About Us

Krista Jacobsen, PhD

Assistant Professor in the UK Department of Horticulture

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Dr. Jacobsen's research focuses on evaluating effects of sustainable agricultural systems on soil quality and fertility in sustainable and organic farming systems, with an emphasis on soil carbon and nitrogen cycling.  An agroecologist by training, Krista and the members of her lab work from an interdisciplinary, systems perspective. This includes understanding not only the functioning of alternative horticultural systems but also considering the social and economic fabric within which these systems are woven.  For example, we may look at economic, human labor and energy requirements, and prefer to work in systems that are applicable to small-holder, local farmers in the regions we work in.  Current Jacobsen Lab projects include:

  •  Improving our understanding of intensification in organic farming systems affects soil carbon and nitrogen dynamics, nitrogen leaching losses, and greenhouse gas emissions.   

  • Incorporating conservation tillage and cover crops into year-round, organic high tunnel production.

  • Testing new cover crops for high tunnel production in the Southeast.

  • Assessing energy use (energy returned on energy invested) in organic vegetable production systems.

  • Ongoing research comparing movable and stationary high tunnels for year round organic vegetable production.

The bulk of our research is conducted on the University of Kentucky (UK) Organic Farming Unit (UK OFU), a 20-acre USDA Certified Organic research and teaching facility on the UK Horticulture Research Farm in Lexington, KY.  We also work with local farmers throughout the Bluegrass Region and Eastern Kentucky. 

Krista is a native to southwest Iowa, but has called Kentucky home since 2009.  She teaches and advises in UK's Sustainable Agriculture Undergraduate Degree Program.  Her courses include Introduction to Sustainable Agriculture (SAG 101), Plant Production Systems (PLS 386, co-taught with Dr. Mark Williams), Agroecology (SAG 390) and a summer study abroad to Indonesia in Tropical Agroecology and Sustainable Development.

Contact Information:  krista.jacobsen@uky.edu


Current Graduate Students

Debendra Shrestha


Debendra is a PhD candidate at the University of Kentucky.  He completed his Bachelor's degree in 2009 and Master's degree in Horticulture in 2011 from Tribhuwan University, Nepal.  He then worked as an Agriculture Development officer for the government of Nepal at the Department of Agriculture.  He is interested in nutrient cycling, organic vegetable production, highland organic coffee production and utilizing organic waste as a source of plant nutrients.  He is currently working with Dr. Krista Jacobsen on Sustainable Nitrogen and Carbon Cycling on Diversified Horticulture Farms at the University of Kentucky. 

Contact Information: dsh243@g.uky.edu

Ammar Al Zubade

Ammar is a PhD student under the supervision of Dr. Krista Jacobsen in the Department of Horticulture at the University of Kentucky.  He completed his Bachelor degree in 2001 and Masters degree in 2009 from the College of Agriculture, at the University of Baghdad.  While at the University of Baghdad, Ammar studied small grain crop production.  He now studies nitrogen management on grain protein content and the backing characteristic for bread wheat in Kentucky along with exploring the nitrogen application rate for organic wheat production in relation with grain protein content and its yield component. 

Contact:  ammar.alzubade@uky.edu 

Undergraduate Student Workers

Savannah McGuire

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Savannah McGuire is a senior at the University of Kentucky and is studying Sustainable Agriculture. She has been an assistant in the Jacobsen lab since February 2015. She is interested in vegetable production and enjoys field work and being outdoors. She plans to graduate in 2018 and attend graduate school.

Contact Information: sjmc233@g.uky.edu



Ellen Green

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Ellen Green is a recent graduate from fourth year student at the University of Kentucky with a bachelor's degree in sustainable agriculture and in environmental studies. She has been an assistant in the Jacobsen lab since January 2016.  Her research interests include community food systems and environmental ethics.  Ellen plans to continue her research and hopes to study sustainable agriculture in graduate school. 

Contact information: evgr223@g.uky.edu

David Smith

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David Smith is a recent graduate of Asbury College in Wilmore, Kentucky.  As a student, David conducted undergraduate research in the Jacobsen Lab exploring differences between high tunnel and field soils around the state.  David is an avid runner and outdoors man, with broad interests in biology, sustainability, and environmental sciences.  



