Resham Thapa, Ph.D.
Assistant Research Professor, Climate Smart Agronomy
Department of Agricultural and Environmental Sciences
College of Agriculture
Tennessee State University

Contact Information:
204I Farrell-Westbrook Building
Telephone: (615)-963-7496

Research Interests:
Precision and sustainable agriculture
Climate-smart practices
Soil health
Soil water and nutrient dynamics
Greenhouse gas mitigation
Resource use efficiency in cropping systems
Data synthesis and meta-analysis
Cropping systems modeling
Decision support tools

Research Publications: 
Singh, M., R. Thapa, M.S. Kukal, S. Irmak, and A. Jhala. 2022. Effect of water stress on weed germination, growth characteristics, and seed production: A global meta-analysis. Weed Science. 70(6):621-640. 

Thapa R., M. Cabrera, C. Reberg-Horton, Dann, K.S. Balkcom, D. Fleisher, J. Gaskin, R. Hitchcok, A. Poncet, H.H. Schomberg, D. Timlin, and S.B. Mirsky. 2022. Modeling surface residue decomposition and N release using the Cover Crop Nitrogen Calculator (CC-NCALC). Nutrient Cycling in Agroecosystems. 124:81-99.

Jennewein, J.S., B.T. Lamb, D.W. Hivley, A. Thieme, R. Thapa, A. Goldsmith, and S.B. Mirsky. 2022. Integration of satellite-based optical and synthetic aperture radar imagery to estimate winter cover crop performance in cereal grasses. Remote Sensing. 14(9):2077.

Thapa R., K.L. Tully, C. Reberg-Horton, H.H. Schomberg, M. Cabrera, J. Gaskin, B.W. Davis, A. Poncet, S.A. Seehaver, R. Hitchcok, D. Timlin, D. Fleisher, and S.B. Mirsky. 2022. Cover crop residue decomposition in no-till corn systems: Insights from multi-state on-farm litter bag studies. Agriculture, Ecosystems, and Environment. 326:107823.

Thapa, R., K.L. Tully, N. Hamovit, S.A. Yarwood, H.H. Schomberg, M.L. Cabrera, C. Reberg-Horton, and S.B. Mirsky. 2022. Microbial processes and community structure as influenced by cover crop residue type and placement during repeated dry-wet cycles. Applied Soil Ecology. 172:104349.

Zhuangji, W., R. Thapa, D. Timlin, S. Li, W. Sun, S. Beegum, D. Fleisher, S. Mirsky, M. Cabrera, T. Sauer, V.R. Reddy, R. Horton, and K. Tully. 2021. Simulations of moisture and thermal dynamics on soil surface with residue mulch and surface runoff. Water Resources Research. 57, e2021WR030431.

Dann, C.E., M.L. Cabrera, R. Thapa, S. Mirsky, K. Tully, C. Reberg-Horton, R. Hitchcock, and F. Morari. 2021. Modeling water potential of cover crop residues on the soil surface. Ecological Modelling. 459:109708.

Thapa R., K.L. Tully, M. Cabrera, C. Dann, H.H. Schomberg, D. Timlin, J. Gaskin, C. Reberg-Horton, and S.B. Mirsky. 2021. Cover crop residue moisture content controls diurnal variations in surface residue decomposition. Agricultural and Forest Meteorology. 308:108537.

Bezak, N., and the Soil Erosion Modelling Team. 2021. Soil erosion modelling: A bibliometric analysis. Environmental Research. 197:111087.

Crystal-Ornelas R., R. Thapa, and K.L. Tully.2021. Soil organic carbon concentrations as affected by organic amendments, conservation tillage, and cover cropping in organic farming systems: A meta-analysis. Agriculture, Ecosystems, and Environment. 312:107356.

Thapa R., K.L. Tully, M. Cabrera, C. Dann, H.H. Schomberg, D. Timlin, J. Gaskin, C. Reberg-Horton, B.W. Davis, and S.B. Mirsky. 2021. Effects of moisture and temperature on C and N mineralization from surface-applied cover crop residues. Biology and Fertility of Soils. 57(4):485-498. 

