Compost Based on Pulp and Paper Mill Sludge, Fruit-Vegetable Waste, Mushroom Spent Substrate and Rye Straw Improves Yield and Nutritional Value of Tomato

Plant biomass in the form of waste materials and by-products from various industries can be a valuable material for the production of composts and growing media for urban gardening. In this study, pulp and paper mill sludge, fruit-vegetable waste, mushroom spent substrate and rye straw were used to produce compost that was further used as a medium component in container cultivation of tomato. The plants were grown in containers with a capacity of 3 dm3 filled with three types of compost-based growing media supplemented with high peat, fen peat, pine bark and wood fiber. The tomato plants grown in 100% peat substrate served as controls. The plants grown in the compost-enriched media had a higher leaf greening index and percentage of ripe fruit, and exhibited an increased content of total polyphenols and flavonoids, potassium, calcium, magnesium and copper in fruit as compared with the control. The tomatoes grown in a medium consisting of 25% compost, 30% high peat, 15% low peat, 20% pine bark and 10% wood fiber reached the highest fresh fruit weight, total polyphenol content and L-ascorbic acid levels. This study demonstrated that the compost produced from natural materials from various sources was a valuable potting medium supplement with positive effects on tomato yield and nutritional value.

Plant Community Diversity at Two Reclaimed Mine Tailing Storage Facilities in Québec, Canada

Mining activities generate residues during the ore concentration process. These wastes are placed into large tailing storage facilities, and upon mine closure, these tailings must be reclaimed. This study aimed to determine how different reclamation methods, involving combinations of planted boreal woody species and organic amendments application (paper mill sludge biosolids, chicken manure, and topsoil) affected plant community diversity at two tailing storage facilities in Québec, Canada. We recorded the composition of the plant communities using the percent cover of plant species within 1 m × 1 m quadrats. At the Niobec mine site, paper mill sludge mixed with topsoil enhanced total plant cover was compared with the use of topsoil only; the former amendment, however, reduced evenness (J′) and diversity (1−D) due to the increased growth of grasses and invasive forbs. At the Mont-Wright site, plots having received paper mill sludge mixed with a “Norco” treatment (a mixture of chicken manure, hay, and grass seeds) produced the highest total plant cover. The Norco treatment mixed with topsoil and the single application of topsoil and biosolids produced the highest evenness (J′) and diversity (1−D). Overall, organic amendment applications promoted vegetation cover on tailings and contributed to the colonization of diverse plant communities.