The soil microbiome is essential for ecosystem health, supporting functions like nutrient cycling and decomposition. However, human-induced land-use changes, such as deforestation and intensive agriculture, disrupt this delicate balance, impacting microbial diversity and functionality. These alterations have cascading effects on ecosystem functions, agricultural productivity, and global carbon cycling. Understanding these relationships is crucial given the widespread land degradation occurring worldwide. Urgent action is needed to implement sustainable land management practices, including conservation, reforestation, and regenerative agriculture, to mitigate land degradation and restore ecosystems. In this chapter, we explore examples elucidating the impact of land-use alterations on the composition and functionality of soil microbiomes, with a specific emphasis on diverse biomes within Brazil.