effect of type, particle size and amount of biochar on some physical and mechanical properties of calcareous soil

Recently, biochar has been considered as a soil conditioner. In research, the effect of the type and amount of biochar on soil properties has been emphasized. This field study was conducted to investigate the combined effect of type, amount and size of biochar particles on the total porosity (TP), penetration resistance (PR), mean weight diameter of aggregates (MWD) in a sandy loam texture. Factorial experiment was performed as a randomized complete block design with three factors of type, amount and biochar particle size in three replications. Wheat straw, vermicompost and apricot firewood biochard were added to the soil in 0.5, 1.5 and 3% and particle sizes of 0.5, 0.5-1 and 1-2 mm. All three biochar increased TP significantly and decreased PR significantly compared to control. Biochar type had the largest contribution in TP and PR changes. The highest TP was obtained in the wheat straw biochar treatment with 3% and particle size of 1-2 mm. The greatest decrease in PR was observed in wheat straw biochar with a value of 3% and a particle size of 0.5-1 mm. Interaction of type, amount and size of biochar particles had the largest contribution to MWD change. The largest MWD (1.22 mm) was observed in wheat straw biochar with biochar amount of 0.5% and particle size of 0.5 mm. The results showed that the amount and size of biochar particles had different effects on soil properties depending on the type of biochar.