Student Science May Save Sycamore Garden
In the summer of 2014, NHTI Natural Science Prof. Tracey Lesser won a $10,000 grant from NH EPSCoR, the state branch of a National Science Foundation program, to help fund original research by students in the Sycamore Community Garden adjacent to campus. Though open to all comers, the Sycamore Garden has been embraced by Concord’s refugee community, and now provides plots to more than 130 refugee families who have resettled here. The gardeners come from Nepal, Bhutan, and a variety of African nations, and each brings a distinctive style of gardening and a preferred range of plants to the garden.
"The Sycamore Garden was established on land that was previously used for growing corn," says Lesser, "which depleted certain nutrients from the soil. Current use patterns vary greatly depending on the cultures of the gardeners. Some may be growing legumes, which might help to restore the missing nutrients. Others may be growing corn, which would only make the problem worse."
NHTI's natural science students – partnering with students from Colby Sawyer College – are analyzing the garden's soil and making recommendations for its improvement. In April 2015, a small army of NHTI and Colby Sawyer environmental science students fanned out over the garden with shovels, trowels and plastic bags to take soil samples. Primarily directed by NHTI Environmental Science major Ashley Barr, who made the Sycamore Garden study her Senior Capstone Project, the group took samples from pre-selected plots representing a range of ethnic groups.
Half the soil samples taken by the students were sent to outside labs for analysis. Matching samples from the same plots were analyzed by NHTI chemistry students. For the most part, the students got the same results as the professionals.
"For pH and nitrate it looks like we can rely completely on our student data," says Lesser. "There is a correction factor for the nitrate, but the data is consistent and good. We can’t test for phosphate yet; we are having issues with ammonia but we’re working through the testing protocol right now and will retest. The calcium data is all over the place, but that is not an important factor. Our soil moisture readings are really good. Overall, we are getting as good data as I could have hoped for."
That’s the good news. The bad news is that the students’ analysis shows nutrient levels in the soil are badly depleted. “It’s a lot worse than we thought,” says Lesser. “The percent organic matter is low over the entire garden. Nitrate levels should be 30-40ppm; our data ranges from .4-5ppm. Every plot needs added nitrogen. They are all consistently a bit low with pH.”
Contrary to Lesser’s expectations, the ethnicity of the gardeners and their choice of plants and horticultural techniques did not seem to have a measurable effect on soil conditions. "There is no consistent pattern with ethnicity,” she says. “I was surprised about the ethnic data, but I think that will come out in future years. The soil is too depleted for that to have an effect right now. As we build the soil, I think more patterns will be able to emerge."
For the moment, however, the entire garden appears to have roughly the same requirements. So on a blustery October day, over sixty NHTI students turned out to enhance the soil in the Sycamore Garden. Armed with picks, shovels and one gas-powered rototiller, the students turned over the soil in each of the 130+ beds laid out by the gardeners. They then spread hundreds of yards of compost and lime on the depleted garden to help restore the missing nutrients and adjust the pH balance.
Beyond improving the quality of the soil, says Lesser, the point of this project is to show that community college students can do meaningful research with low-cost equipment that can be of genuine benefit to the community. Hopefully, monitoring the soil in the Sycamore Garden will become a standard lab for NHTI's environmental studies and chemistry students, and the gardeners will reap the benefits of their work for years to come.
Oct 30, 2015