Final report for FW26-015
Project Information
Sustainable farms are becoming increasingly important in our region for their role in food access and food security. There has been a high demand for local produce from our community over the years and a concern for increasing access to diverse and healthy food for low-income populations. However, there remain few farms and producers in our region. Land is limited and expensive with much of the area consisting of rocky and clay soils. Because the land is not historically agricultural land, often the soil conditions are poor, requiring a lot of labor and input to make it suitable for crop production. Furthermore, water resources are becoming increasingly scarce. Wells are very expensive in these areas, and many growers utilize small ponds or other water catchment for irrigation purposes. Many farms struggle with these obstacles. We paired aquaculture, vermiculture, and mealworm farming, with agriculture to provide examples of ways to improve soil, yields and income for small farmers. We continued to establish a sustainable aquaculture system in one of our ponds and compared this to another catchment system without aquaculture. We irrigated identical fields from each treatment to look at how aquaculture can improve crop yields and soil health. We examined how vermiculture and mealworm farming can benefit these systems, by lowering overhead costs and creating optimal growth in fish. We looked at the benefits of these systems for increasing revenue and providing additional commodities for small farms, increasing profits while lowering costly inputs like organic fertilizers. This helps increase sustainability on farms in our region and provides a much-needed example of how small farmers can overcome obstacles like poor soil, fertility, and high overhead costs. Our results were shared with the community, schools, and producers through organized farm tours, workshops, posters and other educational materials.
We developed and improved the sustainability of an aquaculture system in a small irrigation catchment pond and compared this to conventional watering from catchment tanks without aquaculture. We planted and irrigated identical study areas on the farm for each treatment to look at how aquaculture can improve crop yields and soil health. In addition, we showed how fish production can serve as another commodity for small farms, increasing profits while lowering costly inputs like organic fertilizers. We examined the benefits of vermiculture and mealworm farming to sustain aquaculture and compared fish growths across different worm and insect treatments and developed sustainable methods for producing fish feed on the farm. Our results were shared with the community, schools, and producers through organized farm tours, workshops, posters and other educational materials.
See attached Gnatt chart for details.
Cooperators
- - Technical Advisor
Research
For examining soil health and crop yields, our project consisted of two treatments that expanded on the promising results of our previous SARE grant tilted Increasing revenue and sustainable practices: Improving crop yield, soil health, and diversity by combining aquaculture and vegetable production. It consisted of an aquaculture treatment (a 16,000-gallon, EPDM lined, catchment pond stocked with channel catfish, and a standard treatment (a combined 16,000 gallons of catchment tanks without fish). Catfish were in the aquaculture treatment only. The aquaculture treatment had a small magnetic drive pump (Danner mag drive 18) to circulate water and help with biological filtration. An oxygen diffuser (solar water aerator) was added to supply extra dissolved oxygen critical for treatments containing fish and served as the primary oxygen source. A backup oxygen source was placed in each treatment tank (Aquascape pro air 60). These components served to transition the catchment pond into a system which is suitable for rearing fish. Each treatment had its own independent irrigation system consisting of pump, filters, and drip irrigation for irrigating crops (Rain-Flo Irrigation LLC). Water treatments were applied across 6 identical raised beds, three for aquaculture treatments and three for standard treatments. Each bed was 160 square feet and was planted with either arugula, beet greens, mizuna, or lettuce-all raised beds had the same square feet of each crop and was seeded at the same ratio. The beds were prepared identically at the beginning of the season, amended with applications of aged compost, and lightly tilled prior to planting. A standard soil sample (Ward laboratory) was taken from each bed before planting. Watering frequency was the same for each treatment but varied depending on the time of year. Crops were harvested when determined ready (dependent on weather) and at the same frequency across all treatments. Every bed was harvested with a quick cut harvester at a standardized height just above the first set of true leaves. The weight and quality of the harvests from each treatment was individually recorded. After the final harvest we took another set of soil samples from each bed to be compared with previous samples taken. At the end of the project, we analyzed all the data and compare the overall yields and soil conditions of each treatment throughout the season. Soil samples were compared through an analysis of variance to compare and look for statistical differences in the samples. The result is a written report with visuals graphs and statistical comparison of treatment means with 95% confidence intervals. Mean yields (by weight) were evaluated across treatments using two-sample t-tests (JMP 14 Statistics)
