Developing Vertically Integrated Edible Bio-systems in a USDA Hardiness Zone 5 Environment

[Editor's Note: To see the report with tables formatted properly, open the attached version.]

PROJECT BACKGROUND

PrairiErth Farm is a 300-acre diversified organic farm (certified by ICO) producing corn, soybeans, oats, wheat, alfalfa, vegetables, beef, broilers, and eggs and is located in central Illinois. Dave Bishop is the farm owner and farm manager. He has operated PrairiErth since 1981 and was joined by his son Hans in 2010.

PrairiErth has raised livestock organically since the late 1980’s. In a typical year, 30 head of cattle are grown and finished grass-fed, 1000 broilers are finished and a 400 hen laying flock is maintained. Crop conversion to organic production began in 2000, with the first fields certified organic in 2004. Vegetable production has increased from 2 acres in 2009 to 10 acres in 2013.

All crops have been raised organically since 2009. A crop-livestock rotation is utilized for conventional production. Livestock have been raised organically since the late 1980’s.

PROJECT DESCRIPTION

GOALS

This project seeks to enhance the food producing capacity of marginal and underutilized land by:

(1) using vertical and horizontal space for growing,

(2) developing plant guilds which provide natural fertility and pest protection while

(3) reducing or eliminating synthetic inputs and

(4) producing a wide variety of food products marketable in a local foods environment.

PROCESS

Considerations Before Planting a Food Forest

1). Perform a soil analysis to learn what can and cannot be planted

2). Select disease resistant fruit trees to minimize pest pressure.

3). Select understory perennials based on their functionality (4 goals listed above).

*Use caution when selecting berries due to the spotted winged drosophila. Select early bearing varieties that mature before the fruit fly infestation occurs.

4). Select annuals that are not fussy and do not require nicely weeded soil.

*Lettuce easily became leggy and did not flourish. Sunflowers are excellent habitat beginning at just 6 inches, they grow relatively quickly, and are easy to harvest for bouquets.

5). Determine native species (weed & nonweed) that will be maintained as wildlife habitat.

6). Develop an alternative income source for your initial years.

*The fruit trees will not be producing so annuals and brambles will need to be the sole source of income at least for years 1-3.      

7). Plant trees as early as possible because they take longest to mature.

8). Plant a ground cover or combined ground cover to enrich soil.

*Clover and buckwheat were used at PrairiErth but buckwheat seemed to delay or limit germination of desired species. Red clover caused strawberries to become leggy, consider a shorter clover variety.

9). Plant perennials.

10). Plant annuals.

Including the 4 Goals in the Food Forest Development                   

Utilize vertical and horizontal space

Malabar spinach is an excellent example of a plant utilizing vertical space. The vine is planted from seed near fruit trees utilizing the trees vertical stance as a support system for climbing. Aside from its utility as a space optimizer, it also extends the growing season of leafy greens. Malabar spinach grows best in summer heat and only becomes bitter if stressed by a dry spell.^[1] Experiencing extreme sensitivity to frost, Malabar spinach is not a substitute for cool season greens but an opportunity to maintain greens in the hot summer months. Malabar spinach is grown as an annual in temperate climates but grows as a perennial in frost free zones.

Inspiring the name of this system, fruit trees must be included in a food forest. Dwarf trees are selected to maintain near full sun exposure to all plants in the food forest. Despite their necessary inclusion, fruit trees offer a very versatile use of vertical and horizontal space. The ability to trim a tree offers endless possibilities for filling the canopy with foliage and fruit while maintaining open space in the understory.

The open space under the fruit trees is an excellent space for brambles, herbs, groundcover and roots. A young food forest has sun-filled spaces between the newly planted trees perfect for short-term planting of quicker maturing understory species. Blackberries, red raspberries, and black raspberries all find a place in these spaces while herbs fill in still open spaces left between the bramble and tree layers. The fruit trees’ most immediate neighbors need to be short enough to receive sun exposure when the fruit trees leaf out. Garlic and onions are excellent neighbors able to gather ground-level sun exposure while their strong odors deter pests. In addition, garlic and onions are high value products at a farmers market.

