Planning and Implementing Agroforestry Systems
Agroforestry is complicated and challenging to get right.
Though agroforestry has existed for thousands of years, concerted institutional efforts to advance the practice in the US began only within the last 30 years amid looming ecological crises and a recognition of the environmental and economic benefits of agroforestry. But even as public-private partnerships and federal initiatives catalyze its adoption, agroforestry represents less than 1% of US farmland, compared to 20% globally, with many farmers and asset managers hesitant to invest in tree crops due to perceived risk.
Minimizing risk is part and parcel to planning agroforestry systems. In this article, we share lessons learned from our experience helping 30+ farms adopt agroforestry, and unravel the “how” and “why” of agroforestry system design, implementation and management.
Why agroforestry?
In the face of climate change and compromised natural resources, many producers have shifted acreage towards organic management, integrating cover crops, conservation tillage, and other practices into annual rotations. Although these strategies can improve local biodiversity and soil quality, the net environmental impact of annual organic and conventional systems is often similar: similar rates of nitrate leaching and erosion (Pimentel et al 2014; Bergstrom et al 2009; Arnhold et al 2014) and similar carbon footprints per unit food produced (Tuomisto et al 2014; Muller et al 2012).
Agroforestry – or the intentional integration of annual and perennial crops – outperforms regenerative annual systems on many fronts. Studies have shown that agroforestry is not only carbon negative, emitting fewer nitrous oxides than regenerative annual systems (Robertson et al 2002), but can also lead to greater land use efficiency and profitability than row crops in some cases (Graves et al 2007; Sereke et al 2014; Lehhmen et al 2020). It should be noted that agroforestry is not innately more profitable or productive, but can generate more calories and revenue per acre — if done well.
Whether these ecological and economic benefits are realized depends on context and planning.
Studies show that agroforestry can be more profitable when suitable trees are selected and when the economics line up – when factors such as interest rates and price realization swing in a grower’s favor, if system components are designed efficiently, and if incentive payments are leveraged (Theismeier and Zander 2023). It’s true that permanent crops as an asset class often perform better than row crops, earning on average $17,000 more per acre (Equilibrium Capital, 2013). However, profitability is not a given. Planning around holistic context is essential to realize the benefits of agroforestry.
Holistic Context to Ensure Success
History tells us that the most enduring agroforestry systems are natural outgrowths of context. The pannages of antiquity arose throughout Europe from the cyclic abundance of acorns, beechnuts, chestnuts and other masting trees in Oak forests, as well as the grazing laws of time and place, while the dehesas of Spain and Portugal turned otherwise marginal soils into productive rangelands managed for cork, livestock and hunting, persisting still today across 5 million acres. Anthropologists largely agree that even vast tracts of the Amazon rainforest were planted and managed by humans, who transformed otherwise infertile ground into terra preta – the holy grail of agricultural soils – through intensive biological management. Modern agroforestry practitioners can build on this ancient knowledge, adapting their practices to their current agroecological and socioeconomic contexts.
Context can be understood as a spectrum, which 20th century agricultural engineer PA Yeomans described along a “scale of permanence.” Within this framework, immutable factors like climate and topography provide the guardrails within which more changeable contextual considerations like soil, water, and infrastructure are managed.
Climate – the most important arbiter of context– is as much a social force as it is meteorological, with the socioeconomic, technological and cultural milieu of a farm (and the goals and capacity of the farmer managing it) informing all else. Although each farm will have different reasons for planting trees, common goals include succession planning, improving local ecosystems, and reducing risk through diversification. Ensuring a farmer’s goals align with their knowledge, capacity and farm culture is another matter. For example, a silvopastoralist who prioritizes cattle might opt to graze ground during tree establishment, killing young trees in the process, while a grain farmer might neglect irrigation during a spring dry spell as he hustles to prep his corn or soy ground.
Coming to terms with how your existing operations might preclude trees is the obvious first step in agroforestry planning.
Of course, climate also includes abiotic factors such as temperature extremes as they influence tree suitability; heat and cold accumulation as they interact with plant, pest, and pathogen life cycles; and meteorological considerations such as precipitation, aspect, wind, humidity, and fire. Within broad climatic classifications exist specific bioregions, and within these bioregions specific ecosystems such as oak savannas or deciduous forests. Agroforestry may aim to mimic these ecosystems by integrating native species or livestock to manage vegetation, leveraging natural processes for soil management and pest control, layering shade-tolerant species within multi-strata canopies, and capitalizing on microclimates. Specific agroforestry systems often have their own analogues in nature: for example, working buffers reflect riparian forests, windbreaks mimic ribbon forests, and silvopasture resembles savanna ecosystems.
