Local and regional food systems, soil phosphorus, and resilience in a northeastern regional farmers’ market network

2015 Annual Report for GNE15-105

Project Type: Graduate Student
Funds awarded in 2015: $14,796.00
Projected End Date: 12/31/2017
Grant Recipient: Penn State
Region: Northeast
State: Pennsylvania
Graduate Student:
Faculty Advisor:

Local and regional food systems, soil phosphorus, and resilience in a northeastern regional farmers’ market network


The purpose of this dissertation project is to understand how farmers participating in local/regional food systems (LRFS) manage soil fertility, the many factors that influence those decisions, and soil fertility resilience in a LRFS in the New York City region including parts of the mid-Atlantic and lower New England. These goals will be accomplished through a mixed-methods case study of the New York City Greenmarket network of farmer’s markets that includes farmer interviews, soil analysis, and nutrient supply mapping. This project will provide a better understanding of the many social and ecological factors that influence soil management decisions, and an assessment of the resilience and sustainability of nutrient supply and soil fertility in this LRFS. These findings will be made available to farmers through direct feedback, the web, and future workshops.


The primary focus of work since receiving this grant in August, 2015 has been participant recruitment. This has been done through personal invitations with farmers at Greenmarkets, and through email and phone contact. To date, 22 farms are committed to participating, with another 16 interested and 16 left to contact. Primary data collection is set to begin in December of 2015, and continue through the 2016 growing season.

Objectives/Performance Targets

The research objectives for this project are as follows:



    1. Assess and describe soil fertility management on farms that participate in the New York City Greenmarket farmers’ markets, which includes:
        1. Documenting all farm management practices each farmer attributes to soil fertility.
        1. Documenting and tracing all input sources, frequency and quantity applied, and harvested biomass (actual or estimated).
        1. Measuring soil fertility (P (extractable, soluble), K, Ca, Mg, Zn, Cu, S, pH, cation exchange capacity, soil organic matter, and bulk density), microbial activity (phosphatases and microbial biomass), and phosphorus mass balance on each participating farm.


    1. Explore and document the many factors that influence soil fertility management decisions on these farms, especially the role of participation in the Greenmarket farmers’ markets.


    1. Assess and document soil fertility resilience in the Greenmarket food system.



These objectives have changed slightly since the initial proposal due to feedback from farmers during the participant recruitment processes. These minor changes fall under objective 1(c). In the initial proposal, soil samples were to be aggregated to the farm level, but farmers in the Greenmarket network are much more likely to approach soil management on a field-level, so sampling will now aggregate to the field level to be more useful to participants. This will require more soil tests, thus total phosphorus (which is less useful for farm planning) has been dropped from the analysis to free up funding for more tests. Farmers also expressed significant interest in microbial activity in the soil. Therefore analysis will now include a bioassay for phosphatases (enzymes that render organic phosphorous compounds bioavailable), and microbial biomass C as measured through soil respiration. This work will benefit farmers and provide an additional means of examining phosphorus cycling in the Greenmarket LRFS.


The case study approach used in this project requires that a specific sub-population of farmers in the northeast be targeted for participation. The success of this project requires that participating farmers represent the demographic diversity and spectrum of practices found in the Greenmarket LRFS, and be of significant size so as to provide robust findings. There are currently 72 farms that sell annual vegetable crops through the Greenmarkets, and my target number of participants is 40. Work for this project began during the height of the 2015 growing season, and I anticipated that recruitment would be a long process, and likely require the building of personal connections with farmers. 22 farms are currently enrolled in the project, with 16 interested. There are still 16 farms that I have not been able to contact, and recruitment will continue through the winter of 2016 concurrent with farmer interviews. Given the significant challenges to recruitment, 22 farms with the potential for 16 more is a significant accomplishment, and recruitment is on track to meet the objective of 40 participants. Current participants represent much of the diversity of Greenmarket farmers. The adjustment in the sampling resolution will ensure that sufficient number of soil samples for robust results, even if the final tally falls short of the original goal.


Work on this project since receiving this grant in August, 2015, has focused almost exclusively on participant recruitment. This is an essential first step that will ensure that data collection in 2016 will provide robust results. As mentioned earlier, recruitment is in this context is a slow process that more often than not requires face-to-face invitations – frequently multiple times. The project currently has 22 participants, with 16 expressing interest. 16 farms remain to be approached due to scheduling conflicts, the business of the growing season, and irregular market attendance. Recruitment will continue through the winter of 2016 to maximize the number of participants.


This project was designed for the bulk of data collection to take place during 2016, and this plan is on track. The first phase will be farmer interviews. One interview has been completed to-date, with several scheduled for December of 2016. The bulk of interviews will take place during the winter months of 2016, and continue as needed through the growing season. Soil sampling will begin in March of 2016 with the collection of bulk soil, and continue at 8 week intervals using anion exchange resins to assess soluble phosphorus. Some preliminary soil sampling was conducted this fall on a participating farm to refine sampling methods. Laboratory work will take place during the spring and summer of 2016.

Impacts and Contributions/Outcomes

Since the bulk of data collection will take place in 2016, there are few outcomes or impacts to report. However, the recruiting process thus far has generated good relationships with many of the participants through numerous interactions. This groundwork and shared understanding will provide a strong basis for continuing work with these farmers on soil sustainability. I anticipate that these relationships will allow me to engage significantly with famers on the results of soil analysis and build more sustainable soil fertility cycles on their farms. I also suspect that this rapport will produce better interview data that will allow my engagements with farming and LRFS non-profits to more effectively connect farmers with needed resources.


Dr. Karl Zimmerer

Professor of Geography
Penn State
302 Walker Building
University Park, PA 16802
Office Phone: 8148653433