Contact: Zhao (Jack) Chen, MS, PhD
zhchen29@umd.edu

This work is supported by the U.S. Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) project.

Overview

Waterborne infections are a significant global health concern, causing 1.8 million deaths and approximately 4 billion reported cases of illness annually. The consumption of fresh produce irrigated with contaminated water poses a severe risk for infectious disease outbreaks, both through direct exposure and cross-contamination. To address this issue, the treatment of irrigation water to remove microbial and chemical pollutants is crucial. Chemically activated carbonaceous compounds have been widely used to filter and treat water for various contaminants, including organic pollutants, heavy metals, and microbial loads. However, their reliance on non-renewable carbon sources, energy-intensive thermal activation of charcoal, and high costs have prompted the scientific community to seek cost-effective and sustainable alternatives. One such alternative is "biochar," which is derived from various solid biological waste materials. Biochar offers a dual benefit by providing affordable water treatment and aiding in managing agricultural waste, supporting the culture of organic farming. Biochar is defined as a "carbon-rich product produced through pyrolysis, which involves heating biomass like wood, manure, or leaves in a closed container with limited air supply." Biochar has gained increased attention due to its distinctive qualities, including high carbon content, cation exchange capacity, a large specific surface area, and a stable structure. Importantly, it is three times more cost-effective than activated charcoal. Additionally, the growing consumer demand for organic food has led to a significant rise in the biochar market. It is projected to experience a compound annual growth rate of 16.8% between 2021 and 2028, with California leading the commercial biochar sector in the United States. A wide range of feedstocks, such as cow dung, rice husk, wood dust, sugarcane bagasse, wheat straw, peanut hull, pecan shell, and others, can be used to produce biochar. The characteristics of biochar depend on the specific feedstock, pyrolysis temperature, heating rate, and duration.

Purpose

The impact of biochar on the growth, nutritional composition, and microbiome of spinach and soil microbiome will be evaluated. Microbiomes from soil and plant samples collected from the field trials with optimized biochar will also be performed to evaluate how biochar affects the soil and plant microbiomes. DNA will be extracted from soil and plant samples, followed by library preparation and shotgun metagenomic sequencing. Taxonomic and functional profiling, as well as the functional potential of the entire microbial community, will be conducted. Metagenomic reads will be assembled to recover prokaryote, eukaryote, and viral/phage sequences from the metagenome assemblies for downstream analyses. Microbiomes will be further examined as indicators for soil quality, physicochemical properties, and yield, using machine-learning algorithms, including random forest, support vector machine, and neural networks.