Question

black soils are black in colour give reason

Answer 1

Soil color is mainly produced by the minerals present and by the organic matter content. Yellow or red soilindicates the presence of oxidized ferric iron oxides. Dark brown or black color in soil indicates that the soil has a high organic matter content. Wet soilwill appear darker than dry soil.

Answer 2

Black soil has its parent rocks and lava solidified over the earth surface which is black and hence its color is black too.