Earth Innovations: Buffer Zones

Earth Innovations is a new series from Sound Agriculture that covers the up-and-coming techniques growers are deploying to keep their yields high and their land healthy for generations to come. In each blog post, we break down the benefits and challenges of incorporating new practices, using real growers’ experiences and the Sound Agronomy Team’s expertise. 

In this segment, we explore how buffer zones can improve farm sustainability and provide many indirect benefits to growers when tailored to your field’s conditions and needs, with insights from our very own in house farmer and director of sales agronomy, Jeff Divan.

By adding conservation buffer zones to strategic areas on their farm, growers can reduce erosion, improve water and air quality, provide wildlife habitat, and promote more sustainable land management practices. Join us for this installment of Earth Innovations as we look at the benefits and challenges of implementing this conservation practice. 

Buffer zones are any non-crop vegetation that act as a barrier between cropped land and sensitive environmental features like streams or wetlands or between organic and non-organic production. The first kind may also be called conservation buffers, wildlife corridors, greenways, or windbreaks. The second kind is often required by organic certifying agencies to ensure no pesticide contamination or cross-pollination occurs in organic areas.

Conservation buffer zones are generally placed in response to the slope contours and other geographic features they aim to protect; they are often found along ditches, streams and rivers or perpendicular to a slope. Organic production buffers, on the other hand, are often landform-blind; instead, they are planted wherever a break to prevent cross contamination between organic and conventional production is needed. In organic production, vegetated buffer zones may not even be needed, as a road of adequate width will also suffice.

There are a variety of benefits to be reaped from buffer zones. Growers may choose to install buffer zones for a variety of reasons and receive additional unintended advantages as well. 

• Reducing leaching and erosion: Buffer zones can act as a natural barrier and prevent losses of phosphorus, pesticides, and soil from farmland into nearby water bodies. The stems of buffer vegetation absorb the erosive force of water and the roots help soil in place. In surface water, soil, nutrients and pesticides can negatively impact aquatic life and habitat and water quality.

• Pollinators and beneficial insects: Planting native and pollinator-friendly vegetation can provide habitat for pollinators year round and, in turn, improve yields. Buffer zones may even be able to provide habitat for the natural enemies of pest insects, which could allow growers to reduce the costs associated with pesticides and other crop protection products.

• Wildlife habitat: By providing food and shelter for wildlife, especially sensitive or at-risk species, buffer zones can support broader environmental benefits as well. And, research from the University of Missouri suggests that because yield is often reduced along field edges next to woodlands, installing buffer zones in those fields does not significantly impact yield or the abundance of pest insects. 

The unique features of each grower’s operation, region and even different fields will dictate which kinds of buffer zone can provide the most benefit. In some regions, buffer zones may be used primarily to combat wind erosion, and in others, they may be used to preserve waterways. 

“The specifics of buffer zones are very regional,” says Jeff Divan, Sound’s Director of Sales Agronomy, who is a grower himself. ​“In some areas, buffer zones may be used for wind erosion control and in others they might provide habitat or moisture control.” 

Buffer zones are implemented in response to the features or needs of a grower’s field. Many are placed adjacent to surface drainage, which are generally in the lowest lying part of a field where eroded soil, pesticides and nutrients are carried by precipitation events, tillage and other erosive forces. 

“What’s most popular is to plant a buffer zone about 30 feet wide with grass and/​or a mixture of flowers and vegetation on each side of these ditches to provide an opportunity to reduce erosion and filter the water that ends up in the ditch,” says Jeff.

Buffer zones for organic farms are slightly different, since their primary purpose is simply to prevent cross contamination and pesticide drift. These buffers may be left fallow, used as pollinator habitat or planted with crops that will be sold as non-organic. Because their shape is not driven by the shape or features of the land, growers have more flexibility with regards to how they treat the buffer. 

“On our farm in Iowa, we use buffer zones as a tool to manage excess moisture and provide habitat,” says Jeff. He plants his buffer zones with native grasses and pollinator habitat in wet, poorly drained parts of his fields where crop production is regularly drowned out, improving his net yield on the field overall. 

“If it’s a low-lying area that can’t be drained, that probably means it has its own set of problems associated with nitrogen loss that can be avoided by taking it out of production,” he adds.

“Buffer zones are very easy to manage,” says Jeff. ​“They’re typically planted with either grass seeding or a grass-type seed mix. From there, maintenance is just keeping trees and undesirable vegetation out, which is easily accomplished by mowing the buffer every few years or even a spring burn every so often. They’re very hands off.” 

There are a variety of federal and state programs that offer technical or financial assistance to growers looking to implement buffer zones on their operations, including through the NRCS.

Still, there can be some counter incentives to planting buffer zones. Because the rates for federal programs like NRCS’ EQIP are set in the Farm Bill, the prices offered for implementing conservation practices often lag behind market conditions, Jeff notes.

And depending on the cost of land, that can make buffer zones look pretty expensive. ​“The extremely high cost of farmland creates an incentive to crop every single acre possible,” says Jeff. ​“If a grower is only getting a couple hundred dollars an acre in return for planting a buffer zone and farming it all could give them double or triple that in potential crop revenue, that’s a trade off a grower might make.”

Finding ways to balance farm finances while improving sustainability is an ongoing challenge for growers. ​“Land is a finite resource and growers make their money by farming it,” says Jeff. ​“But at the end of the day, buffer zones are the right thing to do environmentally.”