Final answer:
Moist soil in its natural state consists of inorganic mineral matter, organic matter, water, and air. The water content between field capacity and the permanent wilting point is crucial for plant survival. Soil with reduced organic matter can lead to decreased water retention capacity, causing various issues.
Step-by-step explanation:
In its natural state, a moist soil has a volume composed of inorganic mineral matter, organic matter, water, and air. The inorganic mineral matter makes up about 40 to 45 percent of the soil volume, while the organic matter accounts for about 5 percent. The remaining 50 percent of the soil volume is occupied by water and air.
The water content in the soil is important for plants, and it is held between the field capacity and the permanent wilting point. Sandy soils, with larger pores, can hold less water between these points compared to clay soils, which have smaller pores and can hold more water. The storage capacity of soil for water is crucial for the survival and growth of plants.
Intensive cultivation and reduced soil organic matter content can decrease the water retention capacity of soil, leading to issues such as floods, erosion, and pollution.