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Kate Tully

Associate Professor

Associate Professor

Plant Science & Landscape Architecture 2102 Plant Sciences Building 4291 Fieldhouse Drive College Park, Maryland 20742


  • Assess the sustainability of food production systems by examining their effects on interactions among plants, soils, carbon, nutrient, and water cycles in a changing climate.
  • Identify farm management strategies that can balance food production and environmental health.
  • Investigate sustainable agriculture strategies in developing countries where access to land, water, and inputs are limited.
  • Research focus on saltwater intrusion (the landward movement of saltwater from the ocean) and its consequences for both agriculture and the environment.
  • Research focus on how cover crops can promote efficient on-farm nutrient cycling, sequester carbon, and improve water quality



ORCiD: 0000-0002-6190-2679

Check out the AgroEcoLab Blog for the latest research updates

Kate Tully is an Associate Professor of Agroecology in the Department of Plant Science and Landscape Architecture. Her research assesses the sustainability of food production systems by examining their effects on interactions among plants, soils, carbon, nutrient, and water cycles. Her work in the Mid-Atlantic examines how to balance farm productivity and ecosystem services. Along with collaborators at the USDA, she studies how cover crops can promote efficient on-farm nutrient cycling, sequester carbon, and improve water quality. On the Lower Eastern Shore of the Chesapeake Bay, she is researching saltwater intrusion (the landward movement of saltwater from the ocean) is increasing the potential for large pulses of nutrient release from cultivated lands - with devastating consequences for both agriculture and the environment. 

Kate is the Community Coordinator of the Columbia Heights Green, a quarter-acre urban farm in northwest Washington, DC. The Columbia Heights green promotes a new model of urban agriculture. There are no individual beds. Everyone can garden; everyone can harvest fresh produce. With her partners at Washington Parks and People, the Columbia Heights Green was recently awarded a $50k grant from the USDA to become one the first Community Harvest Hubs in the Nation's Capital.

She comes to the University of Maryland from Columbia University's Earth Institute and the Agriculture and Food Security Center. Her research at Columbia took her to Kenya and Tanzania where she studied the effects of increased fertilizer application in smallholder farming systems. Her research focuses on improving yields and minimizing environmental harm, and is producing some of the first data on environmental impacts necessary for developing sustainable agriculture strategies in this understudied region of the world. Kate is bringing her innovative and integrative research to the State of Maryland to help support agricultural systems that can provide both food and ecosystem services to the region. 

See Kate's research highlighted in The AtlanticMaryland Farm and HarvestHakai MagazineNational Public RadioVoice of America, and Civil Eats.


  • PhD in Ecology from the University of Virginia, Charlottesville, VA 2011

  • MS in Ecology from the University of Virginia, Charlottesville, VA 2007

  • BA in English, Spanish, and Biology from Kenyon College, Gambier, OH 2004

Awards and Honors: 

  • Dean's Grantsmanship Award, University of Maryland College of Agriculture and Natural Resources. 2021

  • Maryland Research Excellence, University of Maryland. 2020.

  • Graduate Faculty Research and Scholarship Award, UMD Graduate School. 2019.

  • On-Campus Junior Faculty Award, University of Maryland College of Agriculture and Natural Resources. 2018

  • Research Excellence Award, University of Maryland College of Agriculture and Natural Resources. 2018

  • Park Champion Award, Washington Parks and People. 2018

  • Research Scholarship Award (RASA), University of Maryland. 2018

  • Earth Institute Postdoctoral Fellowship, Columbia University. 2011-2014

  • US Fulbright - India (declined for EI Fellowship). 2011

  • Dissertation Year Fellowship, University of Virginia. 2010

  • Bankard Fellow for Political Economy, University of Virginia. 2009

  • Excellence in Ecology Award, University of Virginia. 2007

  • Jefferson Graduate Fellow, University of Virginia. 2005-2010

Professional Work

Professional Positions Held: 

