Assessment of Compost Stabilization during Short-Term Composting of Fruits and Vegetable Wastes under North-Eastern Nigeria Conditions

Abstract

This study evaluated compost stabilization during short-term composting of fruit and vegetable wastes (FVW) under tropical conditions in North-East Nigeria. Temperature profiles followed a typical pattern, peaking at 52°C during the thermophilic phase (days 5–6) to ensure pathogen suppression, before stabilizing near ambient levels by day 31. Statistical analysis showed significant fluctuations (p < 0.05) in pH, while electrical conductivity (EC) at maturity (4.39 dS m⁻¹) remained within acceptable limits for soil application. Organic carbon and organic matter declined significantly (p < 0.05) from 18.03% and 31.10% to 9.83% and 16.93%, respectively, driven by microbial respiration. Nitrogen transformation shifted from initial ammonification (NH₄⁺–N: 38.03 mg kg⁻¹) to progressive nitrification, with NO₃⁻–N increasing from 74.03 mg kg⁻¹ to 142.43 mg kg⁻¹. This resulted in a low NH₄⁺/NO₃⁻ ratio, confirming maturity. Additionally, available phosphorus doubled, and exchangeable bases increased, resulting in a final effective cation exchange capacity (ECEC) of 17.47 cmol⁺ kg⁻¹ and 98.47% base saturation. The results demonstrate that short-term composting effectively transforms raw FVW into a stable, nutrient-enriched organic amendment. With enhanced nutrient availability, high CEC, and proven sanitization, the final product is highly suitable for improving soil fertility and microbial activity in tropical agricultural systems where organic matter is a limiting factor.