDF]


  1. Abraha, M., J. Chen, S. K. Hamilton, and G. P. Robertson. 2019. Long-term evapotranspiration rates for rainfed corn vs. perennial bioenergy crops in a mesic landscape. Hydrological Processes 34:201-822. [PDF]
  2. Abraha, M., I. Gelfand, S. K. Hamilton, J. Chen, and G. P. Robertson. 2019. Carbon debt of field-scale Conservation Reserve Program grasslands converted to annual and perennial bioenergy crops. Environmental Research Letters 14: 024019. [PDF]
  3. Basso, B., G. Shaui, J. Zhang, and G. P. Robertson. 2019. Yield stability analysis reveals sources of large-scale nitrogen loss from the U.S. Midwest. Scientific Reports 9: 5774. [PDF]
  4. Duncan, D. S., L. G. Oates, I. Gelfand, N. Millar, G. P. Robertson, and  R. D. Jackson. 2019. Environmental factors function as constraints on soil nitrous oxide fluxes in bioenergy feedstock cropping systems. Global Change Biology Bioenergy 11: 416-426. [PDF]
  5. Hussain, M. Z., A. K. Bhardwaj, B. Basso, G. P. Robertson, and S. K. Hamilton. 2019. Nitrate leaching from continuous corn, perennial grasses, and poplar in the US Midwest. Journal of Environmental Quality 48:1849-1855. [PDF]
  6. Hussain, M. Z., S. K. Hamilton, A. K. Bhardwaj, B. Basso, K. Thelen, and G. P. Robertson. 2019. Evapotranspiration and water use efficiency of continuous maize and maize and soybean rotation in the upper Midwest U.S. Agricultural Water Management 221:92-98. [PDF]
  7. Kravchenko, A. N., A. K. Guber, B. S. Rasavi, J. Koestel, M. Y. Quigley, G. P. Robertson, and Y. Kuzyakov. 2019. Microbial spatial footprint as a driver of soil carbon stabilization. Nature Communications 10:3121. [PDF]
  8. Roley, S. S., C. Xue, S. K. Hamilton, J. M. Tiedje, and G. P. Robertson. 2019. Isotopic evidence for episodic nitrogen fixation in switchgrass (Panicum virgatum L.). Soil Biology & Biochemistry 129:90-98. [PDF]
  9. Shcherbak, I. and G. P. Robertson. 2019. Nitrous oxide (N2O) from subsurface soils of agricultural ecosystems. Ecosystems 22:1650-1663. [PDF]
  10. Wang, S., G. R. Sanford, G. P. Robertson, R. D. Jackson, and K. D. Thelen. 2019. Perennial bioenergy crop yield and quality response to nitrogen fertilization. BioEnergy Research 13:157-166. [PDF]


  1. Abraha, M., I. Gelfand, J. Chen, S. K. Hamilton, and G. P. Robertson. 2018. Legacy effects of land use on soil nitrous oxide emissions in annual crop and perennial grassland ecosystems. Ecological Applications 28:1362-1369. [PDF]
  2. Abraha, M., S. K. Hamilton, J. Chen, and G. P. Robertson. 2018. Ecosystem carbon exchange on conversion of Conservation Reserve Program grasslands to annual and perennial cropping systems. Agricultural and Forest Meteorology 253-254:151-160. [PDF]
  3. Basso, B., B. Dumont, B. Maestrini, I. Shcherbak, G. P. Robertson, J. R. Porter, P. Smith, K. Paustian, P. R. Grace, S. Asseng, S. Bassu, C. Biernath, K. J. Boote, D. Cammarano, G. De Sanctis, J.-L. Durand, F. Ewert, S. Gayler, D. W. Hyndman, J. Kent, P. Martre, C. Nendel, E. Priesack, D. Ripoche, A. C. Ruane, J. Sharp, P. J. Thorburn, J. L. Hatfield, J. W. Jones, and C. Rosenzweig. 2018. Soil organic carbon and nitrogen feedbacks on crop yields under climate change. Agricultural & Environmental Letters 3:180026. [PDF]