For developing sustainable aquaculture methods and reducing overhead costs, we used 6 identical tanks (200 gallons each) to look at fish growth, health, and overall system inputs, across 3 treatments. All tanks were stocked with juvenile catfish produced from brood stock from Browns Fish Farm or at the US Fish and Wildlife aquatic research laboratory operated by David Ward in Flagstaff, AZ. Water temperature in each system was recorded with temperature readers so that growth data can be compared to other studies. These treatments consisted of vermiculture, mealworm, and a standard hatchery feed treatment. All tanks were set up identical for aquaculture production including a bead filter, a pump, and additional aeration. In addition, all tanks had a solar cover on top to increase water temperature needed for fish growth, and to prevent any fish loss due to birds or other predators. For the standard treatment, two tanks were fed ad-libitum daily with a standard hatchery ration of organic fish feed (Aquamax 200 or 600 pelleted feed). This ration was standardized for this treatment and was reduced by 50 percent for vermiculture and mealworm treatments. For vermiculture we developed a red wiggler production system and feed two tanks from this system in addition to the reduced hatchery feed. For the mealworm treatment we developed a mealworm production system and feed two tanks from this system, again cutting hatchery feed rations in half. We took nitrate, nitrite and ammonia water samples as needed, but at a minimum of one time per month to ensure productivity of the aquaculture system. We used water temperature, fish growth, and fish condition data, as well as data on water quality, to determine the benefits of each system. Fish growth was used to look at the marketability of catfish as an additional commodity for the farm. We compared overall costs and labor to determine the profitability of each system and the sustainable benefits for farmers.
Our results looked at growth of catfish in our treatment trials when fed only hatchery feed (control) and a 50 percent hatchery feed reduction and either red wigglers or mealworms. We also looked at growth of catfish in our pond, and at crop yields across treatments irrigated from the pond, and soil conditions. Although there was no statistical significance in the data due to the short duration of the project we did see very strong patterns in our research. Catfish grew substantially during the experimental period during the feeding treatments. The growth across all feeding treatments was very similar which suggests that both red wiggler and mealworms are good substitutes for standard hatchery feed. Across all treatments fish were healthy and had good growth rates. By creating a sustainable feed source on farm, this decreases outside inputs of fish feed and allow farmers to reduce costs. Red wigglers worm populations were easy to manage once a healthy worm population was established and worms could be harvested easily from the worm bins to substitute hatchery feed. Mealworms were also a good feed source, but they were much more difficult to establish populations and took a lot more maintenance to manage as beetles constantly had to be separated and removed. In addition, mealworms were harder to harvest from the bins resulting in an increase cost in labor. With the extra labor involved in mealworm farming, our data does not support that mealworms are a good feed source for small farms. On the other hand, red wiggler worms in our trails were a great feed source which can be produced on farm and managed easily to supplement fish feed costs. Catfish growth SARE 2026
With crop yields we saw an increase in yields in all the treatments that were irrigated from water containing fish. Salad green and mixed greens production was consistently higher for each variety (lettuce, arugula, mizuna, and beet greens) when watered from tanks containing fish. The increase in production is not statistically significant (at a 95%) level, but the pattern of higher production is evident. This experiment needs to be repeated with higher replication to definitively say that production is higher, but these data are suggestive of an effect, and this effect is consistent with what we would expect (higher production utilizing water with higher nutrient content). Even when all leafy green varieties are combined the results are still not statistically significant (at a 95% level), but the pattern of higher production with water containing fish remains evident. Visually we observed improved quality of crops in the aquaculture system, especially with multiple cuts to the crops. Crops irrigated from water with catfish recovered quicker from the first harvest and were more robust and healthier for subsequent harvests. We also noticed that pest pressure (aphid and white flies) seemed to be less in the treatments irrigated with fish water which would support that the plants are healthier and better able to defend against pests. summary stats 2026. Salad Greens (lettuce) production SARE 2026
