Biochar Loaded-Organic Fertiliser Derived from Effluent of Two Phase Anaerobic Digestion (TPAD): Preparation and Evaluation Nimas M.S. Sunyoto(a*), Yusron Sugiarto(a,b), Mingming Zhu(b), Dongke Zhang(b)
(a) Dept. of Agroindustrial Technology, Universitas Brawijaya, Jalan Veteran, Malang 65145, Indonesia
*nimas.sunyoto[at]ub.ac.id
(b) Centre for Energy (M473), The University of Western Australia, 35 Stirling Highway, Crawley 6009, Western Australia, Australia
Abstract
Combining Anaerobic Digestion (AD) effluent and biochar for organic fertiliser is thought to improve their fertiliser properties and reduce nutrient leaching from AD effluent. However, the results of studies on the utilisation of AD effluent and biochar for fertiliser are varied, depending on the type of biochar and tested plants. Therefore, further studies are required. The study aims to prepare, characterise and evaluate organic fertiliser from two phase anaerobic digestion (TPAD) effluent and biochar. The organic fertilisers were prepared by mixing different percentages of biochar, ranging from 0-100 %, with TPAD effluent. The pH, water holding capacity (WHC), macro and micronutrients of the organic fertilisers were further characterised. Soilless petri dish germination bioassay was conducted to evaluate the fertilising potential and toxicity of the fertilisers. The rocket was used as the tested seed. Biochar addition increased WHC with no significant pH change. The addition of biochar significantly increased essential elements for germination and plant growth compared to TPAD effluent alone. Germination test suggested that most of the fertilisers are classified as free of toxic, except the pure biochar (weakly toxic). All fertilisers tested increased sums of root and shoot length compared to the control. The improved macro and micronutrients in the fertiliser were observed to strongly contribute to this. Maximum seed growth was achieved at the fertiliser with 10% of TPAD effluent and 90% of biochar. The study provides evidence of the potential of the biochar-loaded organic fertilisers for agricultural applications.
Keywords: AD effluent, biochar, germination bioassay, organic fertiliser
