Infiltration capacity refers to the rate at which a soil can absorb water. It is an important characteristic of soil that affects the movement of water through the ground. The ability of soil to absorb water is crucial for various applications such as agriculture, stormwater management, and groundwater recharge.

Explanation:

1. Definition of infiltration capacity:
- Infiltration capacity is the maximum rate at which water can enter the soil surface under a given set of conditions.
- It is usually expressed in terms of volume per unit area per unit time, such as inches per hour or millimeters per hour.

2. Factors affecting infiltration capacity:
- Soil texture: Coarse-grained soils, such as sandy soils, generally have higher infiltration capacity than fine-grained soils, such as clay soils.
- Soil structure: Well-structured soils with good aggregation allow for higher infiltration rates compared to compacted soils.
- Vegetation cover: Vegetation can increase infiltration capacity by reducing surface runoff and promoting soil structure development.
- Soil moisture content: Dry soils have a higher infiltration capacity compared to saturated or near-saturated soils.
- Slope gradient: Steep slopes can limit infiltration capacity as water tends to run off rather than infiltrate.

3. Measurement of infiltration capacity:
- Infiltration capacity can be determined through field measurements using methods such as double-ring infiltrometer or single-ring infiltrometer.
- These devices involve applying a known amount of water to the soil surface and measuring the rate at which it infiltrates over time.
- The infiltration rate is then calculated by dividing the volume of water infiltrated by the duration of the test.

4. Importance of infiltration capacity:
- Infiltration capacity is important for understanding the movement of water through the soil profile.
- It helps in designing stormwater management systems by determining the rate at which water can infiltrate into the ground and reduce runoff.
- In agriculture, knowledge of infiltration capacity is crucial for irrigation scheduling and water management.
- Infiltration capacity also plays a role in groundwater recharge, as it determines the rate at which water can enter the aquifer.

In conclusion, infiltration capacity is the rate at which a soil can absorb water. Understanding this characteristic is vital for various applications related to water management and soil science.