Because soil is a complex system it was difficult to see dramatic changes in the living microbial biomass and nutrients in the soil during our trial period. However, again we did see trends supporting soil quality improving in the treatments irrigated from fish waste. When looking at the living microbial biomass we saw that in the treatments irrigated with fish waste, there was an increase in seven different biomass groups. The total bacteria including gram positive, actinomycetes, and gram negative, had a 5.32 percent increase in the fish treatment, while only a 1.47 percent in the treatments without fish water. With total fungi we saw a 1.28 percent increase in treatments with fish waste and saw a 1.09 percent decrease in treatments without fish. Likewise, we saw an increase in protozoan in the treatments with fish and a decrease in treatments without fish. Protozoa feed on bacteria which helps release nitrogen. and a high number of this indicates and active community where nutrients are abundant to support large communities. Though these increases are small they are still present, which suggests that living microbial biomass increases with irrigation from water with fish. This is what we would expect, and it is likely that with more tests and a longer trail period you would see these numbers increase. April 2026 PLFA. Biological-Results-1523437 October 2026 PFLA. Soil-ResultsApril 2026. Soil
To look at differences in total nitrogen we examined nitrogen in parts per million available in the soil across the two treatments (with fish and without fish). We took two soil samples, one at the start of the treatments and one at the end. We calculated the difference of total nitrogen from start to finish and combined all data from each treatment to get a single number to compare treatments with and without fish. The treatments without fish had significantly greater nitrogen loss, almost 50 percent, than treatments with fish.SARE 2026 . Nitrogen PPM. This is consistent with what we would expect as treatments with fish have a steady supply of nitrogen from fish waste when watered. Because the additional nutrients (primarily nitrate) from the treatments with fish, were suspended in the irrigation water, that these nutrients were easily available for plants to uptake. Plants in these treatments do not use up as much of the nitrogen in the soil. Because there is less nitrogen loss in the treatments in with fish this can benefit the soil health which ultimately leads to healthy plants and larger yields. Analysis Report. Soil-Results-1523499 October 2026 Soil Analysis Report. Soil-Results-1549167
Research outcomes
All of our data suggests that farmers can increase yield of salad greens by utilizing water from ponds or tanks containing fish. This is an important outcome and has huge finical incentives for small famers. This is especially true for farms with limited growing space because this additional infrastructure does not take up much space and makes planting multiple crops in a single season more profitable. For farmers who use cut and come again crops such as salad mixes and baby greens, we saw improved crop quality, as well as yields, on subsequent harvests. Crops recovered quicker and were more robust making these harvests more productive in the treatments irrigated from water containing fish. This creates a more marketable crop and a higher quality suitable for higher end markets. Because the plants were healthier in the treatments watered from fish, pest and disease pressure were also observed to be less. This means less work and labor and further increases the profitability of this system. All of these results make a str0ng case for small farms to incorporate fish into their systems. The two main drawbacks for introducing aquaponics are the learning curve and the additional labor, however these can be overcome and should not be a limiting factor.
The increase in nitrogen available in the soil from the treatments with fish water is a huge advantage for heavy nitrogen feeding crops such as salad and leafy greens. These nutrients make the beds more productive and allow for multiple crops to be grown in a single season. Since leafy greens utilize a lot of nitrogen for growth, farmers who specialize in these crops would benefit from these systems, but many other heavy nitrogen feeding crops would also benefit. Irrigating with water from aquaculture systems creates immediate nutrients that become available for plants to take up, because nutrients are suspended in the water column and are immediately available for the plants to take up. This leads to increased growth in the plants and healthier plants, contributing to larger yields and marketability. Furthermore, adding of nitrogen to the soil when irrigating leads to less depletion of nitrogen is the soil, and this is consistent with what we saw. This decreases the labor needed to apply soil amendments or compost to beds at the end of the season. Because many nutrients can be tied up in the soil, in carbon or by other means, the constant supply of nutrients from fish water would allow plants to thrive across a variety of soil conditions. This is also beneficial for areas with higher PH where plants have a harder time taking up nutrients.