Michael Hurak

Michael Hurak is a recent graduate from the University of Kentucky having majored in Sustainable Agriculture. Throughout the course of his college career he studied abroad twice; once in Indonesia with Dr. Jacobsen and an intern program with Maejo University in Thailand.  Michael has been an apprentice at the UK Horticulture farm and has worked with several labs in the College of Agriculture, the latest with Dr. Haramoto at Spindletop Farms. Michael is now a research analyst at the University of Virgin Island's Agriculture Experiment Station where he is involved with several research programs including: animal husbandry, agriculture biotech, tropical agriculture, and sustainable agriculture overall. 


Jennifer Taylor


Jennifer Taylor currently serves as the Jacobsen Lab research analyst. She graduated from the University of Kentucky with a bachelor's in environmental studies and in geography. She has worked with the Jacobsen Lab since May 2016. Her research interests include the impact of conservation spaces on human populations as well as the impact of environmental education on marginalized youth. Jennifer is looking to continue her research and intends to pursue a master's degree in public health.

Contact Information: jenniferdai14@gmail.com

Visiting International Students

Jacques Fils Pierre


Jacques Fils Pierre is a Master´s student at the Federal Rural University of Rio de Janeiro (UFRRJ) in Brazil.  He recieved his Bachelor's degree in 2014 from the Autonomous University of Santo Domingo in the Dominican Republic and received a specialization in environmental management in 2016 from the Federal University of Rio de Janeiro in Brazil.  He is currently working with Doctor Nedda G.R. Mizuguchi in creating a profile of the Family farmers in the Rural Areas of Haiti under the leadership of the Federal Rural University of Rio de Janeiro. He is interested in researching sustainable agricultural practices such as organic vegetable crop production and adequate technologies for small scale production.

During the summer for 2017, he worked as a professional intern with Dr. Jacobsen and the University of Kentucky Organic Farming Unit. As a result, he now has goals to attend a PhD program in sustainable agriculture.

Contact Information: jacquesfilspierre@gmail. com

Dea Hagania Laia


Dea participated in an internship at the University of Kentucky under the guidance of Dr. Jacobsen during the summer of 2017. She is from Indonesia and is currently a student at Sebelas Maret University, Surakarta, Central Java and plans to graduate in June of 2018 with a bachelor's degree in agricultural economics. She is a member of the International Association of Students in Agriculture and Related Sciences, an organization for students wanting to advance agriculture in Indonesia. Dea plans to become an agricultural professor, businesswoman, and wants to inspire young people to play a role in agriculture since it is the backbone of the world. She hopes to continue her master's at the University of Kentucky. 

Contact information: deahagania7@gmail.com

Sunda Nurfiani


Sunda is student at the University of Sebelas Maret, Indonesia and is studying in Agribussiness. In the summer for 2017, Sunda was an intern with the Jacobsen Lab in order to develop skills for her future career and gain an understanding of the United States and its agricultural systems. She is the Co Assistant of Practicum Agroclimatology, Agricultural Extension, Statistic, Management of Marketing, Economic Resources of Agriculture and Trainer of Training Achievement Motivation Trainer (TOT AMT), and also a participant in Appreciation Award for Outstanding Students of Agribusiness 2017. Upon graduation, she wants to continue her study in USA and then return to Indonesia where she will apply her knowledge to build an agriculture association to help farmers in Indonesia.

Contact information: sunda_nurfiani@yahoo.com

Graduate Student Alumni

Alex Hessler

Alex successfully defended his thesis entitled Reduced Tillage and Living Mulches in Organic Production Systems in Fall 2013. He is currently employed as the Sustainable Food Systems Director at Virginia Tech University.

