The Problem with Conventional versus Organic Yield Comparisons
A common critique of regenerative agriculture which came up at our table at the Changemaker Lunch during the NYT Climate Forward Event in New York City is that it can’t feed the world. Conventional agriculture, it is often stated, produces higher yields and is therefore more efficient and capable of feeding us. Favoring practices that produce higher yields is reasonable, but conventional agriculture degrades the very resources on which food production relies (soil, air, water, and biodiversity). While it may have boosted agricultural yields temporarily, it is not sustainable. We are borrowing resources from the future to boost production today. If we want to keep eating, it is clear we need alternatives. But even the idea that yield production is necessarily higher than organic is suspect. Much of the research demonstrating this has a critical flaw: it is being carried out on conventional agriculture’s terms.
Conventional systems are often based on landscape simplification. To maximize efficiency from a management and mechanization perspective, we flatten large areas and wipe them clean of native biological diversity, introducing a monocrop in its place. Without diversity, these landscapes lose their ecological functionality (fertility, water and nutrient cycling; predator - prey population balances; disease suppression; clean air and water provisioning, etc.). We replace the essential functions for crop production with agrochemicals. These are an imperfect substitute with many harmful effects, but when we hyperfocus on one crop at the expense of all else in the ecosystem, we can often get incredible yields on a per acre and per plant basis - at least temporarily.
Often, we compare these yields to an organically grown crop in the same conventional system for a period. That means that the crop, let’s say corn, is still grown on a simplified landscape that has lost ecological function, but we use available organic fertilizers, pesticides, fertilizers, and herbicides instead of synthetic ones. This is an unfair comparison. The conventional system is designed around the ability to use powerful chemicals. Keeping the design but using less powerful organic inputs of course will not produce close to the same yields.
To work best, organic systems are designed very differently. They work with nature, not against it. In healthy ecosystems, there is life in abundance and diversity that performs complimentary ecological functions. For organic, ecological farms, this means growing multiple crops over time and in space, and incorporating non-crop diversity. A classic example of crop diversity is the indigenous system of planting corn, beans, and squash together (known as the three sisters). Because of their complimentary attributes, planting these together “enhances the soil physical and biochemical environment, minimizes soil erosion, improves soil tilth, manages plant population and spacing, provides for plant nutrients in appropriate quantities, and at the time needed, and controls weeds." Non-crop diversity might mean planting trees or hedges that can protect crops from wind, provide appropriate shade, and create habitat for birds that might eat insect and rodent pests. In these systems, the less powerful but also less harmful organic inputs (there is room for discussion and research about which inputs are appropriate) can be complimentary. They can aid with things like soil fertility without excessive harm to the beneficial life that is present.
Comparing these systems - a conventional system to a diversified organic system - on measures of yield per acre or per plant in a given season is inadequate. First, we need to account for what practices are being used. Research has shown that when diversification is implemented in organic systems, yield gaps decline dramatically from what is often reported (~20% to 9%). Second, we need to look at these systems over periods that capture the longer term impacts of the practices. One of the longest running organic versus conventional systems trials (40+ years) at the Rodale Institute has resulted in matching yields over the long term and higher organic yields in years of climatic stress. Finally, we should be looking at measures other than just yield of a given crop. How nutritious is the food being produced? What are the diversity of nutrients being produced? What are the true costs of production to the environment and human health?
When we ask these questions, our understanding of efficient agricultural production changes dramatically. While more work is desired on nutrient density, research shows that phytochemicals are higher in ecologically produced foods while the presence of harmful chemicals is lower. Research on the Three Sisters system shows outsized nutritional benefits of this polyculture to populations relative to monocultures. And while conventional agriculture can produce more corn per acre, it destroys water quality, pollutes the air, kills life and biodiversity, and degrades the soil. Ecological farming can enhance water and air quality, increase life and biodiversity, and improve the soil. We must also question if it is really efficient land use when so few other organisms can survive or even migrate through these landscapes. Ecologically managed farms are often shared ecosystems between wild organisms and domestic ones. They can also provide space for community and recreation. Efficiency isn’t just how little space are we using to produce something, but how much coexistence is happening in that space.
If you want to learn more about ecological farming as a solution to world hunger, check out the work of Raj Patel.
