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Grow Food and Soil With A Food Forest


Soil before and after

After ten years of learning from and collaborating with a mega-diverse, globally inspired, edible forest garden, new wonders are under foot. Paradise Lot, here in Holyoke, Massachusetts, USA, has a soil story to tell, and we are finally getting around to deciphering its wonders.

Since 2004, each year we installed a portion of our design of perennial polycultures of multi-purpose plants into sheet mulched garden beds. Although we knew adding copious amounts of carbon and nitrogen rich materials onto the nutrient poor, lifeless ground, would one day “bear fruit", we got real fruit and lots of it, along with fruit of another kind — humus.

Humus is the be-all and end-all of healthy soil. With aggregates formed by life, able to hold multiple times its weight in water, teeming with unfathomable organisms, and packed chock full of the minerals plants and animals need for growth, humus is what gives us powerful resilience in the garden.

With very little direction from us, life has taken the components we offered: compost, mulch, plants and water to turn a dead lot into a thriving edible ecosystem. Here are the results:

SOIL CONDITIONS: 2004

2014

Compacted clay and sand, no topsoil

6 to 12 inches of new spongy topsoil

Opportunistic weeds like quackgrass, goldenrod

New introduced overgrowth is useful to the system: food, fodder, mulch, nursery stock

Organic Matter 2.4 %

Organic Matter 9%

Wide range pH 5.3 to 6.8

pH 6.2 to 6.7

Base Saturation ~ 86 % Ca / 7.5 % Mg

Base Saturation ~ 68.3 % Ca / 11.7 % Mg

Low to medium: NPK, calcium, magnesium, and trace minerals

“Almost perfect soil” — few mineral adjustments needed according to comprehensive soil audit

3.5 cation exchange capacity

11 cation exchange capacity

Partially polluted with lead

Lead soil is under mulch, healthy plants less likely to accumulate lead

Low diversity, soil smells like damp sand, or sulfurous clay

Dozens of worms in every shovel full of soil, soil smells like a forest

 

From the beginning, the garden has chiefly been an experiment about growing tasty, geeky plants. Eric Toensmeier and I also hoped to answer the question, "Is it possible to grow food by mimicking a young temperate forest?" The answer is looking more and more like "yes!" Growing fruit was expected, creating a living soil — smelling, looking and acting like forest soil — that’s an unforeseen surprise.


Backyard before and after

When starting your own edible forest garden or food forest, consider some of what we learned — a permaculture perspective on healthy soil:

  • Start any planting project by doing a comprehensive soil audit. Bring someone in who knows about biological or nutrient dense farming, who can take soil samples, do the tests and provide recommendations for improvement. There is a cost, but trust me it’s worth it. Northeast US resources include: www.forstersoilmanagement.com; www.bionutrient.org and www.loganlabs.com.
  • Although university soil labs offer basic soil tests, I suggest staying away from them. Their tests are usually geared towards monoculture food production, and the data doesn’t account for the micronutrient complexities of no-till, ecologically rich soil. Labs like Logan Labs are accounting for soil nutrient balancing that the university labs don’t consider.
  • For instance, gardeners are taught that a neutral garden pH (i.e. 7 on the pH scale) is best for growing plants. In fact, a pH of 6.4, in mineral balanced soil, has been shown to grow the best food. Some university labs are now testing for base saturation but usually leave out how to fix it (a base saturation of 68% calcium and 12% magnesium is best). They encourage a good organic matter content but don’t necessarily tell you how to accomplish raising it to excellent (% humus is actually a better benchmark). Cation exchange capacity is tested by universities but not highlighted as important. High total cation exchange capacity means high biological activity and mineral availability.


  • Foot of new topsoil

    Balanced minerals: testing labs will provide you with values for macronutrients as well as some of the more important trace elements. Many of the trace elements that aren’t tested can be balanced with a little broad spectrum fertilizer (seaweed emulsion or liquid sea minerals) each year. The dozens of other trace minerals are taken care of by the soil (it’s very hard to add them precisely, and they are used by plants at low amounts anyway).

  • If and where there is need, build rain capturing swales and catchment areas. This is something we left out, yet should have included. Water can be a life enhancing force. Bring more into your garden for system stability, less irrigating from a fossil fuel powered chlorinated tap (in the city), all the while saving money and time. (If you have too much water, then build raised beds to get above it).
  • Lift and aerate the soil as best you can before planting using a hand powered broad fork or machine-driven keyline plow/chisel plow. Then add a mineral blend based on your soil test. Mulch over the native soil as thick as possible with compost and organic matter, then plant. Thickly cover crop areas that will be planted later. There shouldn’t be a need to disturb the soil again after planting (perennials mean no-till).
  • Good perennial plant diversity, designed to use the sun and root zone efficiently, seems to be key. Imagine what happens underground when a hundred species of plant roots, with their own unique biogeochemical mechanisms, pump life enhancing root exudates into the soil around them. I envision this enormous rhizosphere begetting an extremely vast soil food web, the cornerstone of healthy soil.
  • Over the first 2 to 5 years (we retested at 10 years) you are striving for the highest percent humus you can, holding water in the soil, providing habitat for a high diversity of soil food web organisms, particularly worms and mycorrhizae. Mycorrhizae are the nutrient and moisture accumulators of a forest garden. The more you have, the more resilient the system will be.
  • Bring animals into the system any way you can. They help with organic matter and nutrient cycling (saving labor, while producing a yield like eggs or meat). If the animals can’t be in the garden, bring the garden to them by cutting and carrying the weeds and chopped overgrowth to their pen. The woody prunings can be chopped up and added to the planting beds to feed the mycorrhizae.
  • Once your soil minerals are balanced and in the excellent range, your plants are thriving, pests and diseases are low, and you can’t keep up with the abundant nutrient dense harvests, consider the garden’s long term mineral balance. If you eat from the garden, it makes sense to return your poo and pee, and the nutrients that would otherwise be flushed away, back to the garden.
  • We found that it is important to incorporate copious amounts of human engagement throughout the life of the project, particularly during the first years as we are aerating and mulching (planting, weeding and harvesting later on). We all get a workout, have fun learning and doing, and create important relationships for strong local networks (organize a permabliz in your own yard).