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Alex earned a B.S. in Resource Conservation from the University of Montana, Missoula.  His hometown is Chapel Hill, North Carolina, perfectly situated halfway between the outer banks and the Blue Ridge Mountains. Seasonal jobs in the outdoors have been excellent excuses for him to explore the natural history and management of forests and agricultural landscapes.  Alex has worked as an intern at an outdoor survival skills school for children in New Jersey, a wildland firefighter in Idaho, and a forest research technician in Montana.  His interest in sustainable agriculture grew from an internship at N.C. State University’s Center for Environmental Farming Systems, and by working on the student-run farm at the University of Montana.  The year prior to his arrival at UK was spent on an organic vegetable farm in western North Carolina. He is interested in optimizing weed management strategies and conservation tillage practices for organic vegetable production.  He believes that cover crops, prudent cultivation, creative rotations, and an adaptable approach towards tillage are the foundation of sustainable farming systems.  Alex's graduate research with Dr. Krista Jacobsen was focused on the influence of conservation tillage and inter-seeded cover crops, or “living mulches,” on nitrogen mineralization, weed community composition, and soil aggregate stability in organic bell pepper production.  Alex is grateful to have worked beside the students and faculty of UK’s student run organic CSA, and hope to replicate this model for hands-on learning as an educator in the future. 

Kavita Mizin

Kavita successfully defended her thesis in Spring 2014. She is currently employed at the USDA-APHIS Headquarters in Beltsville, MD.

Kavita began her career in Finance after graduating from McGill University with a Bachelor’s in Commerce in 2009.  However, after feeling a pull to get back to her roots, Kavita left her job and took an Agroforestry and Tropical Horticulture internship at the Jama Coaque Reserva in coastal Ecuador.  After returning to the United States in 2011, Kavita worked on a number of certified organic diversified vegetable and livestock operations throughout the North East United States, including her own family business in Pennsylvania, Plant Magic Perennials.  Kavita’s research interests are focused on the downstream effects of agricultural systems, primarily human health and nutrition. 


Vicky Anderson

Vicky successfully defended her thesis entitled Nitrogen Cycling, Plant Growth and Production of Secondary Compounds of Calendula officials in Organic Production Systems in Spring 2013.  Vicky is currently pursuing a PhD in natural products chemistry at the University of Oklahoma. 

Vicky Anderson is from Silver Spring Maryland.  She graduated from Hood College in 2007, double majoring in chemistry and archaeology.  After graduating she worked for several years as a science assistant in the Directorate for Education and Human Resources at the National Science Foundation (EHR-NSF).  Vicky is pursuing a masters degree in plant a soil science in the horticulture department.  Her research is focusing in part on organic nutrition in a greenhouse setting, using medicinal herb and ornamental flower Calendula officinalis as a model species.  The other aspect of her research examines the effects of nutrition on the medical properties of Calendula officinalis.   

Rebecca Shelton

Rebecca Shelton successfully defended her MS thesis, Investigating nitrogen dynamics and loss in conventionally and organically managed conservation agriculture systems with wheat and hairy vetch cover crops, in 2015.  She is currently pursuing a PhD in Sustainability at Arizona State University.

Rebecca Shelton completed her undergraduate work at Furman University and received her B.S. in Earth and Environmental Science with a biology concentration.  Originally from Kentucky, she returned to UK in order to pursue a masters degree in July 2013.

Her research interests lie within the realm of agroecology and natural resource management.  Specifically, she is interested in agriculture’s impact on climate and the environment, small-scale farm efficiency, and quantification of ecosystem services.  She is working with both the McCulley lab and the Jacobsen lab to study plant available nitrogen produced by leguminous cover crops and trace gas emissions in a reduced till, cover cropped system. 

staff Alumni

Alexandra Williams

Alexandra Williams

Alexandra Williams

Alex Williams served as the research analyst for the is a trained weed scientist for the control of vegetation on golf courses, home lawns, landscapes, and plant nurseries.  She received her PhD in Crop Science from the University of Kentucky where she researched Poa annua biotypes on golf course putting greens and their differential responses to commonly used herbicides and plant growth regulators.   Alex completed her MS in Horticulture from the University of Georgia. Currently, she is an environmental fate scientist at Syngenta. 

Contact Information: alexandra.p.williams@gmail.com

Brett Wolff

Brett Wolff managed the daily activities of the Jacobsen Lab from September 2012 until May 2015.  He now works in the Cooperative Extension Service as a Senior Extension Associate with the Center for Crop Diversification and Kentucky SARE Program. 

Contact Information: brett.wolff@uky.edu




Aaron Stancombe

Aaron Stancombe served as the High Tunnel Manager for the Jacobsen Lab from January 2013 until April 2015.  He is now the co-owner and operator of Bellaire Blooms- a cut flower business specializing in local, sustainably grown cut flowers.  You can read more about their farm and their flower CSA here