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

The past year has been a very busy one for this project as we have exceeded our objectives in several areas. We held two more workshops on legume cover crops and nitrogen fixation management and contributed several presentations to field days and workshops organized by extension educators. We continued to publish our Dear Vicki Vetch column this year in several newsletters reaching a wide audience of thousands of growers in the northeast. Finally, we completed additional on-farm measurements of biological N fixation in farmer’s fields and will continue these efforts for one final growing season. So far we have sampled 25 fields located on 12 different farms. From each field we have data on total cover crop biomass, N content, N fixation rates and total N fixed, total N uptake from soil for both the legume and non-legume. We have compiled enough on-farm measurements to begin our analysis of factors that impact N fixation rates in these farms.

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

   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. Newsletter column: Several newsletter columns were published during 2009. Vicki Vetch continued to be carried by three newsletters: 1) The Small Farms Quarterly is mailed to 27,000 small farms in several states and is also available on-line. 2) The NOFA-NY newsletter ‘Organic Farms, Folks, and Foods’ is distributed to all NOFA-NY members and 3) The Cornell Cooperative Extension newsletter VegEdge is distributed to farmers in Western NY, including Ontario, Yates, and Monroe counties.
Articles published in 2008-2009 are listed below.

Drinkwater, L. E., Schipanski, M., Piombino, A. (2009). Dear Vicki Vetch: Nutrient Budgeting and Cover Crops. Organic Farms, Folks, and Foods (vol. Spring, pp. 1). Cobleskill, NY: The Northeast Organic Farming Association of New York.

Drinkwater, L. E. (2009). The Ins and Outs of Nutrient Budgeting. Organic Farms, Folks, and Foods (vol. Spring, pp. 20-22). Cobleskill, NY: The Northeast Organic Farming Association of New York.

Drinkwater, L. E., Piombino, A. (2009). Dear Vicki Vetch: New Varieties of Hairy Vetch. Small Farms Quarterly (vol. Winter, pp. Page 17). Ithaca, NY: Cornell Small Farms Program.

Drinkwater, L. E. (2009). Dear Vicki Vetch: Nutrient Budgeting and Cover Crops. Small Farms Quarterly (vol. Spring). Ithaca, NY: Cornell Small Farms Program.

Drinkwater, L. E., Schipanski, M. (2009). Dear Vicki Vetch: Red clover vs clover-grass mix for a cover crop in winter grains. Small Farms Quarterly (vol. Summer, pp. Page 17). Ithaca, NY: Cornell Small Farms Program.

Drinkwater, L. E., Gregory, M. (2008). Dear Vicki Vetch: Interseeding Cover Crops. Organic Farms, Folks, and Foods (vol. Summer, pp. Page 15). Cobleskill, NY: The Northeast Organic Farming Association of New York.

Drinkwater, L. E., Piombino, A. (2008). Dear Vicki Vetch: New Varieties of Hairy Vetch. Organic Farms, Folks, and Foods (vol. Fall). Cobleskill, NY: The Northeast Organic Farming Association of New York.

Drinkwater, L. E., Gregory, M. (2008). Dear Vicki Vetch: Interseeding Cover Crops. Veg Edge (vol. 4, issue 9). Ithaca, NY: Cornell Cooperative Extension Vegetable Program.

Drinkwater, L. E., Piombino, A. (2008). Dear Vicki Vetch: New Varieties of Hairy Vetch. Veg Edge (vol.4 issue 12). Ithaca, NY: Cornell Cooperative Extension Vegetable Program.

2. Workshops- farmer and extension educator training: We presented our second workshop on advanced legume cover crop management at the 2010 NOFA-NY conference. This was a 3.5 hour workshop that included 2 researcher and 4 expert farmer presentations and a participatory small group problem-solving exercise led by the expert farmers. We also held additional field and workshop activities which are listed below.

Drinkwater, L. E., Van Zyl, B., The Empire State Fruit and Vegetable Expo, “Supplying Nitrogen With Warm Season Legumes”, Cornell Cooperative Extension, Syracuse, NY. (January 2010), 30 min., (60 attendees)

Drinkwater, L. E., Organic Farming and Gardening Conference: Circles of Caring, “Getting the Most Out of Legume Cover Crops”, The Northeast Organic Farming Association of New York, Saratoga Springs, NY. (January 2010), 3.5 hrs. (24 attendees)

Drinkwater, L. E., Cornell Organic Cropping Systems Field Day, “Evaluating cover crop performance in the field”, Freeville Organic Research Farm. (August 2009), 1 hr., (20 attendees)

Van Zyl, B. (Presenter & Author), Drinkwater, L. E. (Author Only), Cornell Organic Cropping Systems Field Day, “Warm season cover crops: field demonstration”, Freeville Organic Research Farm. (August 2009), 1 hr. (20 attendees)

Drinkwater, L. E., Empire State Fruit and Vegetable Expo & Farmers’ Direct Marketing Conference, “What can legumes do for you? Understanding biological nitrogen fixation from the ground up!”, New York State Vegetable Growers Association, Rochester, NY. (January 2009), 2 hrs. (65 attendees)

We collected detailed feedback from our workshop held at the NOFA-NY meeting. Fifteen participants filled out questionnaires. One hundred percent agreed or strongly agreed that the organization & presentation of material was effective, 80% agreed/strongly agreed that the workshop was beneficial to their work. Responses to a couple of our questions are included below.

