I am a colossal soil nerd; I try to learn as much about soil as possible. However, most of my knowledge comes from a classroom setting, which, frankly, is not the most effective way to learn about soils. Soils are best observed with our senses: sight, touch, and smell. Thanks to my internship at the Agroecology Lab at the University of Maryland, I have been able to apply my classroom knowledge—and passion—to real-world problems. One of these problems involves understanding the consequences of saltwater intrusion on coastal farmlands.
Upon starting my internship, I was completely unaware of saltwater intrusion. I broadly understood that climate change affected food systems through rising sea levels, droughts, and storms. I had not considered how these consequences cause salt from the ocean to seep into agricultural soils, damaging crops. Average yields for critical crops can decrease as much as 50% as a result of sea level rise, droughts, and storms (Shrivastava and Kumar 2015). Rising sea levels brings salt directly into freshwater systems, heavy coastal storms can carry salt from the ocean inland, and droughts can cause salt to accumulate in the soil.
It is crucial to note that climate change is not the only way salt from coastal systems is intruding inland. Extracting freshwater from the ground and existing water control infrastructures, such as canals and ditches, can carry saltwater to inland soils (Tully et al. 2019). Studying agricultural ditches and canals will improve our ability to adapt coastal agricultural lands to rising sea levels and storm surges associated with climate change.
As I've become more familiar with the issues affecting our soils on the Eastern Shore, I have also learned some critical laboratory skills that I did not know before. I had the opportunity to join the lab in the field to collect soil samples, and I process soil samples in the lab with my mentor, Silver. I believe that I am growing as a scientist from working in the Agroecology lab, and I deeply enjoy working with the Agroecology Team. They understand the value of soil, and they know that our lives depend on understanding and protecting it from assault.
Shrivastava, P., & Kumar, R. (2015). Soil salinity: A serious environmental issue and plant growth promoting bacteria as one of the tools for its alleviation. Saudi journal of biological sciences, 22(2), 123–131. https://doi.org/10.1016/j.sjbs.2014.12.001.
Tully, K., Gedan, K., Epanchin-Niell, R., Strong, A., Bernhardt, E. S., BenDor, T., ... & Weston, N. B. (2019). The invisible flood: The chemistry, ecology, and social implications of coastal saltwater intrusion. BioScience, 69(5), 368-378.
- By Mary Gumerov
Saltwater intrusion can be devastating, not just to farmers but to the environment, native species, and ultimately the economy. There are both natural and unnatural factors that drive saltwater intrusion. The five main factors include sea-level, storms and tides, drought, water usage, and hydrologic connectivity . The devastating effects of salinization of farmland due to these factors may include coastal forest loss, salt-tolerant species invasion, decline in crop yields, eutrophication, and marsh migration . While one may think that heavy rainfall and sea-level rise would cause the most rapid salinization of agricultural systems, it is actually drought. Although Maryland’s recorded rainfall this year, 2020, is relatively normal, December 2016 – January 2018 experienced significantly decreased rainfall and even emergency drought conditions in central parts of the state . During a drought, rivers, streams, and other bodies of water become more concentrated with salt, thus allowing nutrient leaching [of fields] to occur at a greater rate. Additionally, the highly concentrated salt affects the ion exchange rate, for example, dehydrated sodium is a powerful positively charged ion, or cation, affected by this change . Legacy nutrients are nutrients that have built up in the soil over time. Soil, particularly clay soil, can hold onto these nutrients via ionic bonds. While these nutrients are not immediately bio-available to crops currently growing, if leached and subsequently washed away these nutrients contribute largely to algae blooms and eutrophication in bodies of water. Yet, with a more attractive, stronger ion (salt), now in the soil, the soil particles may bind to the salt, effectively unbinding from the legacy nutrients (usually nitrogen [N] and phosphorous, [P]). While unbound, the legacy nutrients can be more easily washed away and removed entirely from the field.
There are many methods for evaluation of the level of saltwater intrusion into a farm system. The Tully Laboratory often measures concentrations of different nutrients using extractions. One nutrient often measured is phosphorous. I have been assisting in making the solutions necessary for sequential P extraction in soils, including sodium bicarbonate, sodium hydroxide, and hydrochloric acid. Each sequential extraction (using a different solution) extracts a different form of phosphate found in the soils. Lastly, the P samples are analyzed using the LACHAT (a type of spectrometer) for colorimetric analysis. However, some samples are too acidic, creating bubbles in the tubing of the LACHAT, resulting in a poor curve. This can also be true for a very basic solution. Early in the semester, I assisted in adjusting a very basic (pH 13) extraction to a lower basicity (pH 8) to fix this dilemma.
