Enhancing Strawberry Production by Integrating Rabbit Production to Decrease Fertilizer Use, increase Sustainability and Profit

Final report for FS21-329

Project Type: Farmer/Rancher
Funds awarded in 2021: $14,909.00
Projected End Date: 03/31/2023
Grant Recipient: SLEWZ LLC
Region: Southern
State: Mississippi
Principal Investigator:
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Project Information

Abstract:

By integrating strawberry and rabbit production, these two individual processes can form a sustainable system to increase the efficiency of natural resource conservation. By converting a waste product such as rabbit manure to an effective renewable nutrient source for strawberry production, an integrated process is created to build a sustainable system.

The reduced cost of waste removal and the reduced cost of fertilizer usage work together to make both of these productions more economically viable as a farm operation.

The benefit of cooling by strawberry plant shade and transpiration increases animal wellbeing and ultimate harvest weight and quality.

The use of free-range colony style rabbits allows for a more sustainable and ethical treatment standard for alternative meat production. Their manure is an excellent option for nutrient source for strawberry production. The average NPK value of Rabbit manure is 4:2:1 (Figure 1). This will be diluted with clear water for application to the strawberry plants.

By joining these two production systems a combined solution is generated that is cost saving, more sustainable and increases marketability of the product.

 

Figure 1: Comparison of average NPK values for animal manures *

 

N Nitrogen %

P Phosphorus %

K Potassium %

Rabbit Manure

2.4

1.4

0.6

Cow Manure

0.6

0.4

0.5

Horse Manure

0.7

0.3

0.6

Pig Manure

0.8

0.7

0.5

Chicken Manure

1.1

0.8

0.5

Sheep Manure

0.7

0.3

0.9

*(REF1) Artkinson, J. H., Giles, R. G. and Desjardins, G. T. 1958. Effect of farmyard manure on trace element content of soils and plants grown there on. Plant and Soil, 10: 32–36.; (REF2) https://www.allotment-garden.org/composts-fertilisers/npk-nutritional-values-animal-manures-compost/

Project Objectives:

To achieve the best results from the experiment the system will be started with new strawberry plants and a new set of rabbit breeding stock, selected from current breeding stock. The greenhouse and rabbit production will be integrated. Land is set aside next to the greenhouse for rabbit production.
The soil will be amended to create a sloped area 8’x32’ with compacted earth. The compacted earth will be set at a slope of 5 degrees to allow runoff of rabbit manure and urine. Soil runoff nutrient addition to manure nutrient load will be considered negligible.
Rabbit manure will be captured in a trough and collected in order to produce manure tea.  Manure tea will be distributed to strawberry plants through a hydroponic system.  Electricity used for running of the hydroponic system pumps will be provided through solar panels as an additional sustainable element of the design.
Strawberries will be raised in the commercial style vertical trough system. The strawberry plants will be planted six inches apart in the rows of gutters, vertically with a 7-degree slope and a 0.5-inch drainage hole every six inches.  In order to compare the effect of rabbit manure on strawberry production in comparison with conventional fertilizer use, X total troughs will be used in this study with Y receiving rabbit manure tea and Z(equals Y) receiving conventional liquid fertilizer according to production recommendations.  Treatments will be randomly assigned to troughs in order to control for impact of environmental conditions.
A 256 square foot area, 8’ by 32’ adjacent to the strawberry growing area will house the rabbits. At 10 square feet per rabbit, that allows 25.6 rabbits. For conservative space allotment, 21 rabbits will be used. This is due to our farms findings that decrease population density in free range rabbits decreases pest and injuries as well as increases meat quality and amount.

Data collected in this project will consist of weekly measurement of strawberry yields as well as weekly recording of produce quality on a 0 to 5 scale.  Rabbit production will be evaluated by monthly evaluation of animal weight and health assessment on a 0 to 5 scale.  Nutrient content of commercial nutrient fertilizer and rabbit manure tea will be evaluated on a monthly basis.  Finally, cost inputs to each system will be compared including materials costs for fertilizer, and labor associated with management of the systems.  Value of production will be evaluated using national and regional average market values.  All data will be evaluated weekly and as season totals using an analysis of variance procedure and means separation. 