2014-Present Assistant Professor in Agricultural Ecology Dept of Plant Science and Landscape Architecture, University of Maryland, College Park, MD
2014-2016 Adjunct Associate Research Scientist Agriculture and Food Security Center, Earth Institute, Columbia University, New York, NY
2011-2014 Postdoctoral Research Fellow Agriculture and Food Security Center, Earth Institute, Columbia University, New York, NY
2005-2011 Graduate Research Fellow Dept of Environmental Sciences, University of Virginia, Charlottesville, VA



Current Research: 

My research addresses the relationships among land management, biogeochemical and water cycles, and global environmental change. More specifically, I assess the sustainability of food production systems by examining their effects on interactions among plants, soils, carbon, nutrient, and water cycles. The primary questions that motivate my research are:

  • How can the dual objectives of increasing food production and food security be met in a way that minimizes environmental costs?

  • What is the effect of agriculture on local ecosystem services including: nutrient cycling, carbon storage, food provisioning, and climate regulation?

  • Can the presence and organization of trees on a landscape mitigate environmental consequences associated with food production?

To answer these questions, I combine field measurements, laboratory techniques, and mathematical modeling. I collaborate with researchers from other disciplines but also with farmers in order to test the utility and accuracy of new technologies and decision-support tools in field settings.

effects of sea-level rise and saltwater intrusion on nutrient dynamics in coastal farmlands

Effects of sea-level rise and saltwater intrusion on nutrient dynamics in coastal farmlands


This research project will examine the effects of tidal marsh migration, in response to sea level rise, on plant community and nutrient dynamics. This project is inherently interdisciplinary as our research questions are built on principles from the fields of biogeochemistry, wetland biology, and agroecology. As tidal marshes migrate upland, they consume natural forest and in some cases, encroach on farmland, taking it out of production. Specifically, we propose to quantify the rate of marsh migration into coastal farmland and forest, compare nutrient releases across these ecotones, and investigate downstream effects on marsh plant species diversity, which is known to be affected by nutrient loading. Specifically, we are examining the response of phosphorus (P), which is applied at high concentrations to many lower eastern shore fields associated with poultry operations. P is relatively insoluble when bound to soil, but may be freed by saltwater intrusion. Our findings will be used to inform salt marsh conservation practices, including the management of problem species, Phragmites australis, prioritize protected land acquisition, and probe the capacity of migrating wetlands and transitioning forest to buffer water quality, which could provide the basis for a best management practice for coastal farms. 


  • National Institute for Food and Agriculture (NIFA) Resilient Agroecosystems 2018-2023

  • Harry Hughes Center for Agroecology 2018-2020

  • Maryland Sea Grant Graduate Student Fellowship 2017-2018

  • MAES Agriculture Experiment Station 2017-2018

  • Garden Club of America Graduate Student Award 2016-2017

  • NSF ADVANCE Grant 2015-2016

Cover crops for ecosystem services provisioning

cover crops for ecosystem services provisioning

Cover crops are an ancient technology used to improve soil fertility and are planted during the winter months in temperate climates or during dry periods in tropical climates. Cover crops provide protection from erosion and nutrient losses, and can improve water infiltration and storage among many other agroecosystem benefits. Just as we manage cash crops to optimize yields, so too must we manage cover crops for optimal services. For instance, the earlier you can plant cover crops in the fall, the more nitrogen they can prevent from infiltrating into groundwater and the later you kill them in the spring, the better they are at suppressing weeds. My research on cover crop systems focuses on (1) the effect of management strategies (e.g. termination timing, species diversity, and planting method) and (2) the effect of climate variables (e.g. temperature and precipitation) on nutrient and water cycling.


