Masters Thesis completed 2015

Assessment of the potential for vegetable gardens in elementary schools across a tropical urban watershed in Puerto Rico

Cristina Pilar Ruiz


School gardens provide environmental services and social benefits that can have a wide impact in communities and cities, while preparing future generations for more sustainable ways of living. However, in order for a school to create and sustain a vegetable garden, key social factors and adequate soil conditions must be in place. This project evaluated both social factors and soil conditions in the Rio Piedras watershed of San Juan, Puerto Rico.

By conducting a survey of school principals, we identified the social factors that are considered opportunities and constraints to establishing and sustaining a school garden. By analyzing soils from the schoolyards, we determined the nutrient content, pH, CEC, organic matter, conductivity, texture, bulk density, and heavy metals (Cd, Cr, Pb) of soils sampled from the most suitable locations for vegetable gardens.

A total of 20 school were visited within the Rio Piedras watershed. Eleven schools lacked success in sustaining a garden, while 7 schools had gardens at the time of the visit. The reason for garden failure included invasive species, disappearance of government initiatives, and lack of continuity by teachers or parents. Results from the survey reveal factors that will help in implementing and sustaining long-term vegetable gardens: (a) engagement of stakeholders, (b) sponsorship, (c) gardening skills and logistics, and (d) curriculum integration. Certain social conditions around the school gardens need to be
improved to ensure the support and success of the gardens. The soils are alkaline with mostly clayey or sandy textures, have high Na and high bulk density, are low in CEC and nutrient availability, and have heavy metal concentrations that are below U.S. EPA toxic standards. Not all soil physical and chemical soil properties are suitable to sustain vegetable gardens, so they will need to be managed.

Results emphasize the need to study the potential of urban garden success ensuing a social-ecological perspective. It is hoped that the findings of this study will provide useful information that can inform the development of vegetable gardens and overall soil management at elementary schools in the Rio Piedras watershed.