Characterisation of Liquid Fertiliser from Different Types of Bio-Waste Compost and its Correlation with the Compost Nutrients

Abstract

Liquid fertiliser contains nutrient compounds that could be applied as plant enhancer and are used in urban agriculture as it does not require soil medium and environmentally friendly. An organic liquid fertilizer can be produced from bio-wastes composting as it contains more organic nutrients that are essential to promote healthy plant growth. Liquid fertiliser can be collected during the composting process (compost leachate) or by mixing compost with a certain solution (compost tea). Both the end solid and liquid fertilizer compost could be commercialised as organic fertilisers. Although there are a lot of studies regarding the nutrient characteristic of the end product compost and liquid fertiliser, the correlation of nutrient composition between liquid fertiliser and solid compost is unclear. The variation of waste input creates an unclear nutrient range of end compost in both solid and liquid products. This study aims to develop a correlation between the nutrients available in the liquid fertilizer (both compost leachate and compost tea) with regards to the nutrients available in the end solid compost from different bio-waste source. Based on the physical and nutrient characterisation, liquid fertiliser contains elements such as nitrogen (N), potassium (K) and phosphorus (P) that are essential for plant growth. Due to high organic content in the liquid fertiliser, dilution or pre-treatment is needed to avoid plant and soil damage. By using a graphical analysis and simple linear regression model, a formula can be developed to predicting the nutrient composition of the compost products. The formula allows predicting the nutrient composition of the compost by analysing the liquid fertiliser and save the cost and time of the analysis.