The most useful features of the workshop for me were:
• General mix of discussions
• Advice from experienced cover-cropping farmers who have already walked where I’m trying to get to; the knowledgeable lead organizer/presenter; the attention to using time efficiently
• Discussion about cover crops and weed suppression
• Learning what legume cover crops are used for
• Some of the farmer presentations that discussed specific mixes and specific planting times; presentation on environmental factors affecting N fixation.
• Section on environmental factors impacting legume growth
• Scenarios for NE farmers, small farm situations
• Farmer presentations, Jody, Asher, Asparagus; break-out sessions and report backs; the part about N-fixing on warm season cover crops was useful
• Hearing the experience of farmers; breaking into groups and covering a handful of topics in a short time.
• Practical applications
• Farmer experience
• Presentation of data
• All
• Specifics on cover crop application successes
• Verification of two theories: that legumes fix less nitrogen in the presence of greater levels of soil nitrogen, and that grasses can be used to “soak up” nitrogen, but that the relationship b/w grass and legume needs to be managed so the legume isn’t competitively suppressed to the point where it can’t fix N.

Will the information you learned today change your management of soil fertility and use of nitrogen-fixing green manures? If so, list one specific change you will consider using, at least on a trial basis, in the next year.

• Bell bean and clover seedings
• Yes; mixed legume-non legume cover crop; fava beans; buckwheat/clover mix
• Probably not
• No
• Possibly experimenting with Bell Beans, planting oats with my spring peas
• Trying bare fallow periods targeting specific needs
• Yes, next year I’ll not hesitate to use green manures on newly plowed land, hope to use green manure for last years potato area
• It will shape but not change
• Yes, very helpful, will try peas
• Mixing N and C cover crops
• Yes, keeping fertility curve in mind so legumes aren’t necessarily going into the most fertile beds. Bell beans, using mixes
• Just expanding timing and successions of covers
• Yes, nurse crop change from typical rye/vetch combo

Any other comments?

• Thank you. As a beginning farmer I found the information useful and the presentation enjoyable. Good time management, it made the afternoon pass quickly.
• Thanks! I really appreciate the work you’re doing on this. I think it really has the potential to enable most growers to supply more of their nitrogen needs through leguminous cover crops, while at the same time it will probably save some growers some money on over-applications of compost, and maybe point out where we can be using more aggressive bio-mass producing mixes where that takes good advantage of high fertility veggie soils.

3. On-farm survey plots to assess nitrogen fixation: We continued our work documenting on-farm nitrogen fixation rates. We found that the proportion of N fixed by legumes consistently increased across nearly all farm sites when legumes were grown mixed with a non-legume. The total amount of N fixed in mixes varied, depending on the intensity of competition with the non-legume. Preliminary results suggest that fields with very high soil fertility tended to have reduced nitrogen fixation in legumes. We are in the process of analyzing and summarizing our findings from the on-farm measurements.

Nitrogen fixation measurements for 2009:

In the fall of 2008 and early spring of 2009 on 7 farms in the Finger Lakes area of NY and in the Hudson Valley, 8 sets of microplots were set up in 8 different fields of rye and hairy vetch which were sampled in the spring of 2009. Field sizes ranged from 5 acres to 5 x 200ft beds. Biomass, density, height were measured. The biomass was dried, ground, and analyzed for the N 15 isotope for the N fixation calculations.

In the spring of 2009, on 4 farms, 5 sets of microplots were set up in fields or beds planted to peas and oats mixtures. Those plots were sampled in the summer of 2009 and biomass, density, height were also measured. The biomass was dried, ground, and analyzed for the N 15 isotope for the N fixation calculations as well. In total, 13 fields on 8 farms were sampled in 2009.

Impacts and Contributions/Outcomes

• We have reached more growers and extension educators through newsletters and presentations that originally expected. Thousands of growers have received information on nitrogen fixing cover crops through our newsletter column which is structured to publish responses to specific, grower-generated questions. Furthermore, more than 150 growers and extension educators who have participated in our workshops have learned how they can manage the biology of legumes and have also heard about practical tips for managing cover crops from expert growers. Our questionnaires indicate that significant proportion of these growers and extension educators plan to take action as a result of what they learned in these workshops.

• In this second year of field work, as we establish monitoring plots in farmer’s cover crop fields, we continue find that there is a very strong interest in the actual measurements on nitrogen fixation we are making. Farmer’s are extremely curious to know how much N they are actually getting from these covers. We are in the process of mailing out a report to each farmer who has participated in the on-farm measurements. In this report, we summarize our findings from the on-farm research and highlight the results from their specific fields and cover crop stands. This year we were able to include these results in our presentations. In this final year, we plan to publish a Vicki Vetch article summarizing these findings of actual on-farm fixation rates from this project.

Collaborators: