Cold Climate Syntropic Agriculture

Bringing the Tropics to New York

By Harry Greene

Syntropic Agriculture is an innovative design methodology and set of farming techniques that has quickly swept across the regenerative agriculture space. Ernst Gotsch popularized the practices over several decades, while Agenda Gotsch and Fazenda da Toca most recently catapulted it all into the mainstream with the film Life in Syntropy. Syntropic farming has taken hold in Brazil and the tropics, but today we ask: How can we apply these concepts to cold climates? 

Agroforestry

Agroforestry is the intentional incorporation of useful trees onto working farms. Practices range from adding timber trees to grazing operations, to traditional orcharding, to growing blueberries or mangoes in our yards. Trees slow desiccating winds, create shade for livestock, sequester carbon, and clean our air and water, all while creating marketable economic value.

Tropical forests and temperate forests differ greatly. Tropical forests are much louder, literally and figuratively. Trees grow 4-8 times as quickly in the tropics: many trees in Brazil look like 30-foot-tall burdock plants, and bananas produce 2.5 times as many calories (food) per acre than do chestnuts. Most of a tropical forest’s biomass (living and dead plants, fungi etc.) is above ground, in part because the forest does not need to survive through the winter and store fertility below ground. Tropical soils are relatively low in organic matter, because fallen leaves and branches decompose rapidly. In contrast, cold-climate forests have deep organic soils, and biomass accumulates much more slowly. In layman's terms, the top layer of forest soil in New York looks like chocolate cake, while in Brazil it looks like whole wheat flour. Differences aside, trees are trees, and many principles of agroforestry hold true across the globe. In practice, management practices of these working trees are not directly transferable between climates, but concepts and themes hold true. This article speaks to the overlap between tropical and temperate-climate syntropic agriculture.

Part I: Fazenda da Toca

Here, we will be examining Syntropic farming in the context of Fazenda da Toca. Fazenda da toca is a 5,700-acre farm located 125 miles northwest of São Paulo, Brazil. They are pioneering large-scale mechanized agroforestry, and they cash flow with eggs, jams, and wholesale fruit juice. The Diniz family has owned and managed the land since 1971. Pedro Paulo Diniz, once a Formula 1 pilot, returned to the family farm in 2009 and began a complete conversion to organic. The team is systemically accelerating the regeneration of both soil and the local towns that depend on it. Fazenda da Toca grows organic thought just as much as organic food. The Diniz family founded the Brazilian supermarket chain Pão de Açúcar, and is pioneering profitable, large-scale organic farming in Brazil.

The foreground: forest and mangoes. The background: cropland that was once forest. Moving into the anthropocene, with a deep understanding of the state of humanity, let us recognize that the objectives and mechanics of farming must change. The status-quo of agriculture front-loads cash flow by liquidating biological capital: we’re currently deforesting the Amazon to grow soy to feed pigs in China. Let us recognize this, but set aside the corresponding distress and ask: “How can we create an alternative?” How can farming put carbon back into the soil, pay living wages, feed people healthy food, and reforest Brazil? Fazenda da Toca is a beacon of hope in the time of climate change.

Agenda Gotsch

Syntropic agriculture is a design methodology set of agroforestry practices developed by Ernst Gotsch. Ernst is a Swiss farmer that migrated to Brazil in 1984. After studying indigenous methods of forest management, he bought 1,200 acres of clear-cut and gradually turned it into a shade-grown cacao forest. The terms multi-strata agroforestry, forest farming, and forest gardening are all applicable, but Ernst’s method is widely known as syntropic agriculture. Syntropy is the opposite of entropy, and entropy is the tendency of a system to degrade into disorder: cars break down, and rocks and dirt erode into the ocean. The only thing that counters this chaos is life itself. Plants use sunlight to photosynthesize and counter entropy. Syntropy, is therefore is the process of creating and managing complexity. In our context, this managed complexity is a forest, a farm, and everything in between.

