What are the likely benefits of biochar?
In some soil types and with certain crop species, some biochars have been shown to:
increase water holding capacity of the soil
increase biomass (crop) production
increase soil carbon levels
increase soil pH
decrease Aluminium toxicity
decrease tensile strength
change microbiology of the soil
decrease emissions from soil of the greenhouse gases CO2, N2O and CH4
improve soil conditions for earthworm populations
increase CEC, especially over the long-term
improve fertiliser use efficiency
It should be noted that the wide variety of biochar feedstock materials, process conditions and applications leads to a huge and diverse range of responses that are often contradictory. Some biochars have been shown to have no influence on some of the factors noted above; some biochars have been shown to have adverse effects on crop productivity. More research is required to verify the observed effects and to distinguish beneficial from detrimental biochar products.
Studies thus far have shown that the greatest positive effects of biochar applications have been in highly degraded, acidic or nutrient-depleted soils. Thus, biochar research is of particular relevance in the Australian context, as many Australian soils exhibit very low nutrient and carbon levels, and are at risk of acidification.