  • National Institute for Food and Agriculture Water for food production challenge area 2018-2020

  • Annie's Homegrown Sustainable Agriculture Scholarship (Peterson) 2018-2019

  • Northeast SARE Research and Education Graduate Grant (Peterson) 2018-2020

  • Northeast SARE Research and Education Graduate Grant (Thapa) 2017-2019

  • Northeast SARE Research and Education Research Grant 2017-2019

  • Maryland Grain Producers Utilization Board 2017-2018

  • United States Department of Agriculture Conservation Innovation Grant 2016-2019

  • Northeast SARE Research and Education Professional Development 2016-2019

  • North American Strawberry Growers Association 2015-2016 & 2016-2017

environmental impacts of the African Green Revolution

environmental impacts of the African Green Revolution

This work examines tradeoffs between productivity and other ecosystem services in subsistence agricultural systems in sub-Saharan Africa. Current proposals and policy associated with the call for an African Green Revolution aim to improve food production and soil fertility by increasing nutrient application rates six-fold on smallholder farms. While crop yields are anticipated to rise significantly in response to increased N application, a scarcity of biophysical data makes it nearly impossible to predict the environmental impacts of this widespread change in nutrient management. 

Past Research:

nitrate leaching from continuous maize systems in east Africa

nitrate leaching from continuous maize systems in east Africa


Using a combination of field measurements from lysimeters and computational modeling, we are estimating nitrogen fluxes from maize systems in Kenya and Tanzania receiving different levels of fertilizer. As maize cultivation occurs in remote areas, field ecologists face a variety of obstacles from sample preservation and storage, contamination, and transport. We are using a hand-held ion-selective electrode to measure nitrate concentrations in soil solution, which has proven to be highly accurate and low-cost. See our 2014 publication here.  

mechanisms for nitrogen retention in cultivated soils in east Africa

mechanisms for nitrogen retention in cultivated soils in east Africa

Unlike the Green Revolution of the 1970s to the 1990s in Asia and Latin America, which occurred predominantly on relatively fertile, young soils (Entisols and Inceptisols), the agricultural transition in sub-Saharan Africa is occurring on more highly weathered soils that range from low fertility high clay Ultisols, and Oxisols to very sandy Alfisols. We are examining patterns available N throughout the growing season and at depth in the soil profile (down to 4 meters!) to determine how and where nitrogen is stored in these agricultural soils and how this differs with soil texture and subsoil mineralogy.

Co-benefits of agroforestry in smallholder farming systems

Co-benefits of agroforestry in smallholder farming systems

The term agroforestry usually calls to mind the wooded coffee plantations of Latin America, where coffee bushes are cultivated under the broad canopy of fruit and timber trees.  Agroforestry in sub-Saharan Africa can take many forms, from hedgerows and windbreaks boardering farm fields, to short-term maize-legume rotation, where the "agroforest" is a shrubby covercrop that is grown on the field for a few months during the "short rainy" season. We are examining the effects of growing trees or short-term legume crops on a variety of ecosystem services - nitrogen and carbon cycling, water retention, and microbial diversity and functioning.

Selected Presentations: 

Growing maize efficiently in sub-Saharan Africa: the interactions of soils and fertilizer | Minisymposium in Plant Biology | May 2015

Sustainable intensification of agriculture: Balancing food and environmental objectives | University of Maryland | April 2014


Achievements in Teaching: 

Teaching and Learning Transformation Center Launch Program (2016)

Chesapeake Fellow (2015)

Courses Taught: 


PLSC303 Global Food Systems Fall 2015, Spring 2017, 2018, 2019
PLSC399 Independent Study in Agroecology Every semester and over summers
PLSC405 Agroecology Spring 2016, Fall 2016, 2017
PLSC605 Advanced Agroecology Spring 2016, Fall 2016, Fall 2017
PLSC619 Seminars in Plant Science Fall 2016, Spring 2017

Agroecology (PLSC405 & 605) offered in the Fall semesters

Course Goal: To give students a basic understanding of the interactions between agriculture and the surrounding environmental matrix. Students will integrate concepts across agronomy, ecology, biogeochemistry, soil science, and hydrology. By the end of the class, students will be equipped to apply knowledge to the so-called wicked problem of how to feed 9 billion people while minimizing environmental harm.

Course Description:
How can we balance the multiple, and often competing objectives of sustainable agricultural intensification to promote both agricultural productivity and human wellbeing?
 The answer to this question requires a transdisciplinary, agroecological perspective. Agroecology is the integrative study of the ecology of the entire food system, encompassing ecological, economic and social dimensions. This course is designed to introduce various topics in agroecology – organic agriculture, biodiversity, the Farm Bill. We will take an ecosystems approach to the study of agriculture that will enable students to analyze the environmental, social, and economic interconnections within various types of agricultural systems locally and globally.

