Overstory #247 - Multiple functions of perennial agriculture
Unlike expensive geoengineering approaches to slowing climate change, regenerative perennial agriculture is remarkable in addressing many of the challenges facing humanity today while sequestering carbon. Were humanity to prioritize this strategy to stabilize our climate, we would reap many other benefits and help address challenges from erosion to food sovereignty.
Sequestering carbon is not the only climate impact of permanent agriculture. Perennial agriculture practices require less fossil fuel inputs, both from mechanization and from chemical fertilizers. Implementation of food forestry around the world could reduce fossil fuel use in transport dramatically by increasing local production.
Interestingly, at least in tropical regions, the most powerful climate impact of agroforestry is not in the carbon sequestered on-farm (which is significant), but in the reduction of pressure on wild trees and forests. Because agroforestry provides fuelwood and reduces or eliminates the need for shifting cultivation, every hectare of agroforestry prevents the deforestation of 2.5-10 hectares of wild forest.
Improving Soils and Slopes
Perennial farming systems have dramatic powers to stabilize eroding farmland, especially sloping lands. Practices like using nitrogen fixing perennials, keyline plowing, and intenstive livestock rotation have fantastic soil building abilities. Plantings of useful trees can protect coastlines from damage caused by increased storm activity.
Benefits to Water
On the farm scale, trees and perennials can dramatically improve rainwater infiltration and groundwater recharge. At both the farm and regional scale, permanent agriculture can break the flood-drought cycle by soaking up and slowly releasing water like a sponge, providing a longer season of moderate water flow in streams and rivers downstream. Erosion control and slope stabilization means less siltation and nutrient runoff in streams, having effects from local waters to offshore coral reefs. Finally, at the regional scale large plantings of trees transpire sufficient water to create rainclouds, allowing rain to fall further inland and fight drought and desertification.
Food forests provide many of the same ecosystem services that “natural” forests do. In addition to the water, soil, and climate benefits mentioned above, they can serve as critical habitat for many kinds of life, and their diversity is much higher than annual agriculture. Regenerative practices can heal degraded land and bring it back to biological productivity and health.
Perhaps most interesting is that permanent agriculture not only fights climate change, but it is also resilient in the face of the increased intensity and frequency of droughts, floods, and other extreme weather events. Trees and perennials typically have stronger and deeper root systems than annuals and can survive and continue to yield in conditions that would ruin many annual crops. Polycultures provide a form of insurance against crop failure due to pests, disease, or weather by having multiple backups of additional crops, so that each year there is always a yield of one kind or another.
On the farm scale, shade can be essential for livestock and certain crops, particularly in the tropics. We owe coffee, vanilla, chocolate, ginseng, wasabi, ramps, and many other important products to the shady canopies they grow beneath. Trees in particular are also important for filtering air pollution and particulates, and help create a protected and nourishing microclimate in most places they are planted.
Improving Agroecosystem Productivity
Many perennial farming practices are already in common use due to their positive effect on yields. In many parts of the world windbreaks, living fences, and living trellises are standard farming practices. Agroforestry frequently incorporates nitrogen fixing plants, and growing plants for compost and mulching purposes is common in many sustainable agricultural systems. But all of these practices could be much more widely spread.
Biochar, a farm-made charcoal soil amendment, is a practice with tremendous carbon sequestering potential and a great soil builder. It is currently controversial due to concern over its being used as a large scale monoculture and taking land away from food production in the developing world, much as has happened with corn-based biofuels. It appears to me that as an integrated farm practice, not as a vast monoculture, biochar can have a positive effect on farm productivity while sequestering substantial carbon without impacting food security. Any of these perennial farming systems, if practiced by large corporations in vast plantations, can lose carbon efficiency as well as potentially causing negative social and ecological impacts.
A Vast Array of Products
Permanent agriculture can produce most of our material needs. Foods, biofuels, construction materials, fiber products, plant-based plastics, medicine, ceremonial plants, and more can all be produced. Some perennials can continue to yield for hundreds of years once established.
The human benefits of regenerative agriculture are another reason it is so much more desirable than geoengineering projects like pumping sulfur into the atmosphere or liquidized carbon back into empty oil wells. A global investment in perennial farming systems addresses climate justice by sending funds from the developed countries who have caused most of global warming to the developing countries who did the least to cause it but are, perversely, most effected by it. This body of practices can also address food security, particularly by providing resilient crops that can survive droughts and extreme weather events.