Cooperators

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Research

Materials and methods:

 

Rabbit and strawberry production was hypothesized that a combination of the two would yield above average yield in both and lower costs on fertilizer.

The rabbits were housed together in a open air greenhouse that is roofed in greenhouse plastic and screened in chicken mesh wire.

The strawberries were begun in standard vinyl rain troughs commercially available at home depot.

The rabbits were to be raised colony style in a run the length of the 32' structure and 32" wide.

The strawberry troughs were shelved on the walls in rows of 4 on the north and south walls.

Automatic watering was used with a drip system to deliver water and nutrients to the strawberries.

 

Research results and discussion:

The strawberry production and rabbit breeding program started out well.

Hurricane Ida and flooding rainstorms and predators added variables not foreseen.

Strawberry

Strawberry production was fair to middling but a decent crop despite the setbacks was obtained. Significant improvements in the system were necessary to increase overall productivity to increase to a working profit.

With flooding conditions came a host of pestilence and predators upon the system.

Humidity made drainage of the strawberries difficult as the soil medium would not dry out and some root rot was noted.

Plants on higher ground prospered better in the increased airflow circulation.

Lower level shelved strawberry troughs saw considerable attrition due to excessive moisture.

Shop fans were used to try and increase evaporation to little avail as the rains continued and everything continued to be saturated.

The covered strawberries did fair better than the uncovered strawberries and continued to produce berries while element exposed plants lost blooms and any berries quickly to rain damage or molds and blights.

Rabbit manure tea was brewed from a 5 gallon bucket of rabbit manure filled with water. The tea was steaped for 3 days and then fed into the system using Mister Fertilizer timed waterer:

Mister Landscaper 1 Output Port Digital Hose End Timer in Black | MLWT-TIMERhttps://www.lowes.com/pd/Mister-Landscaper-1-Output-Port-Digital-Hose-End-Timer/3614802?cm_mmc=shp-_-c-_-prd-_-plb-_-ggl-_-LIA_PLB_207_Pumps-Water-Irrigation-_-3614802-_-local-_-0-_-0&ds_rl=1286981&gclid=CjwKCAjwlcaRBhBYEiwAK341jWCalP64q4-7K-3CPwa4K4Lugkzknl5ehqAao4umv2drHdWxTRg6yRoCCwAQAvD_BwE&gclsrc=aw.ds

in conjunction with Chapin International HydroFeed 4701, 24 oz

https://www.amazon.com/Chapin-International-HydroFeed-4701-24-Ounce/dp/B07D9T26D3/ref=sr_1_7?crid=1RC3T78N415YC&keywords=inline%2Bliquid%2Bfertilizer%2Bdispenser&qid=1647461545&sprefix=inline%2Bliquid%2B%2Caps%2C585&sr=8-7&th=1

The plants thrived very equivalently to those that were given a commercially available plant grow food.

Foxfarm GrowBig was used for this:

https://www.amazon.com/FoxFarm-Liquid-Concentrate-Fertilizer-Gallon/dp/B000E1FMGC/ref=sr_1_4?crid=913PNJLTX48P&keywords=fox%2Bfarms%2Bgrow%2Bbig&qid=1647461738&sprefix=fox%2Bfarms%2Bgrow%2Bbig%2Caps%2C168&sr=8-4&th=1

We found that the strawberry production was equivalent with one caveat. When using the manure tea, all the straining of solid organic material was done to the best possible feasibility but still silting was noted as a concern for using this system. The Chapin inline distributor caught the silt at the bottom and a drain plug was opened at the bottom to remove silting but it was of note that this would need to be addressed if continual use of rabbit teas were utilized. There could be the possibility of drip lines becoming clogged or the growing media becoming too heavy with silting materials. Although, we did not see a big problem with this in the duration of strawberry production and with strawberries being commercially removed and replaced along with the growing media replenished every 3 years, this may not be a significant setback and may add more body to the soil over time.

