A new study has found biochar to be an effective component in boosting crop yields and improve the health of soil, helping to mitigate the impact of climate change.
Biochar is produced via pyrolysis, which involves heating biomass residues such as wood chips, animal manures, sludges, compost, and green waste in an oxygen-depleted environment.
Stephen Joseph, a Visiting Professor in UNSW Science's School of Materials Science and Engineering, said the study published in GCB Bioenergy gives "strong evidence" that biochar might help with climate change mitigation.
The findings are backed up by the recent Special Report on Climate Change and Land by the Intergovernmental Panel on Climate Change, which assessed that biochar had significant climate change mitigation potential.
Biochar made from manure can help to lessen the requirement for soil fertilization by acting as a slow-release fertilizer that holds nutrients and carbon in the soil for years while also releasing macronutrients like nitrogen, phosphorous and potassium for plant growth.
In addition, biochar-amended soils' increased water-holding capacity will boost crop output per drop of water applied.
Biochar's porous nature allows it to collect and store heavy metals, reducing plant uptake and subsequent consumption by humans and animals.
According to Joseph, the best responses to biochar were discovered in acidic and sandy soils where biochar was used in conjunction with fertilizer.
For the first time, the study shows how biochar benefits a plant's root zone.
Biochar can accelerate seed germination and seedling growth in the first three weeks as it reacts with the soil. Reactive surfaces are generated on biochar particles over the next six months, boosting nutrient availability to plants.
Biochar begins to 'age' in the soil after three to six months, forming microaggregates that protect organic matter from breakdown.
By addressing crop agronomic needs, cattle manure management could be critical in lowering the need for chemical fertilizers and improving farm productivity.
Manure management, which includes collection and treatment, has significant implications for resource efficiency, farm productivity, and environmental quality.
Biochar sourced from manure has the potential to improve sustainability benefits across crop production practices and agribusiness decisions, and it could be a good policy recommendation in line with President Biden's January executive order on climate change, which encourages carbon management systems and greenhouse gas emission reduction efforts.