When we think about biodiversity, we often think of parks and natural areas. We don’t usually think about most vegetable farms. Picture big fields of weed-free cabbage, lettuce, sweet corn, or broccoli. To be clear, agricultural biodiversity doesn’t mean lots of weeds in the crop fields. But biodiversity is increasingly recognized as critical to long-term agricultural sustainability in a world with shrinking available arable land as the growing human population spreads out across the landscape.
Biodiversity can take many forms. It can be diversity of crops within fields and throughout a crop rotation cycle. It can mean increasing soil organic matter and improving soil health to favor an abundance and diversity of beneficial soil microbes and mycorrhizae with synergistic impacts both on suppression of soilborne pathogens and improving crop yields.
Increasingly, biodiversity also can mean incorporating in-field and edge-of-field practices that encourage a succession and diversity of bees and parasitoids that can aid in pest control and pollination. Biodiversity also can mean genetic diversity within crop species.
The Role Of The Ecosystem
Whether we recognize it or not, crop and livestock production depends on the interactions of thousands of organisms including soil microbes that aid in nutrient cycling and uptake, along with insects, birds, and bats that pollinate crops and feed on pests. When you are just trying to make a living, it’s easy to avoid thinking about ecosystem services and biodiversity.
These days, however, managing for biodiversity can be part of a far-sighted perspective with many benefits at little or no cost. Healthy soil biodiversity is an area of increasing interest and research. There is so much more to learn about the “skin of the Earth.” (For more information on healthy soil biodiversity, go to SoilQuality.org.)
Hedgerows, buffer strips, windbreaks, predatory insects, or pollinator habitat strips, preserving fallow land in diverse cover, multispecies and flowering cover crops, and leaving undisturbed overwintering habitat to allow useful parasitoid insects to complete their life cycle are among the many strategies that can easily be used to promote biodiversity on farms. Crop rotation remains a critical biodiversity practice.
Some smaller vegetable operations build in biodiversity almost by default when they produce many different crops and crop varieties in small plots, and as they maintain sod strips for separation between crop varieties and as pathways for workers and equipment. That same strategy can be scaled up and implemented for larger operations.
Manage Plant Habitat For Bees
With respect to pollinator biodiversity, it’s not just about honey bees. While moving hives around high-value fruit and vegetable crops continues to be a common practice, managing flowering plant habitat for bee and other pollinator diversity is increasingly seen as an alternative or complimentary option, especially for habitat supporting multispecies communities of native bees. (For more information on pollinator biodiversity, go to Pollinator.org.)
Of course, habitat diversity can have some complications. Hedgerows can become travel corridors for deer or raccoons ready to munch on crops just as they are sprouting or ripening for harvest. Geese may take advantage of the grassy area around an irrigation pond for grazing and then spread out into adjacent cropland to satisfy their appetites.
Habitat diversity can introduce challenges if the diversity favors wildlife that can become crop pests. I’ve often wondered, as I’ve watched hawks perched in trees along highways, why we don’t see more avian predator perches purposely placed along the edges of agricultural fields.
The USDA Natural Resources Conservation Service (NRCS), the USDA Farm Service Agency, and many state soil and water conservation agencies provide technical and sometimes financial assistance to help growers make conservation improvements leading to increased biodiversity.
Farms also are encouraged to explore NRCS’s new “Conservation Client Gateway” as a way of accessing farm records, requesting technical and financial assistance, and even electronically signing and submitting payment applications. Visit nrcs.usda.gov/ClientGateway.
Eco-friendly farming practices don’t solve every problem. However, with some attention given to potential management concerns, enhancing the biodiversity of farms can contribute to the long-term success of agricultural operations and lead to an overall healthier agricultural ecosystem.