Climate and Economic Benefits of Agroforestry Systems
Agriculture is well known as a significant contributor to global greenhouse gas emissions, but emerging practices in land management have the potential to curtail these emissions and reverse much of the ecological and climate harm caused by overly intensive systems. One such practice, cultivation and conservation of trees in agricultural practices, or agroforestry, is an important climate-smart solution with many important co-benefits.
There are a range of practices, that can be used for agroforestry, some of which have been employed for thousands of years. Such methods include alley cropping (planting single rows of trees and growing crops in the alley ways in between), silvopasture (combining trees with pasture or livestock grazing areas), forest farming (the cultivation of shade-tolerant crops under the protection of a managed forest), and others. Integrating trees in agricultural systems can certainly be complex and might be difficult to implement in various situations, and there is no one model that works for every region, but the benefits are significant. Overall, incorporating trees introduces more species types in usually one- or few-species systems, and this in turn has been shown to increase crop productivity, improve nutrient cycling, create and change microclimates, and more.
Because of its carbon sequestration potential, agroforestry has been for many years considered a leading agricultural practice for reducing climate impact. Carbon sequestration is the process by which carbon is pulled from the atmosphere and stored elsewhere. In agricultural systems, carbon is stored in above- and below-ground biomass and in soil. In 2010 (authors) published an article thoroughly investigating how agroforestry compared to other farming systems like cropping and grazing, since it had previously not been well studied against such methods. In their research, the authors found that while the amount of carbon that can be stored in soil depends on silt and clay content and soil quality, long-term agroforestry systems tend to store equivalent or higher amounts of soil organic carbon (SOC) than neighboring natural forests. They also found that there was a correlation between organic carbon concentrations, species richness, and tree density and that soil near trees tended to store more carbon than in soil farther away from trees.
Additionally, studies have shown that agroforestry can improve and restore soil quality in degraded lands. In countries that rely on small-scale farms as their main source of income, these practices could improve the standard of living through increased agricultural productivity while also reducing carbon emissions. Pastures can also be restored through agroforestry, allowing communities to better sustain their livestock and benefit from other land-based practices.
The various impacts of agroforestry tie into three main areas where agroforestry can play a positive role: reducing climate pressure, improving soil quality and biodiversity, and strengthening local economies. Because of its impact in these areas, agroforestry should be considered a leading practice in agricultural systems, small and large.