College of Agriculture & Natural Resources
Environmental Science & Technology

Soil Quality Lab


The Soil Quality lab under the leadership of Professor Ray Weil studies physical, chemical and biological aspects of Soil Quality as related to Management of Soil Organic Carbon, Nutrient Cycling and Water Quality, and Sustainable Farming Systems. The lab has developed a practical test for active carbon in soil organic matter –permanganate oxidizable carbon, or POXC - now used by researchers worldwide as a quick indication of soil quality and carbon dynamics under in a wide range of soils. The lab probes fundamental relationships among soil organic matter fractions and soil ecological functions and is contributing to our understanding of the active fraction of soil organic matter. The lab’s nutrient cycling work is focused efficient use of N, P and S in systems, including intensively grazed pastures, tropical small holder farms, and high yield conservation systems in North America. Additionally, the lab is investigating multiple soil, economic and environmental benefits derived from innovative cover crop systems. This work introduced the radish as a cover crop to North American farmers, including the “Tillage Radish” brand developed by a collaborating farmer /entrepreneur in Pennsylvania, Steve Groff. The lab’s cover crop work has had a wide impact, demonstrating, among other benefits, the compaction-alleviation capacity of the radish and other brassica cover crop roots. The Soil Quality lab is fully equipped for a wide range of soil and plant analyses, as well as field studies such as those requiring deep soil cores, continuous soil monitoring, or root images via mini-rhizotron. The lab has also developed field-ready on-the-spot analyses for a number of important soil quality parameters. These have been incorporated into a system of soil analysis called SoilDoc in collaboration with the AgCenter at Columbia University’s Earth Institute where Ray is a senior adjunct research scientist. This systems has been deployed in many tropical countries with less developed lab infrastructure.

Research Group


Sarah is a Ph.D. student.  The principle goal of her PhD dissertation research at University of Maryland is to investigate and implement cover cropping systems that can capture deep soil nitrogen (N) and release it for subsequent crops rather than allow its loss to eutrophication-sensitive waters, while at the same time saving farmers money (e.g., fertilizer costs).  By deep soil N we mean N entrained in the soil profile between 50 and 210 cm deep –deeper than usually investigated.  In the mid-Atlantic, USA, where the winter “off-season” spans seven months (October- April), pools of N found deep in the soil profile will likely leach over the winter beyond the rooting range of subsequent crops. We are investigating various cover crop species within three functional groups—brassica (forage radish), winter cereal (e.g., rye, triticale, oats, wheat), and legume (Crimson clover)—planted in monoculture and in mixtures. We are using heavy-isotope 15-N to track the movement of deep soil N in soil, cover crops, and subsequent corn. We are also testing various species and planting methods (e.g., aerial seeding, interseeding, and irrigation). Sarah is collaborating with farmers and extension agents throughout Maryland and Pennsylvania. The interest and response among farmers has been outstanding and we have performed 24 on-farm cover crop trials during  two years.

“My education and experiences have convinced me that there does not have to be a conflict between agricultural production and environmental quality. I aspire to continue researching ways to have productive, profitable agriculture and yet conserve soil, water, and biodiversity. I enjoy working with diverse communities and farmers. I am passionate about studying agriculture because I see it as a meeting point where the environment is intricately connected to society.”

  • B.S.: May 2009. Grove City College, Grove City, PA.  Majors in Biology and Psychology
  • M.S.: May 2012, Iowa State University, in Sustainable Agriculture and Ecology & Evolutionary Biology
  • Ph.D.: Begun August, 2014. Environmental Science and Technology: Soils and Watershed Science.


Stan is a MSc student in Soil Science from Lilongwe University of Agriculture and Natural Resources in Malawi. He is also a Borlaug Leadership Enhancement in Agriculture Program (LEAP) Fellow  and is working in the Weil lab at UMD  to further sharpen his research skills and broaden his perspectives. He is taking learning about experimental design, sustainable farming at the large mechanized as well as small hand powered scales. He is also taking soil samples, processing foliar samples and conducting chemical analysis for nutrient content. When Stan returns to Malawi, he plans to work in training farmers in conservation agriculture, and planting systems.


Natalie Agee is an undergraduate research assitant and junior in Environmental Science and Technology ay UMd concentrating in Soil Science and Watershed Management.  Currently, she is assisting on a project measuring cover crop efficiency as it relates to nitrogen conservation. With this background, Natalie is interested in studying and working towards a solution regarding food insecurity in urban settings. In addition to working on research, Natalie is earning a minor in Sustainability Studies, is an Ag Discovery Mentor during the summer, volunteers as a student representative for college of Agriculture and Natural Resources, and is a member of the UMD Soil Judging Team. After graduation, Natalie aspires to join the Peace Corps and continue her education in the Masters International Program studying urban sustainable agriculture and agroforestry. Natalie enjoys being “able to apply my academic course work to real-world applications by studying nutrient interaction between soil and plants”.


