Harvest may not be in your sights right now, but thinking ahead to plan for low-dust harvest will pay off when that hectic season begins.
Preparing the orchard floor prior to harvest ensures harvest begins with a clean, level surface.
Preparing the orchard floor prior to harvest ensures harvest begins with a clean, level surface. Filling in ruts and holes where almonds can get stuck will pave the way for smoother equipment passes now and will help reduce the need for extra sweeper passes at harvest, allowing drivers to adjust equipment heads higher. Under these conditions, suction fan speed can be reduced on pickup machines to dramatically reduce dust in the field without loss of harvest efficiency.
Almond Board Research
A decade of research funded by Almond Board of California, as well as a partnership of equipment manufacturers and the USDA Natural Resources Conservation Service, has resulted in methods, resources and incentives to help reduce the dust generated at harvest and keep the dust that is created inside the orchard and away from neighbors. Everyone involved in the harvest of California Almonds should work to reduce dust at harvesttime. Growers should communicate to employees and custom harvesters their expectations for a harvest strategy that reduces dust while maintaining balance with harvest efficiency.
More Dust-Prevention Practices
As harvest approaches, maintaining a clean orchard floor increases the efficacy of specific strategies for reducing dust and PM10 at harvest that have been developed as a result of ongoing research. The dust generated by harvest activities includes significant PM10 emissions and some PM2.5 emissions — both regulated and connected to air quality issues, particularly in the San Joaquin Valley. Dust control tactics include the following:
- Set sweeper heads to optimum level. Sweeper heads should be set at the manufacturer’s factory level, so that wire tines are 0.125 inch off the ground. If the heads are set too low, dust from the pickup is increased substantially. Additionally, if harvesting in hilly terrain, take inclines into consideration when setting sweeper head height.
- Use wire tines on sweeper heads. Wire tines without rubber flaps on sweeper heads can reduce dust, particularly on softer soils.
- Reduce blower passes where possible.
- Making three blower passes doubles the amount of dust released from the orchard during harvest compared to making a single blower pass. Adjusting blower spouts to match field conditions and/or adding an optional berm brush can reduce passes.
- Reduce harvester ground speed. Cutting ground speeds by half will reduce dust by 50%. Gauge speed reduction to match orchard conditions. In orchards with loose soils, slower ground speed allows gravity to drop dirt, reducing the reliance on fans to do it.
- Reduce separator fan speed to the lowest setting possible.
- Blow into the orchard when working near field edges. When operating near roads or homes during harvest, use the trees and their canopies to naturally filter dust. Blowing rows close to the edge into the orchard allows dust to filter and settle out.
Growers who rely on custom harvesters to manage their harvest operations should discuss these strategies as well as the importance of protecting the reputation of the almond industry by taking all steps possible to keep visible dust to a minimum during harvest, even if it means it might take more time to harvest.
Helpful Resources
Almond Board also has made practical guides and videos available to growers and workers to encourage adoption of good management practices for reducing dust at harvest. These resources are available at Almonds.com/HarvestDust. As a result of our greater understanding about how dust is generated at almond harvest, many equipment manufacturers have made changes to sweepers and pickup machines to reduce dust emissions. The USDA’s Natural Resources Conservation Service (NRCS) has funding incentives available through the Environmental Quality Incentives Program (EQIP) for almond growers wishing to utilize clean harvest technology. NRCS this year has more than tripled reimbursements, to $37.50 per acre, for up to three years to almond growers who purchase harvest equipment shown to reduce particulate matter at harvest. The incentive payments apply to growers who purchase new equipment or hire out the process to contractors who use approved lower emission equipment in their orchards. Growers interested in incentive funds should visit their local NRCS office.
