AP BIOLOGY

Detailed explanation-1: -Desert soil is mostly sandy soil (90–95%) found in low-rainfall regions. It has a low content of nitrogen and organic matter with very high calcium carbonate and phosphate, thus making it infertile. The amount of calcium is 10 times higher in the lower layer than in the topsoil.

Detailed explanation-2: -The driest soils, in deserts, have very little organic matter because there is not enough water to support a large or diverse plant community. Desert soils are nutrient poor because of the low organic matter and because the lack of water slows the weathering process that can release nutrients from soil minerals.

Detailed explanation-3: -The soils of arid regions are generally sandy with extremely low organic matter, having very low nutrients and microbial activity. Land degradation is further enhanced by the inherent fragility of soils, sand movements due to wind erosion, and loss of native vegetation cover.

Detailed explanation-4: -Desert soils are downright unusual! They vary tremendously in texture; many are sandy and gravelly, while others contain layers of sticky clay, or even rock-hard, white limy layers. Desert soils may be gray-colored, brown, or even brick red.