Influence of Sustainable Biochars Produced from Kitchen Waste, Pig Manure, and Wood on Soil Erosion

Abstract

The influence of biochars on water retention, mitigating nutrient leaching, and pollutant removal in green infrastructure has been explored in the past. However, there is a lack of understanding on how feedstock (i.e., biomass) would affect biochar physicochemical properties and hence, overall erosion control (including infiltration, surface, and sub-surface runoff) in green infrastructure. The main purpose of this study was to investigate the effect of biochars produced from three different feedstocks (pig manure, wood, and kitchen waste) on the erosion of granite residual soil. Flume experiments were conducted to measure and analyze soil erosion, runoff, and infiltration. The result showed that the runoff and soil erosion of kitchen waste biochar (KWB) samples were reduced by 17.7% and 21.7%, respectively. On the contrary, wood biochar (WB) and pig manure biochar (PMB) were found to enhance runoff and soil erosion. In addition, biochar particles were found in runoff and infiltration in erosion experiment. Thus, it is important to note that measures should be taken to prevent biochar loss when using biochar as a soil amendment. Additionally, the effects of different types of biochar on soil hydraulic and hydrophobicity properties should be taken into account as a selection criterion for choosing amendments in green infrastructure. This study finds that kitchen waste biochar has better performance in improving soil hydraulics and erosion.