The ABCD’s of Agroecology: What Is It All About?

October 15, 2015
Marcia DeLonge
Research Director and Sr. Scientist, Food and Environment

What makes agroecology so great (as I have said before!) is that it combines the best of two time-tested disciplines, ecology and agriculture, to pursue solutions for a healthier world. The list of experts who have agreed that agroecology can address many major challenges keeps growing, but what is this really all about?

Healthy Soils 101

Agroecology starts with healthy soils. Healthy soils support plants by providing a balance of nutrients (for example, nitrogen and phosphorus) and carbon (food to keep the microbes going). They have a texture that holds plenty of water while enabling percolation of water and flow of oxygen to deep roots. They are loose enough to allow growing roots, but firm enough to hold them up.

Agroecological farmers use many practices you’ll find on organic farms, but what tends to set them apart is that they also design their fields, year after year, with a mix of crops, animals, and non-crop plants that lead to more resilient and lower-risk operations with less chemicals, irrigation, energy, and waste. And research (here, for example) is showing that these efforts pay off – in production, environmental metrics, and dollars.

Top “TEN”nets of agroecology

To achieve their goals, agroecological farmers employ an array of practices (those tangible things that you might actually look for when visiting a farm). Just for fun, I’ve boiled these down to ten:

  1. Amendments: Many farmers add organic amendments to their soils to fulfill multiple goals. Neither all soils nor all amendments are created equal, so farmers choose based on their needs. Amendments like compost and biochar often improve soils and in some cases replace chemical fertilizers whereas others, like mulch, are frequently used to control weeds and minimize erosion.
  2. Animal integration: Farms can diversify by including both crops and animals. In some cases, animals occupy crop fields at key times (for example, livestock graze grain fields after harvest, sheep graze vineyards), whereas sometimes they are simply kept nearby. Animal wastes can fertilize crops while their feed is produced locally, reducing transportation challenges. In some cases, by grazing and directly fertilizing fields, animals reduce energy or time-intensive tasks.
  3. Agroforestry: Another way that farmers and ranchers can diversify is by mixing trees or shrubs into their operations to provide additional income and to shade, shelter, and protect plants, animals, or water resources. Silvopasture is a specific system that includes livestock, forage, and trees.
  4. Breeds and seeds (local ones): The crops and animals in many agroecological systems include varieties specifically suited for local conditions (soils, weather, and pests). By growing locally adapted seeds and breeds, farmers can produce tasty food that is resilient to existing challenges while also protecting options to manage the challenges of the future.
  5. Barriers and strips (of non-crop plants). Non-crop plants, like prairie grasses, can be planted as buffers or borders around fields to support pollinators, enhance biodiversity, prevent erosion, and reduce water pollution. When planted in less productive areas, these barriers and strips can rebuild soil health without diminishing profits.
  6. Cover crops and green manure: Cover crops are planted during the off-season to protect soils from erosion, reduce nutrient-loss to waterways, and prevent weeds from expanding into bare areas. Some cover crops boost nitrogen or carbon in soils, reducing the need for fertilizers or other amendments the following season. When crops are grown primarily to serve as an organic amendment, they are often referred to as “green manure”.
  7. Conservation tillage: Tillage refers to the mechanical disruption of soils to incorporate crop residues, manage weeds, or loosen compaction, but it also accelerates the breakdown of organic matter and exposes bare soil to carbon loss, erosion and runoff. Conservation tillage ranges from limited to no tillage approaches that seek to balance the tradeoffs to achieve healthy soils.
  8. Crop rotation: Crop rotation involves switching the crops planted on fields from year to year. Rotating crops disrupts pest and weed reproductive cycles. Because each crop has different impacts on soils, rotations reduce soil depletion or even build soil health.
  9. Diversified fields: Fields can be diversified by mixing crops, intercropping (arranging multiple crops on a single field), or growing different crops in close proximity. Diversification can prevent the spread of diseases and pests, reduce erosion, support pollinators and other beneficial insects, and improve conditions while keeping productivity.
  10. Designed landscapes: The broader farm landscape can be managed to minimize erosion and runoff. For example, terracing on steep slopes, farming along natural contours, and constructing check dams to reduce destructive storm water flow in critical areas can prevent soil loss and degradation.

Ecosystem to ecosystem

The thing about agroecology is that, even though the principles are broadly applicable, one size doesn’t fit all. So, different landscapes, soils, and climates will require unique blends of crops, animals, and practices. The more we learn about the ecology of agroecosystems, the better we’ll get at designing and managing the best systems.

Farm to fork

Farming systems are only truly sustainable if the food they grow winds up on the forks of consumers. This means that transitioning to an agroecological farming system at large scale means more than just picking and choosing from the practices listed above. Instead, thinking big about agroecology means developing the science, business models and policies to support healthier relationships between agroecosystems, producers and consumers, and building from there to produce real transformative change.

Got agroecology?

Now that you know some of the ABCD’s, I sure hope so! At least enough to chew on….