Whole farm nutrient planning for organic farms

Whole farm nutrient planning for organic farms

Summary

Nutrient management is a major challenge on organic farms, and a challenge that organic growers have indicated they need help with. To address this challenge, we convened an intensive training program for agricultural educators in which we studied the issues with nutrient management on organic farms and modified existing soil and compost analysis recommendations to make them more relevant for organic growers. During the training sessions we also evaluated computer-based whole farm nutrient planning tools using situations common to organic farms. We are currently presenting the new recommendations for using organic nutrient sources and our experiences with whole farm nutrient planning tools to grower and agricultural educator audiences in Pennsylvania and New York.

Objectives/Performance Targets

Of the 45 agricultural educators who participate in the project and attend the educational events, 15 will use the new organic farm soil and compost test recommendations and a whole farm nutrient planning tool to assist organic farmers and agribusinesses manage nutrients on organic farms.

Accomplishments/Milestones

We have completed Phase One of this project: Intensive Training Program for 10 Agricultural Educators. For this phase, nineteen agricultural educators from Pennsylvania, New York, New Hampshire and New Jersey were invited to participate in three intensive training sessions to address nutrient management issues on organic farms. Of those invited, fourteen were able to participate. Prior to attending the first training session each participant was asked to meet with an organic grower to discuss their current nutrient management strategies and thoughts on current compost and soil test analysis recommendations. This was requested to determine how best to develop nutrient management recommendations for organic nutrient sources and to strengthen relationships with the organic community. Educators were also asked to take soil and compost tests for analysis and to share the results with the grower and the other participants of the training.

The first training session was held on August 17, 2007 and had the purpose of modifying existing compost and soil test recommendations. After introductions, each participant presented the nutrient management challenges faced by the organic grower they visited. Several themes were identified: 1) growers tended to apply compost based on the amount on hand rather than by calculating the rate to apply based on nutrient needs of the crop to be planted, 2) in general, compost was not analyzed prior to use and 3) soil on many of the farms had above optimum phosphorus, potassium, magnesium and calcium levels. Next, the presentation, Compost: Critical Concepts and Current Recommendations was delivered. Based on the identified themes and presentation, soil test reports from Penn State’s Agricultural Analytical Services Laboratory were modified to include a statement about the hazards of above optimal nutrient levels. Compost reports from Penn State’s Agricultural Analytical Services Laboratory were modified to include a statement on the use of nutrient sources besides compost in the event of above optimal soil nutrient levels. Assumed mineralization rates were also modified for compost analysis reports. The units used to report nutrient contents within compost were also discussed. Additionally, a fact sheet on the use of organic nutrient sources including an example calculation for determining how much to apply based on crop nitrogen needs was determined necessary and a subgroup initiated its writing.

The second training session was held on November 14, 2007 and had the purpose of examining whole farm nutrient management software. The session began with an update on the changes to soil and compost testing reports. After discussion, it was determined that some of the text should be further modified. Also, through conversations with personnel at the soil and compost testing facility it was determined that to more accurately calculate the amount of compost to apply, bulk density should be determined. How to determine bulk density will be included in the fact sheet and incorporated into other educational materials. Participants rated the changes in soil and compost reports as useful for their educational programming (5.63 on a 7 point scale; 7 indicating very useful).

A presentation on the mass balance concept used in the whole farm nutrient management software was delivered followed by an introduction to the NEON and I-Farm tools. Participants then used the tools by entering information from the organic farm they visited. Participants rated their ability to help organic growers with nutrient management as 3.50 before and as 5.13 after the training session.

The third training session, which was held on January 10, 2008, had the objectives of providing feedback on the NEON and I-Farm nutrient management software, learn more about nitrogen mineralization and plan educational events based on information presented and learned throughout the training sessions. At the conclusion of the second training session participants were asked to evaluate the NEON and I-Farm tools prior to the third training session. The third training session began with a discussion of the participants experiences using the tools. Several suggestions for improving the tools surfaced. One suggestion was to address the practicality of using the tools for small acreage operations. The tools are scaled for large sized operations growing large areas of single crops, while most organic vegetable growers in our area operate relatively small sized diverse farms (for example, one participants was working with an organic grower who farms 21 crops on one acre). Another suggestion was to have printer friendly outputs. These suggestions were shared with personnel involved in the development of the NEON and I-Farm tools. Additionally, a new nutrient management software tool was being developed at the University of Vermont and these suggestions were also shared with the principal developer. This discussion was followed by a presentation by Dr. Laurie Drinkwater from Cornell University entitled Nitrogen Dynamics and Mineralization on Organic Farms in the Northeast. The session concluded with a discussion of educational materials and events to develop as a result of the training sessions. The importance of continuing to develop a fact sheet on using organic nutrient sources was stressed as well as presenting the topic at winter meetings. Participants rated their ability to help organic growers with nutrient management as 3.50 before and as 5.50 after the training session. Additionally, participants commented that “I plan to meet with all of my organic fruit and vegetable growers to look at their soil testing and soil amendment histories to determine how they should change/improve their nutrient management. Many over-rely on compost as their sole source of nutrients”, “I will select more growers to use the NEON tool”, “Plan to use a twilight meeting to present information learned”, “Closer work with producers on use of organic nitrogen, organic matter in agronomic systems. Also work to create a greater understanding of the overall systems approach to nutrient management in organic systems. Much still to do.” and “When helping people interpret soil tests, I’ll have a better explanation of the consequences of having high levels of P and K.”

