Fungal community composition in composts of lignocellulosic wastes was assessed via 454-pyrosequencing of ITS1 libraries derived from the three major composting phases. Ascomycota represented most (93%) of the 27,987 fungal sequences. A total of 102 genera, 120 species, and 222 operational taxonomic units (OTUs; >97% similarity) were identified. Thirty genera predominated (ca. 94% of the sequences), and at the species level, sequences matching Chaetomium funicola and Fusarium oxysporum were the most abundant (26 and 12%, respectively). In all composts, fungal diversity in the mature phase exceeded that of the mesophilic phase, but there was no consistent pattern in diversity changes occurring in the thermophilic phase. Fifteen species of human pathogens were identified, eight of which have not been previously identified in composts. This study demonstrated that deep sequencing can elucidate fungal community diversity in composts, and that this information can have important implications for compost use and human health.

The water extract of compost termed “compost tea” retains all the beneficial soluble bioactive components, making it a potent source of plant stimulatory and defensive compounds. The exact nature and extent of these features are, however, modified by composting system, feedstock quality, tea preparation and resultant use and management, including application dynamics of the compost tea. Compost teas contain a significant quantity of total nutrients with the majority being primary macronutrients. Secondary and micronutrient concentrations are more variable, but contents are generally insufficient to satisfy crop requirements. Noting this, compost tea use in agriculture and horticulture supports crop nutrition directly and indirectly. Improvements in soil quality have been widely reported for a range of soils and compost teas. A key feature of compost tea-amended soils is the increase in soil organic matter and microbial diversity and its associated benefits. Research on appropriates rates for field and container use show large variability associated with edapho-climatic factors and crop species. However, foliar application seems best suited to maximising the dual nutrition and phytopathogenic effects of compost tea. Regardless of the purpose of compost tea use, its positive effects on crop growth and soil fertility, whilst controlling pest and disease, make it a contemporary sustainable tool aligned to organic agriculture.

Replacement of commercial peat media buy local composts would greatly improve transplant seedling production efficiency. The quality and effectiveness of substrate mushroom compost (SMS) was evaluated as a complete substitute for promix (PM) in the germination, growth and development of tomato seedling. Contrasting physicochemical properties were observed for the SMS and PM, both substrates falling outside the ideal media range for many properties. Germination percentage was > 95 % for both SMS fine (SMS F ) and PM treatments. The two SMS course (SMS C ) treatments showed significantly lower germination. For all growth parameters the fertilized SMS F treatment showed the greatest values at all sampling times. The non-significant difference between the fertilized PM and unfertilized SMS F treatments was notable. SMS treated seedlings were taller (32 %) and possessed a greater number of leaves (12 %) at 5 weeks after seeding (WAS) than PM seedlings at 6 WAS. SMS was shown to be a better media for tomato seedling production.