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The Applications of Agroforestry

Published
January 18, 2024

Agroforestry is the intentional integration of trees and shrubs into crop and animal farming systems. Planting trees in agricultural environments can create environmental, economic, and social benefits. It is considered one of the earliest forms of agriculture and has been sustainably practiced by indigenous peoples worldwide for generations.

An example of agroforestry where the trees are planted with and between rows of farming crops.

Increased Need for Sustainable Agriculture Practices

Almost 900 million acres of land in the United States are used for agriculture and farming.  As major corporate supply chains press for greener operations, techniques like reduced tillage and off-season cover crops provide farmers with initial ways to enrich soil carbon. Adopting improved soil and cropland management strategies could increase carbon storage by over 250 million metric tons of carbon dioxide equivalent per year across American farms, and sustainable agriculture practices like no-till, cover cropping, and agroforestry have significant potential to mitigate climate change.

Agroforestry takes carbon sequestration a step further through tree planting. As climate change threatens agriculture globally, agroforestry offers solutions to improve farm resilience and mitigate climate impacts.

Agroforestry practices in the US, where trees are planted strategically to act as windbreaks for crops and riparian forest buffers, mitigate runoff, control erosion, and provide nutrients for the waterway.

Agroforestry Productivity in Farming

Improved Crop Health

The trees and crops in agroforestry systems develop complex and beneficial relationships. Nitrogen-fixing trees, like poplar and alder trees, enhance soil fertility and would require less fertilizer to be needed for farming. Trees create more stable environmental conditions and help plants avoid heat stress, as well as increase local biodiversity, which reduces plant diseases. 

From Wolz, K. et al. (2018). (a) Row crops are distinctly separated from the small patches of remaining natural areas. (b) Alley cropping with hardwood tree rows and an alley crop of small grains. (c) Alley crop trees mixed with nut trees and grape vines within tree rows

The value of planting trees cannot be overstated. Local biodiversity integrated with agricultural land has been shown in study after study to suppress invasive weeds, deter pests, and, overall, create a healthier ecosystem for crops and local plants to grow and flourish. Tree planting leads to less resources and lower production costs needed to sustain crops and healthier plants.

Ecosystem Services Spacial Scale
Farm/Local Landscape/Regional Global
Net Primary Production
Pest Control
Pollination/Seed Dispersal
Soil Stabilization/Erosion Control
Clean Water
Flood Mitigation
Clean Air
Carbon Sequestration
Biodiversity
Aesthetics/Cultural
Various ecosystem benefits are provided by agroforestry systems. Source: Agroforestry for ecosystem services and environmental benefits: an overview.

Providing Protection and Erosion Mitigation Through Windbreaks

Trees being utilized as windbreaks are commonly seen in rural parts of the US known as the Great Plains. During the 1930s, increased demand for crops, more submarginal lands being converted into farmland, and minimal soil conservation practices led to The Dust Bowl. From Texas to Nebraska, drought-stricken lands were encompassed by dust storms that led to over 7,000 deaths and hundreds of thousands of lost livestock.

Source: Mystery Science

In 1935, Oklahoma began strategically planting trees as windbreaks and to protect the topsoil. This became wildly successful, and over 220 million trees, also known as the Great Plains Shelterbelt, were planted. The technique proved very effective at stabilizing the land and protecting the topsoil.

Top left: Great Plains States Forestry Project poster. Top right: map showing the major planting areas of the Shelterbelt Project from 1933 to 1942 exemplify the government’s tree-planting efforts. Bottom: Image of trees as windbreaks in the agricultural lands of the Great Plains.Sources: Work Projects Administration Poster Collection and U.S. Forest Service.

Since the early 2000s, there has been a substantial corn and soybean boom in the United States that has caused an increase in erosion on US agricultural lands. Iowa State University has estimated that the soil in Iowa is eroding 16 times faster than natural topsoil can replenish itself. Planting trees is an important and natural solution that will protect topsoil and rehabilitate the nutrients in the soil. 

Trees used as windbreaks do not only protect crops but also lead to higher yields in crop growth. Scientific studies today have shown that soybeans and corn, when protected by windbreaks, yield 15% more in soybeans and a 12% yield increase in corn. Not only do blocking winds help rehabilitate soil and prevent erosion, but they also result in an increase in crop production.

Mitigating Land and Water Impact

Climate change is driving more droughts, rains, and extreme weather, which is disastrous for farms and farmland. Between 2003 and 2017, Iowa was impacted by four “hundred-year storms” that led to torrential flooding and affected major crops like corn and broccoli.

In the Corn Belt region, prairie grasses and wildflowers have deep roots that dig deep into the ground, which protects the topsoil, sequesters carbon, and banks water into local underground aquifers. When major torrential rains cross these plains, rooted plants can naturally ground the topsoil and divert water into the natural aquifers. Today, with the monoculture planting of crops, there are few, if not any, deep-rooted plants that protect the topsoil. This leads to tons of topsoil being washed away during rainfall, and the Daily Erosion Project has shown that as much as 32 tons of topsoil per acre have been washed away by rain.

Strategically planting trees, prairie grasses, and wildflowers with deep root systems can help mitigate drought and flood impacts through their natural abilities to anchor topsoil and recharge aquifers. By diversifying the landscape and restoring native vegetation, farms can enhance resilience. Taking proactive steps to diversify agriculture with climate-smart plants suited to the region could make farms more robust in the face of intensifying weather extremes.

A prairie strip between corn fields. Photo from Iowa State University and Grow Magazine.

Agroforestry for Carbon Removal

Trees naturally capture and store carbon as they grow, making them ideal carbon sinks in agriculture. Incorporating trees strategically into farms maximizes this carbon sequestration while still allowing cultivation in between trees. A common adoption of agroforestry is alley cropping and it is estimated that tree agroforestry practices, even modestly applied, could remove up to 3.4 megatons of carbon per hectare per year.

A diagram of alley cropping, or planting rows of trees between rows of agricultural plants as windbreaks from the USDA.

In the agroforestry process, not only is carbon sequestered by trees, but the root systems developed by the trees lead to an increase in soil carbon sequestration. Depending on soil depth, soil carbon sequestration can increase by 26-34% when agricultural land when agroforestry practices are applied. Living Carbon trees have been scientifically proven to sequester more carbon than traditional trees, with preliminary results showing an increased ability to remove heavy metals like copper from soil.

Our second HQ is located in South Carolina, and our trees are centrally located in this major growing region to be more accessible to major agricultural hubs. Living Carbon can create high-impact, sustainable agricultural forest carbon projects by enabling more permanent carbon sequestration and has the potential to sequester an average of 2 to 5 megatons of carbon dioxide per acre.

Living Carbon photosynthesis-enhanced trees (left), next to grey poplar trees (right). Living Carbon trees have increased biomass by 53% versus native trees.

The solutions to combating climate change and developing sustainable agriculture systems already exist in nature - we need only to implement them. Agroforestry provides a blueprint for that implementation through its strategic mixed planting of trees and crops. By mimicking the biodiversity of natural ecosystems while still allowing for food production, agroforestry has the potential to help feed the planet’s growing population. With smarter land management centered on trees integrated with agriculture, we can create resilient and regenerative farming systems fit for the challenges ahead.

If you're interested in working together, reach out to us at landteam@livingcarbon.com.

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