Concept:Soil fertility is maintained by practices that conserve nutrients, organic matter, and good soil structure.
Explanation:Preventing soil erosion protects the fertile topsoil from being washed or blown away.
Bush fallowing allows the land to rest and naturally restore lost nutrients.
A tendency of becoming waterlogged makes the soil water-saturated and poorly aerated.
This reduces microbial activity and can cause nutrients to become unavailable or toxic to plants.
Therefore, waterlogging is a condition that damages fertility rather than maintaining it.
The other option, porosity and low water retention, describes soil properties, not a direct farming practice.
Answer:C. tendency of becoming waterlogged