Managing Dust: Tips for Each Phase of Harvest

Minor adjustments can have a major impact in reducing overall dust output

Harvest dust can affect our employees, neighbors and surrounding communities. While some dust is inevitable, there are a few simple action steps you can take to drastically decrease your overall dust output. Here are some simple tips and reminders:

Preharvest 

• Start with a clean orchard floor: Make sure your floor is as smooth as possible and does not have excessive ruts or weeds.
• Manage dust on unpaved roads and yards: Try reducing speed and spreading gravel or recycled almond shells to help cut down on dust kick up.
• Communicate with everyone involved: If you’re working with a custom harvester, make sure your contract includes clear expectations for how harvesting equipment should be calibrated, how speed should be balanced and what adjacent areas may be impacted by dust generation.
• Consider your soil: Different soil types will determine different strategies in reducing dust. It’s important to note that during especially dry years, harvest activities may generate an increased amount of dust due to lower soil moisture.
• Consider your equipment: Purchasing low-dust harvest equipment is one way to help lower your overall dust output. Research explored efficiency of four harvesters, and all were found to help lower PM10 dust by 30–60%. If eligible, you may collect incentive funds from USDA Natural Resources Conservation Service (NRCS). The current rate is $38.14 per acre, and a higher payment of $57.20 per acre is available for historically underserved producers. Funding is granted on a first come, first-serve basis. Additionally, local air district offices have information on other funding opportunities for tractor replacement programs, which are especially relevant to the San Joaquin valley.

Sweeping

• Plan your route: Make sure to blow dust back into the orchard whenever possible. Almond trees act as a natural filter and can help settle dust quickly.
• Consider timing: If there are homes, busy roads or businesses nearby, think about the timing of your harvest activities and plan to avoid actions that produce the most dust during the busiest times of day.
• Use wire tines vs. rubber flaps:  Rubber flaps can increase dust from the sweeper, adding dirt to the windrow and increasing dust at pickup.
• Adjust the height of wire tines: Wire tines can be set as high as a half-inch off the ground while still doing an effective job of sweeping. If set too low, the sweeper head will dig into the orchard floor and create more dust.
• Set your blower spout and fan speeds: Make sure the blower spout is set at the proper angle to blow almonds — not soil — around the orchard floor. Cutting back on fan speeds may also help reduce dust.
• Avoid extra sweeper passes: Whenever possible, avoid extra passes and consider using a berm brush.

Pickup 

• Go slow: Speed has the greatest impact on dust output. Reducing pickup speed to 1.5 miles per hour cuts dust by 50% compared to 3 miles per hour[1].
• Adjust pickup head height to local orchard conditions: Make sure the pickup head is not set too low, as this may create more dust.
• Slow down fans: Don’t just slow down the harvester, but slow down the fans, too, and reduce fan speeds to the minimum needed.

Each of these adjustments combined could make a significant difference on your operation. In recent dust management research funded by the Almond Board of California, researchers found equipment that had been set up optimally — based on the above recommendations — performed much better than expected. 

For more information and access to other dust management resources, visit Almonds.com/HarvestDust.