Evaluation of Physicochemical and Agronomic Quality of Biodegradable Food Waste Compost

Abstract

This study assessed the physicochemical and agronomic quality of three composts (C1, C2, C3) produced from compostable food waste, with the aim of promoting them as organic soil amendments. Analysis of the end products made it possible to characterise their maturity degree, nutrient content and trace metal content. The three-phase temperature evolution during composting was consistent with the proper composting process for all three composts. Moisture levels during composting ranged from 50% to 60% at the end of composting, which is the ideal range for mature compost. The composts had a slightly alkaline pH and were very rich in organic matter, with contents well above 20%. They are a significant source of essential plant nutrients, particularly nitrogen (N) and phosphorus (P), thus contributing to improve soil fertility and water retention capacity.  The results also showed that the three composts reached an excellent level of maturity and stability. Indeed, the final C/N ratio, around 18 for the three composts, was within the ideal range for mature compost, indicating advanced humification and good mineralisation of the organic matter. Analysis of trace metals (Zn, Cu, Cr, Ni, Pb) revealed concentrations for most metals that remain low overall.  Germination tests carried out on peppers and spinach showed germination rates of over 50% for all samples. This work demonstrated that composting is an effective solution for the sustainable management of biodegradable household waste. The compost produced is a high-quality, stable and nutrient-rich soil that can sustainably improve soil health and support environmentally friendly urban agriculture.