Multistrata Agroforestry Systems and Biochar for Food Security, Degraded Land Repair and Climate Change Mitigation and Adaption
“The magnitude of the threat from climate change especially to those whose endowment or stage of development renders them more vulnerable and less resilient makes it necessary to shift from mere adaptation and mitigation, towards approaches capable of transforming climate change into a window of opportunity.” — Commonwealth Secretary General, RH Baroness Patricia Scotland
According to the latest Intergovernmental Panel on Climate Change (IPCC) report on climate change, we have a very short time to reduce emissions and drawdown atmospheric carbon before we hit tipping points beyond which the planet will be largely uninhabitable by the end of the century. The target of 1.5 degrees temperature rise from preindustrial levels seems unlikely, and 3 degrees is more realistic. We know that developing countries with less resources and financial reserves will feel the impact soonest and hardest.
There are urgent calls for stopping deforestation of tropical forests or for reforestation to retain carbon in landscapes as a way to mitigate climate change.
Forests are critical for humanity for their ecosystem services. Forests hold, filter and release water, create oxygen, provide goods of timber and non timber forest products and are important industries for much of the world. Forests drawdown and hold carbon. Protecting forests by providing meaningful livelihoods to stakeholders to maintain forests through regenerative land practices leads to regenerative economies.
According to Project Drawdown, in the next 30 years forests can reduce emissions or sequester 5.52–8.75 gigatonnes of carbon.
Wild spaces have great value, but forests as carbon sinks are problematic. Forests are not designed around direct human needs. Evolving needs in adjacent communities can result in forest being cleared for cropping, cattle, timber and bioenergy, or burned by escaped fires from shifting cultivation. Plans for forest management through rangers and/or community buy-in that extend into the next 100 years will be hard and expensive to ensure are observed.
If the land being protected has been a site that adjacent communities previously used for resource extraction, hunting or for cultivation, denying access to that land creates potential saboteurs who often know the land being protected better than those protecting the land.
A persistent argument against forest restoration is that tree plantations do not provide any food or market access. How do we reconcile the need for tree cover and the need for food and other products?
There are an estimated 950,000,000 to 1.1billion acres of degraded agricultural landscapes, landscapes that cannot be returned to the activity that degraded them in the first place. Much of that acreage is in the lowland humid tropics of the Commonwealth. Damaged by misuse and overuse, by monocultures of export crops, such as banana, citrus, sugarcane, pineapple, papaya or African oil palm that have come to the end of their productive lifespan, these lands represent challenges and opportunities to repair. Often these landscapes are best suited for trees. 12.48–20.32 gigatonnes of carbon could be drawn down by repairing degraded agricultural land.
Plans for afforestation or forest restoration targeting degraded land without food as an aspect, and not informed by the cultures, agricultural and food traditions of the communities affected represent a loss of land for farmers to access.
Multi-strata agroforestry systems (MAS) are comprised of different species with different qualities. Eric Toensmeir’s groundbreaking book, “ The Carbon Farming Solution” outlines many of the techniques and species that can be used. MAS have the potential to reduce or sequester 15.45–31.26 gigatonnes of carbon by 2050. The use of agroforestry as a tool for carbon drawdown has huge potential. The trees and subcanopy species of a MAS can be food, fiber, fuel wood, fodder, timber, ornamental, nitrogen fixing, marketable and medicinal plants. They have been part of many indigenous and campesino land management practices and provide diverse outputs. While they offer many of the ecosystem services of primary habitat, providing yields and creating vested stakeholders, they attract little international funding. There has been a concerted and well funded effort to displace traditional knowledge about agroforestry and agroecology in favour of monocultures and agrochemical dependent models of production that funnel money directly from the pockets of smallholders to the board rooms of agrochemical companies.
Rural economies developing landscape level MAS’s address other problems, such as high levels of rural unemployment, common through the developing world, poverty, soil infertility, food insecurity, lack of market access, and loss of habitat. In Belize and the CARICOM region, MAS could address unemployment from contraction of the tourism economy while reversing the tide of rural to urban migration.
