What is Growing Science?
Growing food demand is stressing agricultural and natural systems. Given the large number of people living in urban areas, urban agriculture will help increase available food while potentially decreasing impacts on natural systems. However, research is urgently needed to improve production efficiency in urban environments and to engage citizens in urban agricultural efforts.
The University of St. Thomas Biology Department‘s research project, “Growing Science,” has established community-style gardens at two sites in the city of St. Paul: the West Seventh and Conway community centers.
The West 7th community center in St. Paul was established by the University of St. Thomas in 2014 and is leased from the St. Paul Parks and Recreation department. This urban garden has thirty-two 2×2 meter plots, visible just to the west of the building, and north of the building by the upper circle of the playground, in satellite view.
Conway (plots are visible in the field to the east of the building).
Current “Growing Science” Research
With the rising atmospheric carbon levels, it is important to find ways to reduce our carbon footprint. One way to accomplish this is by finding valuable uses for waste products. This particular project redirects the waste product of a local coffee business, coffee chaff, to serve as a material for a local community garden. Coffee chaff is often burned, releasing more carbon, but has potential as a beneficial input for agriculture. This project aims to study the benefits of utilizing this waste as mulch, which include moisture retention, increased nutrient availability, and improved yield. Little has been reported on the effectiveness of coffee chaff as mulch, so this project addresses this gap. Also, this project evaluates the potential for a sustainable, local source of garden nutrients to further support local food production. Specifically, our project will be in collaboration with Tiny Footprint Coffee who will be providing the coffee chaff.
Our research questions:
How can common waste products be used to increase local food production?
Is coffee chaff (i.e., the husk from a coffee fruit) an effective mulch for urban agriculture?
This study is taking place at the urban garden at West 7th community center in St. Paul, which was established by the University of St. Thomas in 2014 and is leased from the St. Paul Parks and Recreation department. This urban garden has thirty-two 2×2 meter plots. We will use a factorial design: plots will receive coffee chaff only, wood chips only, chaff and wood chips, or no mulch. For the appropriate treatments, the same volume of coffee chaff and/or mulch will be applied on top of the soil or mixed in the top 4 inches of soil at the beginning of the summer. The same number and types of tomatoes, peppers, eggplants, and potatoes will be grown in all the plots; these plants represent a mix of root and fruit crops, and are all susceptible to common diseases. As a result, they should allow for a general assessment of the value of our mulches.
We predict that coffee chaff will be comparable to wood chips, a standard ground cover, for its effectiveness for retaining soil moisture, soil nutrient levels, yield, soil microbes, and the amount of weeds. We predict that the chemicals in coffee chaff will have antimicrobial properties and therefore, be more effective than wood chips at controlling tomato leaf spot virus.