Feed the Future
This project is part of the U.S. Government's global hunger and food security initiative.

Filling the Void: Optimizing Space in Agriculture to Improve Yields and Livelihoods

Throughout the world, the agricultural sector plays a vital role in sustaining local, regional and global economies as well as livelihoods. It is estimated that there are some 570 million smallholder farmers who depend on their land as their main source of income and food. Today, societies rely on conventional farming methods, but are these methods capable of satisfying the income and subsistence needs on an individual level? As the number of people living in hunger and poverty continues to rise, it is clear that more efficient and productive agriculture systems are necessary to support our ever-growing needs.

With conventional agriculture, farmers are taught to intensely plant only one type of crop throughout their field, believing that they are making the best use of the space available, but this is, in fact, far from the reality. Farmers miss out on many valuable returns when they only think laterally and do not account for the vertical and perimetric spaces capable of providing much needed income and subsistence boosts.

This is where the Forest Garden Approach comes in with its ability to capitalize on the horizontal, vertical and perimeter spaces of a farmer’s field to maximize crop yields. By treating the space of a farmer’s field as a 3-dimensional rectangular prism instead of a flat, 2-dimensional rectangle, farmers are able to reap many additional benefits. Where conventional agriculture is lacking, the Forest Garden Approach thrives.

Horizontal Space Optimization

When looking at the use of horizontal space in a farmer’s field, traditional monoculture models instruct farmers to perfectly plant rows of one particular variety/species in such a way that each individual crop is planted geometrically to create a grid. Although this model may seem aesthetically pleasing, its yields cannot compete with unconventional models that emphasize a more effective and efficient use of ground space.

In contrast, the Forest Garden Approach chooses a model based off of a different geometric shape: the triangle. Using Triangular Spacing may seem like a very minor, inconsequential change, but a variety of both tangible and secondary benefits arise from this subtle change.

Planting seeds at an angle from one another allows for greater plant density in the field or garden. When compared to the density of monoculture, the Forest Garden Approach gives farmers the chance to plant up to 35% more.

Figure B and C illustrate the obvious benefit of Triangular Spacing – the increased number of crops a farmer can plant in comparison to Traditional Row Spacing. Looking more closely, there are less tangible but equally important benefits that arise.

One of these less visible benefits is the reduction of water evaporation in the field. By increasing the plant density in the field, a farmer is able to cover more soil with vegetation. This, in turn, greatly reduces the sun’s ability to leach the soil of its moisture and allows for healthier, more vigorous crop growth.

In addition to increasing moisture retention in a farmer’s field, the increased density of triangular spacing limits the weed growth around the crops. Not only does this reduced weed growth provide crops with a higher likelihood of flourishing into productive and healthy plants, it also reduces the workload of farmers and their families. In doing so, farmers have more time and energy to focus on other important aspects of life like family and education. Choosing Triangular Spacing over Traditional Row Spacing appears to be a minor decision, but a farmer’s choice to make better use of the horizontal space available proves to have major benefits in the form of crop yield, crop health, moisture retention and weed growth limitation, all of which enhance the Forest Garden ecosystem and in turn improve the overall livelihood of farmers and their families.

Vertical Space Optimization

This is by and large the biggest oversight of conventional monoculture models. While a farmer in a system of monoculture can still make decent use of the ground space available, a farm implementing the Forest Garden Approach literally goes above and beyond the ground space by making far better use of the vertical space within the confines of the field. While a monoculture model only uses one layer of vertical space, the Forest Garden Approach uses seven! The graphics below identify each one of these layers in addition to the vital role they play in optimizing Forest Garden yields.

When you combine all seven of these different layers and the many species of plants, a guild is created. A guild refers to “a group of plants together in a system that maximizes the service and production potential of each plant.” Instructing farmers to carefully and intentionally plant a multitude of species that work well together to optimize the growth, health and production of their fields sets the Forest Garden Approach apart from most agricultural models. Similar to Triangular Spacing, the benefits appear in more ways than one. The more obvious benefits come from the increased plant density created by so many different layers of vegetation. Just as with Triangular Spacing, the results show that Forest Garden becomes shadier, cooler and more humid. All three of these characteristics describe the optimal conditions for healthy and vigorous crop growth.

A guild and its layers: Everything is better when you work together!

  1. Canopy plants: can be fully grown fruit or nut trees, timber species or pioneer species that grow quickly and produce shade. This is the tallest layer, averaging over 25 m in height.
  2. Subcanopy plants: lower plants utilizing some shade of the canopy plants, including coffee plants or small trees such as banana.
  3. Shrub plants: large bushes or tall annual crops.
  4. Herbaceous plants: often edible and medicinal plants.
  5. Vining or climbing plants: plants that climb their way up subcanopy and canopy plants.
  6. Groundcover plants: shade the soil conserving moisture and preventing soil loss, can be nitrogen fixing.
  7. Underground or rooted plants: become nutrient pumps for the surrounding soil enhancing its fertility, these often include root vegetables such as potatoes, carrots, tubers, onions, etc.

How do they compare?

Moving Forward

After comparing the outcomes of conventional agriculture versus those of the Forest Garden Approach, it is hard to understand why conventional practices continue to be implemented today. By simply taking advantage of all the space available in a field, Forest Gardens are able to eclipse conventional agriculture systems when it comes to productivity, financial return, nutrition and sustainability. The United Nations Development Programme recently reported that 1 in 9 people in the world are undernourished. This translates to a staggering 815 million people lacking the adequate diet to develop and function to their full potential.

Returning to the initial question: Can conventional agricultural systems satisfy the income and subsistence needs of our growing world? The answer seems clear. It’s time farmers began adopting unconventional practices that promote the optimization of space and biodiversity rather than conventional practices that lack the production needed by so many. Change is needed and by working together and maximizing our efforts to implement more productive, bio-diverse and sustainable systems, like the Forest Garden Approach, we can feed the future.

For additional resources and Forest Garden Training, go to training.trees.org.