Using an approach called Integrated Pest Management (a blend of methods and tools from both organic and industrial farming) and increased diversity of crops in rotation, the 22-acre experiment at Marsden Farm in Iowa was able to demonstrate increased yields and decreased chemical usage with stable profits.
According to the study’s abstract:
>“We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity.”
To test their hypothesis, the team at Marsden Farm divided 22 acres into three plots and planted each with different rotations of crops.
The first plot followed a two year rotation of corn and soybeans, the typical rotation for the region. This plot also received conventional herbicide and pesticide application.
The second plot had a three year rotation with corn, soy and oats and the addition of red clover cover crops planted during the winter. The clover serves as a sort of “green manure” to maintain soil health. It is able to absorb nitrogen during the winter so that when it’s plowed over in the spring it serves as a nitrogen rich compost for the new crops.
On a third plot, the researchers substituted red alfalfa as a fourth year crop instead of the red clover and then used the products as animal feed. The animal manure was then added back to the soil before the next crop rotation.
Herbicides and pesticides were still used on the second and third plots, but not in the usual way that they are routinely applied over the whole field as a matter of course. Instead, they were applied only as necessary. Matt Liebman, lead researcher and Iowa State University agronomist, told Wired magazine, “We use low-dose products in the smallest quantities possible. We’re not against their use. What we’re arguing for is using them as carefully deployed tactical options.”
In fact, having different crops with different life cycles rotating on the land made it harder for weeds to grow and less chemicals were required as a result. The low pesticide use and added cover crops provided a habitat for pest-eating bugs and birds to live and eat the harmful pests.
Over an eight year period, the plots with three and four year crop rotations used 8 times less herbicides than the conventional plot. The clover and alfalfa cover crops also meant 86% less synthetic fertilizer had to be used, and freshwater toxicity of the more diverse plots was two orders magnitude lower than the conventional system.
Best of all, the experimental plots produced the same amount of biomass and were just as profitable as the conventional plot despite the need for increased labor to evaluate and apply herbicides judiciously. This is because the decrease in herbicide and pesticide use represented a significant savings.
So just imagine, less chemicals needed, more jobs created for rural communities, and consistently high food yields.
From the report,
>“Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems.”
The potential reverberations from this study are incredible. More diverse crop rotations are more resilient in the face of climate stresses like this past year’s damaging drought. They also allow farmers to bring livestock back into the farming cycle rather than relegating livestock to CAFO’s (Concentrated Animal Feeding Operations) which generate large amounts of waste.
It is clear that the future of agriculture requires innovations like those discovered at Marsden Farm - ideas that incorporate the best of industrial and organic farming in fresh and novel ways to produce more resilient, scalable, hybrid methods of food production.
To feed the future, we will need to find more efficient, less fuel-intensive farming methods. With a growing population and food systems at near maximum operating capacity, we will need to devise inventive ways to grow more food and waste less food on the consumer’s end. We must also learn to farm closer to market in order to reduce the amount of fuel used in transportation – otherwise known as food miles. We applaud these sorts of efforts which are core to our mission of creating a more Sustainable America.