Develop plant guilds that provide natural fertility and pest protection

A food forest design lends itself to natural fertility. Nutrients accumulate in plants and return to the system as leaf litter, roots, and branches that are shed. Accumulated matter retains moisture and regulates the soil climate, as a result, the food forest requires less watering and experiences less soil temperature fluctuation. Decomposition of organic material increases soil fertility and improves soil structure by contributing to the A1 soil horizon. Additionally, organic material offers both food and habitat to microorganisms and beneficial insects, which are required for a healthy productive soil and pest protection. A variety of plants are planted together in a guild to ensure each plant contributes a different combination of nutrients to the soil. In the food forest at PrairiErth, the root system of the fruit trees stabilizes the soil structure and acts as a host for mycorrhizal fungi. Clover is planted as a living mulch to supplement the organic material shed by plants. When clover is cut or tilled, accumulated nitrogen is returned to the system. The extensive shallow root system of clover anchors the soil to prevent erosion.^[2] Not only is clover an excellent nutrient accumulator, it is habitat to minute pirate bugs (Orius tristicolor)^[3] and predatory mites^[4] – with mite populations higher in red clover than white clover. Minute pirate bugs feed on thrips and predatory mites feed on pest mite populations, like two-spotted spider mites. Resident species such as alfalfa (Medicago sativa) were allowed to grow in patches to provide habitat for beneficial insects like big-eyed bugs. Buckwheat (Fagopyrum esculentum) quickly matures offering a nectar supply that can host a large population of beneficial insects such as, parasitic wasps (Dolichogenidea tasmanica)^[5].

Reduce or eliminate synthetic inputs

Synthetic pesticides and synthetic fertilizers were never applied to the food forest. Organic compost developed on site was the only fertilizer input incorporated into the food forest during plantings. In place of insecticides, herbs and edible plants that are habitat for predator insects were added to the food forest to develop natural pest control. Pest problems were minimal in part because the food forest is young and has just begun to produce fruit. Flea beetles and spotted-winged drosophila were the major pest problems. Flea beetles attacked cool season vegetables like bok choy. Flea beetles prefer warm, sunny locations so herbs were added around bok choy to increase the density of plantings and increase shade and cool spots. Cilantro was planted to draw in predator insects that consume flea beetles. Spotted-wing drosophila is an invasive species that lays eggs in mid-season red raspberry varieties – the invading species was identified by Amanda Christenson, University of Illinois McLean, Livingston, and Woodford County Extension. There are no methods of deterring larvae development without using synthetic inputs. University of Illinois Small Farms Extension Bill Davison suggested planting early season red raspberry varieties as peak fruit fly breeding occurs midseason.

Produce a wide variety of food products marketable in local food environments

High value fruits, including red and black raspberries, blackberries, apples, pears, peaches, rhubarb, asparagus, and strawberries will be the major crops of the food forest. These crops all require at least a year of growth, or more, before fruit is produced. Annuals herbs, vegetables, and flowers are planted to supplement low perennial production in the early years.

PEOPLE

Dave Bishop – Managed transition of the project between Food Forest Managers. Advised Food Forest Managers on best practices and best planting options.

Kelly Schneider – First year Food Forest Manager. Selected trees with the assistance of Dave Bishop. Established the food forest layout.

Liz Pegg – Second year Food Forest Manager. Replanted lost trees and continue to establish perennials throughout the food forest.

Chris Konleczka – U of I Extension Coordinator for McLean, Livingston, and Woodford County assisted in evaluating insect and disease pressure.

Amanda Christenson – U of I Extension Professional for McLean, Livingston, and Woodford County assisted in evaluating insect and disease pressure.

Deborah Cavanaugh-Grant – U of I Small Farms Coordinator for Logan, Menard, and Sangamon County offered resources for farmers market prices.

RESULTS

The food forest produced a revenue of $184 in year two. Production was not substantial enough to record a revenue for year one. The revenue was determined by pricing harvested produce according to prices set at Illinois Farmers Markets. These prices were retrieved from Illinois Farmers Market Report^[6]. A list of harvested produce can be seen in Table 1.

Table 1. Food Forest Income

Entering the second year, the blackberries and red raspberries offered almost no berries. The black raspberries have been very productive and future plantings will include more black raspberries. Mint and blueberries were added the second year but not harvested. As an aggressive spreader, mint may be one of the easiest herbs to grow and one of the best perennials for a quick turn around time for harvest.

Ten strawberry plants planted in the first year yielded only 30 strawberries in the second year. Twenty-five strawberry plants were planted in the second year and buds were plucked off to stimulate root growth. Strawberries are quicker to establish, in terms of perennials, but they may not end up being very productive in a crowded food forest.