Other notes of strawberry difficulties were:

  • Ants infesting the trough and ruining berry production and blossoms.
  • Chicken mechanical damage from scratching when they sneaked into the greenhouse.
  • Note: (Chickens grown from chicks for egg production, chickens sold after damage to greenhouse and gardens and upon learning they carry several diseases that affect rabbits negatively.) DO NOT RAISE CHICKENS AND RABBITS TOGETHER.
  • Excessive humidity caused Anthracnose fruit rot consistently forcing berry picking before full ripe, otherwise fruit lost completely.
    • Anthracnose Ripe Fruit Rot in Field

Data on strawberry production continued to be recorded as these issues continued. Weakness of the plants in production and survivability was being noted in these commercially available rain troughs and additional research was conducted in an ongoing manner to understand what was sub-optimal with the current system. HortAmericas came to the rescue with the needed empirical data to improve and revise the system. Once the berry production season was completed, the strawberry plants were transferred to California Strawberry substrate troughs: link below.

https://hortamericas.com/catalog/growing-supplies/containers/california-strawberry-substrate-trough/

Karla Garcia provided pivotal information. Strawberries require a minimum of 2 litters of growing media per plant. The troughs were filled with 70" peat moss and 30% perlite to provide an optimal growing media.

Below is the technical discussion taken from our emails: (keeping the entirety of the discussion for full details)

*************

Hi Stephen,

Here are the answers to your questions! Hope you find the information useful
 
How close should I space strawberry plants in troughs for maximum health as in no leaf rot or pest and disease issues? 
- We need to provide at least 2 L of substrate per plant. For example, if working with 18L troughs I will separate plants in order to have 9 plants per linear meter. Zig zag orientation is better!
 
Is there a better liquid fertilizer?
- Attached I am sharing the recipe to produce high-quality strawberries!
 
How do I increase fruit production?
- Strawberry is a very sensible plant so in order to increase yields we need to work with a good substrate
The average daily temperature should be 24 C, and in order to get good Brix levels night temperature should not be higher than 16 C
 
What stands are best to hold the troughs most economical?
- We usually recommend to use a table top system but you can even use blocks!
 
Can the troughs be hung?
Yes, but this will be a more complex system, if looking for something economical I will avoid this option
 
Are there any plants that can be grown below the troughs to make use of the runoff below?
We can do it but based on research this is not recommended due to lack of uniformity in lighting
 
Should I water 2 times daily?
Strawberry prefers to have multiple irrigations per day. The recommendation is to provide 30 ml of solution per plant, per irrigation event. The number of irrigation events will depend on greenhouse environmental conditions. Usually, we do from 6 to 11 events.
Drainage should be about 30%
 
*************

Attached are the fruit production and runner production recommendations for fertilizer in the system

St fruit production(1)

St Runner production(1)

*************

From this data the strawberries were transplanted to the new trough system and built on posts with 2x4' runners. The feet of the troughs fit snuggly within the width of the 2'x4' and a light bead of silicone outdoor rated caulk was used to secure them better than just using there own weight.

Rabbits:

Starting out initially we bred several does with our best bucks to make a breeding stock for the strawberry/rabbit system. The breeding went well and kindles were strong until several factors nearly decimated the entire herd.

The rabbits faired little better during the flooding. The spread of coccidiosis through the breeding system was prevalent in the colony style housing that was to be used for the breeding lot for the controlled system. Mortality rates skyrocketted as flooding increased and conditions deteriorated.

Once rains did begin to abate the predators that heretofore had not been an issue began to descend on the surviving kindles. Several kindles were raided and lost.

Swift action was required to save the system and considerable time and sweat went into designing a new system that the heretofore successful colony style system could be shifted too.

The surviving females and kits were transferred to the 32' run as soon as it was completed and there they prospered for a good amount of time.

The system was fenced all around with a significant amount of chicken wire and fasteners. Despite this, rapacious raccoons found their way in and caused additional damage to the system and the breeding stock. The weak point was found to be in an upper corner of overlapped chicken wire that was fastened but the racoon full the fasteners out 7' up and wedged his body through the wire to get in.

VERY LITTLE YOU CAN DO WILL STOP A RACOON UNLESS THE ENTIRE SYSTEM IS HEAVILY SECURED FROM EVERY ANGLE.