Allen Burke is an undergrad research assistant. He is a Soils and Watershed Science major planning to graduate in Spring 2017. He collects field soil cores and plant biomass samples, and then back in the lab he weighs, dries, and extracts soils for the deep nitrogen study. He also works on research on Soybean Sulfur Fertility. He hopes “to use the knowledge and experience I gain from these jobs to have a successful career in figuring out ways to make agriculture more efficient and sustainable.”


Dan is an undergraduate research assistant concentrating in Soil and Watershed Science with a minor in Hydrology. He is conducting research that the Weil labis conducting with the National Park Service, Inventory & Monitoring Program. He is surveying soil quality at national park sites in the Mid-Atlantic Region. He also worked on a Capstone team advised by Professor Weil studying nitrogen leaching in the porewater under different crop species and mixtures of cover crops species. Once he completes his undergraduate studies he plan to enroll in the graduate program for soil and watershed science at the University of Maryland, College Park.


Keri is a Junior Plant Science major at the University of Maryland. She is currently assisting in the Weil lab on a research project to determine how cover crops interact with deep nitrogen. Her duties include soil core and biomass sample collection, as well as sample processing. In the plant Science Dept. she previously worked research involving blueberry breeding. In the future, Keri hopes to continue researching new, more efficient and environmentally friendly ways to grow crops, and “eventually, settle down into a small greenhouse with a good book, WWOOF, or simply take time to travel the world.”


Alexandra Kramer is an undergraduate research assistant, working in both the lab and in the field. She has worked primarily on research investigating multi-purpose cover crops, and will continue to work full time on the project over the summer of 2016. She is an Environmental Science and Policy major with a concentration in geoscience and restoration. Beginning in April, she will began her year term as an Undergraduate Student Representative for the College of Computer, Mathematical, and Natural Sciences (CMNS) on the 2016-2017 University Senate. She was also the winner of the 2014-2015 Green Scholarship in Environmental Science and Policy from CMNS. After graduation from the University of Maryland, Alexandra hopes to work in the Peace Corps before attending graduate school for Environmental Science.  


Rachel is an undergraduate Plant Science major and undergraduate research assistant in the Weil lab working on sulfur (S) fertility for soybeans with a focus on the contribution of sulfur content to protein quality and crop nutrition. She has previously worked on genetic diversity and developmental mechanisms of diploid strawberry. Through these experiences and her continued work with the Sustainable Agriculture Research and Education program,

She is interested in gaining experience in both research and outreach aspects of sustainable agriculture so that, after she graduates, she can be part of a successful research base in support of more ecologically-motivated and productive agriculture.


Shelley is a Soil and Watershed Science major in the Dept. of Environmental Science and Techology. She is also a member of the U of MD soil judging team. She works as a research assistant in the Soil Quality Lab assisting with reseaech on cover crop systems and deep nitrogen. Her primary duties involve collecting biomass and taking deep soil soil cores from research sites and from on-farm experiments with commercial farmers. She is expert at preparing samples for carbon and nitrogen analysis. She is excited to also be a summer interning with the National Park Service Inventory and Monitoring Program.  Shelley hopes to use her research and internship experience to begin a career in soil conservation after graduating in May 2017.


Philip Schwartz is anundergraduate research assitant. H was raised in Kensington Maryland and is a Environmental Science and Technology major at the University of Maryland. He enjoy taking the deep soil cores in the field and visiting the various farms across the region. He also does a lot of soil processing in the lab. He is interested in soil conservation and hopes to join the Peace Corps after graduating with theBS degree


Albert is an undergraduate student pursuing a Bachelor's Degree in Environmental Science with a concentration in Soil and Watershed Science. He has completed his Associate Degrees in Environmental Science, Biology, and Mathematics from Cecil College. As a research assistant, he contributes towards the extraction and processing of soil and biomass samples. He is supporting research projects investigating the efficiency of various cover crops, namely clover, radish, and rye/triticale, in retaining nitrogen in the soil; thus limiting the need for chemical fertilizers. He has a passion for the outdoors and has extensive experience working in the field. Upon graduation, he plans to join the Peace Corps, WWOOF, or simply take time to travel the world.

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