Kenneth G. Cassman

Kenneth Cassman

Emeritus Robert B. Daugherty Professor of Agronomy

Area of Expertise:

B.S., Biology, University of California-San Diego, 1975

M.S., Agronomy and Soil Science, University of Hawaii, 1977

Ph.D., Agronomy and Soil Science, University of Hawaii, 1979

Area of Focus

Ecological intensification of crop production systems; food security and yield gap analysis at local to global spatial scales.

Research Interests

Soil fertility and plant nutrition; crop ecology and yield potential; environmental performance metrics; nutrient cycling processes; soil quality and sustainability of intensive cropping systems; global food security.

Current Activities

The goal of my research is to find ways to increase crop yields substantially on existing farm land without compromising the quality of soil and water resources or damaging the integrity of natural ecosystems – a process called ecological intensification. Current efforts focus on contributing to a global collaboration to develop the Global Yield Gap Atlas (, which provides state-of-the-art estimates of the gap between current average farm yields and the potential yield of major food crops throughout the world. The Atlas supplies essential information to guide development policies and research prioritization at global and national scales while also supporting efforts to identify yield constraints and technologies to overcome them at local to regional levels. Other work seeks to identify and validate metrics for estimating agriculture’s environmental impact that are robust yet parsimonious by “simplifying of the far side of complexity.”


Electronic copies available upon request, and most are available from Google Scholar.

