Biochar research has recently increased due to its effectiveness as a sustainable fertiliser and toxicological adsorbent. However, major oversights appear in the impacts of biochar on arbuscular mycorrhizal fungi (AMF) due to a lack of standardized pyrolysis and application methods. This review paper finds that infrequent biochar application leads to higher AMF root colonisation rates as well as increased biodiversity. Furthermore, conjunctive use of biochar and AMF is useful at increasing drought resistance of crops as water resources become scarce.

Gravel-sized soil particles greater than 2 mm in size exist in farmers’ paddocks but are routinely excluded from laboratory tests and glasshouse experiments. Ironstone gravel can supply phosphorus to plants, but can also influence other soil properties such as the amount of moisture plants can access. Soils containing large amounts of ironstone gravel are likely to require lower applications of phosphorus fertiliser to achieve maximum crop yield, but can also limit plant growth due to low soil moisture.