Needless to say we were distraught by this onslaught which had never been a problem before.

WARNING: GRAPHIC INFORMATION ON RACOON ATTACK. PLEASE SKIP NEXT PARAGRAPH IF YOU DO NOT WANT TO READ THE DETAILS OF THE RACOON ATTACK. ADDED HERE FOR COMPLETENESS OF DATA IN THE HOPES OF SAVING OTHER LIVESTOCK.

The difficult thing to grasp was the ferocity and seemingly senselessness of the raccoons in their killing. They killed and did not devour the entire animal. In the case of the young kits, they would only kill and eat the upper portion of their skulls. Several young were bitten and killed but not eaten as well. Several older rabbits were maimed and killed but not eaten. This is what led us to believe these raccoons were displaced and starving from habitat loss. Our hypothesis was that the Hurricane Ida and flooding rains displaced several wild animals from their natural settings sending them into areas they had not before had in their domain, seeking food sources near humans not before considered, but then were due to starvation.

CONTINUE:

Additional fencing and 4x8 paneling were used to secure the few remaining breeding stock and a new system was decided upon that was needed to be able to succeed, as we were determined to do, despite the hurricanes, flooding rains and predator problems.

2'x4' cages were designed and constructed onsite from vinyl coated 1"x.5" wire. The rabbit breeds used are on the large end of the rabbit spectrum and additional movement room has been touted as excellent for not only meat quality but rabbit physical and mental health.

The cages were placed on 24x48 shelves. Green epoxy coating and brackets made this an ideal space saver and sanitation increased.

https://www.webstaurantstore.com/regency-24-x-48-wall-mount-green-epoxy-wire-shelf/460EG2448WSK.html

alt

We focused on best practice and found an automatic watering system from KW cages and followed there recommendations.

https://www.kwcages.com/a-guide-to-rabbit-watering-systems

External pellet feeders were attached to the cages for ease of feeding.

Once complete all of the stock was moved into this system. 6 cages on both sides of the wall were used with the north wall covered where the 32"x32' rabbit run side was. No predator issues have occurred since then. The cost of the wire was high but worth it as the .5"x1" is too small for raccoons to get there hands in and cause any issues. Raccoons can cause issues with feet where they can grasp at the rabbits feet.

Additional breeding stock was purchased and breeding was resumed slowly at first, then increasing with time. By the end of the study the breeding program was proceeding well. The evidence of coccidiosis in the system is still evident in the mortality rate of some of the kits. Further study on removing this issue over time is the current focus of the continuation of the system. Rabbits that survive to 4 months do not show signs of any issue with this. Typical kit mortality is at 8 weeks and 4 months. A Cinnamon rabbit was introduced with pedigree lines but died two weeks after her first kindle. ARBA mentions that any sign of listlessness typically ends in the loss of the rabbit and there is no vetting procedure to save them at that point. ARBA also notes that saving kits from a lost doe is nigh impossible. We were able to save 6 of her 7 kits. She kindled on a near freezing night during an electrical storm. I had an active blink camera to watch for her kindle. After sighting them at 9 pm in the middle of the storm, I suited up and rushed out into the storm. She had not kindled in the box but I had left out hay for this eventuality. I moved all 7 kits into the nesting box. 1 kit died, from exposure we believe, and was removed from the box on day 6. It was not found as it was buried deep in the nest box and may have been a complication to the loss of the doe.

2 DAYS AFTER KINDLING OF RABBITS, REMOVE 80% OF NESTING MATERIAL AND REPLACE WITH FRESH NEW MATERIAL RETAINING ONLY PERFECTLY CLEAN FUR AND OR HAY FOR BEST HEALTH OF DOE AND KITS.