Syntropic Agriculture: Managed Complexity

In places where it rains a lot, fields will slowly turn into scrubland, and then into forest. This process is known as ecological succession, or the way in which a living landscapes changes in structure and species composition. In cold climates, poplars, locust, alder, and wind-pollinated conifers move into deforested areas. These trees have small, light seeds, and act as early-successional species. They grow quickly, and generally don’t live a very long time. Oaks, whose seeds are distributed by rodents, move into fields much more slowly. They are known as late-successional or climax species. They grow much more slowly, and are more shade-tolerant. Young oak saplings can dwell under a canopy until a poplar above them dies, at which time they’ll grow up into the light, they themselves becoming the canopy. The poplar will lie on the ground, decompose, and feed the fungi in the soil. That fungal soil will in turn supply the oak with water and fertility.

This forest in Craftsbury, Vermont has been thinned of conifers. On the left side the photo, we can see a sugar-maple seedling which will go on to become the canopy. The non-marketable conifer branches and logs are left on the forest floor to decompose. This is an example of traditional forestry, but it depicts managed succession.

Agroforestry as the oldest form of agriculture

Managing forests for food is the oldest form of agriculture: anthropologists no longer consider the grains of mesopotamia to be the first crops. Imagine that you’re a native american living in present-day Pennsylvania in the year 1400: you see poplars shading out a chestnut and an oak, and you know that chestnuts and oaks produce food. Having a deep understanding of forest dynamics, you cut the poplar down and leave the chestnuts. In the tropics, this practice consists of opening up enough light in the canopy to grow fruit and cacao. Connecting syntropy, ecological succession, and forest management gives us syntropic agriculture, which is Ernst’s version of forest farming. He plants fast-growing species such as acacia, gliricidia, and eucalyptus, together with bananas, limes, cacao, and other food-producing trees. He systematically prunes the branches of the biomass trees, and leaves them on the ground to decompose. Pruning fosters fungal activity in the soil, both by adding carbon on top of the soil and stimulating root growth. Forests in adolescence grow quickly, and syntropic agriculture keeps certain components of the system in perpetual adolescence, when they are growing most quickly. The goal is the system is for the support species to produce most or all of the needed fertility and irrigation for the food crops below. If this process seems complicated, that’s because it is. The goal at Fazenda da Toca is to apply the principles of syntropy to commercial agriculture, and mechanize much of this biomass accumulation. 

Here, the overstory of eucalyptus is maintained in a "high pollard:" it is periodically given a haircut, and the pruned branches are then used as mulch. This is similar to the pine logs and branches above, in Vermont, but here the biomass is arranged more strategically in such a high-touch system.

Fazenda da Toca is pioneering syntropic agriculture on a large scale. Ernst Gotsch lived at Fazenda da Toca for two years to design and establish the farm’s multi-species agroforestry plots. Eucalyptus and bananas are staples of the designs. Though eucalyptus is native to Australia and may not readily associate with the native mycorrhizae of Brazil, they cannot be beat in the game of biomass accumulation. Other species include limes, cacao, mahogany, and many more.

The author of this article in a 2-year-old eucalyptus tree. These trees create partial shade, fix soil carbon, and go on to be used for biomass accumulation.

Fazenda da Toca grows and manages biomass in syntropy:

Fazenda da Toca’s system accumulates biomass in the form of grass, banana stalks, eucalyptus branches, and wood chips. A sample succession that the farm employs is to first sow organic cover crops such as sorghum and millet to improve the soil. They then establish perennial grass, which they cut and rake into windrows. This initial accumulation of organic matter covers and improves the soil. Trees are then established in repeating patterns and consortiums. The biomass species are pruned to a fixed height. When the eucalyptus trees are young, their branches are cut with pruners and loppers. As they get older, the chainsaws and wood chippers come out.

Syntropy: the continuous, rapid, and strategic accumulation and placement of biomass in a system.

The white filaments running through this hay, at the base of this tree row, are fungi. Fungi are the internet of the soil: they distribute water and nutrients, extract minerals from the subsoil, and reach farther than tree roots do alone.

In-situ biomass: What can we learn?