MAS systems designed by smallholders provide an abundance of yields that create vested stakeholders to manage their “forests” as carbon sinks while getting returns on their work.
Early work with pioneer species, such as pigeon pea/Cajanus cajan, pineapple, banana/plantain, cassava, cocoyam, mulberry, okra, sweet potato, sesame, sorrel, moringa, chipilin/Crotolaria longirostrata ensures harvests within the first year. Many of these species improve soil fertility through nitrogen fixation or soil structure by breaking up the soil. The end goal is for tree cover with perennial crops.
One acre with a few perennial staple trees will outproduce an acre of beef, of rice or corn, or any annual crop in terms of calories, and once established will do so at minimal expense in labour. Depending on initial and subsequent design work, that land can also produce fuel, fibre, fruit, fodder, edible oils, staples, marketable and medicinal crops and timber. Landscapes dedicated to agroforestry offer long term solutions to carbon drawdown by creating stakeholders who will maintain the tree cover in perpetuity out of self interest because the yields meet their various needs.
On a landscape level, MAS can be contiguous with adjacent managed farms, function as biological corridors between blocks of forested land, or buffer zones between cultivated and wild land, reducing fragmentation of habitat.
Perennial crops as elements in agroforestry create long term food security and multigenerational wealth. In the next 30 years, if widely implemented, perennial food crops can sequester or reduce emissions of 15.45–31.26 gigatonnes of carbon while enhancing food security.
I manage a small non-profit in southern Belize called Maya Mountain Research Farm (MMRF) focused on food security, degraded land reversal, climate change mitigation and adaption through agroforestry. While the NGO was founded in 2004, the work on the farm has been ongoing since 1988.
At MMRF we have had success with tropical staple trees for food production. We use a lot of breadnut/Artocarpus camansi, breadfruit/A. altilis and jackfruit/A. heterophylla, and ramon nut/Brossimum allicastrum, and coconut for human food and for poultry. Palms such as coconut, pacaya palm/Chamaedorea tepijilote, açai berry and peach palm/Bactris gasipaes, provide impressive yields in kilos per hectare for food or fodder value, or as marketables. Coconut palms provide edible oils and feed for poultry. These species provide advantages over annual crops. Being deeper rooted than annual staple crops such as maize and rice, they are able to access soil moisture inaccessible by short rooted grasses, and also help to hold water in the landscape. They can also withstand some degree of flooding. Once established, they can provide significant yields at a favourable return on energy invested, year after year without needing reestablishment.
An overstory can have food, nitrogen fixing trees to boost soil fertility, and timber species for long term harvests. In Belize we use mahogany, cedar/Cedrela odorata and samwood/laurel/Cordia alliadora, mayflower, and leguminous trees, such as leaucaena, the ingas, the bauhinias, the erythrinas, guanacaste, Samanea saman and the albizias. The canopy of these various species creates an understory for sub canopy shade requiring crops that have market value such as cacao, coffee, turmeric, ginger, cardamom and vanilla. Many of these canopy species also provide fodder for bees.
From 1997–2004 I managed the Toledo Cacao Growers Association, exporting cacao from Belize to Green & Black’s in the UK. Our extension program grew the association from 225 farmers to over 700 when I left. We found that training via traditional classroom pedagogy had limited results. Lateral movement of information through farmer to farmer trainings allowed increased information transfer and adaption. Showcasing exceptional farmers, techniques and systems at selected venues was fruitful.
The four things that facilitate the creation of this regenerative economy:
1. Extension, outreach and education
2. Nurseries of plants selected through stakeholder engagement
3. Access to markets
4. Secure land tenure for smallholders
Extension and outreach programs staffed by accomplished farmers will not only laterally transfer information better than classroom exchanges, but also facilitate the movement of seeds and plants, which can be sources for nurseries. Tying Extension to ongoing Access to markets and Nurseries to propagate planting material can meet the needs and desires of the communities.