In the second year there was an attempt to plant a large variety of annual species to maximize revenue before the perennials had begun producing. Table 2 lists all the annuals introduced plus established or newly planted perennials. Of the species in this list, sunflowers, malabar spinach were planted minimally and not harvested. Future plantings will be more intensive as these plants offer excellent opportunities for use of vertical space, habitat inclusion, and potentially high value sale at a farmers market. Peas were planted at a greater density than malabar spinach and sunflowers but they were planted in open plot not utilizing vertical spaces created by the food forest. Future plantings of peas and malabar spinach will be stationed near trees and staking posts. Sunflowers will be planted near staking posts allowing the vining plants to anchor the sunflowers to the stakes preventing the sunflowers from drooping or falling.

Buckwheat was not planted this year but as an excellent self-seeding species it grew everywhere in the food forest from seed dropped by the plant last year. I think it may have negatively impacted many annual plantings. Buckwheat has an allelopathic affect inhibiting seed germination of nearby seed. As a result, this plant has great value as a cover crop. The food forest benefits from this plant as a supplier of phosphorus to the soil and insectary habitat. So easily grown, buckwheat could also be harvested for its groats.

Huckleberries were planted but not harvested. This plant is not enjoyable to most people raw so it would likely only be successful sold as a jam.

Rutabagas were harvested late in the fall and stored through the winter. They are not a very high value crop but may be valuable for selling in the dead of winter.

Table 2. Seed Plantings: Successes & Failures

Observed insect pressure was minimal but bok choy and some lettuce plantings experienced insect pressure with flea beetles consistently observed on the bok choy. Hans Bishop suggested planting bok choy in the fall when flea beetles are less active. To reduce flea beetle pressure, bok choy was shaded by denser plantings, as well as, planting of species that harbor beneficial insects.

Spotted-wing drosophila were not an observed problem in raspberries but were sighted by Amanda Christenson, U of I Ext Extra Help. An infestation would severely limit berry sales so soft bodied fruits will need to be monitored for infestation. Integrated Pest Management techniques include netting with 0.98 mm mesh, picking or clearing ripe or fallen fruit, and monitoring with vinegar traps. As a last resort, the insecticide spinosad may be required.
To avoid initial infestation, Bill Davison, U of I Ext, suggested planting early season and late season varieties. Berries of these varieties mature outside peak breeding season of the spotted-wing drosophila. Future strawberry plantings will be June-bearing varieties. Primocane berry varieties which fruit in fall and early spring may be considered for future plantings.

Aphids were also observed, but they did not cause any apparent damage.

DISCUSSION
Before planning a food forest, determine what plants do well in a multistory planting (Lettuce was not successful. It became leggy when competing with the clover for light.) and have a realistic expectation of how long it will take perennials to reach peak production. If you require an income before peak production of perennials, develop a market in which your perennials can replace your annuals. For example, if all your perennials are fruit but you grow annual vegetables, your customers will build a relationship with you based on your vegetables. When you switch to fruit, the customers will have lost their vegetable supplier and may already have a fruit supplier.

Diversify the system within your means. After planting this spring there were 45 species in the system – there were too many establishing plants to monitor. As the food forest is beginning, start with a few species – ones that are easy to establish, self-seed readily, offer a valuable harvest, and are relatively easy to harvest. Sunflowers and nasturtiums should be the first addition of annuals to the food forest. Both meet all four criteria. Nasturtium flowers and leaves can be sold as edibles. What decadent salads they would make at the farmers market! Sunflowers could be sold as bouquets or for edible seeds. Chamomile, feverfew, sorrel, cilantro, and alyssum would all be excellent additions to the food forest as self-seeders but they were not given enough attention to reach maturity. These species all readily self-seed so once nurtured to maturity, these species should be self-sustaining. Buckwheat self-seeded readily and would be a good crop if the groats were harvested for sale. Of the root crops, rutabaga seemed to establish well because it was the only root crop to grow to maturity.

I think the value of a food forest is in its ability to be self-sustaining. Unlike a conventional organic farm, this is not a system designed to annually plant and tend new seedlings but rather a system that requires less tending as it matures and hopefully future generations of self-seeding plants are more resilient to insect pressure, possibly even offering protection to other plants in the food forest. Species like bok choy and lettuce, which have such trouble establishing and thriving in a multistory system, are not likely to be the most successful species in a food forest.

Asparagus successfully sprouted from seed but made little progress as it was planted on the end of a strip and was continually mowed over. To more easily identify planting locations, species should be established in identifiable locations. Future plantings of asparagus will be planted within rows instead of row ends.