 Tully, K., Gedan, K., Epanchin-Niell, R., Strong, A., & Bernhardt, E. S. (May, 2019). The Invisible Flood: The Chemistry, Ecology, and Social Implications of Coastal Saltwater Intrusion. Bioscience, 69(5), 368-378. doi:10.1093/biosci/biz027
 Maryland Department of the Environment. (2020, September). Maryland's Drought Status: Current Conditions. Retrieved from https://mde.maryland.gov/programs/water/droughtinformation/currentconditions/Pages/index.aspx
 Tully, K. L., & Weissman, D. S. (February, 2020). Saltwater intrusion affects nutrient concentrations in soil porewater and surface waters of coastal habitats. The Ecological Society of America, 11(2). doi:10.1002/ecs2.3041
- By Madison Curtis
On Thursday, 29 October 2020, Resham Thapa successfully defended his PhD on decomposition and nitrogen release from cover crops. He produced an amazing body of work while in the Agroecology lab, including two publications not related to his dissertation! We are thrilled that Dr. Thapa is staying on to do a postdoc with us and remain a part of the Precision Sustainable Ag team! CONGRATS, DR. THAPA!
The AgroEcoLab's research was highlighted in a recent Local Motives video that focuses on saltwater intrusion.
Check out an interview with Kate on Stem to the Sky. She talks about agroecology, work-life-balance, and a day in the life of a professor.
I applied for my position at University of Maryland from the guest house at the Kanisa Anglikana Tanzania (Anglican Church of Tanzania). I am not a religious person, but it was inexpensive compared to the one hotel in town where all the wealthy game hunters would stop over for a night. I much preferred learning how to make chapatti from the nuns than listening to the drunken banter of someone who just shot a zebra for sport. My house had spotty power, no internet, and no hot water. The day before the application was due, the power to the entire town was cut off and I had to ride my bike to my friend Rashid's family store. Where I sat atop a pile of bursting bags of sugar and hooked up my dying laptop to the generator as I tried to submit my application. There was no time for last minute edits and agonizing. It was submit now or never.
Joining the faculty in a Plant Science Department felt odd. I am an agroecologist, soil scientist, and biogeochemist. I still don't claim the "plant hat." But, I feel like I have made a home for myself at Maryland in the College of Agriculture and Natural Resources. I have the best students a professor could hope for. I love teaching undergraduates as much as I love mentoring my graduate students.
The journey to tenure has not been easy, just like grad school wasn't easy. Being a woman in science isn't easy period. I am fortunate to have wonderful colleagues (who I now call friends), brilliant students (who are now becoming colleagues), and a host of cheerleaders outside of academia who kept me sane throughout this process.
It is an especially difficult time to be pre-tenure with the looming budget cuts across Universities as COVID-19 strips their rainy day funds and fall enrollments plummet. It is also an incredible time to be an educator. For the first time, my single voice is being echoed by the administration - we can't talk about food systems without talking about food justice. We can't talk about food justice without talking about racist policies.
I have the luxury of being on the other side of the tenure line, which means I can speak out. I can amplify voices that need to be heard. I can help change racist policies within the University system. We educators have a duty to have uncomfortable conversations with others and with ourselves. Hell, isn't that what learning is all about? Turns out we are wrong a LOT of the time. But as long as we do something about it, as long as we try to correct it, understand it, we will end up better off than when we started. Some people say, "Ah, now you have tenure, you can take a deep breath and relax." Rather, I like to think of it as, now I have tenure, I can take a deep breath and start speaking loudly.
- By Kate Tully
In the United States, health is often defined by deficiency and lack rather than vigor and abundance — and rightfully so. The World Cancer Research Fund found that, in 2018, the United States had the fifth highest rates of cancer worldwide. Additionally, a report in the International Journal of Cardiology found that the U.S. has the highest rates of heart disease among “High Income Countries”. It is likely that you know at least one person with cancer, heart disease, and/or other chronic illnesses. Suffice it to say that Americans are not the healthiest bunch.
While we may not be able to immediately control several of the factors that contribute to the ubiquity of chronic illness — genetics, medical racism, environmental hazards, etc — there are many factors that we can, and therefore ought to, control. And for some, the food they purchase is something they can control. One responsible way to boost personal health is to maintain (safe) participation in farmers’ markets, CSAs, urban agriculture projects, and other alternative foodways. In doing so, you also support local agricultural systems, farmers, and overall community health.
It is important to acknowledge that the ability to choose the source and quality of one’s food is a privilege. Due to historic and structural systems of oppression, including wealth inequity, racism, and the heteronormative patriarchy, access to environmentally, socially, and culturally sustainable food systems is not equally afforded to every person and community. Therefore, those who have the ability to participate in holistically sustainable and just food systems have the responsibility to do so.
- By Dylan Fishbein
On 4 Apr 2020, Dani Weissman successfully defended her dissertation, earning the title, Dr. Weissman!! I couldn't be more proud of her. Mentoring her was a joy and I am so happy that she will be sticking around the lab for a while and continuing to work on conservation efforts in the Chesapeake Bay Region.
- By Kate Tully
AgroEcoLab alumna, Elizabeth de la Reguera, published a great blog post about saltwater intrusion for Sustainable, Secure Food Blog. Check it out!
A collaboration between the AgroEcoLab and the Northeast Climate Hub resulted in a newly published factsheet! Check it out here.