Evidence suggests that biochar influences soil physical properties, especially soil hydrology, yet relatively little
data exists on this topic, especially in relation to soil type or characteristics. This paper presents a novel attempt
at analysing the influence of biochar (applied at 0.1, 0.5 and 2.5%) on the physical properties of soilwith respect to
quantified soil variables. Pot experiments were used to establish the effect of biochar on: bulk density, soil moisture
content at field capacity and available water capacity. The aggregate effect of biochar across all soilswas significant
(P b 0.01) for all of the properties. With increasing amount of biochar, changes to bulk density, field
capacity and available water were more pronounced. In the 2.5% treatments these changes ranged from −4.2%
to −19.2%, 1.3% to 42.2% and 0.3% to 48.4%, respectively. Regression revealed that soil silt content negatively
moderated the influence of biochar on field capacity and availablewater capacity. The results suggested that medium
(20 t ha−1) and high (100 t ha−1) biochar applications could improve water-holding capacity (by up to
22%) and ameliorate compaction (by up to 15%) and that soils low in silt are likely to be more hydrologically responsive
to biochar application.