College of Agriculture & Natural Resources
Environmental Science & Technology

Soil Quality Lab

Soil Quality Lab

The Soil Quality lab under the leadership of Professor Ray Weil studies physical, chemical and biological aspects of Soil Quality and Health as related to Management of Soil Organic Carbon, Nutrient Cycling and Water Quality, and Sustainable Farming Systems. 
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 is known for developing a practical test for easily oxidized, microbially active carbon as part of soil organic matter. Our lab’s permanganate oxidizable carbon test (termed POXC in the scientific literature) is now used by researchers worldwide as a leading indication of soil health and carbon dynamics in a wide range of soils. 
The lab’s nutrient cycling work is focused efficient use of N, P and S in various agroecosystems, including intensively grazed pastures, tropical smallholder farms, and high yield conservation grain production systems. Our work on sulfur fertility has shown that optimizing the supply of this of-neglected essential nutrient can dramatically improve the nutritional quality of legume proteins as well as yields. Our work on nitrogen has revealed large pools of mineral N that remain deep in the soil after summer crop growth. Stable isotope tracer work has shown that this nitrogen can be captured by deep rooted vegetation.
Additionally, the lab is investigating multiple soil, economic and environmental benefits derived from innovative cover crop systems. This work introduced the daikon type radish as a cover crop to North American farmers, including the “Tillage Radish” brand developed by Steve Groff, a collaborating farmer-entrepreneur in Pennsylvania. 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. Our recent work has demonstrated the importance of establishing mixed-species cover crop early in the late summer or fall, generally even before harvest of summer cash crops. Similarly, the  lab is researching how to achieve the benefits of allowing cover crops to grow longer in spring, sometimes even beyond the planting of summer cash crops (a practice known as “planting green”). 
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 is doing pioneering research on the use of portable X-ray fluorescence to analyze plant tissue for nutrient element content. 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 was a senior adjunct research scientist, and now with the University of Florida. This system has been deployed in many tropical countries that lack a well-developed soil testing lab infrastructure.

Research Group

Matt Bright

Matt is postdoctoral research associate. He spent much of his childhood playing in the Maryland woods, and the experience helped spawn an early career choice to conduct soils research in some of the same forests he grew up in. Specifically, he studies the chemical and physical properties of forest soils in the eleven National Park Service units of the National Capital Region Network (Washington, D.C. metropolitan area). The overall goal is to examine forest soil health in the region, and this project is part of the larger national Inventory and Monitoring Program: an NPS directive to improve park management using scientific data about the state of park natural resources. Matt's doctoral research focused on the agroforestry potential of native shrubs to improve food security in the West African Sahel. He lived in Senegal for a year and a half while examining the long-term yield and soil quality effects of planting pearl millet and groundnuts next to shrubs at high densities. He also studied the diversity, beneficial water and nutrient effects that arbuscular mycorrhizal fungi provide to pearl millet growing within the rooting zone of this shrub. This research was aimed at developing effective and sustainable agricultural systems in the Sahel. Long ago as an undergraduate, Matt spent a semester investigating the effect of brassica crops on carbon and nutrient dynamics in nursery soils used for tree propagation as part of Dr. Ray Weil's lab. As part of his post doc duties, Dr. Bright is also teaching ENST 200 - Fundamentals of Soil Science – in spring semesters and managing the associated lab sections. Matt says he is “very excited to be back at his alma mater working with friends and colleagues!”

Nathan Sedghi

Nathan is a Ph.D. student and lead graduate student on a collaboration with Mid-Shore River Keepers to research ways to keep rivers clean and farmers in the watersheds profitable at the same time. He came to us after earning a MS degree at Old Dominion University in Norfolk, Virginia working on wetland hydrology. Soil is one of the most important factors connecting a community. As such, it plays an integral role in biogeochemical cycling, nutrient storage, and greenhouse gas sequestration; all of which are fundamental research interests of mine. As humans, agriculture is our most important use of soil as a natural resource. In an agricultural setting, all of my research interests in soil are tied together, and research to improve agriculture in a sustainable way improves peoples' lives. My dissertation project involves extending the growing time of a winter cover crop mixture, and observing the effect this has on nutrient cycling; it's expected that this research will allow farmers to save on fertilizer costs while also reducing nitrogen pollution lost to the watershed. By working on this project, I hope to contribute to the body of knowledge encouraging farmers to participate in sustainable practices, thus helping to protect our valuable natural resources.

