Final answer:
Desertification is the process where productive land loses its topsoil and becomes desert, often due to destructive agricultural practices like overgrazing and slash-and-burn farming. It can lead to diminished agricultural productivity, loss of ecosystems, and severe socio-economic consequences.
Step-by-step explanation:
The term for the loss of topsoil so that productive land becomes desert is desertification. This environmental issue can occur from various factors including degradation of fertile land, poor land management, and climatic variations. Practices such as slash-and-burn agriculture deplete the soil nutrients rapidly and frequently result in a significant loss of topsoil. Overgrazing by livestock in semi-arid regions causes similar damage where vegetation is removed, exposing soil to erosion, and subsequently leading to desertification. The impact is severe, as healthy soil can take millennia to form but can be destroyed in just a few years.
Historical examples include the Dust Bowl in the 1930s where extensive farming without proper erosion controls turned vast swathes of productive land in the Southern Plains into a dust-laden landscape. Moreover, soil degradation and desertification are a global concern, with FAO reports indicating a significant percentage of farming land being adversely affected worldwide. Immediate consequences of desertification include reduced agricultural yields, loss of biodiversity, and negative impacts on human health and economies.