Global Food Systems (PLSC303) offered in the Spring semesters

Course Goal: To give students a holistic understanding of the global food system. Students will integrate concepts across a variety of disciplines and be equipped to access, organize, and apply knowledge of (1) the core elements of food production systems, (2) human malnutrition, and (3) global food security and food policy.
Course Description:
How do we balance the often competing objectives of producing food, preserving the environment, and promoting human well-being?
 This course begins with a tour of the types and distributions of crops across the globe, then we will focus on the core biophysical resources needed to produce that food – land, soil, nutrients, and water. We will discuss the human dimensions of the food system through an examination of nutrition and (shifting) diets. We will examine the role of big business in ensuring global and local food security. We will end the term with a series of discussions related to hot-button issues such as biotechnology, biofuels, organic agriculture, and food waste. 


Selected Publications: 

See/access Kate's publications on her ResearchGate profile.


Status of trends of land degradation and restoration and associated changes in biodiversity and ecosystem function. Ch.4 In The IPBES assessment report on land degradation and restoration. 2018. Montanarella, L., Scholes, R., and Brainich, A. (eds.). Secretariat of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, Bonn, Germany. 744 pages.

Neill C, Palm CA, Lefebvre P, Tully K. 2016. Using Soil Characteristics to Target Sustainable Intensification of Maize-based Agriculture in East Africa. Report to International Maize and Wheat Improvement Center (CIMMYT).

Kuyah S, MbowC, Sileshi G, van Noordwijk M, TullyK, RosenstockTS. 2016. Chapter 6: Quantifying carbon stocks and carbon stock changes in biomass on smallholder farms and in agricultural landscapes. In Rosenstock TS, Rufino MC, Butterbach-Bahl K, Wollenberg E, Richards M. (eds.), Methods for Measuring Greenhouse Gas Balances and Evaluating Mitigation Options in Smallholder Agriculture. Springer International, p 119-134.


* indicates undergraduate student   | ** indicates graduate student | *** indicates post-doctoral student

Weissman D***, Tully K. 2021. Saltwater intrusion affects nitrogen, phosphorus, and iron transformations under aerobic and anaerobic conditions: A microcosm experiment. Biogeochemistry.

Wang***, Timlin D, Li S, Fleisher D, Dathe A, Luo C, Don L, Reddy VR, Tully K. Numerical simulations of maize root growth MAIZSIM based on the spatial continuous model. In press Agricultural Water Management.

de la Reguera E**, Tully K. Farming carbon: the link between saltwater intrusion and carbon storage in coastal agricultural fields. 2021. Agriculture, Ecosystems & Environment.

Wang Z***, Timlin D, Kojima Y, Luo C, Chen Y, Li S, Fleisher D, Tully K, Reddy VR, Horton R. 2021. A piecewise analysis model for electrical conductivity calculation from time domain reflectometry waveforms. Computers and Electronics in Agriculture. 182: 106012

Thapa R**, Tully K, Cabrera ML, Dann C, Schomberg HH, Timlin D, Reberg-Horton C, Gaskin J, Davis BN, Mirsky SB. 2021. Effects of moisture and temperature on C and N mineralization from surface-applied cover crop residues. Biology and Fertility of Soils.

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

Basche A, Tully K, Álvarez-Berríos N, Reyes J, Legnick L, Brown T, Moore-Kucera J, Schattman R, Koepke-Johnson L, Roesch-McNally G. 2020. Evaluating the Untapped Potential of U.S. Conservation Investments to Improve Soil and Environmental Health. Frontiers in Sustain. Food Syst., 26 November 2020 |

de la Reguera**, Veach J, Gedan K, Tully K. The effects of saltwater intrusion on germination success of standard and alternative crops. Environmental and Experimental Botany 180:104254

Weissman D**, Tully K, McClure K, Miller C. 2020 Saltwater intrusion: A growing thread to coastal agriculture. Northeast Climate Hub FactSheet.

