Planning and Implementing Agroforestry Systems
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.
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.
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.
Agroforestry in Action
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.
References:
Pimentel, D.; Hepperly, P.; Hanson, J.; Douds, D.; Seidel, R. Environmental, Energetic, and Economic Comparisons of Organic and Conventional Farming Systems. BioScience 2005, 55, 573–582.
Wilson, M.H.; Lovell, S.T. Agroforestry—The Next Step in Sustainable and Resilient Agriculture. Sustainability 2016, 8, 574. https://doi.org/10.3390/su8060574
Bergström, L.; Kirchmann, H.; Aronsson, H.; Torstensson, G.; Mattsson, L. Use Efficiency and Leaching of Nutrients in Organic and Conventional Cropping Systems in Sweden. In Organic Crop Production—Ambitions and Limitations; Kirchmann, H., Bergström, L., Eds.; Springer: Dordrecht, The Netherlands, 2009; pp. 143–159.
Arnhold, S.; Lindner, S.; Lee, B.; Martin, E.; Kettering, J.; Nguyen, T.T.; Koellner, T.; Ok, Y.S.; Huwe, B. Conventional and organic farming: Soil erosion and conservation potential for row crop cultivation. Geoderma 2014, 219–220, 89–105.
Tuomisto, H.L.; Hodge, I.D.; Riordan, P.; Macdonald, D.W. Does organic farming reduce environmental impacts?—A meta-analysis of European research. J. Environ. Manag. 2012, 112, 309–320.
Muller, A.; Aubert, C. The Potential of Organic Agriculture to Mitigate the Influence of Agriculture on Global Warming—A Review. In Organic Farming, Prototype for Sustainable Agricultures; Bellon, S., Penvern, S., Eds.; Springer: Dordrecht, The Netherlands, 2014; pp. 239–259.
Robertson, G.P.; Paul, E.A.; Harwood, R.R. Greenhouse Gases in Intensive Agriculture: Contributions of Individual Gases to the Radiative Forcing of the Atmosphere. Science 2000, 289, 1922–1925.
Graves, A.R.; Burgess, P.J.; Palma, J.H.N.; Herzog, F.; Moreno, G.; Bertomeu, M.; Dupraz, C.; Liagre, F.; Keesman, K.; van der Werf, W.; et al. Development and application of bio-economic modelling to compare silvoarable, arable, and forestry systems in three European countries. Ecol. Eng. 2007, 29, 434–449.
Thiesmeier, A., Zander, P. Can agroforestry compete? A scoping review of the economic performance of agroforestry practices in Europe and North America, Forest Policy and Economics, Volume 150, 2023, 102939,ISSN 1389-9341, https://doi.org/10.1016/j.forpol.2023.102939.
Sereke, F.; Graves, A.R.; Dux, D.; Palma, J.H.N.; Herzog, F. Innovative agroecosystem goods and services: Key profitability drivers in Swiss agroforestry. Agron. Sustain. Dev. 2014, 35, 759–770.
Lehmann, L.M.; Smith, J.; Westaway, S.; Pisanelli, A.; Russo, G.; Borek, R.; Sandor, M.; Gliga, A.; Smith, L.; Ghaley, B.B. Productivity and Economic Evaluation of Agroforestry Systems for Sustainable Production of Food and Non-Food Products. Sustainability 2020, 12, 5429. https://doi.org/10.3390/su12135429
Equilibrium Capital. (June 2013). "The Opportunity in Permanent Crops." Retrieved from: https://eq-cap.com/wp-content/uploads/2020/05/The_Opportunity_in_Permanent_Crops-2013_09_04.pdf