Evolution of Macrofauna Structure during the Composting Process of Household Waste

The fact that Morocco is an agricultural country and the large volume of biodegradable waste produced by the population make composting so important. The degradation of organic matter is facilitated by faunal and floral macro and micro-organisms that act in different stages of maturation; studies on this fauna are quite rare both nationally and internationally. On a sample of two tons of household waste, we documented invertebrates that colonized compost heaps and then assessed the changes in the structure of the invertebrate population during the different phases. Our study revealed the presence of several zoological groups colonizing the compost heaps during the different composting phases; we noted the presence of: (1) Macroscopic invertebrates, in order of number of individuals: insect larvae, ants, earthworms, sowbugs, spiders, springtails, and millipedes, and (2) Microscopic invertebrates, the most abundant in terms of individuals: mites and nematodes. As for the order of appearance, we observed that insect larvae were the first to colonize the compost heap from the very first days of installation, followed by woodlice observed during the thermophilic phase and disappearing towards the end of the process. Earthworms were observed during the end of the thermophilic phase, while springtails were observed more during the cooling and maturation phases. Our study revealed the presence of a good quality of fauna during the composting process, which are indicators of good compost quality and play a major role in the circulation of nutrients, thus ensuring the provision of essential elements for plant nutrition.