Composting of tomato wastes and sheep manure: An eco-friendly waste valorisation for enhancing the environmental sustainability in Souss Massa region (Morocco)

Summary

Each season, a huge amount of crop residues is regenerated by horticultural production. The main type of wastes are tomato stalks, leaves and axillary buds which are subsequently the result of crop operations like trimming and plants trellising and uprooting. The landfilling of corps residues is a serious problem that need to be solved. Therefore, the valorisation of these organic wastes by composting is a simple way for suitable management and the produced compost could be used as an organic amendment to satisfy the crop growth needs and agronomic soil requirements. The aim of the study is to investigate the impact of the mixing proportion of tomatoes residues and sheep manure using an experimental biocomposter of capacity 220 L with passive aeration system. Two different mixing ratios were set-up on volume basis: R1 (2/3 tomato plant residues ‘’TPR” + 1/3 sheep manure “SM”) and R2 (1/3 tomato plant residues ‘’TPR” + 2/3 sheep manure “SM”) and two controls CTRP (1/1 tomato plant residues ‘’TPR”) and CSM (1/1 sheep manure ‘’SM’’). Parameters such as Temperature, pH, EC, Carbon-to-nitrogen ratio, mineral and organic nitrogen, potassium and phosphorous were monitored for a period of 60 days. According to the results, tomato wastes proportion is negatively correlated to the Germination Index (GI) of the final compost, the nitrogen and the organic matter loss. After 9 weeks of composting, GI was 87%, 91%, 92%, and 95% respectively for CTRP, R1, R2 and CSM. Tomato plant residues are not adequate for composting alone, and could limit the efficiency of the process.