Determining if Comfrey Fermented Plant Juice is a viable alternative to traditional purchased fertilizers

Final report for FW22-397

Project Type: Farmer/Rancher
Funds awarded in 2022: $24,963.00
Projected End Date: 03/31/2023
Host Institution Award ID: G370-22-W8613
Grant Recipient: Rainshadow Organics
Region: Western
State: Oregon
Principal Investigator:
Sarahlee Lawrence
Rainshadow Organics
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Project Information


The cost of fertilizers is a significant factor in an organic farmers’ budget.  Quality fertilizers may be difficult to source and ship to the farm. Producing on farm fertility is a cheaper and more sustainable alternative, compost being one example. At Rainshadow Organics we have developed a method using comfrey fermented plant juice (CFPJ) that we believe could be an alternative to traditional fertilizers.  Our main questions are how safe and effective is the CFPJ, and is it feasible for a farmer to produce systematically?  First, we plan to use CFPJ as we have the past two seasons on our 25-acre field as a demonstration plot.  Second, we plan to implement experimental plots in our hoop houses.  The experimental plots will be used to collect data regarding crop yields, in situ observation, soil biology, and soil nutrients.  We will also compare the cost of CFPJ production with purchasing traditional fertilizer.  The benefits of this research are numerous.  A sustainable farm system must be a closed loop, this is a method to move closer to that ideal.  Traditional fertilizer is also expensive; this research provides an alternative that would make organic farming more economically viable. This research is widely applicable as comfrey grows abundantly in a variety of climates. To reach other growers and farmers we plan to provide farm tours/field days to interested growers and community members, submit our findings to the Central Oregon Ag-newsletter, and present our findings to the Quivira Coalition.

Project Objectives:


Research objectives:

  1. Determine if Comfrey (Symphytum officinale) Fermented Plant Juice (CFPJ) is an effective alternative to traditional fertilizer with regard to crop yield, plant health, and soil health.
  2. Determine if CFPJ is safe to use and does not contain unsafe or pathogenic bacteria.
  3. Show the cost comparison of the production and application of CFPJ versus traditional purchased fertilizer.  

Education objectives:

  1. Provide a framework for farmers to safely produce their own on-farm fertility using comfrey.
  2. Create space for community to learn about the innovative research their farmers are conducting to create a healthier local food system.
  3. Work with The Quivira Coalition to reach their network of ranchers, farmers, researchers, teachers, government and Tribal agency staff in the West.

Please see the attached media, spread sheet to view project timeline.



Click linked name(s) to expand/collapse or show everyone's info
  • Zoe Griffith - Producer (Educator)
  • Tracy Wilson - Technical Advisor
  • Simon Yoklic - Producer (Researcher)


Materials and methods:
  1.  Determine if Comfrey (Symphytum officinale) Fermented Plant Juice (CFPJ) is an effective alternative to traditional fertilizer with regard to crop yield, plant health, and soil health.

To accomplish this objective we produced CFPJ using our standard protocol (see attached How to make Comfrey FPJ) and applied every 2 weeks starting 5/3/22.  We produced enough to apply to our 25 acre field as a demonstration plot and also for the regular applications required for our test plots as detailed below.

To test the CFPJ we used the Jimmy Nardello Pepper and the Iko Iko Pepper. We chose these peppers because they are popular crops we have experience growing successfully. They are reliable and productive, but sensitive enough that the effects of the fertilization treatments are observable throughout the season. We started seeds for all peppers on 3/7/22, in our propagation greenhouse in 144-cell flats. All flats were seeded in a potting mix we make on the farm. On 5/3/22 the seedlings were transplanted into our hoop houses. We had two 70ft beds prepared for this experiment. Each bed was divided into five zones representing our five different test cases detailed below. Each zone had 26 plants, watered on drip irrigation, one plant per emitter, 18 inch spacing between plants, three hoses per bed. Zones were separated by zinnia flowers in order to clearly visualize and physically separate the different test cases.  The entire bed was treated with compost at a rate of 200 lbs/70 ft bed and gypsum at a rate of  5 lbs/70 ft bed. Compost was chosen because even if we were to use no purchased soil amendments or fertilizer we would always make compost. Gypsum was chosen because we know that our soils are particularly low on calcium, therefore it is our standard practice to apply some gypsum everytime we prepare our beds for planting. This gypsum amendment is particularly important for plants like peppers that are prone to blossom end rot in soil that is low in calcium. Our five test cases were as follows. The control received nothing beyond the compost and gypsum as described above. One zone received the standard amendment and fertilizer treatment we use at Rainshadow Organics: compost and gypsum as described and Perfect Blend© (processed granular chicken manure fertilizer, widely available, NPK 4-4-4) 2.5 lbs per zone. At transplant this zone received approximately 1 oz of Kelp Help© flat, which we use to mitigate transplant stress. The other three zones were the CFPJ test zones. Each zone received compost and gypsum as described above. Each zone also received CFPJ at rates of 3 oz, 6 oz, or 9 oz diluted in one gallon of water, applied every two weeks starting at the time of transplant. Finally, as an additional trial we potted 3 plants individually, in a mix of native soil and compost. These potted peppers received undiluted CFPJ, at rates of 12 oz, 15 oz, or 18 oz respectively. The purpose of the potted test is to investigate if over exposure to the CFPJ would damage the crops or how they will respond to strong dosage.

