Composting olive pomace: evolution of organic matter and compost quality
¹Mohammed V University, High School of Technology, Civil Engineering and Environment Laboratory (LGCE), Materials Water and Environment team, MA11060 Sale, Morocco
²INRA, Regional Center for Agricultural Research in Rabat, Research unit on Environment and Conservation of Natural Resources, MA10112 Rabat, Morocco
Morocco is one of the major olive-producing countries with an annual production of 1.56 million tonnes, part of which is dedicated to olive oil production. This important production generates, in addition to oil as the main product, a significant amount of waste (pomace and olive mill wastewater). The latter, when released in large quantities into the natural environment, cause fatal pollution. A suitable valuation of this waste will allow a clean and sustainable production for the sector. This work consists of composting olive pomace from the traditional system with two structural agents (poultry droppings and cattle manure) and comparing the two composts in terms of composting process parameters (pH, electrical conductivity, organic matter temperature, etc.), organic matter dynamics and compost quality, with manual aeration of the compost. Despite the high humidity level of the used pomace (80%), the adopted composting conditions have been effective in reducing high levels of organic matter and therefore organic carbon, as well as reducing the extreme phytotoxicity of the pomace. The experiment showed that the stabilization process in all the four treatments studied is comparable, and the final quality of the composts was adequate for agricultural use.