Silvopasture in Patagonia: Poplars and Beef Cattle

Written by Harry Greene of Propagate Ventures

Silvopasture is the intentional incorporation of trees and livestock. To create a silvopasture, a farmer can rotationally graze cattle and sheep through forest plantations, or they can add trees to grazing land. Silvopasture is an ecologically-sound method of producing meat, and is the 9th most potent way to pull carbon dioxide out of the atmosphere, according to Project Drawdown.

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Today I’m in northern Patagonia, in the Alto Valle of Río Negro, Argentina. This region receives 7 inches of rain per year, and the wind gusts at 40 miles per hour. The rain from the Pacific Ocean falls on the Chilean side of the Andes, and the Patagonian Desert extends eastward to the Atlantic. The Río Negro and Río Limay are fed by snowmelt, which farmers divert through a network of canals to flood-irrigate their crops. The banks of the river are man-made forests of fruit and poplar, and a corridor of dark green meanders through these arid grasslands. The region is known for its apple and pear production, but both uncertain markets and farmers’ desire to diversify have brought beef and timber onto the scene.

I’m venturing through the Alto Valle with Norberto Serventi and his son Mauro. Norberto  measures his age in turnos de corte, or how many years it takes to plant and cut down a poplar tree: between 12 and 15. He is now retired, but has been working with poplar as both timber trees and windbreaks for decades. This network of trees started about 100 years ago, and he has been immersed in the thick of it for at least half that time.

Silvopasture in practice: Trees onto pasture

In addition to being a hot topic in sustainable agriculture, silvopasture is ecologically regenerative and can be highly profitable: adding trees to pasture amplifies the productivity of a farm. In the heat of the summer, trees provide cattle with shade and shelter from hot, desiccating winds. If cows are too hot, they would rather lounge in the shade than eat. Protection from cold winds in the winter does just as much to keep stress levels low and weight gain consistent: the fewer calories a cow has to burn to stay warm, the more its body will allocate to putting on muscle. Greater weight gain translates to higher farm income. Looking out at the horizon, we can see brown clouds of dust, made up of soil loosened by over and under-grazing, and blown up into the air by the wind. Trees and windbreaks also prevent wind erosion: soil that stays put is fertility retained. Below ground, tree roots access deeper soil horizons than grasses do: they pull water up from below and decrease the effects of drought. Positive externalities aside, timber is marketable. When properly pruned, trees in a silvopasture are homogenous, free of knots, and larger than those grown in a traditional single-species plantation. This means better wood, and higher net income.

 This silvopasture is a widely-spaced poplar plantation that is managed with cattle. It is planted at 8x3 meter (26x10 ft.) spacing: the amount of light that filters through the tree canopy is enough to keep the grass growing, while also providing sufficient shade for the cattle. This system doesn't just cultivate the ground: it takes full advantage of vertical space.

This silvopasture is a widely-spaced poplar plantation that is managed with cattle. It is planted at 8x3 meter (26x10 ft.) spacing: the amount of light that filters through the tree canopy is enough to keep the grass growing, while also providing sufficient shade for the cattle. This system doesn't just cultivate the ground: it takes full advantage of vertical space.

Graziers can also rotate ruminants through native forest or existing plantations. Cattle, sheep, and goats keep brush and grass down, and eat invasive and undesirable plants, all while producing meat, milk, and fibre. Grazing in a silvopasture is management-intensive, however, meaning that if animals stay in one spot for too long, they will compact tree roots and slowly kill the trees. Animals in a well-managed silvopasture are moved daily, which is also standard practice in good grazing. The mantra of grass-fed beef and workplace romance: “Don’t shit where you eat.” Animals are moved through a system as a high-density herd, as wildebeest would move. A single strand of electric fencing keeps them eating what they should eat, when they should eat it: the cows get fresh pasture daily, but they don’t get to pick and choose which plants they eat.

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 Flood irrigation turns the clouds on and off.  A network of canals diverts water from the Río Limay and Río Neuquén , irrigating hundreds of thousands of acres of farms.

Flood irrigation turns the clouds on and off. A network of canals diverts water from the Río Limay and Río Neuquén, irrigating hundreds of thousands of acres of farms.

Farmers design their land in order to fit their context, and silvopasture varies greatly in design. First, we’d like to feature the beef herd of Loma de la Paisana, grazed through a widely-spaced poplar plantation, because the system is both intentional and digestible. Here, flood irrigation speeds grass growth, tree growth, and cattle growth. According to the water requirements of the trees and grass, farmers or a hired irrigator open the gates and turn on the clouds. In the early years of the system, the farmer grew alfalfa (cow food) in between the tree rows. After the tree canopy began to shade out the ground below, he moved to a system of management-intensive grazing. He was diligent about pruning lateral branches to insure long, high-quality sawlogs. A very large number of poplar trees combined with a large number of cattle can be managed very few people. This operation has 1500 head of cattle on 400 hectares (988 acres), 130 hectares (296 acres) of which are in poplar cultivation. The farm also grows olives with which to make olive oil, and maintains a small artisan vineyard.