To provide significant data supporting our findings we did a series of soil tests on both soil nutrients and biology. We took one soil sample the week prior to planting on 4/28/22 to establish baseline data. The second soil sample was taken on 7/30/22 which was about mid-season when plants were growing vigorously. The third and final soil sample was taken on 10/14/22 which was about one week before peppers were removed from the garden and the garden was prepared for winter. In addition to soil data, we collected data on crop yields per bed. Each harvest we recorded the weight of peppers harvested per bed. Finally, we monitored the plants in the field with hands-on observations. 


          2. Determine if CFPJ is safe to use and does not contain unsafe or pathogenic bacteria.

Our understanding of the CFPJ is that the fermentation process allows the naturally occurring microbes on the leaves of the comfrey plant to amplify to the point of breaking down the nutrients present in the comfrey leaf and leaving them in a water soluble, plant-available form.  This process also boosts the microbes present in the soil when CFPJ is applied. This process is similar to a lactobacillus fermented food, like sauerkraut. CFPJ being made from non-toxic comfrey leaves, it is assumed that the CFPJ is safe to use.

However, caution is not misplaced. Most commercially available fertilizers are sterilized to guarantee their safe use; we had CFPJ tested in its ready-to-apply form. We tested the microbial communities present in the CFPJ. We also received accompanying analysis to determine if any of the microbial life in the CFPJ is potentially harmful or if there are any precautions/alterations we should make with our fermentation process.


         3. Show the cost comparison of the production and application of CFPJ versus traditional purchased fertilizer.  

One main benefit of CFPJ is that it can be grown and produced on farms by farmers. We provide a cost comparison of CFPJ vs. the purchased fertilizer used in this test. We tested the CFPJ for NPK and micronutrients which allows for a more direct comparison of the nutrient profile of CFPJ to traditional fertilizer. The cost comparison tracks the time it took to create and apply the CFPJ, the costs of inputs, and cost of materials. The results are compared to the cost of purchased fertilizer, time applying that fertilizer, and cost of procurement. Results will show the cost of the most viable CFPJ test case to the production level of the Perfect Blend.

Research results and discussion:
  1. Determine if Comfrey (Symphytum officinale) Fermented Plant Juice (CFPJ) is an effective alternative to traditional fertilizer with regard to crop yield, plant health, and soil health.

The three metrics we used to evaluate the effects of CFPJ as laid out above were soil samples, yields, and qualitative observations. Each is discussed in turn and a summary of findings is provided at the end along with how we would have changed our research and opportunities for further research.


              a. Soil data tests

Our series of three soil tests unfortunately was an inconclusive source of data. After being scrutinized by our PI, Research Lead, and Technical Advisor no meaningful trends were forthcoming.  


              b. Yields

The yields from our different test cases were the most obvious and revealing indicator of the success or failure of our different test cases. To review the data see the attached data Jimmy Nardello Yeilds and Iko Iko Yeilds. Here I will discuss the findings first for the Jimmy Nardellos and second for the Iko Ikos.

The Jimmy Nardello’s behavior was almost exactly as one would expect. From control, 3 oz, 6 oz, 9 oz, to Perfect Blend/Kelp the average and total yields increased slightly respectively, the control being the lowest and the Perfect Blend being the highest. This was also clearly visible when simply looking at the plants in the field. These plants were darker green in color, had more leaf density and were generally larger.  During our field day, our research lead asked guests to identify which test zone was which application, and all applicants were able to identify simply by plant health which zones were associated with which treatment. It is clear from the data that the CFPJ has some effect that leads to increased plant health, vigor, and most importantly yield.