We saw significant fish growth, even over the relativity short period of the project, and fish growth was similar across all treatments. This suggests that with proper management farmers can produce an additional commodity (fish) to sell at existing markets. This further increases farm revenue generated from the addition of aquaculture systems. Catfish are a hardy fish, and we observed good fish condition throughout the experiment, which makes this species a good choice for aquaculture on farms. The main cost in rearing fish for a farm is feed, so creating a sustainable feed source on farm allows farmers to reduce cost. The growth across all feeding treatments was very similar which suggests that both red wiggler and mealworms are good substitutes or additions for standard hatchery feed. Red wigglers populations were easy to manage and easy to harvest. We would highly recommend red wiggler production as a sustainable fish feed on farms. In addition, worm bins create excellent compost which can be utilized on the farm or sold at markets. We found that there was a demand for compost from our community and also utilized the compost tea from these bins throughout the season. Mealworms were also a good feed source as far as growth and fish condition, but they were much more difficult to manage and therefore not recommend.
Education and Outreach
Participation summary:
We developed a variety of outreach goals focused on making our project and results known to the general public, schools, and growers in our region. For the general public we held tours twice a year, produced fliers for distribution, and shared information on our social media platforms. The goal for this component was to gain awareness of the project and focus on sustainable and ecological growing, fish production, and the benefits of vermiculture and mealworm farming. The farm tours involved an up-close look at the systems and discussions around the project, focusing on the benefits of adding diversity to farms in our region. They were developed to inspire the community and encourage home growers to grow their own food. Our fliers included descriptions and pictures of the project and its relevance to sustainable agriculture and conservation. Forestdale Farm displayed the fliers at their booth at the Flagstaff Community Market, at our farm share produce pickups, and in the farmstand. For the next outreach goal, we developed a poster that highlights all aspects of the project. This poster will continue to be on display in our farmstand for the public to view. With Western SARE and LD productions we filmed a video that described our project and the benefits of SARE farmer/producer grants. To reach schools, we worked with Flagstaff Junior Academy's gardening and sustainability programs and highlighted parts of our experiment relevant to the fields being studied and shared it with relevant classes. For the last component, workshop for producers, we reached out to other producers and interested commercial growers in our region and offer a workshop and discussions around the project. We looked at the project as a whole so that those who participated in it had sufficient knowledge necessary to design their own systems. We reached out to farms at the local farmers markets, farmers on the nearby Hopi and Navajo reservations, and other small producers in our region. Participants become acquainted with fish production, keeping healthy fish, and the benefits of fish production for crop yields and soil health. In addition, they saw how vermiculture and mealworm farming can increase the sustainability of a small farm and learned about all the practical applications; from compost generation to producing feed for fish or other farm animals. All relevant information we learn from the project was shared with producers. At the end of the project, we shared details including yields, fish growth and condition, and lessons learned. We detailed what systems are the most beneficial for increasing revenue, sustainability, and diversity on farms.
