Spent SubstratesWe use peanut hulls and wheat bran to make our mushroom substrates. The spent mushroom substrate makes a great compost/fertilizer for farming and gardening. We put our spent substrates into bulk bags that weigh over 1000 lbs and four bags can cover an acre of farmland. We are offering our substrate at $120 a ton bag or two bags for $200 to be picked up on one trip.There is no minimum we can load the bags onto your trailer or truck. Scheduling a pick up time is required.You may contact us anytime if you have any questions.We have exclusive contract with Griffin’s Landscape Supply for our substrates so you are welcome to pick up from them too ! Order compost