The Iko Iko peppers tell a different story. When reviewing the data the trend proceeds as follows from lowest yields to highest: 3 oz, 6 oz, 9 oz, control, perfect blend/kelp. It looks almost like the CFPJ was detrimental to these plants, whereas the control did better than all of the test cases.  The real story is much less clear cut. The greenhouse where the Iko Iko’s were located had an extremely aggressive ant population, especially during the first 2 months of the season. This was particularly true at the north end right next to the 9 oz test case. When the peppers were small we were able to replace some of the peppers killed by ants with seedlings left over in our propagation houses. However, we eventually ran out of replacement seedlings. Additionally, as the plants matured, the replacement seedlings had less and less of a chance to catch up. When finally played out the 9 oz zone only had 21 plants remaining from the initial planting or from seedlings that were replaced in the first few weeks after transplant. That may not seem like much, but each test zone only had 26 plants; a loss of five is just over 19%. If you were to account for this with regard to the total yields that would take the total yield of 62.43 lbs up 19% to 74.3 lbs.  This would have put the 9 oz zone into the second place position similar to the results found with the Jimmy Nardello’s. This does not however account for the 3 oz or 6 oz zones. Why would the control have done better than either of these zones? One possible answer is that these plants were not fertilized enough. If you refer to the attached data you will see that the Iko Iko’s started producing weeks before the Jimmy’s and that the total yields were almost three times more than for the Jimmy’s. Iko Iko’s are a much loved pepper cultivar for these reasons. However this could imply that these are much hungrier plants, needing more nutrients to thrive, and that the small amount of nutrients being provided by the CFPJ was not enough for this particular cultivar.  


             c. In Situ Observations

As discussed above the main observations made were related to any specific differences between the test cases. The Jimmy Nardello’s had a fairly uniform outlay and the Iko Iko’s were less straightforward. In general plant health for the Jimmy Nardello’s was consistent with yields. The plants that looked the healthiest and grew the most vigorously also produced the most. The Iko Iko’s were somewhat unclear, consistent with the yield results.  In fact during our field day we had attendees walk through our test beds and try to identify which zone was receiving what treatment. Most people had no idea about the Iko Iko’s, the second most common answer was that the control of the Iko Iko’s looked the healthiest. This is somewhat misleading however because the control did have some of the largest plants, but it also had some of the smallest and most stunted plants. 

Which leads to one important observation made during this experiment: that any amount of CFPJ or Kelp Help at transplant reduced plant stress significantly, increased transplant success, and led to more uniform plant growth over the course of the growing season. This was apparent in both of the controls. Referring back to the Iko Iko control zone, some of the plants were very vigorous and healthy; however some of the plants in this zone were some of the most stunted of the whole experiment. This trend was apparent from the week after transplant through the growing season. I attribute the excessive growth of some plants in this zone over others to a lack of competition from those stunted plants. The implication of this observation is that CFPJ can be used effectively as a stress reducer for crops. This finding is in line with biodynamic use of CFPJ which specifically designates the use of Comfrey Ferments during times of high plant stress. 

Another observation of note was again with regard to the Iko Iko’s specifically. As discussed above the soils at Rainshadow Organics are normally quite low in calcium, and blossom end rot is common. Bell peppers seem to be quite prone to this. Iko Iko’s are a bell pepper type pepper and are well known to have this defect at Rainshadow Organics. This was consistent with our findings during this experiment. All of the test zones of Iko Iko’s experienced fairly consistent rates of blossom end rot based on our observations alone. During the course of the season it was determined that it was too logistically challenging and time consuming to quantify these losses during the very busy harvest season. However upon reviewing the results it may have been valuable to be able to compare these losses across the different test zones. Perhaps there would have been a trend that could have illuminated the unclear results from the Iko Iko test beds. If we were to repeat this experiment this is a factor that we would definitely quantify. The Jimmy Nardello’s were not significantly impacted by blossom end rot.