  4. Hamilton, S. K., M. Z. Hussain, C. Lowrie, B. Basso, and G. P. Robertson. 2018. Evapotranspiration is resilient in the face of land cover and climate change in a humid temperate catchment. Hydrological Processes 32:655-663. [PDF]
  5. Hess, L., E.-L. Hinckley, G. P. Robertson, S. K. Hamilton, and P. Matson. 2018. Rainfall intensification enhances deep percolation and soil water content in tilled and no-till cropping systems in the US Midwest. Vadose Zone Journal 17:180128. [PDF]
  6. Jones, C. D., L. G. Oates, G. P. Robertson, and R. C. Izaurralde. 2018. Perennialization and cover cropping mitigate soil carbon loss from residue harvesting. Journal of Environmental Quality 47:710-717. [PDF]
  7. Kleinman, P. J. A., S. Spiegal, J. R. Rigby, S. C. Goslee, J. M. Baker, B. T. Bestelmeyer, R. K. Boughton, R. B. Bryant, M. A. Cavigelli, J. D. Derner, E. W. Duncan, D. C. Goodrich, D. R. Huggins, K. W. King, M. A. Liebig, M. A. Locke, S. B. Mirsky, G. E. Moglen, T. B. Moorman, F. B. Pierson, G. P. Robertson, E. J. Sadler, J. S. Shortle, J. L. Steiner, T. C. Strickland, H. M. Swain, T. Tsegaye, M. R. Williams, and C. L. Walthall. 2018. Advancing the sustainability of US agriculture through long-term research. Journal of Environmental Quality 47:1412-1425. [PDF]
  8. McGill, B. M., S. K. Hamilton, N. Millar, and G. P. Robertson. 2018. The greenhouse gas cost of agricultural intensification with groundwater irrigation in a Midwest US row cropping system. Global Change Biology  24:5948-5960. [PDF]
  9. Millar, N., A. Urrea, K. Kahmark, I. Shcherbak, G. P. Robertson, and I. Ortiz-Monasterio. 2018. Nitrous oxide (N2O) responds exponentially to nitrogen fertilizer in irrigated wheat in the Yaqui Valley, Mexico. Agriculture, Ecosystems and Environment 261:125-132. [PDF]
  10. Roley, S. S., D. S. Duncan, D. Liang, A. Garoutte, R. D. Jackson, J. M. Tiedje, and G. P. Robertson. 2018. Associative nitrogen fixation (ANF) in switchgrass (Panicum virgatum) across a nitrogen input gradient. PLoS ONE 13:e0197320. [PDF]
  11. Spiegal, S., B. T. Bestelmeyer, D. W. Archer, D. J. Augustine, E. H. Boughton, R. K. Boughton, M. A. Cavigelli, P. E. Clark, J. D. Derner, E. W. Duncan, C. Hapeman, D. H. Harmel, P. Heilman, M. A. Holly, D. R. Huggins, K. King, P. J. A. Kleinman, M. A. Liebig, M. A. Locke, G. W. McCarty, N. Millar, S. B. Mirsky, T. B. Moorman, F. B. Pierson, J. R. Rigby, G. P. Robertson, J. L. Steiner, T. C. Strickland, H. M. Swain, B. J. Wienhold, J. D. Wulfhorst, M. A. Yost, and C. L. Walthall. 2018. Evaluating strategies for sustainable intensification of US agriculture through the Long-Term Agroecosystem Research network. Environmental Research Letters 13:034031. [PDF]
  12. Sprunger, C. D., S. W. Culman, G. P. Robertson, and S. S. Snapp. 2018. How does nitrogen and perenniality influence belowground biomass and nitrogen use efficiency in small grain cereals? Crop Science 58:2110-2120. [PDF]
  13. Sprunger, C. D. and G. P. Robertson. 2018. Early accumulation of active fraction soil carbon in newly established cellulosic biofuel systems. Geoderma 318:42-51. [PDF]