Access to markets can be created though the creation of micro-enterprises and processing hubs. Centralised purchasing and exportation of commodities such as coconut oil, cacao, coffee, spices and medicinal crops, though private enterprises, cooperatives or farmers associations, provides opportunities for smallholders to collectively access external markets and/or value add at a scale smallholders cannot access.
Land tenure through titled land or recognised communal land in indigenous communities provides a legal basis to keep out large scale monocultures and cattle. Agroforestry is a potentially multigenerational endeavour. Land tenure is critical as monocultures and cattle ranching are often initiated by people with access to capital and influence and the absence of secure land tenure leads to dispossession. These practices can lead to robust economies in rural areas, while drawing down carbon.
The other part of the equation that I see for climate change mitigation and adaption is the sequestration of carbon into the soil through pyrolysis of crop residues called “biochar”.
Biochar is biomass that is pyrolized, or burned in the absence of oxygen in kilns designed for that purpose. Biochar can be made from crop residues such as nut shells, rice hulls, corn stover, grain chaff, coconut husks, cacao pods and coffee shells, and forestry residues such as waste wood and sawdust. Biochar can be made from sargassum, which is a problem in much of the Caribbean. Worldwide, these residues can provide a nearly unlimited amount of carbon to sequester through pyrolisis that would otherwise oxidise to the atmosphere as CO2. While figures such as 2.22–4.39 gigatonnes of carbon drawn down are suggested at Project Drawdown, the actual figure could be much, much higher as the supply of crop residues and biomass that could be converted to biochar is significantly higher.
As explained in and ’s excellent book, “Burn: Igniting a New Carbon Drawdown Economy to End the Climate Crisis”, biochar can be made at various scales based on amount and kinds of feedstock. Small holders may not need large biochar kilns, while plantations of coconut, mills that de-hull rice, and sugar cane refineries that burn bagasse will need larger systems. Much like the cooperative and farmer associations that provide centralized markets for multiple small holders, biochar “Cool Labs” as hubs can provide centres for centralising processing and creation of multiple outputs.
Pyrolysing these crop residues into biochar converts them into a stable form of carbon. Heat generated by pyrolysis can be harvested to generate electricity, run steam turbines, for motive power, cooking, heating, for drying crops or for cooling.
When the resulting biochar is applied to the landscape, the biochar represents a stable non-labile form of carbon that will remain in the soil for centuries. Biochar has a great amount of surface area, which will be colonised by soil biota. Biochar inoculated with soil biota improves soil health and the soil biotic communities make nutrients available to plants. This increases yields.
Biochar also make landscapes less fragile in times of diminished moisture availability, increasingly important as drought is an anticipated consequence of climate change. One tonne of inoculated biochar can retain 30 tonnes of moisture, helping to make farms less susceptible to drought.
Biochar also has many other uses that will keep the carbon from returning to the air, ranging from water filtration to feed amendments that decrease methane emissions in cattle, to an admixture to concrete.
Multistrata agroforestry systems, with their multiple yields and multiple ecosystem services combined with biochar from converting crop residue into biochar can drawdown carbon while revitalising landscapes, enhancing food security and building the rural economies of the lowland humid tropics.
People ask, “What is the return on investment of these activities?” And the answer has a lot of variables. Perhaps a more important question is what will the cost be if we do not actively engage in widespread forms of carbon drawdown across the globe?
The planet needs a Manhattan Project of carbon drawdown to address the pending climate catastrophe. The implementation needs to be immediate, it needs to be widespread and well funded. Multistrata agroforestry and biochar should be front and center.
How do we get small holders invested in models of production that meet their needs while also sequestering carbon and creating resilience? The ONLY thing that does that is tree planting, creating markets and industries that drawdown carbon with biochar from forestry and crop residues.
If the world is to address these impending problems of climate change, there is no better way to address them than to begin with the simple act of planting trees, and finding ways to sequester carbon/crop residues as biochar back into the landscapes.
