Soil is life – let’s keep it healthy! Reflections from an undergrad researcher

Each summer the KBS LTER supports students to participate in the Research Experiences for Undergraduates (REU) program, funded by the National Science Foundation. This is part of a larger undergraduate research program at KBS. Alessandra Zuniga, a senior at New Mexico State University, writes about her REU experience working with KBS LTER scientists Christine Sprunger and Brendan O’Neill.

Coming from the hot arid deserts of the southwest, I never expected to find myself in the middle of lush green Michigan. I was born and raised in the city of Las Cruces, New Mexico and had the privilege to attend college there as well. I am now a fifth year senior graduating this December with a bachelor’s degree in biology from New Mexico State University. With all the pressures that came with graduating, I felt the need to jump into a new and different experience in hopes that it would shine some light in a good direction. So I began my search for a summer internship where I could improve my lab skills and also experience working in the field. My college mentor emailed me some possible internships that she thought would be of interest. Reading over the Kellogg Biological Station (KBS) Research Experience for Undergraduates (REU) application and some of the great projects I could be a part of, I was quickly drawn in by the beautiful location and the prestige of their published work.

KBS LTER REU Alee Zuniga using a penetrometer to measure soil compaction in an alfalfa plot in the KBS LTER experiment.

KBS LTER REU Alee Zuniga taking soil samples in an alfalfa plot on the KBS LTER experiment.

My first day at KBS, part of Michigan State University, was May 31st, 2014. I was cordially welcomed by other incoming students and quickly felt at home. I was placed with not only one but two amazing mentors, Brendan O’Neill and Christine Sprunger, who have taken me by the hand making the journey more enjoyable and less nerve-wracking. Despite the fact that they were grad students intensely working on their dissertations, they were very attentive about my interests. They had great plans for me working as their REU with the KBS Long-term Ecological Research (LTER) program that investigates the ecology of row crop agriculture. I began my research just a few weeks after arriving at KBS. My mentors helped me brainstorm some project ideas that would parallel their current research and we quickly began the data collecting process.

My research looks at soil health characteristics such as carbon and nitrogen measures across a variety of different treatments. We sampled soils from the KBS LTER including Alfalfa and Early Successional treatments and the Resource Gradient Experiment. The Resource Gradient Experiment consists of nine different fertilizer (nitrogen) treatments that range from small amounts to large amounts applied to a corn crop. Some of our sample collection also required extensive traveling across the state of Michigan from county to county conducting short interviews with farmers about their field quality and taking soil samples of their fields. These soils were taken back to the lab and run under different protocols to gather information on the soil quality. The goal was to test one of their high yielding fields and a low yielding field and observe whether our soil health measures can demonstrate significant differences between the two.

One of the soil indicators that we were interested in investigating was Potentially Mineralizable Nitrogen (PMN) that can give us the amount of available nitrogen in the soil that is ready for plants to take up. The two forms available for plants are ammonium and nitrate which can be extracted from the soil using a potassium chloride solution and controlled under anaerobic conditions. These PMN values are important to understand how much nitrogen can be efficiently used by plants and how much is going through nitrification or released as harmful greenhouse gases to the atmosphere.

The fundamental idea is to try to reduce the amount of nitrogen applied to fields without hurting crop productivity. Excess use of fertilizer (nitrogen) can lead to higher emissions of nitrous oxide, a major greenhouse gas caused prominently by agricultural activity. Another issue is that nitrogen that is not consumed by plants can immediately undergo a process of nitrification that converts that available ammonium into nitrate. Nitrate can be harmful because it is easily transported through rivers and channels to surrounding ecosystems. These copious amounts of nitrate that go to runoff and travel downstream create hypoxic zones, which limit the oxygen in the water disturbing the ecological balance of aquatic systems.

Another important indicator we wanted to study was carbon mineralization. This method determines the production of carbon dioxide from microbial activity on soils of different treatments. Soil microbes are responsible for decomposition of litter and breaking down carbon that will be available for plants. Therefore, soils that have a higher carbon dioxide flux tend to be richer in microbial communities and higher in carbon with better aggregate stability. These carbon dioxide flux rates reveal the soil fertility and how well the field has been managed as well as how productive it can be for farming. We can then inform farmers on what they might need to improve on to promote soil health such as putting in a cover crop, reducing tillage, implementing practices that store more carbon, and many other methods. Ultimately, understanding carbon and nitrogen cycling in soils is critical when looking at soil health and the environmental footprint of cropping systems.

Getting out of the classroom and being able to work in the field and lab allowed me to understand the importance of not only collecting and analyzing data, but also being able to communicate our findings in an understandable way that can spread awareness of current environmental issues. I realized a deeper importance of soil management and the influence that discoveries can make, leading to more sustainable agricultural practices. This summer was a great stepping stone for me, and I am hoping to continue on this track and become thoroughly involved in soil science in my graduate studies.

Not only did this REU position provide me with a solid research background, it also led me to making unforgettable memories with fascinating people who had similar interests and scholarly goals. The great thing about planning weekend activities with all the KBS students was that it made a great balance between my research and social life. And by the end of the summer I was able to make friendships that will last a lifetime.

This summer was an experience beyond my expectations for a research program. I was extremely fortunate to be part of an elite group of scientists that was so gracious and eager to share fascinating knowledge and expertise with me. I came into this position not knowing what to expect but it made me open minded and willing to learn everything that intercepted my learning path. I got to absorb myself in the critical conservation that is important in today’s changing world. I have come a long way over the course of these two months. I have grown a tremendous amount intellectually and have realized my true potential in the sciences.

KBS LTER REU Alee Zuniga making  some observations on the aggregate stability of soil. This is a healthy soil!

KBS LTER REU Alee Zuniga makes observations on the aggregate stability of soil in a Michigan farm field.