How do I select a site for a conservation buffer in an organic field?
Answer: Conservation buffers are generally strips of vegetation placed in the landscape to influence ecological processes and provide a variety of services. They are called by many names including wildlife corridors, greenways, windbreaks, and filter strips.
Buffers represent an opportunity to implement conservation practices that benefit the operation by creating habitat for beneficial organisms (birds, pollinators, or parasites and predators of crop pests), as well as providing a barrier against weed seed migration, preventing wind damage to crops and protecting water quality.
There are several considerations when choosing a buffer site:
Location: The overall design of a buffer site must meet Natural Resources Conservation Service (NRCS) practice criteria, as well as the standards of the producer’s certifying agency and the USDA National Organic Program (NOP). To address NOP buffer requirements, the site selected should be adjacent to an area from which there is a risk of contamination from pesticides or chemical fertilizers not allowed in organic systems. This is commonly along property lines, but in situations where the producer has both organic and conventional operations, the buffer could be in the middle of an operation at the boundary between the two types of production.
Width and height: The site selected for the buffer should be wide enough and have space for plants to grow tall enough to intercept any significant pesticide drift from the adjacent conventional operation.
Irrigation access: The site should also have access to irrigation water to establish the plants and, in drier areas, address long-term water needs. Drip irrigation works well for plugs or potted plants. For native grasses and wildflower mixes that are broadcast, planting should be done during the rainy season, with back-up sprinkler irrigation.
Soils: Soil type will influence the plants that will thrive in an area. Amending planting holes with good quality compost also improves growth rate.
Sunlight: Most native perennial shrubs, forbs, and grasses do best in locations with full sunlight. Plants, however, should be selected based on the site conditions and some varieties thrive in shade.
Accessibility: The site should be accessible to equipment for site preparation, planting and maintenance.
Ready to learn more? The publication Conservation Buffers in Organic Systems: Western States Implementation Guide will be a worthwhile read. It discusses benefits of buffers, site design and preparation, weed management options, and maintenance and planting considerations.