Beyond nutrition, transforming degraded land to tree-based farming provides income and regenerative enterprise opportunities to rural people, and could help drive a return to the land for rural people who moved to cities in search of income. Permaculture works best with large numbers of people on small parcels of land, and some research seems to indicate that carbon sequestration is actually higher on small, intensively managed parcels. Thus rural economic revitalization may be another impact of regenerative carbon-sequestering agriculture.
Fossil fuels used in transportation of agricultural goods today are a major source of global warming pollution, so fighting climate change means relocalization of agriculture on a massive scale, whether perennial crops are grown or not. Food sovereignty takes the notions of local food and food security and unites them with broader human rights concerns. The food sovereignty platform includes the right to food and land to grow it on, regional self-sufficiency, prioritizing nutrition and natural resources over international trade, and peaceful democratic control rather than corporate dominance of the food system. Broadscale implementation of perennial farming systems would support food sovereignty by providing a regenerative farming toolkit for community self-determination. A permanent agriculture movement can serve as an ally to food sovereignty against the multinational interests whose drive for short-terms profit is the cause of so many social and ecological problems. I also see permanent agriculture as greatly supporting the development of communities of prosperous smallholders around the world. I like to call this key element of perennial food sovereignty “tree-based Jeffersonian democracy.”
Once established, perennial farming systems require less labor and inputs than annual agriculture. In this light, food forests can be a tool for movements for democracy, nutrition, and human rights. Steering climate change funds and efforts in the direction of regenerative, permanent agriculture can thus help improve the quality of life of people around the world.
Obviously converting land use on such a scale would be a massive undertaking perhaps unprecedented in history. It would also have to take place on an extremely tight timeline as well–probably a few decades at most. But addressing climate change requires us to rethink every aspect of our civilization, and agriculture is no exception.
Food forestry has always been a great idea, but in this time of climate crisis it has become an essential one. For many years permaculturists have focused on our own backyards and farms. While that has been critical for developing our ideas, its carbon sequestration impact is barely noticeable on the global scale. Permanent agriculture needs to be spread much, much more widely to have a significant impact. To prevent runaway climate change we need to change our civilization’s infrastructure – and we need to be engaged in our food systems to make that transformation happen.
My emphasis on perennial farming systems is not to discount the many other important contributions that permaculture has made and can make to address climate change. Everything we do, and everything that the transition and climate change movements are doing, is critical to finding a solution. No single strategy is sufficient to do what is required. But large scale conversion of degraded land to regenerative perennial agriculture is a project that we can put forward to the broader climate change movements, and get the world’s resources behind. What a great way for the world to get to know us better – through this strategy that so beautifully expresses our ethics and principles.
We need as well to be honest about what is and isn’t known about permanent agriculture, particularly in cold climates. Let’s target more of our experimentation on replicable models that can be applied at farm-scale in our own regions and beyond. And what better way to demonstrate permanent agriculture than developing regenerative enterprises that allow us to prosper while charting a new course for agriculture.
It seems to me that this is a critical moment in history for permaculture. Terraforming the planet into a perennial food-producing paradise may be the only way to avert climate disaster. Let’s step up as a movement and show the world what we have to offer.
This article was excerpted from the original with the kind permission of the author:
Toensmeier, Eric. 2011. Climate Stability with "Permanent Agriculture." Permaculture Activist #80.
Eric Toensmeier is the author of Perennial Vegetables and co-author with Dave Jacke of Edible Forest Gardens. His writing and teaching is currently largely focused on regenerative agriculture for climate stabilization. His writings, videos, and upcoming workshop schedule can be viewed at www.perennialsolutions.org.
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- The Overstory #216--Introduction to temperate edible forest gardens
- The Overstory #213--Urban Forestry for Multifunctional Urban Land Use
- The Overstory #205--Smallholder agroforestry carbon storage
- The Overstory #186--Introduction to tropical homegardens
- The Overstory #147--Major Themes of Tropical Homegardens
- The Overstory #142--Urban Trees and Forests
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- The Overstory #61--Effects of Trees on Soils
- The Overstory #51--Protecting and Expanding Traditional Agroforests
- The Overstory #29--Tropical Green Manures/Cover Crops