Issue link: https://www.e-digitaleditions.com/i/1390079
ALMOND ORCHARD 2025 GOAL However, prior to understanding the agronomic benefits of applying compost to the surface of an almond orchard, growers and handlers undoubtedly want to know if the practice is safe – especially since almonds are harvested off the ground where compost is applied. "Our research included producing the compost and then characterizing the physical and chemical properties of that compost," said Dr. Ruihong Zhang, the project's principal investigator and research team leader. "Field measurements included a quality and safety step where we sampled for the detection of pathogens such as E. coli O157 and Salmonella." "We're pleased to report that our pathogen study came out negative, where all the soil amendments we produced with dairy manure tested free from Salmonella and pathogenic E. coli." In July 2019, the UC research team started the process of developing two composts: One derived from dairy manure only and the other comprised of an 80% dairy manure and 20% almond stick-and-twig mix. Active composting took place over an eight- to ten-week period, where the material was monitored, turned and tested to ensure proper temperatures were reached. "Some of the composted material was then pelletized so we could test different treatments in our almond orchard test block," said Hossein Edalati, a member of the UC research team. "Five treatments were developed and applied to our test orchard in March 2020, including a manure-only compost, a manure-stick compost, a pelletized manure compost, a pelletized manure-stick compost and an unamended treatment." The treatments were applied to a randomized block of Independence ® almond trees at a rate of four dry tons per acre, which equated to a nitrogen, phosphorus and potassium (NPK) application of 100-28-72 lbs. per acre for the manure-only composts and 84-18-60 lbs. per acre for the manure-stick composts. Edalati noted that the difference in nutrient make-up between the manure-only and manure-stick composts is attributable to an increased carbon-to-nitrogen ratio in the manure-stick composts from the addition of the woody biomass. "In addition to our year one finding that the compost and field samples were pathogen free, no difference was observed in almond yield or carbon dioxide and nitrous oxide emissions (greenhouse Pelletized manure and almond woody biomass compost. Continue on page 17 ABC Develops Biomass Strategy The Almond Board's Biomass Workgroup is made up of grower and handler stakeholders charged with reviewing research proposals and making funding recommendations related to all things almond woody and fleshy biomass. The group recently outlined a long-term strategy for finding practical, higher-value outlets and uses for almond hulls, shells and woody biomass. "The Biomass Workgroup has pulled together a research and outreach plan for each of the three almond coproducts," Huang said. "The ultimate goal of these plans is to stabilize demand from local users that carry volume and to expand uses to other markets that create value-added solutions for the long-term." The Biomass Workgroup also identified more immediate actions to accelerate progress toward the Almond Orchard 2025 Goal of putting everything grown in the orchard to optimal use. These actions include: communicating findings from recent ABC-funded projects to relevant industries and stakeholders, conducting assessments on the business feasibility of production of clean coproducts and market potential of livestock feed uses, completing ongoing research and launching research on new and novel uses of hulls, shells and woody biomass, and partnering with regulators to expand incentive programs to mitigate in-field burning. The Almond Board has invested more than $2 million in research to better utilize hulls, shells and woody biomass to help our industry progress toward the 2025 Goal regarding zero waste. Almond Board of California 16