  1. Austin, E. E.,  K. Wickings, M. McDaniel, G. P. Robertson, and A. S. Grandy. 2017. Cover crop root contributions to soil carbon in a no-till corn bioenergy cropping system. GCB Bioenergy 9:1252-1263. [PDF]
  2. Izaurralde, C., W. B. McGill, J. Williams, C. Jones, R. Link, D. Manowitz, D. Schwab, X. Zhang, G. P. Robertson, and N. Millar. 2017. Simulating microbial denitrification with EPIC: Model description and initial testing. Ecological Modelling 359:349-362. [PDF]
  3. Jones, C. D., X. Zhang, A. D. Reddy, G. P. Robertson, and C. R. Izaurralde. 2017. The greenhouse gas intensity and potential biofuel production capacity of maize stover harvest in the US Midwest. GCB Bioenergy 9:1543-1554. [PDF]
  4. Kravchenko, A. N., S. S. Snapp, and G. P. Robertson. 2017. Field-scale experiments reveal persistent yield gaps in low-input and organic cropping systems. Proceedings of the National Academy of Sciences USA 114:926-931. [PDF]
  5. Kravchenko, A. N., E. R. Toosi, A. K. Guber, N. E. Ostrom, J. Yu, K. Azeem, M. L. Rivers, and G. P. Robertson. 2017. Hotspots of soil N2O emission enhanced through water absorption by plant residue. Nature Geoscience 10:496-500. [PDF]
  6. Reimer, A., J. E. Doll, B. Basso, S. T. Marquart-Pyatt, G. P. Robertson, D. Stuart, and J. Zhao. 2017. Moving toward sustainable farming systems: Insights from private and public sector dialogues on nitrogen management. Journal of Soil and Water Conservation 72:5A-9A. [PDF]
  7. Robertson, G. P., S. K. Hamilton, B. L. Barham, B. E. Dale, R. C. Izaurralde, R. D. Jackson, D. A. Landis, S. M. Swinton, K. D. Thelen, and J. M. Tiedje. 2017. Cellulosic biofuel contributions to a sustainable energy future: Choices and outcomes. Science 356:eaal2324. doi: 10.1126/science.aal2324. [PDF]
  8. Ruan, L. and G. P. Robertson. 2017.  Reduced snow cover increases wintertime nitrous oxide (N2O) emissions from an agricultural soil in the upper U.S. Midwest. Ecosystems 20:917-927 [PDF]
  9. Sanford, G. R., R. D. Jackson, L. G. Oates, G. P. Robertson, S. Roley, and K. D. Thelen. 2017. Biomass production a stronger driver of ethanol yield than biomass quality. Agronomy Journal 109:1-9. [PDF]
  10. Sprunger, C. D., S. W. Culman, G. P. Robertson, and S. S. Snapp. 2017. Perennial grain on a Midwest Alfisol shows no sign of early soil carbon gain. Renewable Agriculture and Food Systems 33:360-372. [PDF]
  11. Sprunger, C. D., L. G. Oates, R. D. Jackson, and G. P. Robertson. 2017. Plant community composition influences fine root production and biomass allocation in perennial bioenergy cropping systems of the upper Midwest, USA. Biomass and Bioenergy 105:248-258. [PDF]
  12. Valdez, Z., W. C. Hockaday, C. M. Masiello, M. E. Gallagher, and G. P. Robertson. 2017. Soil carbon and nitrogen responses to nitrogen fertilizer and harvesting rates in switchgrass cropping systems. BioEnergy Research 10:456-464. [PDF]
  13. Yang, Q., X. Zhang, M. Abraha, S. Del Grosso, G. P. Robertson, and J. Chen. 2017. Enhancing the soil and water assessment tool model for simulating N2O emissions of three agricultural systems. Ecosystem Health and Sustainability 3:e01259. [PDF]