Research on preparing seedling substrates using edible mushroom waste and application

To improve the utilisation of mushroom residue waste resources and identify a replaceable matrix material for peat, 10 different formula substrates and three commercially available substrates were examined to determine their physiochemical properties. Furthermore, the correlation and influence of these physicochemical properties on the substrates were explored. Pot experiments were conducted using Brassica campestris L. ssp. chinensis Makino var. communis Tsen et Lee (cabbage), Brassica chinensis L. (pakchoi), Cucumis sativus L. (cucumber), and Cucurbita moschata Duch. ex-Poiret (pumpkin). The results showed that the matrix was most significantly affected by water-holding porosity, aeration porosity, air-water ratio, total porosity, pH, electrical conductivity (EC), available phosphorous (AP), and available potassium (AK). The random forest (RFF) model indicated that pH and total nitrogen (TN) had the strongest influence on the plant height and stem diameter of the cabbage. Moreover, pH, water-holding porosity, and total porosity most significantly influenced the plant height, stem diameter, and seedling vigour index. AP and air-water ratio substantially affected the root length and root-to-crown ratio of the cucumbers, while EC, air-water ratio, and AP influenced the stem diameter, root length, and seedling vigour index of the pumpkin most. The biological characteristics of the four vegetables during the pot experiment indicated that the overall effect of the 10 substrates supplemented with perlite and vermiculite was better than in the basic group. Of these, T2 (mushroom waste: sawdust: catalyst: vermiculite = 8:2:5:5) displayed the best result and could be used as an alternative for peat seedling.