The potential of indigenous microbes from beef cattle waste to convert organic materials into macronutrients in liquid organic fertilizer

Microbiology and Waste Management Laboratory, Department of Livestock Product Technology, Faculty of Animal Husbandry, Universitas Padjadjaran. Jl. Ir. Soekarno Km. 21 Jatinangor Sumedang 45363, West Java, Indonesia

^* Corresponding author: eulis.tanti@unpad.ac.id

Abstract

Implementing effective waste management practices involves using an aerobic fermentation system to produce liquid organic fertilizer. The study investigates the chemical and microbiological properties of liquid organic fertilizer (LOF) made from beef cattle waste, which is extracted and filtered using rice straw as a carbon source for decomposer microbe growth. The research experimented with three C/N ratio treatments (P1= C/N 22.5, P2= C/N 25, and P3= C/N 27.5). The parameters tested include the dynamics of bacterial and mold populations in the initial decomposition process, macronutrients and nitrogen-fixing bacteria, and phosphate-solving bacteria in the LOF. Data were analyzed using ANOVA and Tukey's Test. The study found that a C/N ratio of 25 produced the highest average total bacteria on day 5 and the highest mold population on day 7 of initial decomposition. The macronutrient content of the LOF was N: 1.00 - 2.13%, P2O5: 0.46 - 0.53%, and K2O: 1.42 - 1.68%. The highest population of nitrogen-fixing bacteria was found at a C/N ratio of 27.5, while the population of phosphate-solubilizing bacteria did not differ in all treatments. The LOF meets Minister of Agriculture Regulation No. 01/2019's quality requirements for liquid organic fertilizers, with a content of N+P+K >2%.