The long term viability of our agricultural system is being questioned for many reasons. Our modern farming structures, often termed conventional or industrial, are largely characterized by monoculture, high chemical input, and large water usage. This system is based on the belief that nature is a competitor to overcome, and that humans can outsmart nature to ensure maximum efficiency. However, over time evidence has confirmed that conventional farming negatively impacts three areas:
- Ecological health: soil degraded, water overuse, deforestation, pollution
- Economic health: market competition limited, breakdown of local economies
- Human health: pesticide use harmful to farmers & consumers, decreased food security
The idea of sustainability is difficult to define in a changing world. Questions emerge like: what are we sustaining? Are we too late? However, the word sustainable is a helpful umbrella term to better understand the practices and changes necessary to ensure a brighter future. Sustainable agriculture describes a system that will provide for the basic needs of its present inhabitants while preserving the resources for the next generations
Although there are many different ways to practice sustainability within the agricultural sector, there are several common threads, including:
- High biodiversity
- Low input
- Thoughtful management of natural resources
Sustainable agricultural operations take different forms depending on the regional climate, capital input, and land area. However, sustainable agriculture can be broken down into three categories.
Agroforestry is defined as the integrated approach in which trees and crops are intercropped, or grown together, in interacting arrangements. Trees act as windbreaks that reduce soil erosion and protect crops from intense sunlight and weather variations. Additionally, trees create a habitat for birds and pollinators that support a healthy ecosystem.
As a result, this system fosters a variety of ecological and economic benefits including increased yields, increased food security, and increased environmental resilience. These deep-rooted agroforestry systems have a higher capacity to store carbon in plants and soil and therefore can make a significant contribution to climate change mitigation.
Beyond tree intercropping, agroforestry systems take on many different forms. According to Project Drawdown, multistrata agroforestry systems mimic natural forests by maximizing horizontal and vertical space by utilizing several layers of trees and crops to achieve greater rates of carbon sequestration and food production. For example, multistrata agroforestry systems of macadamia nut trees with a shade-grown coffee understory in Hawaii represent two commercial crops that not only support ecosystem health but also lessen the impact of market fluctuations on farmers.
Another manifestation of agroforestry is silvopasture. Silvopasture integrates trees, pasture, and forage into a single system for raising livestock. According to Project Drawdown, pastures containing trees sequester five to ten times more carbon in both biomass and soil than treeless pastures. Furthermore, the financial benefits are considerable. Because livestock and trees (particularly fruit and nut-producing trees) generate income over different time horizons, and because land health is increased by biodiversity, silvopasture is more resilient and farmers are better financially protected.
Urban agriculture, describing systems of farming in city spaces, has become an increasingly attractive branch of sustainable agriculture as equitable food access has declined as a result of urbanization and small-farm consolidation. The global pandemic COVID-19 has sparked questions regarding the sustainability of our large-scale food production system, and recent trends have shown a shift towards localized food economies. Community-supported agriculture (CSA) boxes are one example of how people are looking to source their food locally and sustainably.
Today, the link between dense inner-city neighborhoods and known food deserts, defined as regions characterized by limited access to fresh and affordable food, remains clear. However, converting unused space such as parkways and vacant lots into community gardens is a form of hyper-localized agriculture that not only cultivates nutrition and societal health but also creates more green space that helps combat the detrimental environmental impacts of urbanization.
Green roofs present an additional opportunity to reimagine urban space. Green roofs function as living insulation and reduce wastewater runoff. Because green roofs moderate building temperatures year-round, and less energy is required, greenhouse gas emissions and costs are reduced. They may support a cover of non-edible vegetation, or they may hold a full garden or farm. Rooftop gardens help mitigate supply chain issues and allow more communities to participate in the local food movement.
Permaculture, perhaps the most practiced form of agroecology, which is the study of ecological processes applied to agricultural systems, views agriculture within an ethical framework and set of design principles based on systems thinking.
The twelve principles of permaculture can be summarized into the fundamental principle of maximizing the interconnected relationships between agricultural components to achieve the most united and optimal design. Therefore, permaculture design aims to cut down waste, human labor, and resource input by building systems with maximum benefits between design elements to achieve a high level of holistic integrity and resilience.
This principle-based style of sustainable agriculture has the potential to reduce energy, pesticide, and freshwater usage while creating more biodiverse food systems. Known examples for the application of permaculture in agriculture are still rare due to a lack of science funding. However, scientific evidence backs up all twelve permaculture principles. Given this, permaculture design has real potential for climate change mitigation and feeding the planet.
Many different approaches to agriculture can address the increasing urgency to sustain both the planet and the people on it. Whether it is implementing agroforestry in the tropics, or building a community garden in the city, more intentionally stewarded land and green space is the common theme. To meet our Sustainable Development Goals of addressing global challenges of climate change, poverty, inequality, and environmental degradation, these agricultural systems need to be a part of the conversatiom.