Get Examining Infiltration Rates Of Various Soil Types - Purdue University

For example, a sandy surface soil normally has a higher infiltration rate than a clayey surface soil. A soil survey is a recorded map of soil types on the landscape. Crust: Soils that have many large surface connected pores have higher intake rates than soils that have few such pores.

It is usually measured by the depth (in mm) of the water layer that can enter the soil in one hour. An infiltration rate of 15 mm/hour means that a water layer of 15 mm on the soil surface, will take one hour to infiltrate. In dry soil, water infiltrates rapidly.

The infiltration of water into the sand is faster than into the clay. The sand is said to have a higher infiltration rate. The infiltration rate of a soil is the velocity at which water can seep into it. It is commonly measured by the depth (in mm) of the water layer that the soil can absorb in an hour.

Infiltration is caused by multiple factors including; gravity, capillary forces, adsorption, and osmosis. Many soil characteristics can also play a role in determining the rate at which infiltration occurs.

Infiltration rate usually is determined from field data. Many dif- ferent methods and types of equipment have been used for measuring infiltration rate, but the principal methods are flooding of basins or furrows, sprinkling (to simulate rain), and measuring water entry from cylinders (infiltrometer rings).

Highly aggregated soil has increased pore space and infiltration. Soils high in organic matter also provide good habitat for soil biota, such as earthworms, that through their burrowing activities, increase pore space and create continuous pores linking surface to subsurface soil layers.

In general, the steady infiltration rates for different soil textures are: Gravel and coarse sands - > 0.8 inches per hour. Sandy loams – 0.4 to 0.8 inches per hour. Loams – 0.2 to 0.4 inches per hour. Silty clay loams & clay soils - < 0.2 inches per hour.

Soil texture (percentage of sand, silt, and clay) is the major inherent factor affecting infiltration. Water moves more quickly through large pores of sandy soil than it does through small pores of clayey soil, especially if clay is compacted and has little or no structure or aggregation.