  • Andrade JF, Cassman KG, Edreira JIR, Agus F, Bala A, Deng N, Grassini P. 2021. Impact of urbanization trends on production of key staple crops. AMBIO.
  • Edreira JI, Andrade JF, Cassman KG, van Ittersum MK, van Loon MP, Grassini P. 2021. Spatial frameworks for robust estimation of yield gaps. Nat Food
  • Cassman KG, Grassini P. 2020. A global perspective on sustainable intensification research. Nature Sustainability 3: 262-268
  • Deng N, Grassini P, Yang H, Huang J, Cassman KG, Peng S. Closing yield gaps for rice self-sufficiency in China. 2019. Nat Commun 10: 1725.
  • McLellan E, Cassman KG, Eagle AJ, Woodbury PB, Sela S, Tonitto C, Marjerison RD, van Es HM. 2018. The nitrogen balancing act: Tracking the environmental performance of food production. Biosci. 68: 194-203.
  • Edreira JIR, Cassman KG, Hochman Z, van Ittersum MK, an Bussel L, Claessens L, Grassini P. 2018. Beyond the plot: technology extrapolation domains for scaling out agronomic science. Environ. Res. Lett. 13 (2018) 054027.
  • Guilpart, N, Grassini P, Van Wart J , Yang H, van Ittersum MK, van Bussel LGJ, Wolf J, Claessens L, Leenaars JGB, and Cassman KG. 2017. Rooting for food security in Sub-Saharan Africa. Environ. Res. Lett. 12: 114036.
  • van Ittersum MK, van Bussel LGJ, Wolf J, Grassini P, Van Wart J, Guilpart N, Claessens L, de Groot H, Wiebe K, Mason-d’Croz D, Yang H, Boogaard H, van Oort P, Saito K, O. Adimo O, Adjei-Nsiah S, Alhassane A, Bala A, Chikowo R, Kaizzi KC, Kouressy M, Makoi JHJR, Ouattara K, Tesfaye K, Cassman K. 2016. Can Sub-Saharan Africa feed itself? Proc. Natl. Acad. Sci. 113: 14964-14969
  • Gobbett DL, Hochman Z, Horan H, Navarro Garcia J, Grassini P and Cassman KG. 2017. Yield gap analysis of rainfed wheat demonstrates local to global relevance. J. Agric. Sci. 155: 282–299.
  • Cassman, Kenneth G. 2016. “Long-Term Trajectories: Crop Yields, Farmland, and Irrigated Agriculture.” Federal Reserve Bank of Kansas City Economic Review, Special Issue, pp. 21–46.
  • Ladha JK,Tirol-Padre1 A, Reddy CK, Cassman KG, Verma S, Powlson DS, van Kessel C, Richter DB, Chakraborty D, and Pathak H. 2016. Global nitrogen budgets in cereals: A 50-year assessment for maize, rice, and wheat production systems. Sci. Rep. 6, 19355; doi: 10.1038/srep19355
  • Van Wart J., Grassini P, Yang HS, Claessens L, Jarvis A, Cassman KG. 2015. Creating long-term weather data from thin air for crop simulation modelling. Agric. For. Meteoro. 208: 48-58.
  • Grassini P, van Bussel LGJ, Van Wart J, Wolf J, Claessens L, Yang HS, Boogaard H, de Groot H, van Ittersum MK, Cassman KG. 2015. How good is good enough? Data requirements for reliable crop yield simulations and yield-gap analysis. Field Crops Res. 49–63.
  • Stevenson JR, Serraj R, and Cassman KG. 2014. Evaluating conservation agriculture for small-scale farmers in Sub-Saharan Africa and South Asia. Agric. Ecosys. Environ. 187: 1-10.
  • Laurance WF, Sayer J, and Cassman KG. 2014. Agricultural expansion and its impact on tropical nature. Trends in Ecol. Evol.29:107-116.
  • Cassman KG and Grassini P. 2013. Can there be a green revolution in Sub-Saharan Africa without large expansion of irrigated crop production? Global Food Security 2: 203-209.
  • Grassini P, Eskridge KM, and Cassman KG. 2013. Distinguishing between yield advances and yield plateaus in historical crop yield trends. Nat. Commun. 4:2918. doi:10.1038/ncomms3918
  • Van Wart J, Grassini P, Cassman KG. 2013. Impact of derived global weather data on simulation of crop yields. Global Change Biol. 19: 3822-3834.
  • Sayer J and Cassman KG. 2013. Agricultural innovation to protect the environment. PNAS 101:8345-8348.
  • Van Ittersum M,K., Cassman K.G., Grassini, P., Wolf, J. Tittonell, P., Hochman, Z. 2013. Yield gap analysis with local to global relevance-A Review. Field Crops Res. 143: 4-17
  • Grassini P and Cassman KG. 2012. High yield maize with large net energy yield and low global warming potential. Proc. Natl. Acad. Sci. 109:1074-1079.
  • Connor D, Loomis RS, Cassman KG. 2011. Crop Ecology. Cambridge University Press, Cambridge UK. 2nd Edition. 556pp
  • Chen XP,1, Cui ZL, Vitousek PM, Cassman KG, Matson PA Bai JS, Menga QF, Hou P, Yue SC, 2011. Römhelde V, and Zhang FS. Integrated soil-crop system management for food security. Proc. Natl. Acad. Sci.
  • Grassini P, Yang H, Irmak S, Thornburn J, Burr C, Cassman KG. 2011. High-yield irrigated maize in theWestern U.S. Corn Belt: II. Irrigation management and crop water productivity. Field Crops Res. 120:133-144.
  • Grassini P, Thornburn J, Burr C, Cassman KG. 2011. High-yield irrigated maize in theWestern U.S. Corn Belt: I. On-farm yield, yield potential, and impact of agronomic practices. Field Crops Res. 120:142-152.
  • Cassman KG, Grassini P, van Wart J. 2010. Crop yield potential, yield trends, and global food security in a changing climate. pp. 37-51. In Rosenzweig C and Hillel D (eds): Handbook of Climate Change and Agroecosystems. Imperial College Press, London.
  • Setiyono TD, Cassman KG, Specht JE, Dobermann A, Weiss A, Yang H, Conley SP, Robinson AP, Pedersen P, De Bruin JL. 2010. Simulation of soybean growth and yield in near-optimal growth conditions. Field Crops Res. 119:161-174.
  • Lobell DB, Cassman KG, Field CB. 2009. Crop yield gaps: their importance, magnitudes, and causes. Annu. Rev. Environ. Resour. 34:179-204.
  • Liska AJ, Yang HS, Bremer VR, Klopfenstein TJ, Walters DT, Erickson GE, Cassman KG. Improvements in Life Cycle Energy Efficiency and Greenhouse Gas Emissions of Corn-Ethanol. 2009. J. Industrial Ecol. 13:58-74.
  • Cassman K.G. and Liska A. J. 2007. Food and fuel for all: Realistic or foolish? Biofuels Bioprod. Biorefin. 1:18-23.
  • Cassman K.G. 2007. Can organic agriculture feed the world-science to the rescue? Renewable Agric. Food Sys. 22:83-83.
  • Olk, D.C, Cassman, K.G., Schmidt-Rohr, K., Anders, M.M., Mao, J.D., Deenik, J.L. 2006. Chemical stabilization of soil organic nitrogen by phenolic lignin residues in anaerobic agroecosystems. Soil Biol. Biochem. 38:3303-3312.
  • Haishun Y., Dobermann A., Cassman K.G., and Walters D.T. 2006. Features, Applications, and Limitations of the Hybrid-Maize Simulation Model. Agron. J. 98:737-748.
  • Cassman, K.G. and Wood, S. 2005. Cultivated Systems. pp 741-789 In Millennium Ecosystem Assessment: Global Ecosystem Assessment Report on Conditions and Trends. Island Press, Washington D.C.
  • Verma, S.B., Dobermann, A., Cassman, K.G., Walters, D.T., Knops, J.M., Arkebauer, T.J., Suyker, A.E., Burba, G.G., Amos, B., Yang, H.S., Ginting, D., Hubbard, K.G., Gitelson, A.A., Walter-Shea, E.A. 2005. Annual carbon dioxide exchange in irrigated and rainfed maize-based agroecosystems. Agric. Forestry Meteorol.
  • Peng, S, Huang J, Sheehy JE, Laza R, Visperas RM, Zhong X, Centeno GS, Khush G, Cassman KG. 2004. Rice yields decline with higher night temperature from global warming. Proc. Natl. Acad. Sci. (USA) 101: 9971-9975.
  • Nguyen Bao Ve, Olk, D.C., and Cassman, K.G. 2004. Characterization of two humic acid fractions improves estimates of soil N mineralization kinetics in for tropical lowland rice. Soil Sci. Soc. Am. J. In Press. 87:1266-1277.
  • Cassman, K.G., Dobermann, A., Walters, D.T., Yang, H. 2003. Meeting cereal demand while protecting natural resources and improving environmental quality. Annu. Rev. Environ. Resour. 28: 315-358.
  • Tillman, D., Cassman, K.G., Matson, P.A., Naylor, R. and Polasky, S. 2002. Agricultural sustainability and intensive production practices. Nature 418: 671-677.
  • Cassman, K.G., Dobermann, A., and Walters, D. 2002. Agroecosystems, nitrogen-use efficiency, and nitrogen management. AMBIO 31:132-140.
  • Cassman, K.G. 2001. Crop science research to assure food security. In Noesberger, J. et al. (eds) Crop Science: Progress and Prospects. CAB International, Wallingford, UK. pp. 33-51.