Finally the potted pepper test did not produce any quantifiable data. However, the results were interesting. Despite the large quantities of CFPJ, undiluted, the plants did not show any significant signs of stress or burning from over-fertilization. In fact these plants were all quite healthy, and even produced edible peppers. The yields were quite small as the plants were confined to 1 gallon pots. Nonetheless, the strong doses of CFPJ did not seem to have any significant effect on the plants in question. Again a missed opportunity was that the potted plant test was performed using only Jimmy Nardellos, and after reviewing the final results, perhaps Iko Iko’s under these conditions would have produced some significant findings.


               d. Modifications

Upon reviewing the results of this experiment there are a few changes we would have made to the experimental design should we have performed the experiment again. The comparison between Perfect Blend and the CFPJ was not exactly appropriate.  Perfect blend is a solid manure based fertilizer and being such it requires some time for the soil to break down. Perfect Blend is intended to be a slow release long-term sort of fertilizer. It perhaps would have been more appropriate to compare the CFPJ to another liquid fertilizer. For example Fish On ©,  which is an organic fertilizer we use at Rainshadow Organics from time to time. The results of this comparison would have perhaps been more appropriate as the behavior of these two fertilizers is more similar than the behavior of the CFPJ and the Perfect Blend.    

Additionally, if we were to repeat this experiment we would change the application of CFPJ from 3 oz, 6 oz, and 9 oz to 9 oz, 18 oz and 27 oz. It was clear from our results that the most viable concentration was at least 9 oz of CFPJ. Also, the potted plant test showed that heavy applications did not stress the plants. Therefore, it would be interesting to see if higher concentrations of CFPJ could meet, or even outperform, the yields of a conventional organic fertilizer. A producer would want to use the highest safe dosage, that produced highest yields without sacrificing plant or soil health, or crop quality.    


  1. Determine if CFPJ is safe to use and does not contain unsafe or pathogenic bacteria.

We sent a sample of the CFPJ to be tested for food safety.  See attached  CFPJ Food Safety Results to review this data.  E. Coli was found in the CFPJ.  After an extensive discussion with the scientists at the laboratory that performed these tests, it was determined that the CFPJ was safe to use as a liquid fertilizer. I am not a microbiologist and therefore must preface this discussion. It is highly encouraged that any producers that wish to utilize CFPJ perform their own due diligence if they are concerned about the implications of these results. I will share a few key points gathered from the experts who performed our tests and a few of the best practices for application of the CFPJ that producers should adopt (if these are not practices that they use already). Firstly, all surface water contains e. Coil; therefore, if you are not using well water there will be some amount of e. Coil in the water. The shiga toxin producing E. Coli can originate only in the intestines of a rumen or in their manure. This shiga toxin producing E. Coli can then be transferred to surface water by a grazing animal or a fly on contaminated manure can transfer the shiga toxin producing E. Coli from that manure to a water source or plant leaf. The leaf of a comfrey plant will never naturally be contaminated by shiga toxin producing E. Coli. However, Rainshadow Organics uses primarily surface water for irrigation, as do most producers in this region. Rainshadow Organics is neighbored by several ranches and has a few dairy cows of its own. It is impossible to say exactly where the shiga toxin producing E. Coli came from, only that it was found in the CFPJ at the time of testing. 

Therefore there are certain best practices for the production and use of CFPJ that should be utilized by adopting producers.  Firstly, CFPJ should not be consumed directly. If a producer's hands are contaminated by the CFPJ they should wash their hands before returning to work. CFPJ should not be applied before harvest. For example, at Rainshadow Organics our weekly harvests were finished by Thursday morning, and CFPJ (and other fertilizers) were applied every other week on Thursday afternoon (or once harvest was finished). The next possible harvest was the following week, usually 72 to 96 hours later. Additionally, when applied to our fields the CFPJ was injected through wheel lines. We would apply 50 gallons of CFPJ during the first hour of a 4 - 6 hour set. The subsequent 3 - 5 hours would be only irrigation water. Not only is this an extremely dilute application, but any CFPJ that did contact an edible plant part was likely washed off in the subsequent watering.  Another option that producers could use would be injecting through drip lines, which would prevent plant contact altogether. We do not have this kind of system in place at Rainshadow Organics. Finally post-harvest washing and packing should be performed using best practices as laid out by USDA GAP guidelines or other equivalent sources. Doing all of these things should prevent any risk of food contamination from the application of CFPJ.


  1. Show the cost comparison of the production and application of CFPJ versus traditional purchased fertilizer.


             a. Cost Analysis

To perform this analysis numbers will be extrapolated from the Research Leads notes and from the data collected for the JImmy Nardello peppers.  Since the results for the Iko Ikos were inconclusive, the data from that portion of the experiment will not be included.