The rabbits new housing was intrinsically placed within the strawberry plants rows for ease of management, for animal well-being and quality of life. There is a strong case for larger cages for rabbit production. The challenges that the system faced did not allow for final yield weight of the growing rabbits but the kindles of the rabbits in this system were strong and much easier to manage. The larger area allows the doe to move around freely and the 1x2x1 wooden box for shelter was added 5 days after kindle. This allowed the doe to escape the kits later as they emerged from the nest so she was not driven frantic in their constant search for milk. The does settled into a 1 or 2 a day feeding and the kits did well. All of the rabbits that were more unmanageable before, became more docile and approachable in the new system. The addition of the strawberry plants allowed the rabbits a natural feel of foliage and the added transpiration from the plants aided in overall air quality. The other added benefit for having rows of rabbits next to rows of strawberries is the synergy of management. When working on the rabbits it is easy to cast a quick eye to the strawberries. Likewise when working the strawberries and removing any foliage or working on the water system maintenance, it gives time to enjoy the rabbits and check on their general health, not just viewing them in the normal feeding and cleaning schedule. The objective of overall system increase by adding a hybrid symbiotic system was seen between the strawberry and rabbit production. The overall health of the rabbits and the extra care, focus and maintenance that came along with there proximity to the strawberries made this a very effective system.

The remaining rabbits are going strong and we are looking forward to a productive and effective spring and summer.

Conclusion main take aways:

  1. DO NOT USE COMMERCIAL RAIN GUTTERS FOR STRAWBERRIES
  2. DO RAISE STRAWBERRY TROUGHS ABOVE 32"
  3. DO NOT STACK STRAWBERRY TROUGHS DIRECTLY ABOVE EACH-OTHER
  4. RABBIT MANURE TEA IS AN EFFECTIVE FERTILIZER FOR STRAWBERRY PRODUCTION
  5. RABBIT PREDATORS NEED TO BE GUARDED AGAINST BY SIGNIFICANT MECHANICAL MEANS

Thank you and good luck.

Farming is not for everyone, but those that persevere are richly rewarded.

 

 

 

 

Participation Summary
2 Farmers participating in research

Educational & Outreach Activities

4 On-farm demonstrations
2 Online trainings
7 Tours
1 Webinars / talks / presentations
1 Workshop field days

Participation Summary:

21 Farmers
21 Ag professionals participated
Education/outreach description:

The outreach plan for presenting the findings of this project will be held as a cyber on-farm demonstration with limited onsite physical presence in accordance with any requirements at that time. The cyber on-farm demonstration will be live streamed to YouTube. The feed from the live presentation will also be uploaded to YouTube for future referencing by other farmers and organizations. Accompanying literature will be made available through a link in the YouTube channel. The YouTube Channel StrawBunny has already been claimed for the video feed and distribution of the project findings and future updates as the project proceeds. The website http://www.strawbunny.com has also be claimed and registered to mirror the YouTube channel for additional resources to be distributed in additional multi-media fashion.

All finding and research as well as photo and video documentation will be uploaded to these two cyber locations respectively. 

This cyber presence will allow the largest possible cross section of information distribution to interested parties that could benefit from this research.

SLEWZ LLC will also participate in MSU Extension field days to distribute information and have active discussions with other producers and interested parties. 

Learning Outcomes

15 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation

Project Outcomes

1 Farmers changed or adopted a practice
7 New working collaborations
Project outcomes:

The project affected agricultural stability by demonstrating the aspects of the hypothesized system that worked and failed during the experiment. The resulting successes and failures will help future small farmers avoid these startup challenges.

The main challenges we faced were bred from misinformation or mixed information sources. The idea of trough strawberries is a good one but the type of trough, substrate requirements. Significant data was available will contribute to future sustainability. 

Recommendations:

The study has been a wildly successful research into combined systems while also noting the massive pitfalls to avoid during setup of the system. The original concept of the system was a good one but no where near optimized. The effects of weather, predators and pestilence were variables that could only be dealt with as the system progressed. This is what made the outcome of the system so successful, was its sub-failures. Having a coccidiosis outbreak, and a massive flooding record rainfall and hurricane Ida, as well as a continual attack by predators never before seen on the system forced us to put systems in place that guarded against all of these inevitable in not consistent deleterious effects on the system. The rabbit and strawberry system that evolved from the original inception to the completed project is astoundingly optimized and weather, pestilence and predator protection optimized.

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.