A fourth training was proposed; however, the objectives for the training sessions were met with three sessions and therefore a fourth session was not held.

Based on the training sessions, a PowerPoint presentation on using compost for organic vegetable crops was developed and presented at the Western Pennsylvania Vegetable and Berry Growers Seminar on November 10, 2007, at the Pennsylvania Certified Organic Annual Meeting on December 4, 2007 and the New Holland Vegetable Day on January 21, 2008. One hundred thirty-five growers and agricultural educators attended these events and response was very positive. Additionally, an article entitled Tips for Using Compost was included in the December issue of The Vegetable & Small Fruit Gazette. The Gazette reaches over 350 growers and agricultural educators and articles are reprinted in other newsletters throughout Pennsylvania and the Northeastern U.S. Several other presentations/workshops are planned for early 2009.

Additionally, a 20 page publication entitled Using Organic Nutrient Sources is in development and will be available through Penn State Cooperative Extension soon. Sections in the publication include:
National Organic Standard Summary on Soil Fertility Management,
National Organic Standard Summary for Fertilizers and Soil Amendments Use
Soil Testing
Soil Test Values
When Nutrient Levels Exceed Crop Needs
Balance and Imbalance of Nutrients in Organic Nutrient Sources
Nutrient Availability from Organic Nutrient Sources
Increasing Soil pH and Calcium and/or Magnesium Levels
Decreasing Soil pH
Recommendations for Nitrogen, Phosphate and/or Potash
Adding Phosphate
Adding Nitrogen and/or Potash
Calculating Sodium Nitrate (Chilean Nitrate) that can be Applied on Organic Farms
Adding Nitrogen with Leguminous Green Manures
Soil Organic Matter Content
Mineralization
Using Compost
National Organic Standard Summary on Compost
Nitrogen, Phosphorus and Potassium in Compost
Carbon to Nitrogen Ratio
Tips for Using Compost
Calculating How Much Compost to Apply
Estimating Residual Nitrogen from Compost
Using Manure
National Organic Standard Summary of Manure Use
Additional Sources for Information

Once the publication is in print, the goal is for the publication to accompany soil tests reports through Penn State’s Agricultural Analytical Services Laboratory.

Impacts and Contributions/Outcomes

Fourteen agricultural educators have participated in three intensive training sessions on whole farm nutrient management for organic farms. All participants indicated an increase in their ability to help organic growers manage nutrients after each session.

Soil test reports from Penn State’s Agricultural Analytical Laboratory were modified to include a statement on the hazards of above optimum nutrient levels. Additionally, categories of soil nutrient levels were changed to better indicate the hazards of nutrient levels that are not within the optimum range. This laboratory processes samples primarily from Pennsylvania, New Hampshire and New Jersey and the changes will benefit numerous growers in these states.

Compost reports from Penn State’s Agricultural Analytical Laboratory were modified to include the statement – “when compost is applied on an N basis most composts have an excess of P and K relative to plant demand. These mineral elements and salts can accumulate above optimum with repeated application. Growers using compost should regularly soil test to monitor P, K and salt accumulation and should consider using nitrogen fixing legumes and/or other nutrient sources.” Additionally, assumed mineralization rates were changed. Lastly, the compost value of ammonium nitrogen was changed so that it is now reported as a percent and can be more easily used to calculate how much compost to apply.

A fact sheet on the use of organic nutrient sources has been developed for organic growers.
This publication is 20 pages long and will be available through Penn State Cooperative Extension as well as through Penn State’s Agricultural Analytical Services Laboratory accompanying soil test reports.

Each participant met with an organic grower strengthening relationships with the organic community.

Additionally, participants were able to make recommendations to the organic grower they visited on managing nutrients.

Whole farm nutrient management software was evaluated for usefulness in helping manage nutrients on organic farms. Many participants found these tools useful for illustrating soil nutrient levels to growers.

One hundred thirty-five growers and agricultural educators attended presentations on the use of compost developed as a result of the training sessions.

An article on using compost was developed as a result of these training sessions and delivered to over 350 growers and agricultural educators.

A series of workshops/presentation are scheduled on using organic nutrient sources for early 2009.

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