Why are desert soils often alkaline and low in organic matter?

Desert soils are typically alkaline and low in organic matter primarily due to the arid climate and the resulting lack of moisture.12

Why Desert Soils Are Alkaline

The alkalinity of desert soils is largely a consequence of minimal leaching. In more humid environments, consistent rainfall washes away soluble minerals and bases, which often leads to soil acidity. In contrast, deserts experience high rates of evapotranspiration and very low annual precipitation. Because there is insufficient water to percolate through the soil profile and remove these constituents, carbonates and other salts accumulate, maintaining an alkaline chemical environment.431

Why Desert Soils Are Low in Organic Matter

The scarcity of organic matter is driven by the same environmental constraints:
* Limited Vegetation: The fundamental shortage of available moisture restricts plant growth, which is the primary source of organic material in soil.1
* Biological Inactivity: Due to the extreme heat and lack of water, desert soils are often biologically inactive, slowing the decomposition and accumulation of organic matter.14
* Reduced Enrichment: Compared to more humid regions, these soils are less enriched by organisms, resulting in weakly developed soil profiles.24