Utilization of Wood Waste and Agricultural By-products in High-value Gourmet Mushroom Production
Land which is too steep or poor to be cropped is often left as woodlands. The potential exists to use these woodlands to produce high-value crops such as gourmet mushrooms. In fact, mushrooms play critical ecological roles in woodlands, as well as in agricultural lands, as the primary and secondary decomposers of wood and agricultural by-products such as straw, manure, seed hulls, etc. Mushrooms are very efficient at turning agricultural by-products and wood waste into profit. They are also the vegetative bodies of mycorrhizal fungi that, through their symbiotic relationships with plants, help most forest and agricultural crops take up water and some nutrients.
Many species of mushrooms command prices of three to nine dollars per pound, fresh weight, on the wholesale gourmet and medicinal markets. Gourmet mushrooms are relatively high in protein (about 20 percent on a dry-weight basis), high in fiber and low in fat (typically below 3 percent).
Methods of cultivating wood-decomposing fungi exist which convert 20 percent of the dry mass of a substrate (such as straw or sawdust/woodchip blocks) into mushrooms. In other words, 20,000 pounds of dry sawdust and 10,000 pounds of woodchips (roughly the amount generated by harvesting less than one tree per acre annually from 75 acres) when supplemented with 8000 pounds of organic oat bran and 1200 pounds of gypsum, can be converted into 7000 pounds of dried mushrooms (about 70,000 pounds fresh weight) in one year or less.
Our proposed approach is to annually harvest a sustainable volume of the lowest quality timber off our own farm (about 100 board feet per acre for a total of 7500; less than one tree per acre), and use the by-products like stumps, tops, sawdust, planer shavings and woodchips to grow nine species of gourmet and medicinal mushrooms.
University of Kentucky