 Between yielding better wood sooner and producing more beef, there is little compromise. In the case of combining trees and grain together in a dense alley cropping system, timber yields are slightly less than a pure plantation, and grain yields are slightly less than grain alone. However,  wheat intercropped with poplar in France yielded a net income 140% of that of the timber and grain crops grown separately , accounting for the time value of money at a 4% interest rate. Trees in a silvopasture have the uniformity of plantation-grown logs, but silvopasture produces the wood that society needs without taking agriculture land out of production or over-harvesting from native forest.

Between yielding better wood sooner and producing more beef, there is little compromise. In the case of combining trees and grain together in a dense alley cropping system, timber yields are slightly less than a pure plantation, and grain yields are slightly less than grain alone. However, wheat intercropped with poplar in France yielded a net income 140% of that of the timber and grain crops grown separately, accounting for the time value of money at a 4% interest rate. Trees in a silvopasture have the uniformity of plantation-grown logs, but silvopasture produces the wood that society needs without taking agriculture land out of production or over-harvesting from native forest.

Grazing cattle involves setting up mobile electric fencing and watering infrastructure for the cows to drink. The trees require pruning, which can be done at any point during the dormant season. Different people live different lifestyles: some are social and some are solitary. Combining timber and beef cattle gives a farmer the ability to adjust the amount of people he or she works with, while, in comparison, intensive apple production requires an army of employees. The land must fit the context of the people that work it, in particular when planting long-lived trees on it.

 In the foreground of this photo is a  Populus nigra  hybrid, and  Populus canescens,  the silver poplar, is a fast-growing hybrid of the white poplar and Swedish aspen. Poplars are a versatile genus that also includes aspens and cottonwoods, and different varieties do well in different soil types.

In the foreground of this photo is a Populus nigra hybrid, and Populus canescens, the silver poplar, is a fast-growing hybrid of the white poplar and Swedish aspen. Poplars are a versatile genus that also includes aspens and cottonwoods, and different varieties do well in different soil types.

Given that a grazier can seed a silvopasture with cool-season grasses that the shade of the trees won’t affect nearly as much, the compromise is even less. In high latitudes, the limiting factor for tree-system productivity is how much light hits the ground. Certain crops, such as wheat and clover, don’t need as much light and heat as corn to mature. Therefore, they are good candidates to combine with tree crops. Corn can absolutely be grown between trees, but the space between the trees must be wide enough to allow more light to penetrate the canopy. In places like Brazil, Costa Rica, and Vietnam, crops such as coffee, cacao, and yerba mate can be grown beneath a much denser tree canopy, because the sun is stronger in the tropics, and the growing season is 12 months long.

 Over time, the trees shaded out the grass below, but this was a known quantity: with more distance in between rows, grass will grow throughout the life of the system, and light penetration is 100% quantifiable. This system was planted at 6x6 meter spacing (20x20 ft.), and Norberto now recommends 8x3m spacing: some hypothesized that 3m between trees would result in oval-shaped saw logs (to match the tree crowns), but the harvested trees have yielded normal, cylindrical logs.

Over time, the trees shaded out the grass below, but this was a known quantity: with more distance in between rows, grass will grow throughout the life of the system, and light penetration is 100% quantifiable. This system was planted at 6x6 meter spacing (20x20 ft.), and Norberto now recommends 8x3m spacing: some hypothesized that 3m between trees would result in oval-shaped saw logs (to match the tree crowns), but the harvested trees have yielded normal, cylindrical logs.

 Poplar windbreaks shelter the Saralegui orchard. Orchards without windbreaks produce 19% less A-grade fruit.

Poplar windbreaks shelter the Saralegui orchard. Orchards without windbreaks produce 19% less A-grade fruit.

Historically, this region has been a hub of fruticultura. Farmers grow and export apples, pears, peaches, nectarines, and cherries. When we buy off-season apples from Argentina in April, they likely come from these orchards. (link to apple article) Sandro, a farmer I had the chance to speak with, manages a beef silvopasture, and has been producing organic fruit for over 30 years. Walls of poplar trees slow the wind: just as wind compromises beef production, orchards grown without windbreaks, on average, produce 19% less A-grade fruit. From a satellite image, one can discern a grid of green and a sea of wood.

 Francisco's farm produces beef, pears, and timber for short, mid, and long-term cash flows.

Francisco's farm produces beef, pears, and timber for short, mid, and long-term cash flows.