This section of the farm, the original syntropic plot, is too steep to grow grain on, and tractor access is a challenge. Remote farms may have a comparative advantage in growing biomass in-situ.

Managed on a small scale or in remote areas with limited access to external inputs, syntropic methods are highly applicable. On a small scale, available labor enables syntropic farming, and and in remote areas, growing biomass in situ can be more cost effective (convenient) than importing it. What Mr. Gotsch and Fazenda da Toca are pioneering is a mechanized syntropic system for establishing and managing commercial tree crops organically, and we in temperate climates can learn a great deal from their experiences. The first multi-species plots at Fazenda da Toca were established in 2014. Four growing seasons later, we can analyze what has worked well and also look at where the farm is now headed.

The author, at 6 feet in height, standing in one of the farm's older plots. The most obvious form of available biomass here: the grass.

Creating contact between the grass and the soil favors nutrient cycling and in-ground biomass accumulation. This can be done with machinery or with mob-grazed livestock.

Raked grass and a pruned wood mimic the fungal duff layer of a forest floor. They suppress weeds and create organic soil fertility. Now how can we do this most efficiently?

Successes at Fazenda da Toca

Many banana plantations are grown with flood irrigation. While non-irrigated bananas might be out of the question for some, Fazenda da Toca is producing organic tree crops on dry land, successfully, albeit with drip and overhead irrigation. “Water is planted!” Ernst says. By covering the soil, syntropic farming makes the best use of the water available.

Drip irrigation provides the water necessary for production agriculture. The catch is that the pruned eucalyptus branches and spent banana stalks below act as a carbon sponge: water use drops considerably, and drought resilience increases greatly. This section of Toca is mostly just bananas and eucalyptus. A nearby section adds in mangos trees as well.

The farm has established incredible pilot projects and economically-productive agroforestry systems. The oldest syntropic plot were planted in 2014. Four years may seem like a long time in the tropics, but this is rapid prototyping on the time scale of tree crops.

To quote Darren Doherty, “The climate of the mind is the hardest thing to change.” By straying from the norm of chemical-dependent monocultures, be they of soy or fruit, in the largest agricultural nation of South America and a global hotspot of biodiversity, Fazenda da Toca is doing much more than planting trees. They’re moving quickly with organic tree-crops in a country that has few, and changing agriculture from both the top-down and the bottom-up. The proof of concept and extensive validation phases are concluding, and Toca is on track to scale these systems with investment capital. We must change farming, and these regenerative practices must scale in every plausible way.

Toca's next steps

Fazenda da Toca is now inquiring as to how they can develop the most efficient iteration of large-scale syntropic agriculture, without sacrificing ecosystem processes.

Conceptually, the multi-species rows of trees have been a success: the biomass species are pruned and accumulate organic matter, which nourishes the fruit trees below. Ecology however, must be balanced with economy, in all interpretations of the latter. This is not to say that we must sacrifice the ecological soundness of the system. Instead, given that we are growing food to sell to people, we must be efficient when managing complexity. If a process is economical, it is efficient, and we can shatter the tradeoff between planet and profit. Toyota records and minimizes how much time and energy each step of their manufacturing process takes: this practice comes from Taiichi Ono, and is known as Lean Manufacturing. The objective is to minimize muda, or waste. Waste is defined as anything that does not add value, and includes raw materials, time, and movements. Consumers will pay for better food, but we cannot expect them to pay for our inefficiencies. Fazenda da Toca is now inquiring as to how they can develop the most efficient iteration of large-scale syntropic agriculture, without sacrificing ecosystem processes. How much time does pruning and mulching take? How can we design management efficiency into the system? This is the frontier of agroforestry.

