Converting tree nut byproducts into gourmet mushrooms and mulches

View the project final report

Commodities

• Miscellaneous: mushrooms

Practices

• Crop Production: conversion of agriculture wastes to mushrooms

This project has three primary objectives: to test woody nut shells as substrates for a variety of gourmet mushrooms, to produce high quality fresh gourmet mushrooms for the local market, and to use the spent substrates as mulches for soil enrichment and water conservation.
The United States is the largest producer of almond and pistachio nuts in the world with California as the major growing region. Million tons of nut shells are generated as byproducts per year. The woody shells used to be burned for power generation but it can cause air pollution and currently there is no good use for them. It is necessary to find new sustainable ways to recycle these byproducts.
Mushrooms such as shiitake, lion’s mane and oyster mushrooms are fungi decomposer of wood wastes.
They have high nutritional and medicinal values. Hardwood sawdust is the standard substrate for growing these mushrooms but farmers in southern California need to get it from as far as Oregon. The cost is too high to be sustainable. Using the woody nut shells to grow mushrooms will give mushroom farmers plenty of low cost substrates and also help nut farmers get rid of biowastes. The nut shells after mushroom growing will be used as mulch for local farmers to conserve water.
Our farm have produced certified organic oyster mushrooms from local wheat straws and planned to grow Shiitake, Lion’s Mane and other gourmet mushroom varieties to enrich the local food market. We will research conditions for optimal growth of various strains of mushrooms using nut shells as substrates and develop a protocol for mass production of these gourmet mushrooms. We will educate farmers and the public about the available new substrate, mushrooms and mulches through our outreach programs. It will be a win-win for farmers, consumers and the environment.

1. to test woody nut shells as substrates for a variety of gourmet mushrooms
We will work out the conditions and protocols to use nuts shells for mushroom farming. We will
determine the economic viability of these substrates based on the yield of mushrooms,
cultivation time, contamination rate and other special requirement.
2. to produce high quality fresh gourmet mushrooms for the local market
We will evaluate the quality of mushrooms grown from nut shells and test their marketability.
3. to use the spent substrates as mulches for soil enrichment and water conservation
We will work with avocado farmers, vegetable farmers, and college student interns to evaluate
the effectiveness of mulches from spent mushroom substrates.