From fruit trees to meat production, and everywhere in between: trees diversify farms by taking advantage of vertical space. In recent years, imported fruit from Chile and Brazil has been undercutting the Argentine producers. As a result, many farmers in the Río Negro are diversifying from wholesale apples to juice and cider production, viticulture, and beef. Beef is ingrained into Argentine culture, and the time to market is much shorter: an apple tree takes 4-6 years to reach peak production, but a cow is ready for slaughter in 18 months. In the United States, silvopasture is often seen as the creme de la creme of grass-fed beef production, but in Argentina it is more common. Francisco, for instance, is a young man and third-generation farmer from General Roca, Río Negro, Argentina. He studied agronomy at the University of Buenos Aires and has returned to his family farm. They focus on pears and beef. They graze their poplar plantations, but also finish their cattle on silage corn and alfalfa that they grow themselves. The market for 100% grass-fed beef has yet to take off in Argentina, but farmers employ management-intensive rotational grazing because it makes economic sense. This is not because labor is cheap: the Argentina standard and cost of living isn’t so different from that of the United States.

 Julio Garcia, state forester, and Francisco Pili. Francisco grazes a beef herd beneath his poplar plantation, and works ecological soundness into production agriculture. Their pear orchard is in the second year of organic transition.

Julio Garcia, state forester, and Francisco Pili. Francisco grazes a beef herd beneath his poplar plantation, and works ecological soundness into production agriculture. Their pear orchard is in the second year of organic transition.

 Sandro and Francisco are less likely to manage turkeys this way, however, because no one imports the white electronet fencing into Argentina, and Argentines aren’t ready to pay for apple-fed turkey, never mind turkey alone. Just as Americans don’t eat much duck, Argentines don’t eat much turkey. Sandro feeds his excess fruit to his pigs to produce apple-fed boar. 

Sandro and Francisco are less likely to manage turkeys this way, however, because no one imports the white electronet fencing into Argentina, and Argentines aren’t ready to pay for apple-fed turkey, never mind turkey alone. Just as Americans don’t eat much duck, Argentines don’t eat much turkey. Sandro feeds his excess fruit to his pigs to produce apple-fed boar. 

Now what of producing fruit and livestock on the same piece of land? We cannot graze cattle through tightly-spaced pear orchards: fruit trees are an expensive scratching post. Sheep and poultry can tread lightly on an orchard, however. First and foremost, context is everything. In order to produce pastured turkeys profitably, the birds have to have a market. Consumers have to be willing to pay for the added value of fruit-finished turkey or lamb. For example, The Good Life Farm in Interlaken, New York grazes turkeys through their orchard. This past summer, bad weather and scab rendered their peach crop not worth harvesting. They chose to leave the peaches on the ground to rot. Rotting fruit houses insect pests that over-winter and emerge in spring to ravage tree crops once again, but turkeys are omnivores: they eat grass, grain, fruit, and bugs. They are scavengers.

Melissa and Garrett of Good Life Farm fence the turkeys beneath the fruit trees, where the birds gorge on the fallen fruit and insects. This year at Thanksgiving, the turkeys were much larger than anticipated due to the excess food. Sandro, our Argentine apple farmer fertilizes his trees with chicken manure, while Good Life’s birds convert grain into fertilizer, and apply it directly to the trees. Silvopasture can be as simple or as complex as a farmer is willing to make it.

 It took a great deal of energy to create these systems, but now the simple re-routing of water amplifies the ecosystem. Wetland ecologies emerge in what was once desert, and former moonscapes now produce fruit.

It took a great deal of energy to create these systems, but now the simple re-routing of water amplifies the ecosystem. Wetland ecologies emerge in what was once desert, and former moonscapes now produce fruit.

200 years ago, this land was grassland. The Patagonian Steppe is currently desertifying due to both overgrazing and under-grazing, but the juxtaposition between the natural ecosystem and the anthropogenic forest is striking. Humans have moved the banks of the river beyond its climax ecosystem: what would naturally be scrubland now supports canopy species like walnuts, oak, and apples. The productivity of the trees brings a greater diversity of insects, birds, rodents, mammalian predators, and birds of prey. All things considered, the canals and terraces of the region took a great deal of time and energy to create. Bulldozers leveled the ground, and cement trucks made the canals a reality. Nonetheless, this mecca of agroforestry shows that humans can have a beneficial impact on a landscape. Humans need not be viewed as the scourge of the earth. The discussion of sustainability is so often centered around doing less harm. Can we not do more good? Being beyond the climax ecosystem, and dependent on active irrigation, these blocks of silvopasture and fruit are -generative or emergent. Perhaps they are not re-generative, but what is regenerative agriculture? How does it differ from sustainable agriculture?