Black raspberries are prolific on this site and should be the focus of future berry plantings.
Mint would likely be most valuable as a value added product at a farmers market – mint jelly, candied mint, and mint refreshments.

OUTREACH
PrairiErth Food Forest was shared through one professional field day, two college field trips, three school age field trips, and three talks. Visiting the food forest offered guests an opportunity to get up close and personal with an unconventional food producing system and the wildlife that maintains it. On one occasion, a group of visitors spotted, with some disappointment, a nasty bout of pests chewing delicious produce. But suddenly, a lacewing flew down to devour the pest. The system of natural pest protection was functioning right before the visitors’ eyes.

The field day was advertised through social media with assistance of Illinois Stewardship Alliance and through dissemination of informational flyers. Approximately 50 farmers, conservation and farm industry professionals, and researchers attended the field day. The food forest was presented in conjunction with a cover crop study, a naturalist survey, PrairiErth farm techniques, and crop consulting by Dr. Bill Becker in order to draw a larger audience. The food forest received additional public exposure through local news media covering the field day. Reception at the field day was positive. Bill Davison, U of IL Ext McLean, Woodford, and Livingston County expressed interest in the project and informed me of a food forest developing in Normal. Two members of the public expressed interest in the project and several industry professionals expressed interest. A number of these individuals expressed an interest in a particular component of the food forest. Some discussed their own orchard experience, one was curious why stands of buckwheat remained during the growing season, and others offered unapplied management practices for pest control. All inquiries were positive responses to the system.

The remaining events were organized by direct contact with the visitors. The college field trips were Dr. Himley’s geology class and Dr. Kopsell’s horticulture class, both from Illinois State University each with about 15 students in the class. Both professors were very interested in the food forest as a part of the whole farm experience. Students in both classes could appropriately apply our land use techniques to their coursework. Dr. Kopsell’s class viewed the food forest as an alternative production method to an orchard. Dr. Himley’s class could apply their understanding of rock relationships to the soil when discussing marginal land of the food forest versus high quality friable land of conventional field systems.

The children were my favorite visitors. Between the three groups, around 60 children visited the food forest. They were so excited to explore the food forest: searching for bugs and food! Their desire to explore was a sure sign they enjoyed the visit. With a growing interest in school gardens, orchards and food forests are better food producing systems to implement than traditional gardens. A large percentage of children are absent in peak gardening season, food forests require less work and produce is ripe when school is in session. This is an excellent reason to promote food forests. They are the most appropriate systems for children and school gardens.

PrairiErth Food Forest has been the topic of several talks. These talks could be the most powerful outreach. The first talk I attended was in March during the Russell Allen Garden Day in Lincoln. I wanted to attend the garden day when I saw the brochure and a talk on a food forest. It was after hearing this talk that I became the new food forest manager. Just a few weeks ago, at the end of March, Dave and I gave a talk to a horticulture class at Illinois State University. Two students were very interested in getting involved in nonconventional agriculture systems. One of those students will be assisting with the food forest this year.
Posting results and photos to PrairiErth Farm’s website, Facebook page, and farmers market stand all would be the best avenues for further promotion of PrairiErth Food Forest.

[1] Cornell University. (2006). Growing Guide – Malabar Spinach. Retrieved from http://www.gardening.cornell.edu/homegardening/scene9529.html.

[2] Clark, A, ed. 2012. Managing Cover Crops Profitably. Handbook Series Book 9. SARE, College Park, MD.

[3] Young-Matthews, A. 2013. Plant Guide for Crimsom Clover (Trifolium incarnatum). USDA-Natural Resources Conservation Service, Plant Materials Center, Corvallis, OR.

[4] Edson, C. et al. 2003. Cherry Orchard Floor Management: Opportunities to Improve Profit and Stewarship. MSU Extension Bulletin E-2890. Michigan State University Extension, East Lansing, MI.

[5] Stephens et al., 1998.Enhancing Biological Control of Leafrollers (Lepidoptera: Tortricidae) by Sowing Buckwheat (Fagopyrum esculentum) in an Orchard. Biocontrol Science and Technology. 8(4). (Abstr.)

[6] Aly, B., Cavanaugh-Grant, D., and Shi, A. 2014. Illinois Farmers Market Report. Center for Crop Diversification, University of Kentucky, Lexington, KY.

• Food Forest Final Report 2