Mulching must also be done safely. Pruning 50 biomass trees can easily be done by hand in a forest garden. Pruning thousands of biomass trees across 5,700 acres allows less room for error. The tops of the eucalyptus trees at Fazenda da Toca are cut off at a height of six meters. A tractor with a raised frame on it moves alongside the rows, carrying a chainsaw operator. Once the branches are on the ground, a chip crew turns them into mulch. To the loggers among us, this sounds somewhat exhilarating, but it does not sound efficient. Let us also consider that loggers have the most dangerous job: injury rates are comparable to those of deep sea fishermen. Climbing arborists are urban loggers than climb trees with chainsaws. They are the crew that stops by after a hurricane snaps a limb onto power lines. The statistics on their injury rates are lumped in with logging as a profession, but their job is regarded as the most dangerous job. To design the work of a climbing arborist into our system is therefore questionable. And this is a purely utilitarian perspective: we won’t be managing an orchard for very long with a broken back. 

This eucalyptus tree is pruned to 30 feet in height. This style of management may create an ideal canopy, but it also creates management challenges. Canopy management can likely be done from waist height.

Canopy Design: How much sunlight should we intercept?

This system was designed to accommodate large-scale grain production. The triple rows of trees are spaced 13 meters apart. 

We have established that multi-layer agroforestry systems are viable and reasonable. Now, precisely how much sunlight can we afford to intercept with an overstory? The principal economic advantage of agroforestry is that it takes advantage of vertical space that otherwise would go to waste. We can grow trees with and above grain, while increasing farm profitability. The overstory trees indeed intercept sunlight, but the cost-benefit ratio is in our favor. The questions we must ask are: How much sunlight can we intercept? What is the optimal amount of sunlight to allocate to an overstory?

The triple rows of trees, pictured above. The dark green block to the right is a eucalyptus plantation, and the curved rows at center are pictured below.

Here, the rows of trees are mulched with both raked hay and wood chips. The high-pollard photo, above, was taken in this section. Below is a photo of what the this section's soil looks like.

The soil here is very sandy, but Toca's management has increased soil organic matter to 6%, which is as high as it will reasonably go in the tropics.

In the tropics, a certain amount of shade increases understory yields: breaking up the strong tropical sun moderates the leaf temperature of crops such as coffee, cacao and even citrus. In cold climates however, there are very few crops that prefer as much shade as coffee or cacao. The sun in New York is not strong enough to merit a thick overstory of poplar above apple trees. Aside from a number of forest medicinals such as ginseng and cohosh, very few cold-climate crops grow in deep shade. We go on to discuss canopy structure in Part II.

This is the understory of the eucalyptus plantation pictured in the satellite image above. In relatively deep shade, grass growth is still substantial. This undoubtedly speaks to the viability of silvopasture in the tropics.

Part II: Temperate Climate Syntropic Agriculture

Our guiding questions are two:

How can we apply the principles of succession to commercial agroforestry?

What is the role of early-successional species in commercial agroforestry?

Let us begin this discussion with three differences between tropical and temperate forests. First, trees grow much more slowly in cold climates. Second, in cold climates, much more of the system’s biomass is below ground, in the soil. Thirdly, the sun is stronger in the tropics, and how we manage shade must differ between Brazil and Wisconsin.

How much mulch can we realistically expect from trees?

Chipped wood is a better mulch than hay is, but hay may be easier to manage. Those that have spent time chipping brush and branches know how little mulch one ends up with. Given that eucalyptus grow 4 times as fast as poplar, we would need to plant 4 times more poplar trees to obtain the same amount of mulch. Perhaps we should plant those trees! However, consequently, hay may be a more realistic source of grown-in-situ mulch than wood is. Rotary-raking cut grass up against rows of trees is a well-accepted practice in agroforestry. It is known as “mow and blow.” Complexities abound, however: piles of grass in cold climates become a rodent night club in winter. Voles kill apple trees, and tree guards are imperative. This being said, wood chip mulch is of very high quality and should unquestionably have a place in organic tree crop management. Ramial wood chips are chips that are made of tree branches, and they contain 3 times more nutrients than logs, given that the ratio of vascular cambium (bark) to cambium (inner wood) is higher in branches. Mulching with the pruned branches of poplar, willow, and alder makes good sense. While we chip pruned apple branches, we can also chip branches from other trees. For more information on this subject, pick up a copy of Michael Phillips’ The Holistic Orchard. 