Borrelli, P., and the Soil Erosion Modelling Team. 2021. Soil erosion modelling: A global review and statistical analysis. Science of the Total Environment. 146494.

Thapa R., S.B. Mirsky, and K.L. Tully. 2018. Cover crops reduce nitrate leaching in agroecosystems: a global meta-analysis. Journal of Environmental Quality. 47(6): 1400-1411.

Thapa R., H. Poffenbarger, K.L. Tully, V. Ackyord, M. Kramer, and S.B. Mirsky. 2018. Biomass production and nitrogen accumulation by hairy vetch-cereal rye mixtures: a meta-analysis. Agronomy Journal. 110(4): 1197-1208.

Thapa R., and A. Chatterjee. 2017. Wheat production, nitrogen transformation and nitrogen losses as affected by nitrification and double inhibitors. Agronomy Journal 109(5): 1825-1835.

Thapa R., A. Wick, and A. Chatterjee. 2017. Response of spring wheat to sulfate-based salinity stress under greenhouse and field conditions. Agronomy Journal 109(2): 442-454.

Thapa R., A. Chatterjee, A. Wick, and K. Butcher. 2017. Carbon dioxide and nitrous oxide emissions from naturally occurring sulfate-based saline soils at different moisture contents. Pedosphere 27(5): 868-876.

Ghosh U., R. Thapa, T. DeSutter, Y. He., and A. Chatterjee. 2017. Saline-sodic soils: potential sources of nitrous oxide and carbon dioxide emissions? Pedosphere 27(1):65-75.

Thapa R., A. Chatterjee, R. Awale, D.A. McGranahan, and A. Daigh. 2016. Effect of enhanced efficiency fertilizers on nitrous oxide emissions and crop yields: a meta-analysis. Soil Science Society America Journal 80:1121–1134.

Chatterjee A., N. R. Cattanach, R. Awale, and R. Thapa. 2016. Can we reduce rainfed maize (Zea mays L.) nitrogenous fertilizer application rate with addition of nitrapyrin? Communication in Soil Science and Plant Analysis 47(4): 527-532.

Thapa R., A. Chatterjee, J.M.F. Johnson, and R. Awale. 2015. Stabilized nitrogen fertilizers and application rate influenced nitrogen losses under rainfed spring wheat. Agronomy Journal 107(5): 1885-1894.

Conference proceedings/Presentations: 30

Research bulletin/ Report/Extension Publication: 8

Participation in workshops/Field days: 5

Decision support tool:
Cover Crop Nitrogen Calculator ( This calculator aids farmers and agricultural professionals with decision support regarding cover crop residue persistence, as well as the amount and timing of nitrogen availability following cover crop termination. This calculator is parameterized using data from multi-state on-farm experiments and thus, can be used for science-based, site-specific N recommendations for subsequent cash crops following the preceding winter cover crops.

Major Honors and Awards:
Jacob K. Goldhaber Travel Award, University of Maryland-College Park, USA (2019)
ASA Nutrients and Environmental Quality Community Poster Session, American Society of America, USA (2018, 2nd place)
Dean’s Fellowship, University of Maryland-College Park, USA (2016-2020)
IPNI Graduate Scholar Award, International Plant Nutrition Institute, USA (2015)
Environmental Quality Outstanding Graduate Student Award, American Society of America, USA (2015).
Roy A. Erickson Scholarship, North Dakota State University, USA (2013)
Dr. Karnam Lokanadhan Award (Gold medal), Tamil Nadu Agricultural University, India (2013)
ACCOSA Award for Academic Excellence, Tamil Nadu Agricultural University, India (2013)
Nepal Aid Fund Scholarship for Undergraduate Program, Government of India (2009-2013)

Education and Training:
Research Associate, North Carolina State University, Raleigh, NC, USA (2021-2022)
Ph.D. Plant Science, University of Maryland, College Park, MD, USA (2016 – 2020)
M.Sc. Soil Sciene, North Dakota State University, Fargo, ND, USA (2014-2016)
B.Sc. Agriculture, Tamil Nadu Agricultural University, India (2009-2013)

Date Joined Staff:  January 2023