What is Infiltration? Agristudent.com


What is Infiltration?


What is infiltration?

The process of entry of water into the soil by downward flow through all or part of the soil surface is termed as infiltration

It is the entry of fluid from one medium to another

What is infiltration rate?

It is defined as the volume of water flowing into the profile per unit of soil surface area per unit time

It is not constant over time.

Generally, it is high in the initial stages of infiltration process, particularly where the soil is quite dry, but tends to decrease subsequently and becomes steady

It may be easily measured using a simple device known as a double ring infiltrometer insitu

How is infiltration rate calculated?

It is calculated by the formula

I = Q/ A x T


I = Infiltration rate (mm or cm/min or h)

Q = Volume quantity of water (m3) infiltrating

A = Area of the soil surface (m2) exposed to infiltration, and

T = Time (min or h)

What are the factors influencing Infiltration rate?

The factors influencing are

1. time from the onset of rain or irrigation,

2. initial water content,

3. hydraulic conductivity,

4. presence of impeding layers in the profile and vegetative cover

What is the unit of measuring infiltration rate?

It is measured in (mm or cm/min or h)

What are infilteration rates of different soils?

Infilteration rates of different soil types are as follows in mm / Hr

1. Sandy 30

2. Loamy sand 20 – 30

3. Sandy loam 12 – 20

4. Silt loam 7 – 12

5. Clay loam 3 – 7

6. Clayey < 3

What are other important related terms?


The lateral movement of water through soil pores or small cracks in the soil profile under unsaturated condition is known as seepage


It indicates the relative ease with which air and water penetrate or pass through the soil pores

Permeability of soils is generally classified as rapid, moderate and slow

Thus the permeability is rapid in coarse textured soils and slow in fine textured soils.

Deep percolation

Infiltration is a transitional phenomenon that takes place at the soil surface

Once the water has infiltrated the soil, the water moves downward into the profile.

This post-infiltration water movement downward with in the soil profile under the influence of both gravity and hydrostatic pressure is termed as deep percolation.

Sandy soils facilitate greater percolation when compared to clayey soils due to dominance of macro pores

Likewise the loss of water by percolation in cropped fields is generally less than that in bare soils

Further readings and references


Handbook of Agriculture

Author: agristudent

Team Agristudent is a young and dynamic team of Agriculture specialists who have acquired specialised knowledge in their respective subjects. Their mission is to create a unique online encyclopedia of agriculture, which can be useful to millions around the world as an online reference library

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