Much of the mulch we acquire from lumber yards and arborists is from conifer trees. While pine mulch is better than no mulch, conifers associate with brown-rot fungi, instead of white-rot fungi. They decompose cellulose but not lignin, creating an environment more conducive to conifers than to fruit trees. Our wood chips should ideally be 80% deciduous to foster white rot fungi, but decomposed pine mulch is better than no mulch at all.

Look below ground! There is syntropy in the soil.

To understand the role of early-successional species in temperate-climate agroforestry, we must look beneath our feet. Early-successional species such as poplar, willow, and alder associate with both pasture fungi and forest fungi, formally known as endomycorrhizal and ectomycorrhizal fungi. This makes them well suited for abandoned pasture or cropland that is in a transition to forest or agroforest. Mycorrhizae are soil-fungi that associate with roots. Ectomycorrhizae in particular extend up to 12 feet away from a tree’s roots, bringing back water and nutrients in exchange for photosynthate (sugars). They are the internet of forest soils. Endomycorrhizae on the other hand also increase water and nutrient availability, but they operate in close proximity to a tree’s roots. Both endo and ectomycorrhizae increase soil carbon, which constitutes fertility and resilience: glomalin (mushroom-root skeletons) makes up 1/3 of carbon in soil. Ectomycorrhizae associate with plants (trees) that are either climax species in a forest, or trees that help turn pasture into forest. Fruit trees do best in a forest-edge ecology, and early-successional species help create that environment. For approachable information on mycorrhizae, consult Michael Phillips' book Mycorrhizal Planet. Just as folks in the tropics work eucalyptus into their agroforestry designs, temperate climate managers can do the same with our fast-growing trees. They provide a very similar benefit, but we must simply expect different things from them.

This organic orchard in Argentine Patagonia is surrounded by poplar windbreaks. In addition to slowing the region's desiccating winds, they fix beneficial fungi that otherwise would not associate with fruit trees.

This is not to say that tropical syntropic agriculture is not soil-centric, because it is. The majority of a tropical forest's woody biomass being held above-ground, the appropriate syntropic practice is to increase biomass accumulation on the soil surface, where leaves and branches otherwise rapidly decompose and turn back into carbon dioxide. A syntropic manager in the tropics places these whole or chipped branches next to desired species, such as fruit trees: isolating the practice, this is simply a specific way to mulch fruit trees. In cold climates, much more of the biological action (syntropy) takes place below ground in the rhizosphere. Covering the soil surface in Pennsylvania or France with dead grass and wood chips is still imperative, but we can also rely on and trust what is already going on underground.

Let us hypothesize that at least in part, having grown up in Switzerland, Ernst Gotsch was originally, consciously or intuitively, mimicking a temperate-climate forest duff layer. The forest floor in Maine or Sweden is covered with 6 inches of dead leaves and sticks. In Brazil: it's really just dirt with a few leaves on top. 

Light! Dappled sunlight and canopy structure

Our goal is to optimize the amount of light energy that our production crops absorb. How much light can we intercept with an overstory of trees while meeting production goals? Any crop we produce: be it corn, coffee, cattle or citrus, has a specific range of light energy that it needs to thrive. This optimal zone is a function of the light itself, of heat, and of both.

What does “too much sunlight” mean?

Plants and animals can receive too much sun, and "getting too much sunlight" is largely a function of heat. When grass and coffee leaves get too hot, their stomata (pores) close to conserve moisture. Consequently, some grass species will actually grow faster in partial shade, and partial shade can increase coffee and cacao yields. When cattle are heat-stressed, they spend time lying down, instead of eating. Cows that aren’t heat stressed can gain up to 1.2 more pounds per day, which is a massive increase. Too much heat can also dry out the soil: moisture optimization is critical regardless of climate.

What happens when there is too little sunlight?

