Concept:Land degradation in savanna zones is caused by actions that damage vegetation or expose soil to erosion.
Explanation:I. Constant annual bushfire burns grasses and destroys soil organic matter, leading to land degradation.
II. Overgrazing of grassland removes protective vegetation cover, exposing soil to erosion.
III. Application of cattle manure adds nutrients and organic matter, so it does not cause land degradation.
IV. Cutting of woody species for fuel wood removes vegetation, leaving soil exposed and degraded.
Therefore, the practices that lead to land degradation are I, II and IV only.
Answer:B. I, II and IV only