Can biochar conserve water in Oregon agricultural soils?

•Biochars increased water content at saturation but not at field capacity in 4 soil textures.•Differences in biochar properties did not translate to differences in soil water retention.•Biochar did not have a drought benefit in the first year following incorporation. Few studies have evaluated the ability of biochar to improve soil water content under field conditions. Our objective was to assess the potential drought benefits of biochar across a range of soil textures by measuring indicators of hydraulic capacity and water-retention curves for field-amended soils. Two biochars, conifer wood and wheat straw, were incorporated by rotary tillage at amendment rates of 9−36 Mg ha−1 in four locations. All four soils showed a significant increase (p≤0.04) in saturated water content of 0.05–1.7 % volume per Mg ha−1 biochar added, but no increase in water content at field capacity. There were significant (p