Too little sunlight reduces understory crop yields, due to competition. However, intercepting that light with a tree overstory can increase a system’s total economic value created. Secondarily, sunlight can dry out tree trunks and decrease pressure from fungal pathogens: sunlight and airflow are both vital. Shifting our focus to higher latitudes, the number one factor in designing a multi-species agroforestry system is light competition. There is less sunlight-energy to be had in Northern Europe than there is in Brazil.

For both conceptual and practical purposes, it is best to understand the work done with Silvoarable Agroforestry For Europe (SAFE) consortium. The SAFE initiative entails the long-term monitoring and documentation of alley cropping systems throughout Europe: their decades-long research and final report details the interactions of timber trees and grain.

The SAFE report shows us that high-pruning timber trees (removing branches up to 10 meters) vastly increased light penetration, and more than doubled understory grain yields. Short-season crops such as wheat were ideal for a treed system, as light interception delayed crop maturity, but did not decrease yields.

Combining timber trees and wheat was 145% as profitable as growing them in separately. Photo: Dupraz et al.

Out of all of the alley-cropping sites in Europe, the populus-wheat intercropping system in Vezenobres, France stood out. As the trees grew older, they intercepted more light. Over the 15-year period, the system produced 71% of the control’s non-treed grain yields: yields were 90% of the control in early years, but dropped to 30% in year 17. Shortly after, the timber was harvested, and crop yields increased once again. The system was planted with 139 timber trees per hectare (55 trees per acre). And how much profit was created? To understand this, let us compare this alley cropping system with a system that separates wheat and timber production. Over the life of the alley cropping system, the net present value of the net income, inclusive of grain and timber yields, was 145% of that of a wheat field and a poplar plantation in isolation. The timber was valued at a 4% discount rate to account for the time value of money (inflation and opportunity cost). This is an example of a system that worked: by combining crops and trees, the farmers increased total economic value created.

We could dive into the nuances of why this system was successful, but in the lens of temperate climate syntropic agriculture, we should simply view it as a manageable, culturally-accessible canopy design. Fortunately, the researchers provided us with an equation to that displays how much light a timber tree will intercept:

Light interception (I) was predicted by diameter breast height (DBH), canopy width (Cw), and the distance to the tree trunk (D). So if we’d like to calculate how much light our understory crop needs, and manage our overstory trees accordingly, this will be useful, at least conceptually. An alternate (and perhaps more reasonable) approach would be to understand the tradeoff or complementary relationship between understory and overstory yields, and design a profitable, mechanically-simple system that fits the operational context of the land manager while yielding ecosystem services.

If we try and calculate how much shade we should have in a system, we’re missing the point. In most cases, we shouldn’t optimize for shade. We should optimize for management efficiency, and design some shade into the system. If there’s too little, we can plant more canopy trees. If there’s too much, we can buckle up our chaps and start the chainsaw. Photo: Silvopasture in Patagonia

Take on the design challenge of increasing profit and ecological complexity, while keeping management simple.

Adding trees to an agricultural landscape is challenging, but many worthwhile endeavors indeed are! Syntropy is a complex lens with which to view farming and forestry, but it yields great insight. Regenerating landscapes is the great task of our time, and there is no time to waste. Agroecology, agroforestry, and syntropic agriculture systems create a unique type of harmony, happiness, and sense of place. When done right, they exhibit the anthropic grandeur of the Pyramids at Giza combined with the sensory inundation of an old forest. But all of these systems have management costs, and must be planned. Planting trees is easy in comparison to planting culturally-accessible, useful trees that come with a dynamic 20-year management plan.

At Propagate Ventures we constantly discuss the opportunities and mechanics of scaling agroforestry. Of note is that the workings of the land must be in concert with wills and desires of the people that inhabit it: scale, consequently, has much to do with breadth. Agroforestry will grow in proportion to our success in engaging people in this process and building holistic wealth together. We can all do this by planting tree-crop systems that are profitable across multiple forms of capital. Success looks like livelihoods created and soils brought back to life. Let us breathe new life into our agricultural landscapes. The time to move is now.

This article was originally published in May of 2018, and re-released in June, 2022. Learn more about Overyield, Propagate’s agroforestry financial planning engine.