The research lead was able to produce about 200 gallons of CFPJ in about 2 hours of work. This rate changed based on the farm’s need throughout the season. In general that was about how much time it took to produce enough CFPJ for the entire farm every two weeks. It then took the research lead about 1 hour every two weeks to apply this CFPJ to the entire farm (30 acres total). This time is negligible however because it would take this long to apply conventional organic fertilizer as well, therefore time to apply is not included in subsequent math.  The research lead was paid $15 per hour. That means the total cost to make the CFPJ every two weeks was $30. In order to determine the cost of labor per gallon we divide the labor cost ($30) by the gallons made (200).  The resulting cost $0.15 of labor per gallon.

The comfrey plants were given to Rainshadow Organics and have been propagated over several years to be able to produce this amount of biomass. However, at this point they are ultimately free, requiring no care other than harvest. 20 certified organic comfrey seeds cost $5.  A negligible cost considering these plants will grow with essentially no care for as long as the farm is in operation. To make CFPJ according to this methodology required 4, 55 gallon barrels about $400 total. These will last a very long time. The cost of barrels spread over 10 seasons is $40 per season. To make the CFPJ also requires 8 burlap sacks (or similar permeable sack) about $20 total and some bailing twine, less than $5 total. These things will need to be replaced about every 3 seasons, which works out to $8.34 per year. So the total yearly cost of CFPJ specific tools is $48.35. This cost may seem like a lot, however it is a fixed cost, the more CFPJ you make the less the materials cost per gallon. At Rainshadow Organics we made 12, 200 gallon batches this season. That is a total of 2400 gallons. The cost of materials $48.35 divided by 2400 gallons equals $0.02 per gallon. Other materials like an injection pump, watering can, etc would also be required for conventional organics fertilizer applications and are therefore not included.   

Perfect Blend can be purchased by the pallet (40 x 50 lbs bags = 2000 lbs) for $2200.00 plus an estimated freight cost of $200.00, for a total of $2400.00. There is no sales tax in Oregon where Rainshadow Organics is located. The resulting cost per pound is $1.20 per pound. Kelp Help costs $23.00 per gallon or $1.44 per ounce.  

At Rainshadow Organics one full bed of Jimmy Nardello’s is about the maximum we require. Therefore that is the volume comparison we will use, or 5 times the test case as there were 5 test cases per garden bed used in the experiment. The resulting applications would be 12.50 lbs of Perfect Blend for $15 and 5 oz Kelp Help for $7.22 a total cost for one bed of $22.22. The application rate of the most successful test case was 9 oz CFJP, an entire bed is 5 times a test case totaling 45 oz, to be applied every 2 weeks. For the entire growing season that is approximately 12 applications totaling 540 oz or 4.2 gallons. Cost per gallon, as shown above is cost of labor per gallon and cost of materials per gallon ($0.15 + $0.02) for a total of $0.17 per gallon.  The total cost per gallon multiplied by the gallons used ($0.17 x 4.2) equals a total cost of CFPJ for this example as $0.71.

The total yield for the Perfect Blend zone was 31.39 lbs, times 5 for an entire bed, would be 156.95 lbs. The total yield for the 9 oz zone was 22.57 lbs, times 5 for an entire bed, would be 112.85 lbs. The difference between the two is 44.1 lbs. If we sell peppers for $8 a pound that represents a total of $352.80. This ignores increased time to harvest, wash, pack, and sell.  There is not directly $8 additional dollars of profit per pound of pepper, unfortunately that analysis is overly complex for this example here. Then one must remove the difference in fertilizer cost of perfect blend and kelp ($22.22) minus cost of CFPJ ($0.71) for the total cost benefit of CPFJ -$21.51. That difference in cost deducted from the increased yield benefit ($352.80 - $21.51) equals $331.29 more income from the Perfect blend and kelp than from CFPJ.