Some resources to check out regarding balancing and building soil in gardens and farms: Jeff Lowenfels two books; any of the editor’s picks at Acres USA; and the resources recommended by Dan Kittredge at bionutrient.org.


Backyard — before and after

~~~~~

Jonathan Bates is co-designer and garden inhabitant of the Paradise Lot Holyoke Edible Forest Garden, and contributing author of Paradise Lot: Two Plant Geeks, One-Tenth of an Acre, and the Making of an Edible Garden Oasis in the City, with Eric Toensmeier.

Update: For those who are interested in some of the actual soil test results: https://paradiselotblog.wordpress.com/2016/02/03/soil-health-and-mineral-improvement-persimmon-polyculture/

20 Comments

    1. Hello DeepGreen. Before sheet mulching the first year we did add a limited amount of aragonite calcium to “boost” the pH on 1/4 of the lot that was most acidic. In the first years we also broadcast small amounts of a commercial broad spectrum organic fertilizer to most beds. But, I would suspect most of the soil improvement, including changes to base saturation, came from a combination of 10 years of hand applied leaf, straw and woodchip mulch, compost and cow manure, and biogeochemical activity. We are currently in the process of adding a custom mineral blend created by our soil auditor to get the garden’s mineral balance into the “excellent” range.

        1. It’s a shame that the before and after soil tests have not been posted. If Jonathan has not checked in since the request, perhaps Craig could email him.

  1. What a fantastic documentation of a site over the course of a decade Jonathon. We all know that building soil to produce food takes time, hard work and consistent (at least in the beginning) soil biology support through chop and drop, mulches, etc. I appreciate the note on swales or catchment as an element that you feel you should have added. I tip my hat to you Jonathon, well done and thank you for sharing.

  2. I was thrilled to pieces reading this, right up until I came to the part about “eggs or meat”. Meat?! Why would anyone with a concern for the environment still be eating meat? How many years ago was it that the UN told us the single most important thing we could do for the planet would be to stop eating meat? To say nothing of compassion for our fellow animals! This was a deep, deep disappointment to me. Still, what you’ve done for your little piece of land is quite wonderful! Now please consider going vegan!
    Thanks, Jean C

    1. Hello Jean,
      I completely respect your choice of diet. I know this might spur a long conversation, I don’t expect one on this post. In regards to eating animal products from bugs to beef. I have a few critiques of veganism. There are hundreds of traditions and cultures around the world that depend on meat in their diet. I don’t plan on telling them they are doing it wrong. It is possible, and maybe necessary, to increase environmental regeneration while incorporating animals. There are thousands of breeds of livestock and if we stop eating them they would go extinct. Last, with our current industrial food system, it is impossible to be completely vegan… How many vegans have driven a tractor in a field that is harvesting soy beans? Because if they have, they would know many animals live in the field and are killed by the wheels of those tractors. Not to mention the millions of acres it takes to grow the soy beans, that at some point use to be a thriving rain forest… I’m not trying to offend, just want to put another perspective out there for consideration… That we need to rethink our entire industrialized food system, for vegans and meat eaters alike.

  3. “Bravo, Felicitations !” from France. I have a dream… One day, the earth will be fully gardened, everyone will eat his fill and be happy…

  4. Fantastic system! I wouldn’t recommend adding my pee though. I am post liver transplant and the medications I take result in such a toxic pee that it kills Agapanthus! Which is quite a feat. I have been thinking of bottling my pee and selling it as Deano’s highly effective biocide.

  5. I love permaculture and other natural agriculture, livestock and forestry. Hope to keep connected in order to obtain information and knowledge from all over the world.
    Deepak D. Tamang
    Matatirtha Village, House No. 6, Ward No. 3, Bimbu, Chautara; 16 kilometers south-west of kathmandu center, EcoSolutions farm. See my garden in FaceBook by typing secret_neema or Deepak Tamang

  6. the organic matter in our soil is less than 2% to changes to sponging black soil the organic matter must be 30 – 35 % so before 30 year ago they advance to add ( 5 – 8 ) m 3 manure for 1000 sq meter before plant trees

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