Pyrolysis temperature affects pore characteristics of rice straw and canola stalk biochars and biochar-amended soils

•Biochars pyrolyzed at different temperatures affect differently soil pore characteristics.•RSB increased total pore volume (TPV) in soil, while CSB decreased soil TPV.•Biochar altered the pore size distribution of soils, differing with soil type and feedstock.•RSB promoted the formation of 0.1–30 μm pores, and CSB increased 0.1–5 μm pores in soils.•Biochars made at 450 °C was the optimal for improving soil pore characteristics.