Use of Spent Mushroom Substrate in New Mushroom Crops to Promote the Transition towards A Circular Economy

Abstract

The use of spent mushroom substrate (SMS) in new cultivation cycles has already been reported due to its economic and environmental viability. When considering the application of the circular economy concept in the production of edible mushrooms, the re-use of the SMS within the same process is highly attractive, because it allows a better use of the biomass and the energy involved in the process and, therefore, tends to improve energy efficiency and resource conservation. However, this alternative generates important challenges, which derive from maintaining the quality standards of the mushrooms produced and, at the same time, not incurring excessive costs that are detrimental to the process itself. In our opinion, the main difficulty of the process in achieving success is regarding the biological and agronomic parameters that involve the production of the mushroom. It is useless to apply SMS in new cycles if the mushroom harvest is impaired and farms become non-viable. However, numerous examples are reported here where SMS was recycled into new substrates for either the same or different mushroom species without negatively affecting yield compared with using substrates prepared from 100% fresh raw materials. Thus, we suggest that each farm has its own specific technological study, since a small variation in the raw material of the compost, and mushroom cultivation practices and casing layer used, can influence the entire viability of the mushroom circular economy.

Organic Matter Properties of Spent Button Mushroom Substrate in the Context of Soil Organic Matter Reproduction

“…It is a very positive characteristic in the context of applying the tested wastes as fertilisers to acidified soils which are a dominant type of ploughed land in Poland [32,33]. CaCO 3 presence in the experimental material is due to the necessity of applying large amounts of alcalifying products (in the form of carbonates) during substrate and cover production so as to assure mushroom bed has an optimum reaction [5]. Carbon and nitrogen contents recorded in the present study confirm claims of other researchers that the material displays a marked potential when applied to enrich soils in biogenic elements [3,4].…”

“…In Poland, a popular method used to dispose of this waste material is to apply it for fertilisation purposes and introduce it to the soil. There are numerous published works on the reasonability of such a solution; the major focus of these papers is on the concentration of nutrients in the waste which are likely to increase soil fertility and crop production profitability [3][4][5]. Spent substrate contains low amounts of heavy metals whose forms are unavailable for plants and safe for the environment [6].…”

The Utilisation of Pholiota nameko, Hypsizygus marmoreus, and Hericium erinaceus Spent Mushroom Substrates in Pleurotus ostreatus Cultivation

“…The possible utilisation of SMS in subsequent mushroom production is of great importance. In a review by Zied et al [26], the need to re-use SMS considering environmental viability, which can create a transition towards a circular economy, and the call for scientific information in this regard were emphasised.…”

“…There are many potential agricultural, horticultural, and industrial uses of SMS [21,23,31,32]. According to several authors [26,[32][33][34], the effective utilisation of SMS has great potential in a circular economy.…”

“…The best and most economically viable method for the disposal of SMS is considered to be its re-utilisation in successive mushroom cultivation. Several studies have reported the use of SMS for mushroom re-cultivation [26,[35][36][37][38][39][40][41].…”