Agricultural landscapes in the United States, from the Central Valley of California to the Corn Belt of the Midwest, are largely similar in that the lands encompass expanses of single crops. Whether it is almonds or grapes or tomatoes or a fallow field, the one thing they have in common is their imposing homogeneity. This has become the face of modern agriculture around the world.
The unintended consequences of our agricultural food system, in terms of polluted air and water, soil erosion, dead zones in coastal seas and biodiversity loss, have profound implications for human health and the environment. To maintain Earth’s capacity to produce food, it is imperative that we change the face of agriculture soon.
Comparing agricultural systems
Contrast your image of industrial agriculture with an alternative landscape: a fine-grained, mosaic of different crops like orchards, vegetable row crops, flowering field margins and pastures. This landscape supports a greater variety of wildlife, some of which would help to pollinate crops and control pests. Different techniques are employed to promote healthy soils that reduce run off while delivering the necessary nutrients to the crops. This vision of agriculture is much more similar to nature because it mimics natural systems and encourage ecosystem services. The end result is a more sustainable system with less reliance on external inputs, such as chemical fertilizers and pesticides.
Such systems (e.g. agro-ecological, ecologically-intensive, biologically-diversified or regenerative farming systems) are becoming more popular as concerns about industrial agriculture grow. The most widely practiced and studied alternative agriculture practice is organic, which now takes place on approximately 0.9% of agricultural lands globally. At the most fundamental level, organic agriculture has no synthetic inputs, but organic farms may also practice a variety of diversification techniques that mimic natural systems.
The dominant perception, however, is that alternative forms of agriculture, such as organic, are not and can never be as productive as the vast, single crop farms with large chemical inputs. This sets up the debate as to whether we should focus on getting as much production as possible out of the smallest amount of land, using all the chemicals necessary, or concentrate on farming in a less harmful, but less productive way. This is a false choice. In our study, published in Proceedings of the Royal Society B, we found that organic farming systems, when done right, come close to matching the productivity of conventional systems.
To compare the yields of organic and conventional agriculture, we compiled studies from across the globe that compared organic and conventional yields over three decades. We found that, although on average organic crop yields are about 19% lower than conventional yields, two common diversification practices significantly reduce this gap. Specifically planting multiple different crops at the same time (polyculture) and planting a sequence of crops (crop rotation) on an organic farm cut the difference in yield in half.
Interestingly, when both production systems used crop rotations or polycultures, the difference in yield between the systems was the same as when both systems did not include those practices. This suggests that both systems receive similar yield benefits from incorporating diversification practices. Our study strongly suggests that we can develop highly productive organic farming methods by creating ecologically diverse farms.
Harnessing the services provided by nature through diversification practices, crop rotations, and polyculture are not novelties—people have been practicing these techniques for thousands of years. Using the terms “conventional” to describe the relatively young form of high input, low diversity agriculture and “alternative” to represent the forms of agriculture practiced for most of human civilization is therefore a clear misnomer when put into a historical context. However, in the present a variety of socioeconomic and political factors have led high input agriculture to be the conventional form of agriculture. Our study suggests reincorporating diversification practices into agriculture will maintain or even improve yields, which will be important for transitioning to a more sustainable and resilient food system, while also feeding a growing population.
Making the transition
Transitioning to more diversified systems, however, faces many challenges. Particularly, the context-dependent constraints of labor, cost, mechanization, and scale will interact to decide what agricultural systems are possible where. For example, diversification practices like crop rotations often require more labor because their practice is not so easily mechanized. In many parts of the world, particularly developing countries, underemployment is a concern, and increased labor demands in the rural sector would be welcomed. In places like the Midwestern US, however, where labor is difficult to find, using techniques that require more labor would be more difficult to implement. We therefore need more research aimed at developing/refining methods to mechanize more heterogeneous systems while untangling barriers to adoption. Less than 2% of the USDA’s research funding is dedicated to alternative forms of agriculture. Conventional agricultural productivity has benefited greatly from research dollars. Investing in alternative agriculture could provide significant gains in alternative agriculture productivity while also reducing the harmful impacts of agriculture in general.Lauren Ponisio and Kevi Mace are both PhD candidates in the department of Environmental Science, Policy and Management at the University of California, Berkeley.