Learning from farmer innovation in nitrogen fixation for improved nutrient management on organic farms

Learning from farmer innovation in nitrogen fixation for improved nutrient management on organic farms

Summary

Biological nitrogen fixation (BNF) is the major source of new nitrogen in organic agriculture and conventional growers are also becoming increasingly interested in cover crops due to the increasing costs of purchased fertilizers.  However, there has been almost no research devoted to determining how soil management practices impact this process on working farms. This project will benefit vegetable growers in two main ways: 1) We will conduct a survey of BNF on working farms to provide farmers with rates of N-fixation in their fields; and together with Northeast Organic Farming Association of New York (NOFA-NY), 2) we will develop two farmer learning opportunities – a workshop series and a newsletter column. For the survey, we will conduct in-depth interviews with 25-30 collaborators from whose farms we will sample BNF using natural abundance stable isotope methodology to learn about their cover crop management. The farmer learning opportunities will be designed together with NOFA-NY. We will develop workshops for growers to learn about BNF from both basic and advanced perspectives. We will also develop a newsletter column to be published in NOFA-NY quarterly newsletter.  

Objectives/Performance Targets

1. Over 2000 growers and those working as grower educators will read answers to farmer questions on green manure management for BNF in our column

2. Overall, the 60 farmers trained in green manure management for BNF will act as informal educators to another 60 farmers who were not directly trained  

3. Of the 50-60 farmers involved as workshop attendees, collaborators, or advisors, 25 will adjust their management of green manures within 6 months of project completion.  

Accomplishments/Milestones

1. NOFA-NY Workshop: Over 2000 members of the Northeast Organic Farming Association learned about a first of two SARE-sponsored workshops through NOFA-NY website, newsletters, and the annual meeting program guide. The half-day workshop is scheduled for January 25th, the initial day of the NOFA-NY annual meeting that is attended by hundreds of farmers, stakeholders, academics and students from greater NY state and beyond. The workshop, entitled “What Can Legumes do for YOU?  Understanding Biological Nitrogen Fixation from the Ground Up,” will be taught by 3 experienced farmers, and the SARE project coordinators. The first farmer, Eero Rutilla from New Hampshire, was invited to attend for his extensive knowledge about cover crop options in vegetable systems, especially in the face of recent climatic variations such as severe flooding and drought that has required flexibility in his own rotation plans. The next two farmers are a father/son team from Ithaca NY, Tony and Dakota Potenza, who are known and respected for their long history of organic grain production in the area. Our program includes various strategies of legume cover crop use, and introductory information about the ecology and biology of biological nitrogen fixation in the field. The workshop is designed to be participatory in order to encourage dialogue between farmers new to using legumes, experienced farmers who would like to learn about new legume rotations, and researchers studying how to improve nitrogen fixation in cover crops. Although the workshop has not yet been taught, we have heard numerous positive comments about the potential usefulness of the workshop topic.

2. Newsletter column: Originally planned to be launched in Fall, 2007, our newsletter ‘question and answer’ column on the use of legume cover crops in organic systems has been postponed until winter 2007/2008. There were two main reasons for this postponement. The first is that NOFA-NY was undergoing a change in management, with a new interim executive director, Greg Schwartz, replacing Sarah Johnston who had originally offered her support to our project. After contacting Greg, we determined that a better time to launch the column would actually be in the winter, and not the fall, as farmers will have more time to participate by sending us questions. The announcement for the column will be forthcoming in NOFA-NY’s winter issue of their quarterly newsletter.

3. Survey plots to assess nitrogen fixation:  In 2007 we established 10 plots on a total of 8 working farms for assessment of nitrogen fixation. Preliminary contact was made with 40 vegetable farms from the NOFA list, followed up with a personal phone-call.  A total of 10 farms planting winter legumes intercropped with a non-legume were identified from a comprehensive list of organic farms in our region. The eight farms chosen for plot establishment are listed below. Most farms were planting hairy vetch intercropped with rye, oats, or winter wheat.  On each farm, four replicate plots in one or more field were established. Within two weeks of seeding, each plot was weeded accordingly to create three sub-plot treatments including a) legume only, b) non-legume reference plant only (rye, oats or wheat), and c) farmer practice (both legume + non-legume). Plots will be allowed to grow over the winter and will be sampled for 15N abundance in the spring before cover crop incorporation. On each of the farms on which we established plots, we described the experiment to the grower and answered any questions. Presently a survey is being designed to gather more detailed information from the farmer about their legume management practices. This survey will be carried out in early 2008.

Farmer collaborations included:
Anne and Eric Nordell; Beech Grove Farm
JenBokaer-Smith; WestHaven Farm
Robin Ostfeld and Lou Johns; Blue Heron Farm
Nathaniel Thompson; Remembrance Farm
Theresa Vanek and Brent Welch, Red Tail Farm
Louis Lego; Elderberry Pond Farm
Elizabeth Henderson; Peacework Farm
Paul Martin and Evangeline Sarat; Sweet Land Farm
Andy Leed: Starflower Farms

Impacts and Contributions/Outcomes

We have held detailed conversations about our work with the eight farmers who are hosting our on-farm trials this winter. These growers are extremely excited to see the outcomes of our work, as the data is a direct measurement of the nitrogen fixation activity on their own fields.  In our SARE-sponsored workshop we will directly reach over 25 farmers who are interested in improving the management of their legume cover crops. Part of our SARE/NOFA workshop has been designed so that farmers or educators attending the event can identify concrete ways in which they can transfer information to other growers who are interested in nitrogen fixation in legumes on their own farms. We have established a strong working relationship to the new executive director of NOFA-NY and are eager to deepen this relationship in the coming year through joint design of our newsletter column.

Collaborators: