Torrefied almond shells were added to these flower pots to test their ability to increase stability and heat resistance.Almond Board of California (ABC) is stepping up its efforts to identify more outlets for the productive use of almond by-products (hulls and shells) and woody biomass (prunings and whole trees) with investments in research, outreach policy and regulatory issues. At the same time, a new task force has been formed to advise on and oversee these efforts. The ABC Biomass Task Force is made up of technical experts in the field of biomass utilization and members of the California Almond industry. The Almond Board’s chief scientific officer, Karen Lapsley, D.Sc., is the staff representative to the new task force.
The new Biomass Task Force met for the first time in October to discuss the status of both new and traditional ways of disposing of almond biomass, the collective term for both by-products and the woody material that result from tree prunings and whole orchard removal. The task force was created because the industry recognized the need to coordinate and direct multiple areas of research already underway to find solutions that are feasible, sustainable and economically viable.
The commitment by ABC to explore options and technologies and to invest in research is spurred by the growing amount of biomass resulting from larger crops in the face of shrinking markets for these materials. The California Almond industry generates about 2.5 million tons of dried biomass each crop year. With a downturn in the dairy industry, the market for hulls and shells has declined, and with the closing of cogeneration plants, the market for biomass from orchard removals is also reduced.
Setting Priorities
At its first meeting, task force members discussed the four priorities previously explored by ABC staff:
- Keep biomass in orchards.
- Send biomass to co-gen/next-gen processing.
- Investigate innovative feed uses, both for domestic consumption and for export.
- Explore the possibility of higher value-added and niche products and extracts.
Whole Orchard Recycling
The first priority is being addressed by research that is looking at the effects of incorporating the biomass of an entire orchard on soil characteristics as well as the growth and productivity of second-generation almond trees planted in the orchard. This promising alternative has been studied by farm advisor Dr. Brent Holtz, San Joaquin County, for eight years. Supported by ABC’s Accelerated Innovation Management (AIM) program, Dr. Holtz’s ongoing research suggests that the breakdown of biomass in the soil from a whole orchard removal results in increased organic matter, soil carbon, nutrients and microbial diversity, including beneficial fungi, as well as an increased water-holding capacity of the soil, which may be important in holding applied nutrients in the soil, thus preventing leaching into the groundwater. If ongoing studies continue to produce these results, growers will potentially save on both water and crop inputs, such as fertilizer and soil amendments.
Research is also evaluating the possibility of recycling ground or composted pollinator hulls back to orchards to replace some nutrients that would otherwise be supplied by fertilizer.
Hulls as Livestock Feed
A highly nutritious feed for cows, almond hulls are still utilized by the dairy industry, but only about half the industry’s output of hulls is now included in dairy rations. Investigations by Almond Hullers and Processors Association (now Almond Alliance of California) suggest that dairy rations could include twice the amount of hulls currently being added. Moreover, the potential for inclusion of hulls in swine rations and other livestock species is being explored, as well as an export market for hulls as an animal feed.
Value-Added Technology
Of the many potential uses of by-products in various processes that were evaluated by the task force, the most promising is the use of torrefied almond shells to improve the properties of certain plastics, such as flowerpots. Torrefaction is a thermal process that converts biomass into a hardened substance. Working with a plastics company that markets packaging to the agricultural and food-packing industries, researchers with the USDA Agricultural Research Service, Western Regional Research Center, Albany, are investigating the use of torrefied almond shells to produce an ingredient for plastic packaging that potentially adds such properties as strength and heat resistance, and also creates a “green” label for the packaging products.
Accelerated Innovation
The Biomass Task Force is the second ABC task force to be created in recent years, following the Accelerated Innovation Managment Task Force, which was created in 2015. Both task forces are the result of changes in the conditions under which California produces, processes and markets almonds, and with an eye to the future of the industry. The Accelerated Innovation Management (AIM) Task Force advises and oversees the AIM initiatives program, which focuses on the innovative almond-farming practices that will be required to meet the future needs of the California Almond industry.
