Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Plant and Soil Science

First Advisor

Ernesto V. Méndez

Second Advisor

Rachel E. Schattman


Vermont’s vegetable farms are highly valued for their contributions to the state's food system, environment, and communities, yet their continued success is impeded by many challenges. Specifically, soil is a valued and vulnerable resource, but management of it requires knowledge, money, and time. This dissertation applies an agroecological approach to understanding soil health practices on vegetable farms in three distinct studies.

In the first part of this dissertation, data is collected from six on-farm research trials in 2017-2018 to better understand the nitrogen (N) dynamics following two commonly planted legume-grass cover crop mixes: field peas (Pisum sativum, var. ‘4010’) and oats (Avena sativa, var. ‘Kayouga’), seeded in spring; hairy vetch (Vicia villosa) and winter rye (Secale cereale) seeded in autumn. Understanding the timing and quantity of available N from legume cover crops promises to help growers produce on-farm fertility while reducing inputs of phosphorus-based fertilizers, the overuse of which can harm water quality. The results of this project demonstrate the context specific nature of nutrient dynamics and associated challenges of predicting soil N availability.

The next chapter focuses on a participatory research project to better understand yield outcomes related to newly revised high tunnel tomato nutrient recommendations. This project collected data from 46 farms in Maine, Massachusetts, New York, and Vermont in 2020-2021, revealing that the new recommendations led to predictably better yields, but that on farm practices had a significant impact.

In the final chapter, co-created mental models were used to better understand opportunities and barriers to soil health practice implementation. This project analyzed data from 12 vegetable farmer interviews conducted in spring 2022. The findings revealed that growers were enabled by knowledge, innovation, and peer to peer support, while they were limited by money, land, equipment, and time. This chapter suggests adapting mental models for future Extension and outreach work.

This dissertation highlights the range of soil health practices on Vermont vegetable farms and the associated diversity in metrics and outcomes. Farmers will best be served in the future with support and resources that account for each farm’s unique context.



Number of Pages

161 p.

Included in

Agriculture Commons