The first tour was held on the farm was a general farm tour where we focused on discussions around the SARE grant. We looked at project as a whole outlining what we expected to find. There was a lot of interest in the fish side and how incorporating different systems can benefit the farm as a whole. Guests were very excited to see the systems and talk details and a few requested additional information as we got results. The second tour was part of Flagstaff's annual Anti-Hunger Summit where the public as well as professionals involved in Flagstaff's food systems were invited to attend. This turned into more detailed examination of the systems as there were many interested people with lots of good questions. We discussed many aspects of the project and got into more specific details on how to manage and make these systems work on a small farms. At the end of all tours we had everyone who participated fill out the "Western Region Sustainable Agriculture Research and Education Program Outreach Survey" and had discussions after the project. We recorded all these results and took notes of what people gained from each tour. This helped spread awareness of the project and provided an up-close look at the systems and discussion of the project, focusing on the benefits of aquaculture growing in our region. We found that many people gained new knowledge from these tours and we had positive responses from all participants. For the next outreach goal, we developed a poster that highlights all aspects of the project. This served as a way to document the project so we can share on our website and across social media platforms as well as put on display in our farmstand. This was a great way to document the project results and make the information available to the public in an easy-to-read format. To reach schools we worked with Flagstaff Junior Academy's gardening and sustainability programs, and examined parts of our experiment relevant to the fields being studied. We had everyone who participated fill out the "Western Region Sustainable Agriculture Research and Education Program Outreach Survey." All responses were positive and there was an increase in knowledge across all participants. This group was very interested in the soil side and how it increases biological communities in the soil and nutrients. We spoke with community writers and photographers and got a stories put together for sharing with the community. Article. Forestdale Farm in Flagstaff Grows More Than Food. Edible Central Arizona Article 2026 Salad Greens (lettuce) production SARE 2026 Stewardship in the high desert. Article. 2026. For the last component, workshop for producers, we reached out to other producers and interested commercial growers in our region to come to the farm for discussion of the project. We had Northern Arizona's Growers Coalition out to the farm to look at the system in depth and discuss the benefits associated with the project. Everyone who participated filled out the "Western Region Sustainable Agriculture Research and Education Program Outreach Survey." We also combined all the data and information from the project and shared it with the Northern Arizona's grower's coalition. These results showed lots of enthusiasm for the project and people responded that they were interested in learning more and perhaps adapting certain parts into current growing operations. We had several people ask about best ways to set up and how to start on a small scale. We put together fliers detailing the project which we shared with the public at our farmstand and at local markets and events. This was a very useful tool for general information about the project and for following up with interested parties.
Education and Outreach Outcomes
For the general public we held tours twice a year, produced fliers for distribution, and shared information with our community. The farm tours seemed to be the most positive experience for the general public. Many participants were not aware of how these systems work and were very interested an excited about the project. These tours helped inspire the community and many expressed a new desire to grow their own food at home. By far the most interactive tour was the one held in conjunction with the annual Anti-Hunger Summit conference. This tour had participants from the general public as well as policy and people involved in local food systems. Having part of the participants familiar with food systems made for a lot of very good questions and discussion. The flier for the project was a great resource to share at events and at the farmers market and farmstand. We could share this document with any customers who heard about the project and wanted more information. In addition it was a useful tool to send to tour participants and local growers to detail more information for reference. The poster is a great comprensive look at the project as a whole and is a lot more interactibe and will serve as a gerat reference in the farmstand for customers to the farm. In addition, these documents will be useful for the future as we can continue to share them with anyone who is interested or those who ask about the project, and the poster can be used for any conferneces or presentations that may come up. The short video that highlights all aspects of the project completed with Western SARE and LD producitons came out very well and was of a very high quailty. This is a great resource to show the beniftis of the western SARE grants for growers and we were able to share this infomation with the growers coalition as well to help generate interest in our project and the Western SARE farmer/producer grants.. This was another great way to document the project and reach a larger audience. Flagstaff Junior Acadamey students were very interested in the project and having them out to the farm to learn was very impactful. For school groups the best part of the event was open questions and discussions after the tour. For the last component, workshop for producers, we reached out to other producers and interested commercial growers in our region to come to the farm for discussion of the project. However, sharing the information (the flier and SARE video) with the Northern Ariona's Growers Coalition was the most impactful as it reached a wider range of growers including those in rural areas or with a busy farm season which made attending the in person events difficult.
Farmers were most interested in improving soil and increasing crop yeilds