Composting process of Dipterocarpus alatus and kitchen waste (vegetables and fruits) at isolated military units

Dipterocarpus alatus is widely planted in military units due to its strong adaptability to various soil types, high drought tolerance, and deep root system, which enhances stability and minimizes wind damage, thereby ensuring the safety of military infrastructures. At present, the fallen leaves of this species are mostly collected and burned, causing environmental pollution because they contain 50 - 70% essential oils and 30 - 40% resin, which release toxic compounds during combustion. This study aimed to develop and evaluate a composting process utilizing Dipterocarpus leaves combined with kitchen waste. The composting mixture consisted of 60% dried D. alatus leaves, 15% rice husk, and 25% kitchen waste (vegetables, tubers, and fruits) by weight. The application of the Bima bio-agent effectively accelerated the decomposition process. The resulting compost product met the Vietnamese industry standard 10TCN 526:2002 for microbial organic fertilizer derived from household waste, with the following characteristics: 97.1% of particles passing through a 5 mm sieve, moisture content of 32.26%, pH of 7.58, total organic matter content of 34.16%, total nitrogen content of 2.61%, and absence of Salmonella spp.