In plain language; There are two hypothetical beds of Jimmy Nardellos with data extrapolated from our findings.  One was treated with Perfect Blend and Kelp Help.  For the Perfect Blend bed the total cost would be $22.22, the total yield would be 156.95 lbs, and the total income minus cost would be $1233.38.  The other bed was treated with 9 oz of CFPJ.  For the CFPJ bed the total cost would be $0.71, the total yield would be 112.85 lb, and the total income minus cost would be $902.09.  This means in this hypothetical example that the Perfect Blend bed produced $331.29 more income than the CFPJ bed.


             b. Nutrient Comparison

Attached here are the laboratory results of the macro and micro nutrients (CFPJ Nutrients) and the biological activity of the finished CFPJ (CFPJ Biology). The NPK of the CFPJ is 0.6 - 0.15 - 0.91. This is quite a lot more than we expected. The NPK of the perfect blend is 4-4-4. The test results also tell us the lbs per gallon of CFPJ is 8.65. This is helpful to compare CFPJ and Perfect Blend. We used 2.5 lbs of Perfect Blend in our test case. In order to get the same amount of Nitrogen application from the CFPJ it would have required 1.92 gallons of CFPJ!   The total amount we applied to the 9 oz zone was approximately 108oz, or 0.84 gallons. Less than half than would have been needed to provide equivalent Nitrogen levels as the Perfect Blend. Obviously these numbers would be different to provide equivalencies for Phosphorus and Potassium, but the Nitrogen case exemplifies the point. This information harkens back to the modifications recommended above to the experimental design. If we were to double, or even triple the volume of CFPJ applied, then this would get much closer to the same total nutrient application as the Perfect Blend.

The macro and micro nutrients do not tell the whole story. One of the supposed, albeit unquantifiable, benefits of a fermented fertilizer over a treated fertilizer is that the fermented fertilizer contains a whole host of biological activity that is already active in breaking down the nutrients into more available forms. Not to mention feeding the soil with a more diverse set of microbes. If you refer to the CFPJ biology testing results you can see this is true. The aerobic bacteria and bacterial biomass values are quite high which is exactly what you would expect from this type of fermented fertilizer. The low fungal levels are expected as this is a bacterially dominant ferment not intended as fungal feed.

Participation Summary

Research Outcomes

Recommendations for sustainable agricultural production and future research:

This experiment had mixed results.  The Jimmy Nardello Peppers showed a trend that indicated a clear and definable effect from the CFPJ however the Iko Iko Peppers were ultimately inconclusive.  Some in situ observations indicated that the 9oz zone of Iko Iko’s could have been comparable to the 9 oz zone of Jimmy Nardello.  This does not account for the  3 oz and 6 oz zones of Iko Iko’s that significantly underperformed the control.  As mentioned above one possibility is that the lower levels of CFPJ simply did not have enough nutrients for the Iko Iko’s to thrive.  It is not corroborated by the results of the Jimmy Nardellos that the lower doses of CFPJ could have stunted the Iko Ikos as the Jimmy Nardellos showed a clear trend.  The clear modification to the experiment, as discussed above,  would be to increase the volume of CFPJ to a level that provided nutrients at a similar level of the comparison fertilizer.  This possibility is corroborated by the results from testing the CFPJ itself.

In the cost analysis the increased income from the hypothetical Perfect Blend / Kelp bed was $331.29.  For some producers that is enough to say “Why would I bother?” If you follow the example it becomes apparent that the CFPJ is essentially a negligible cost to produce. A producer could optimize their CFPJ system in order to reduce the labor required. For example: plant all of your comfrey plants together in the direct vicinity of your fermentation station and directly inject the CFPJ into your drip lines. This could reduce the labor required from very little to almost none, once the system was established. Unfortunately, the infrastructure at Rainshadow Organics does not allow this kind of optimization. 

It is also interesting to consider that the primary use of CFPJ at Rainshadow Organics is not in the garden or in the green houses but actually in our 25 acre field. The limitations of this experiment were determined in order to produce quantifiable metrics. However, one may have wondered, from the above example, where 200 gallons of CFPJ were going every other week when an experimental bed required less than 45oz. The vast majority of CFPJ was getting injected directly into our irrigation system and applied to the crops growing in our big field. In the past we have used Fish On© as a fertilizer on our big field. Without getting too nuanced in the costing, it costs upwards of $7000 per season to apply that fertilizer at its recommended dosage in our field. On the contrary it could cost a producer under $500 to make as much CFPJ as they want.  Unfortunately with the inconclusive results from the Iko Iko’s it is not possible to recommend how much that would be.

Additionally, it is impossible to quantify the value of having working closed loop fertility systems. These systems increase resilience and freedom for producers. What if a fertilizer becomes unavailable? What if freight costs become cost prohibitive? What if existing remoteness makes the possibility of importing large volumes of fertilizer already cost prohibitive? Moreover, as most organic producers know, soil health is much more complicated than what kind of fertilizer you use. Closed loop nutrient systems require long term holistic management practices, and CFPJ would only be one part of that system that could be of benefit to a producer.  At Rainshadow Organics CFPJ is one of the fertility solutions we use in a complex system.  We have produced and utilized a variety of ferments and biodynamic preps over the years with varying uses and effects. 

