Natural Resources and Biodiversity Conservation on Organic Farms
Natural Resources and Biodiversity Conservation on Organic Farms
By Valley Stewardship Network
In 2016, the National Organic Program published its guidance on Natural Resources and Biodiversity Conservation. Adherence to the guidance: “...requires the producer to incorporate practices in his or her organic system plan that are beneficial to biodiversity on his or her operation.” This is timely guidance because research has demonstrated declines in biodiversity over recent decades in regions throughout the globe. Reversing these trends by promoting biodiversity within our organic operations will be essential for long term biodiversity conservation.
The strongest declines in biodiversity have been observed in insect groups. Pollinators are one of the key groups of concern not only because of the reports of recent declines, but also because they are essential for the production of many of our crops. The honey bee gets a lot of the press about pollinator declines and they also receive most of the credit for pollination services. However, recent research has shown declines in several of our native pollinators, and that much of the credit for crop pollination should actually go to our native pollinators. The array of native pollinators is incredible. For instance, there are over 400 native bee species in Wisconsin alone; compare that to the solitary honey bee species. There are also countless other insects that visit flowers and could pollinate crops, some of which will also consume crop pests. While we emphasize the importance of pollinators, any efforts to improve biodiversity for one group of organisms can also promote the diversity of other groups, and will ultimately make our agricultural ecosystems more sustainable and resilient.
Our agricultural landscapes have great potential to foster and sustain biodiversity. Indeed, farms have been an important repository of natural biodiversity historically. However, pesticide development, genetic modification, antibiotics, and chemical fertilizers, coupled with farm specialization and consolidation, has greatly simplified our agricultural landscapes. This is important because more complex agricultural landscapes with many different types of operations, crops, livestock, and land covers host greater biodiversity than simplified ones. Maintaining biodiverse agricultural landscapes is going to require efforts from all forms of agriculture, but organic operations have the greatest potential to preserve and enhance biodiversity.
There are many components and options to promote biodiversity on your farm:
Restoration: Within your farm there may be areas of the property that are remnants of natural ecosystems. Some examples might include an old pasture or hay field that still contains some native prairie species, a wet area that has indications of being a sedge meadow, or a steep slope with large sprawling oaks that was once an oak savanna. Efforts to remove or reduce the presence of weedy or brushy species, will allow the native vegetation to flourish to help bring these habitats back to their former glory. These types of remnant ecosystems have the potential to be the most biologically diverse areas of your farm.
Enhancement: There may be areas of the farm that are already reserved for natural habitat such as CRP fields or pastures that are largely grass dominated. Areas with existing perennial vegetation can be enhanced with seed or plants that provide resources for wildlife. Establishing plants within existing sod often requires some special preparation before seeding or planting. Consult with a resource professional for a list of species to plant and methods for establishment.
Meadow Plantings: Planting a diverse mix of grasses and flowers will provide resources for pollinators, predators/parasitoids of crop pests, and habitat for grassland birds. Native tallgrass prairie plants are highly recommended for meadow plantings because they are the flower species that many of our native pollinators are adapted to. However, using less costly alternatives such as red clover or alfalfa can help also benefit pollinators. The most important consideration when selecting flower species to plant, is to ensure that there is always something in bloom at any given time throughout the growing season. Meadow/prairie plantings can still be utilized for haying or grazing, just not as frequently as a field or pasture managed specifically for forage production. In meadow/prairie plantings, haying should be delayed until after July 1st to allow time for nesting birds to fledge their young.
Buffer/Filter Strips: When placed at the downslope edge of fields, buffer strips can help control erosion, slow down water flow, and filter out nutrients and sediments to prevent them from entering our waterways. Any perennial plants can be used in a buffer strip, including certain tree species. Using a diverse planting of native tallgrass prairie may provide advantages over other plant options. Native tallgrass prairie will have more resources for pollinators and better habitat for grassland birds. Also, prairie plants have thick stems that slow down water and hold up better in large rain events, and their prolific root systems provide greater water infiltration. Researchers at Iowa State University have found that native tallgrass prairie strips reduce sediment and nutrient runoff by over 84% (www.prairiestrips.org).
Diverse Cropping Systems: Diversifying crop rotations, intercropping, and cover crops can all have positive benefits on biodiversity as well as improving soil health and water quality. Rotating crops helps reduce the presence of crop pests, and improves soil health and biodiversity. Intercropping involves growing two or more crops in close proximity, such as alternating rows. Cover crops will certainly improve soil biodiversity and when allowed to flower can provide important resources for pollinators and predators/parasitoids of crop pests. Having different types of crops, fields and/or types of livestock creates niches that provide habitat and resources for different organisms. A diverse operation will have more biodiversity than a more specialized/simplified operation.
Low-maintenance for Habitat: Farmers take great pride in their operations and work hard to maintain the aesthetics of the farm. General maintenance might include felling dead trees, removing brush, or planting sod to areas with poor vegetation cover. Indeed, these types of practices are necessary at times, especially if they pose a safety or environmental quality concern. But when appropriate; brushy areas, dead trees, patches of bare earth, and the presences of some weeds can provide important habitat and resources for beneficial wildlife. For instance, some pollinators nest in dead trees while some nest in bare soil, and others nest in hollow stems of some brush species. Also, many “weeds” can serve as excellent food sources for pollinators, predators/parasitoids of crop pests, and birds as long as they are not the types of weeds that invade and harm our agricultural or natural environments.
Mimic Natural Processes: In many natural ecosystems, maintenance of biodiversity relies on periodic disturbance to sustain a healthy and diverse mix of species. Prehistorically, in grasslands of the upper Midwest, natural disturbances like fire and grazing were critical for maintaining biodiversity. Today, we can mimic the movement of grazing herds that once roamed the prairie by implementing rotational grazing. Grazing different portions of a pasture at different times and altering the sequence from year to year helps to promote pasture diversity. For instance, many grassland bird species thrive in rotational grazing operations and have a specific preference for the height of vegetation they like to nest in. By providing different heights of vegetation, a greater number of bird species will find their particular preferred height in a single pasture. Also, burning sections of our hay fields or pastures can reduce weeds and pests, promote new growth, and even alter the palatability of forage to influence grazing patterns or increase the selectivity of undesirable forage species.
Resources and Technical Assistance
When considering implementation of a conservation practice don’t hesitate to consult with a local resource professional. Your local Land & Water Conservation, NRCS, and FSA offices are a great place to find out about conservation options and cost share funding that might be available to help you achieve your goals. Local non-profit organizations can also be a great place to find conservation expertise. For instance, Valley Stewardship Network provides landowners with free whole farm mapping services and planning for prairie and pollinator plantings. We work with multiple partners who provide landowners with expertise on a multitude conservation initiatives including: whole farm planning, managed grazing plans, cover crop assistance, stream restoration, forestry, and conservation easements. These partner organizations include the Pasture Project and Wallace Center at Winrock International, Mississippi Valley Conservancy, Trout Unlimited, Southwest Badger RC&D, Kickapoo Grazing Initiative, and The Prairie Enthusiasts. If you are located in SW Wisconsin and are looking for some free assistance to get started with on-farm conservation practices and projects, contact Valley Stewardship Network at firstname.lastname@example.org or 608-637-3615.