Weissman D** and Tully K. 2020. Saltwater intrusion alters nutrient cycling in coastal ecosystems. Ecosphere.

Otte B**, Rice CP, Davis BW, Schomberg HH, Mirsky SB, Tully K. 2020. Phenolic acids are released to soil during cover crop decomposition. Chemoecology. 30:25-34 doi: 0.1007/s00049-019-00295-z

Wang Z, Timlin D, Kouznesov M, Fleisher D, Li S, Tully K, Reddy V. 2020. Coupled model of surface runoff and surface-subsurface water movement. Advances in Water Resources. 137:103499.

Huddell AM, Galford GL, Tully K, Crowley C, Palm CA, Neill C, Hickman JE­, and Menge DNL. 2020. Meta-analysis on the potential for increasing nitrogen losses from intensifying tropical agriculture. Global Change Biology. 26:1668-1680.

Tully K and McAskill C. 2020. Promoting soil health in organically managed systems: A review. Organic Agriculture. 10:339-358. doi:10.1007/s13165-019-00275-1

Tully KGedan K, Epanchin-Niell R, Strong A, Bernhardt E, BenDor T, Mitchell M, Kominoski J, Jordan T, Neubauer S, Weston N. 2019The invisible flood: the chemistry, ecology, and consequences of saltwater intrusion. Bioscience.

Tully K, Weissman D**, Wyner WJ*, Miller J, Jordan T. 2019. Soils in transition: Saltwater intrusion alters soil chemistry in agricultural fields. Biogeochemistry.

Thapa R**, Mirsky SB, Tully K. 2019 .Cover crops reduce nitrate leaching in agroecosystems: a global meta-analysis. Journal of Environmental Quality 47:1400-1411

Yu K, Carr D, Anderegg W, Tully K, D'odorico P. 2018. Response of a facultative CAM plant and its competitive relationship with a grass to changes in rainfall regime. Plant and Soil 427:321-333.

Thapa R**, Ackroyd VJ***, Poffenbarger H, Tully K, Kramer M, Mirsky SB. 2018  Biomass production and nitrogen accumulation by hairy vetch-cereal rye biculture - A meta-analysis. Agronomy Journal 110:1197-1208.

Koivunen EE, Swett CL, Tully KIn press. Crab meal and other amendments improve soil quality while promoting degradation and microbial antagonism of Botrytis cinerea sclerotia. Plant and Soil.

Tully K, Abwanda S, Thiong’o M, Mutuo PM, Rosenstock TS. 2017.Nitrous oxide and methane fluxes from urine and dung deposited on Kenyan pastures. Journal of Environmental Quality 46:921-929.

Tully K, Ryals R. 2017. Nutrient cycling in agroecosystems: Balancing food and environmental objectivesInvited Special Issue in Agroecology & Sustainable Food Systems. 7: 761-798.

Russo T, Tully K, Palm C, Neill C. 2017. Nitrate leaching losses from Kenyan agricultural site receiving different fertilizer treatments. Agriculture Ecosystems & Environment 108:195-951.

Palm C, Neill C, Lefebvre P and Tully K. 2017. In press. Targeting sustainable intensification of maize-based agriculture in East Africa. Tropical Conservation Science. DOI:

Michelson H, Tully K. 2017. In press. The Millennium Villages Project and Local Land Values: Using Hedonic Pricing Methods to Evaluate Development Projects. World Development.

Hickman JE, Palm CA, Tully K, Diru W, Groffman PM. 2017.  Non-linear response of nitric oxide fluxes to fertilizer inputs and the impacts of agricultural intensification on tropospheric ozone pollution in Kenya. Global Change Biology 120:938-951.

Tully K, M, Hickman JE, McKenna M, Neill C, Palm CP. 2016.Fertilizer application alters vertical distributions and temporal dynamics of soil inorganic nitrogen in continuous maize systems in East Africa. Ecological Applications 26:1907-1919.

Tully K, Wood SA, Neill C, Palm CP. 2015The effect of African Green Revolution interventions on nitrogen balances in smallholder maize farms in Western Kenya. Agriculture, Ecosystems & Environment 214:10-20.