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.
Daniel Colopietro

Daniel is a Masters student and no stranger to the Weil lab. He graduated from the University of Maryland, College Park with a B.S in environmental science and technology, concentrating in soil science with a minor in hydrology. As an undergraduate he worked under Weil on his capstone project studying nitrogen leaching in the porewater under different crop species and mixtures of cover crops species.  He also worked in the Weil lab as an intern two summers surveying soil quality on a project with the National Park Service to characterize soils in National Capital Region forested Park sites. He is currently conducting research with the National Park Service, Inventory & Monitoring Program, evaluating soil carbon concentrations, stocks and depth distributions at forested park sites in the Mid-Atlantic Region.

Dana Rushovich

Dana is a graduate student pursuing a Master's degree. After graduating from the ENSP department at UMD in 2013 she spent five seasons working on diversified vegetable farms in both urban and rural settings. During the time spent on farm she noticed missed opportunities for farmers to integrate soil building crops into their rotations. She also developed an interest in the potential viability of using these missed opportunities to incorporate staple crops into vegetable rotations and capitalize on their benefits to soil health as well as growing marketability. These experiences and interests led her to pursue a Master's degree. She is working on crop rotations for small and medium scale organic vegetable producers that integrates a high biomass specialty summer grain crop (food grade grain sorghum) with cool season vegetable crops (brassicas, spinach, lettuce, peas, etc.).  Her goal is to improve soil health stressed by high tillage/low residue vegetable crops and add a new source of income and diversity to farms.

Harry Huntly

Harry is an undergraduate research assistant working on nutrient and soil quality management with cover crop systems. “I've been fascinated by plants and agriculture for years, and while I knew that soil was important to it, I had no idea just how much there was to learn until I took an introductory class with Dr. Weil. With such an interesting topic, I had to educate myself more, and I wanted to be on the cutting edge of research. As someone who is also studying economics, I am interested in the private and social costs of improving and destroying soil to increase crop yields in hopes of finding an equilibrium that is economically viable and environmentally sustainable for farmers around the world.”

Ian Goralczyk

Ian is an undergraduate research assistant working on cover crop research and is a senior chemistry major at the University of Maryland, College Park. His duties include collecting and documenting data on soil, pore water, biomass, and greenhouse gas samples from local research fields and assisting in Gas Chromatography analysis of gaseous samples at USDA facilities. He has also been involved in the authoring process of research magazine articles on behalf of the lab to describe research results and implications from cover crop experiments. He is hoping to work in science education, environmental science, or in chemical industry after graduation, and he is also involved with the American Ecological Engineering Society at UMD. "As a native to Maryland, studying local environment is something very rewarding and interesting and I hope to use my work within the lab to continue to contribute to positive scientific discovery and enhance my understanding of ecological practices in agriculture."

Mia Godbey

Mia is an undergraduate Environmental Science and Technology major with a focus in the Natural Resources Management concentration and a minor in Sustainability. She feels she has learned many skills in her time working in the Weil lab. She is now expert at collecting and preserving soil leaching water samples from field suction lysimeters, as well as collecting greenhouse gas samples from field sampling chambers. She also helps in collecting soil samples, and in organizing data and spreadsheets online. Her early involvement at Anita C. Leight Estuary Center as both a camper, and later, a camp counselor, sparked her passion in pursing an environmental science degree. “I basically spent my childhood outside, either exploring the creek that winds through my neighborhood, or searching for snakes, turtles, and frogs at camp. Spending many summers in one of the few remaining freshwater tidal marshes in the upper Chesapeake Bay has revealed the importance of reducing nutrient and chemical flow into the watershed. This research is vital as a way to educate farmers the benefits on longer cover crop growing times so that they can reduce their use of fertilizers.” Excited about her recent promotion to undergraduate lab manager for cover crop research, Mia is eager to take on more responsibility and be involved in more sophisticated analytical instrumentation such as our Lachat® auto analyzer. She hopes that this research will lead to more sustainable agricultural practices in our effort to protect our Earth.