Wood

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All components of a silvopasture should be profitable. The animal component of silvopasture produces meat, milk, and fibers such as leather and wool. The tree component produces fruit, wood, medicine, and other arboreal products. What becomes of the poplar? In Argentina, poplars have been used as windbreaks for the last century. Windbreaks are often thinned, which means that selected trees get turned into crates and pallets. Fruit must be shipped in crates and boxes, and regional sawmills were designed to produce these crates. The infrastructure of these sawmills is outdated, to say the least: I had the fortune of visiting a local sawmill in Allen, Argentina, and the sawmill owner was honest and frank about this. Fruit crates don’t require high-quality wood, as they only need to be functional and not aesthetically pristine. This particular sawmill is moving into value-added products such as doors, but their equipment inhibits them from producing Ikea-grade furniture. The regional drop in fruit production has resulted in a drop in wood processing, sending the poplar industry into a state of transformation.

 Argentina has had erratic changes in agricultural policy. Taxes wax and wane with the tides, and fruit production is monitored by crate-count. Wooden crates that are made in-house are hard to trace, and have historically been used to transport both above-the-table and black-market fruit.

Argentina has had erratic changes in agricultural policy. Taxes wax and wane with the tides, and fruit production is monitored by crate-count. Wooden crates that are made in-house are hard to trace, and have historically been used to transport both above-the-table and black-market fruit.

Once destined for pallet production, poplars are now becoming dining-room tables. The climax of poplar windbreaks occurred in the 1970’s: there were 300 sawmills in the region, and poplar was the second-most economically-important industry, behind fruit. According to Norberto Serventi, who has lived through these cycles, each year the region uses 8-9 million poplar fruit boxes. At 60% of total box cost, manufacturing costs are high due to antiquated infrastructure: new infrastructure would reduce this figure to 30% of total cost. There are 5,000 linear miles of poplar windbreaks in the region, sawmills are outdated, and Argentina has a swiftly growing middle class. A state of the art sawmill, geared to produce a variety of value-added poplar products, with granularly-modeled costs, appears to be the greatest leverage point in moving agroforestry forward. Vetta - Diseño de Mobiliario (furniture design) is doing just that.

 Vetta specializes in coffee tables, dining room tables, and night stands.

Vetta specializes in coffee tables, dining room tables, and night stands.

Vetta is a furniture manufacturer of General Roca, Argentina. Belén Daniele and Mauricio Fritz started the business in 2013 as design students, in the context of adding value to poplar. They now have two employees and are growing steadily. Vetta’s competitive advantage lies in using local wood. High-end oak doesn’t make economic sense to use due to limited scalability, and shipping in pine causes freight costs to soar. Vetta focuses on common items such as coffee tables, night stands, and custom-length dining room tables. As designers, they are influenced by Japenese and Scandinavian techniques, and maintain an inspirational brand that aligns with the old adage, “local wood, local good.” Forest regions such as Japan and Northern Europe have long traditions of carpentry, and the Alto Valle being a man-made forest, woodworking is just coming into its own. With Argentina’s new wave of incentivizing entrepreneurship, the state recently began to fund technical training in carpentry. Though Vetta is able to use windbreak poplars, homogenous sawlogs that are free of knots greatly lowers processing costs. Silvopasture wood caters to that need.

Plantation forestry is conducive to growing uniform logs, but taking valuable land out of production isn’t an option. Widely-spaced rows of timber trees present the ultimate compromise: farmers can grow cash crops such as alfalfa in between tree rows, and when the trees cast more shade as they mature, the farmer can convert his or her system into a silvopasture at the drop of a hat. These trees, planted at wider spacing, grow quicker and yield 100% more higher-quality wood than that of a pure plantation. Francisco, our farmer out of General Roca, is on this exact train.

In the middle of a desert, why are the Argentines so intent on planting trees? Where did this culture come from? Is our natural inclination to plant trees or to cut them down? Or is it both? Perhaps God instilled in us a desire to manage trees, control the planet’s photosynthetic engine, and express our dominion over plants, be they corn or poplar. Human intervention isn’t inherently good, or bad, but it will happen, and we must question both the objectives and results of our agriculture. What kind of landscape do we envision for our children? On a daily basis, what are we doing to get there? In 20 years, what will indicate success? Trees are permanent, relatively. When designing for multiple decades, these questions are imperative. Silvopasture is fascinating, productive, profitable, and frankly breathtaking. It’s wild, but it’s also very human, and is therefore empowering. In this time of a broken carbon cycle and an erratic climate, what’s next? The future is in our hands, and in our trees.

We at Propagate Ventures are grateful to those that welcomed us to their region. Norberto, Julio, Mauro, Mariano, Francisco, Sandro, Sandro’s son, and Belén. Agroforestry finance knows no borders, and we looking forward to planting trees in all corners of the humid-climate globe.

read more about this region's organic orchards

For more photos of these systems, be sure to find us on social media.

 Harry Greene, the author, with Norberto Serventi, state forester and  salicaceae  extraordinaire. 

Harry Greene, the author, with Norberto Serventi, state forester and salicaceae extraordinaire.