2020 Crown Nut Company Hulls & Shells Research Summary

Project Type: Research and Education
Funds awarded in 2020: $349,807.00
Projected End Date: 12/31/2023
Host Institution Award ID: G126-21-W7899
Grant Recipient: University of California Davis
Region: Western
State: California
Principal Investigator:
Dr. Sat Darshan Khalsa
University of California Davis
Dr. Patrick Brown
University of California Davis
Dr. Amelie Gaudin
University of California, Davis
Almond hulls, shells, and mixes of the two materials are annually stockpiled at Crown Nut Company processing facility. These materials are a source of accessible, nutrient-rich organic matter amendments that are used on nearby orchards. During processing, materials are separated into Nonpareil/Independence hulls, shells from all varieties, and a mix of hulls and shells from pollinizer varieties. There is a need to find new waste streams for hulls and shells since growth in the almond industry is outpacing the dairy industry where these materials are typically sold as cattle feed. In recent years, Crown Nut Company has spread excess shells along roadsides and in orchard alleyways as a mulch. This helps reduce dust and facilitates field access of machinery after rain. In addition to the benefits provided by mulching, almond hulls and shells contain significant amounts of potassium and other nutrients. Following nitrogen, potassium is the nutrient in second highest demand for almond trees. The highest fertilizer costs in almond production tend to be associated with potassium. This research trial asks the question: Can almond hulls and shells be used as a soil amendment over almond tree roots to supply potassium for crop uptake?
Ellie Andrews, UC Davis
Target audiences:
Farmers/Ranchers; Educators
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.