Utilizing co-composted biochar as a growing medium for buttercrunch lettuce

Abstract

In this study, we explored the utilization of co-composted biochar (COMBI), the end product of co-composted poultry carcasses and biochar, as a growth medium for buttercrunch lettuce in a controlled environment. Despite the potential benefits that COMBI could provide, its use is currently limited, as reported in previous studies. The study's objective was to compare the performance of COMBI with various types of biochar with a comparison to a control group that used soil only. The results indicated that the application of COMBI treatment led to an increased water-holding capacity of the soil, ranging from 29% to 34%, which could help to mitigate drought stress and retain water-soluble nutrients under certain circumstances. However, there were no significant differences in stem diameter, dry shoot weight, or dry root weight of lettuce between the COMBI and control groups. While the use of COMBI did not result in increased crop yield, the study found that the application of wood-based biochar (WBC) and distiller's grain biochar (DGBC) in COMBI reduced the nitrate content in lettuce by 20.3–29.7% compared to the control group. Additionally, the application of COMBI treatment significantly lowered the Cu content of lettuce leaves. These findings suggested that the use of co-composted biochar as a growing media can have some benefits, particularly in terms of water-holding capacity and reduced nitrate and Cu content in lettuce leaves. However, the study highlights the need for continued research and development of this approach to ensure that it meets safety and quality standards and is a viable and sustainable option for crop production.