Question

Why are desert soils low in organic matter

Answer 1

The climate is too dry and with the very minimal rain fall , not many plants can survive due to the desertification. 

Answer 2

Desert soils are dry soil with some hot and sandy. Desert soils have low soil moisture that prevents minerals from leaching out of the soils and are only able to support little vegetation due to very high temperatures and lack of water (very low rainfall) in the desert. Desert soils are low in organic matter because there is limited plant remains and any organic matter in the soil are destroyed by the excessive heat at a very high rate.