Hanson Liao

Hanson is an ENST undergraduate research assistant studying Ecological and Technological design and has focused mainly on water quality and ecosystem restoration. Growing up in rural Maryland, he often spent his days exploring the forest, collecting fish and tadpoles, and building dams and bridges. Hanson truly discovered his passion for the environment after interning with the Chesapeake Bay Foundation, where he learned about the crucial role of wetlands in the Chesapeake's ecosystem. Later on, he worked with the Anacostia Watershed Society on wetland restoration, nutrient capturing, and awareness of DC's extensive watershed. At the University of Maryland, he was able to work with both Dr. Needleman at UMD on nitrate capturing through cover crops, and Dr. Zuckerman with analyzing the rate of tree transpiration through seasons and weather in upper Baltimore. In Dr. Weil's lab, Hanson works on both sulfur fertility and cover crop projects. He helps with collecting and preparing soil samples, implementing soil extraction procedures and in x-ray fluorescence scanning to analyze the chemical composition of soil and plant samples. At field experimental sites he helps harvest and prepare plant biomass for analysis and uses suction lysimeters to obtain samples of leaching water. Looking ahead, Hanson hopes to further his education at the University of Maryland in not only ecosystem restoration but also sustainable architecture, ultimately bringing mankind and the natural world one step closer back to harmony.

Maggie Psurek

Maggie is an undergraduate research assistant majoring in Chemistry and hoping to minor in Sustainability and/or Soil Science. She first discovered her interest in sustainability on a trip with the Chesapeake Bay Foundation in 6th grade. Since then she continued to develop her passion for environmental research by interning at the National Institute of Standards and Technology, as well as writing about the Chesapeake Bay for her high school senior paper. In the Soil Quality Lab she works mainly on a project that aims to enhance legume protein by managing sulfur fertility. She prepares soil extractions for test for available sulfur and has been trained and certified to use x-ray fluorescence to analyze elements in plant tissue. Additionally, she helps collect soil and plant samples in the field. Maggie is enthusiastic about learning and working on research that addresses real-world issues.

Karla Rosales Lobos

Karla is an undergraduate research assistant working on a project to enhance the protein nutritional quality of grain legumes by managing sulfur fertility. Although the project at first worked exclusively with soybeans, Karla’s family history with Central American farming inspired Dr. Weil to expand the sulfur and protein project to black beans, which are more commonly eaten directly by people.  Karla first developed her passion for sustainability and nature with the work she did with the Chesapeake Bay Foundation. She has also done volunteer work to restore environments and help control invasive species around Maryland. 

Melissa Stefan

Melissa is an undergrad research assistant in her senior year in the ENST Department’s Soil and Watershed Science major. In the Soil Quality Lab, she is assiting with a research project aiming to measure the ability of sulfur fertilization to maximize growth and protein quality in various grain legumes important in human and animal diets. She previously worked with Dr. Weil on her ENST Capstone research project focused on the effect of cover crop planting date on N cycling. Also, she has interned at the Harry R. Hughes Center for Agroecology where she produced an agricultural leasing guide for farmers and landowners seeking to adopt new farming practices in their operation. She has a B.S. in nutritional science and hopes to pair that skill set with a B.S. in environmental science in order to pursue research opportunities related to achieving global food security in a changing climate. She has a specific interest in studying issues related to sustainable agriculture in East Asia and will be pursuing Master’s degree programs focused in that area upon graduation.

Lab Alumni

Natalie Agee 

Allen Burke 

Daniel Colopietro 

Keri Grant

Alexandra Kramer 

Rachel Patterson 

Shelley Porter 

Philip Schwartz 

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