Another important contextual consideration is topography, which influences soil erosion, machinery access, grazing laneways, water drainage, and crop suitability. Whereas conventional farming tends to conflict with hilly terrain, agroforestry systems often capitalize on marginal land, employing keyline geometry to optimize water movement and retention on a site while selecting species like chestnuts that thrive on slopes, or flood-tolerant species such as elderberry or hazelnuts for lowlands. Species selection is often the most exciting choice, but largely circles back to a farmer’s production goals and capacity.
Equally important to plant productivity, but more changeable than topography, is soil. While soil type and texture are relatively fixed, other aspects of soil quality are amenable; this includes soil structure, pH, organic matter percentage, compaction, water retention, and nutrient balance. Other variables that an agroforestry designer must consider include land-use history, water, machinery access, utilities, roads, and infrastructure– and on top of these design factors, the inevitable question of cash. How much will installation cost? How will I finance the system? How will operational costs and labor needs evolve as the trees mature? When will I break even? In the past, rigorous business planning spanning months and years was required to answer these questions.
Our agroforestry planning software Overyield integrates design tools with economic data for 50+ species to resolve these questions in 40 hours or less.
Common pitfalls
Planting trees is hard. Killing trees is easy. Here are some pitfalls that agroforesters may encounter during project implementation.
Failing to gather stakeholder input: Agroforestry systems designed without the input of land managers are more likely to fail, as lack of buy-in leads to undermanagement of planted trees.
Poor seedling quality: Low quality nursery stock can introduce diseases and pests to your orchard that lead to tree mortality, while improperly shipped and stored trees can break dormancy early leading to cold damage once planted. Graft failures, root defects, genetic quality, and trunk damage are among the many factors impacting the success of planted trees.
Inattention during establishment: Across agroforestry and nature-based solutions more broadly, the post-planting establishment period of trees is critical to ensuring success. Inadequate precipitation, inattention to irrigation, and failure to mow regularly prevents trees from competing with surrounding vegetation, leading to low survivorship.
Underestimating wildlife. Deer, rodents, livestock, and other herbivores are skilled assassins of trees. No matter how tall or deer-proof a fence may appear, clever deer will likely find their way inside, with tree tubes often the most effective solution to prevent damage. Regular mowing to control rodent populations can be beneficial, and monitoring of pest populations through trapping and scouting is non-negotiable. Finally, precautions should be taken to protect trees from grazing livestock until trees are above browse height or strong enough to withstand rubbing damage. Tree guards, tubes, and various types of fences can be employed to this end.
Phenological blind spots: Failure to learn observe the life cycles of the trees you’re managing the pests and diseases that threaten them can lead to poorly timed management that creates or exacerbates issues. For example, pruning chestnuts while picnic beetles are active can enable the vectoring of oak wilt to trees via inoculation of open wounds. Similarly, letting goldenrod flower across your black locust plantation can attract locust borer to your stand. Properly timed mowing, pruning, fertilization, spraying, irrigation, and harvest activities should follow the natural phenological rhythms of plants, pests, and diseases, which depend on climate & weather.
Agroforestry in Action
Public-private partnerships connected innovative farmers with technical resources and funding to implement agroforestry as a revenue-generating water quality solution.
Riparian zone distance from waterways determined buffer form and function, leading to integration of traditional forest buffers with “working buffers” – i.e. silvopasture, alley cropping, etc.
Selection of marketable native and hybridized species tolerant of flooding or marginal soils allowed farmers to keep their most productive land in row crops.
Turnkey implementation made the project feasible for busy growers.
This project brought together row crop farmers with impact investors to enable agroforestry at scale.
Chestnuts, a perennial staple crop, sequester carbon and support biodiversity while diversifying farmer incomes. Hay harvested in the alleys provides annual income until chestnuts begin to bear. Biodiversity species interspersed throughout the landscape support pollinators and wildlife.
A long-term lease model reduces upfront capital requirements.
The unique topography, acidic soils, and climate of Northern Kentucky / Southern Ohio are well-suited to Chinese chestnuts, even in a changing climate.
Forward contracts with genetic partners enable procurement of regionally-adapted, high-performing cultivars at high volumes.
Making the transition
Farmers, landowners, and asset managers looking to transition land into agroforestry, tree crops, or other nature-based solutions have several options. Some may take pleasure in a DIY approach, bootstrapping agroforestry with their available resources. There are many upsides to this approach, though the downsides may involve more tangible risk. Unlike building a barn or a greenhouse oneself, both of which present a flexible timeline, planting trees is extremely time-sensitive. If you get it wrong, you often have to wait another year. Working with technical service providers (who have worked out all of the kinks) makes agroforestry adoption more efficient and increases the likelihood that the trees survive and thrive.
As an agroforestry service provider, Propagate’s unique technology-driven approach streamlines analysis and adoption across many different scales, offering Overyield access for suitability analysis and scenario modeling, as well as implementation services that include site visits, system design, site prep, financing and installation. Then come tree survival guarantees, a dedicated project manager, and access to our trusted service provider network that buffer you from risk.
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