Education and Outreach

3 Curricula, factsheets or educational tools
1 On-farm demonstrations
3 Published press articles, newsletters
5 Tours
1 Workshop field days

Participation Summary:

10 Farmers participated
30 Ag professionals participated
Education and outreach methods and analyses:



  1. Provide a framework for farmers to safely produce their own on-farm fertility using comfrey. 


We invited farmers and our local community to a field day at our farm for a tour around our closed-loop system with a demonstration of how to make and apply CFPJ. This event was primarily catered to farmers so they could ask questions about how to integrate CFPJ into their own systems. Attendees saw the CFPJ infrastructure we started with as a more economically feasible example, as well as our new infrastructure we were able to set up with this grant. Fact sheets, comfrey plant starts, and data acquired up to the date of the field day was provided. A farm-to-table lunch was provided using peppers from the experiment. The field day was held in early September at which time we will have collected a substantial amount of data to share, and will still be regularly injecting CFPJ into our irrigation system. 


       2. Create space for the community to learn about the innovative research their farmers are conducting to create a healthier local food system.


As an educational farm, Rainshadow Organics seeks to invite our community onto the farm in several ways. This includes our interns, volunteers, CSA members and their families, as well as people just stopping by the Farm Store. We will create the space for self-guided tours, during normal business hours, on our farm. Paper maps will be provided in our Farm Store and there will be permanent, informational signs along the pathways. 


We will also utilize our online presence for conducting outreach. This will allow us to reach more individuals who cannot make it out to our farm for either a scheduled field day or a self-guided tour. Our primary lines of online communication are our monthly newsletter with over 2,000 subscribers and Instagram with about 5,000 followers. This is also where we update and invite our community to farm happenings and events. 

Education and outreach results:

The field day was hosted on the farm on September 15th, 2022. There were 30 attendees.  Several were local producers, several were from local food and agriculture non-profits, and the remainder were neighbors, CSA members, or community members who were interested in the farm's activities. This event was advertised through our events notice, Instagram, and local networks. A hand-out was produced for the perusal and reference of the attendees (Field Day Hand Out). Included was a participant survey. We received 17 survey responses back, the results of which have been tallied and attached here (Survey Results). 


In September 2022 a brief article went out to our community through our farm news letter describing the project and some of the results that had been gathered to date.


As part of the grant, a self guided tour of our farm was produced including signage and a pamphlet. Digital copies of the self guided tour signage are attached here (Self Guided Tour Signs).


An article will be released via the Central Oregon Ag Newsletter that will highlight this project and provide a link to the final report once it is released. 

5 Farmers intend/plan to change their practice(s)
1 Farmers changed or adopted a practice

Education and Outreach Outcomes

Recommendations for education and outreach:

Those farmers that came to the field day were very impressed with what they observed.  Most if not all of them said they would witness one or more of the methods that we use at Rainshadow Organics.  Of course, on a field day more comes up than just the specific grant work.   Discussions about the whole farm system that the grant work fits into is equally as valuable the grant work itself.  For an observer understanding what a farm system looks like that can efficiently utilize something like Comfrey Fermented Plant Juice is equally as complicated as determining if the CFPJ is useful in and of itself.   Educational programming then should attempt to give a larger perspective of the farm as a whole.  Through this grant work we have attempted to do that but as with many pursuits of this nature attempting to zoom in on a particular problem has made it even more difficult to zoom back out and bring perspective. 

The farm newsletter and central Oregon ag Newsletter reach potentially several thousand people.  Presumably many of these are farmers, however there is no way to quantify what level of engagement this outreach engenders.  The main purpose of that form of outreach is hopefully to tickle the mind of those people who do choose to engage.  Sustainable agriculture involves living systems,  there are numerous ways to organize and optimize those systems,  Fermented Plant Juice is just one tool that could be utilized as part of an entire strategy.  Presenting this kind of methodology to people who may or may not have had any exposure to this kind of work or thinking  hopefully serves a greater value than is directly quantifiable. 

5 Producers reported gaining knowledge, attitude, skills and/or awareness as a result of the project
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.