With harvest right around the corner, almond growers and other harvest stakeholders are encouraged to consider their soil and their neighbors.
Commitment to being a good neighbor starts in each block, and includes keeping harvest dust inside the orchard as much as possible. Orchard-by-orchard harvest decisions specific to local conditions may not seem impactful, but the combined effects of those efforts can help everyone breathe easier at harvest.
Research Shows the Way
Based on a decade of research funded by Almond Board of California (ABC), almond growers can reduce harvest dust, particularly in sweeping and harvest pick-up, by making small adjustments throughout the harvest season:
Start with a clean orchard. Clean orchard floors make all dust management practices easier. When you fill in ruts and holes where nuts can get stuck, you can eliminate extra sweeper passes and adjust equipment heads higher. This knocks unnecessary dust out of the process without a loss of harvest efficiency.
Plan your route. Take every opportunity to blow dust back into the orchard using the tree canopy as a natural filter. Note that the trees and their canopies can help capture dust before it reaches roads and homes. Plan your passes and travel direction to direct dust away from roads, homes and sensitive locations such as schools, hospitals and day-care centers. If you are near a busy road, consider placing traffic signs to warn motorists of harvest activities, and timing sweeping and pick-up to avoid high-traffic commute times.
Go low, but not too low. Set sweeper heads to optimum level, taking into account each orchard’s particular characteristics. Don’t set heads any lower than is necessary to recover the crop. Often, wire tines can be set to as high as a half-inch off the ground and still do a good job sweeping. If set too low, the sweeper head will dig into the orchard floor, washboarding the soil and creating ruts that will make it more difficult to move and pick up nuts during harvest. Additionally, that extra dirt gets swept into the windrow, substantially increasing dust during pick-up.
Fine-tune sweeper settings to local conditions. Extra attention to blower spout adjustment and fan speed can help reduce dust from the blower. The spout should be adjusted to match local orchard conditions, properly angling the airflow so it moves only nuts, and not the soil. Reducing the fan speed can minimize dust and even result in fuel savings. Adding a berm brush to the sweeper can improve performance in some orchard conditions and layouts.
Avoid extra sweeper passes. Use fewer blower passes when and where possible. This may mean a nut or two gets left behind, but you’ll save on fuel. One blower pass instead of three can reduce the amount of dust produced by half.
Go slow and not too low. Taking almond harvester ground speeds down a notch is a big help with dust reduction. Research shows that a pickup speed of 1.5 miles per hour cuts dust by 50% compared to 3 miles per hour. Slower ground speed lets gravity do more of the work by separating dirt from the crop, meaning less dust overall. In addition to speed, set the pick-up machine head height to optimum level by matching local conditions, taking care to not go too low.
Slow fans down, too. Dialing back the rpms on harvester separator fans is another good way to reduce dust. Reducing separator fan speeds to the minimum needed for varying harvest conditions still allows you to harvest thoroughly and efficiently.
Tools to Help You Breathe Easy at Harvest
To best share the research and tips described above, Almond Board offers videos at Almonds.com/HarvestDust, where you can also view a laminated technical guide in English and Spanish and a Harvest Dust Tool Kit.
Small changes in harvest practices add up to big improvements in dust reduction across the growing region. We’re all in this together, and with the tools described above, every member of the California Almond industry can play a part.
For more information or additional materials, please contact Rebecca Bailey at rbailey@almondboard.com or (209) 343-3245.