Tully K, Sullivan C, Weil R, Sanchez P. 2015The state of soil degradation in sub-Saharan Africa: baselines, trajectories, and solutions. Sustainability 7(6):6523-6552. Invited review article.

Hickman JE, Tully K, Groffman PM, Diru W, Palm CA. 2015. A potential tipping point in tropical agriculture: Avoiding rapid increases in nitrous oxide fluxes from agricultural intensification in Kenya. JGR-Biogeosciences. 120:938-951.

Wood SA, Bradford MA, Gilbert JA, McGuire KL, Palm CA, Tully K, Zhou J, Naeem S. 2015.Agricultural intensification and the functional capacity of soil microbes on smallholder African farms. Journal of Applied Ecology 52:744-752.

Wood SA, Almaraz M, Bradford MA, McGuire KL, Naeem S, Palm CA, Tully K, Zhou J. 2015. Farm management, not soil microbial diversity controls nutrient loss from smallholder tropical agriculture. Frontiers in Microbiology 6:1-10.

Tully K, Weil R2014.Ion selective electrode offers accurate, inexpensive method for analyzing soil solution nitrate in remote regions. Communications in Soil Science and Plant Analysis. 45:1974-1980.

Rosenstock T, Tully K, Arias-Navarro C, Butterbach-Bahl K, Neufeldt H, Verchot L. 2014. Agroforestry with N-fixing trees: Sustainable development’s friend or foe? Current Opinion in Environmental Sustainability, 6:15-21.

Tully K, Lawrence D, Wood SA. 2013. Organically managed coffee agroforests have larger soil phosphorus but smaller soil nitrogen pools than conventionally managed agroforests. Biogeochemistry, 115:385-397.

Tully, K, Wood SA, Lawrence D. 2013. Fertilizer type and species composition affect nutrient leachate in coffee agroecosystems. Agroforestry Systems. 87:1083-1100.

Tully K, Wood TE, Schwantes AM, Lawrence D. 2013. Soil nutrient availability and reproductive effort drive patterns in nutrient resorption in Pentaclethra macrolobaEcology. 94:930-940.

Tully K, Lawrence D, Scanlon TM. 2012. More trees less loss: Nitrogen losses decrease with increasing biomass in coffee agroforests. Agriculture, Ecosystems and Environment. 161:137-144.

Tully K, and Lawrence D. 2012. Canopy and leaf composition drive patterns of nutrient release from pruning residues in a coffee agroforest. Ecological Applications. 22:1330-1344.

Huang C-Y, Tully K, Clark DA, Oberbauer SF, McGlynn TP. 2012. The δ15 N signature of the detrital food web tracks a landscape-scale soil phosphorus gradient in a Costa Rican lowland tropical rain forest. Journal of Tropical Ecology. 28: 395-403.

Tully K, Lawrence D. 2011. Closing the Loop: Nutrient balances in organic and conventional coffee agroforests. Journal of Sustainable Development, 35: 671-695.

Tully K, Lawrence D. 2010. Declines in leaf litter nitrogen linked to rising temperatures in a wet tropical forest. BIOTROPICA. 42: 526-530.

Goeghegan J, Lawrence D, Schneider L, Tully K2010. Accounting for Carbon in Models of Land Use and Implications for Payments for Environmental Services: An Application to SYPR. Regional Environmental Change. 42: 526-530.

Lawrence D, Radel R, Tully K, Schmook B, Schneider L. 2010 Untangling a global decline in tropical forest resilience: constraints on the sustainability of shifting cultivation. BIOTROPICA. 40: 21-30.

Vandecar K, Lawrence D, Wood TE, Das R, Oberbauer S, Schwendenmann L, Tully K. 2009. Diurnal fluctuations in labile soil phosphorus in response to climatic conditions and soil CO2 efflux in a wet tropical forest, La Selva, Costa Rica.  Ecology. 90: 2547-2555.

Tully K. 2002. Tilting. Kenyon Chapbook Series: Featured work for emerging authors. ISBN: 0-9726005-5-8.