Effect of the compost mixer machine on the quality of compost made from shredded oil palm fronds (OPF)

Abstract

In general, the composting process made from oil palm fronds (OPF) is to reduce their size, mixing, and fermentation. One of the essential factors composting process is a mixed uniform between shredded OPF with other raw materials. In this paper, we discuss the quality of compost, which is stirred using a compost mixer machine (drum rotary double helix type). Composting methods chosen are natural inoculum and bokashi inoculum. Rotational speed of the mixer is applied at the levels of 100 rpm, 300 rpm, and 500 rpm. Parameters such as compost mass and temperature are recorded every five days for 60 days of composting duration. The N, P, K content, and C/N ratio were analyzed for 30 days and 60 days of composting duration. A total of 5 kg of mixed raw material was composted. Maximum temperatures recorded during the composting process of natural inoculum and bokashi methods were 35°C, 40°C, respectively. Mass loss of the two composting methods is 75%. A composting method, rotation speed, and composting duration do not significantly affect to achieve the Indonesian National Standard (SNI) quality of composting. Therefore, the use of various types of composting methods, low rotational speed compost mixer machine, and short composting duration can be applied to making compost using this machine.