Permeability and Infiltration

What is Soil Permeability? Infiltration?

supplies for rainfall infiltration demonstration

Photo credit: Christina Curell, Michigan State University

Permeability is the ability of soils to transmit water and air through its layers. Soil permeability is greatly affected by porosity, type and size of pores and properties that affect porosity like organic matter levels, aggregation, shrinking and swelling of clay particles, dispersion caused by low calcium levels versus sodium and magnesium and traffic. Infiltration is the rate at which water can move through a soil and its layers. It can be measured as the saturated hydraulic conductivity of a soil. Soil water infiltration depends upon texture, structure (aggregation), initial moisture levels, pore size and type and calcium levels versus sodium and magnesium.

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Regional Educator ResourcesOther Educator ResourcesTechnical Resources
Title Source Resource type and Date Short Summary / Preview
Soil Health Demonstration: Tabletop Rainfall Infiltration Soil Health Nexus How-to Video
May 2019

Gary Lesoing from University of Nebraska Extension will show you how to use a tabletop rainfall simulator.

Soil Health Assessment: Rainfall Infiltration Soil Health Nexus How-to Video
May 2019

Gary Lesoing with the University of Nebraska Extension looks at rainfall infiltration rate for soil health in the field.

Soil Health 101 Soil Health Nexus Extension Webpage
Jan 2017
This resource looks at how different soil health factors affect the permeability and infiltration of the soil.
Soil Compaction: The Silent Thief University of Missouri Extension Webpage

Oct 1993

Generally, a good soil for crop production contains about 25 percent water and 25 percent air by volume. This 50 percent is referred to as pore space. The remaining 50 percent consists of soil particles. Anything, for example, tillage and wheel traffic, that reduces pore space results in a dense soil with poor internal drainage and reduced aeration.
Rainfall simulator – soil health demonstration Michigan State University Video Demonstration
Sep 2019

Paul Gross and Dean Baas, from Michigan State University Extension, give a rainfall simulator demonstration. The demonstration covers soil health topics such as runoff, water holding capacity, and aggregate stability.

On-Farm Soil Monitoring for Water Resource Protection: Farm Assessment for Water Resource Protection Purdue University Extension Publication
December 2003
These five on-farm soil monitoring methods are intended to replace analytical soil tests. These monitoring methods and indicators include: Water infiltration rate, earthworm count, soil aggregate stability, penetration compaction, and plant and crop residue cover.
Youth Soil Quality Lessons and Videos – Soil Infiltration University of Nebraska Extension Webpage
not dated

The quality of soil depends upon a variety of factors. NRCS has developed Soil Quality Kit Guides, fact sheets and materials for teachers to integrate into their soils curriculum. In addition, a curriculum has been developed to use in the classroom. These materials were created with funds provided by the Nebraska Environmental Trust. YouTube videos supplement these curricula as well.

Visualizing Soil Properties SARE Videos

This series of videos illustrating soil processes such erosion, runoff, and infiltration can be used as a model for demonstrations in a classroom.

Infiltration rate Soil Health Institute Definition
Dec 2017
The Soil Health Institute’s definition of infiltration rate.
Infiltration – NRCS & others Webpage
Sep 2011
Infiltration is an indicator of the soil’s ability to allow water movement into and through the soil profile. Soil temporarily stores water, making it available for root uptake, plant growth and habitat for soil organisms.
Soil Quality Indicators: Infiltration USDA NRCS Factsheet
Jun 2008
Infiltration is the downward entry of water into the soil. The velocity at which water enters the soil is infiltration rate. Infiltration rate is typically expressed in inches per hour. Water from rainfall or irrigation must first enter the soil for it to be of value.
Soil Health Assessment: Collecting Rainfall Simulator Samples Soil Health Nexus How-to Video
May 2019

Paul Gross with Michigan State University Extension discusses how to collect soil samples for a rainfall simulator.

Soil infiltration – guide for educators USDA-NRCS Educator’s guide / lesson plan
May 2014
Information on soil infiltration management, importance, and how to measure.
Soil Health Assessments: Grass Soil Pit and Row Crop Soil Pit Soil Health Nexus How-to Videos
May 2019

Using soil pits can show many properties of soil. In the video above, Gene Campbell with the NRCS assesses a grass soil pit. In the video below, Travis Harper with University of Missouri Extension assesses a row crop soil pit.

Soil Health Assessment: Soil Core Test Soil Health Nexus How-to Video
May 2019

Todd Lorenz with University of Missouri Extension shows how to use a core sampler instead of a soil pit.

Title Source Resource type and date Short Summary
Soil Permeability Testing for Earthen Secondary Containment Areas New Jersey Department of Environmental Protection Guidance Document
Nov 2013
This testing guidance document was created to assist in creating and executing a solid permeability testing program.
Title Source Resource type and Date Short Summary
The Effects of Soil Health Management on Soil and Water Relations USDA-NRCS NRCS Whitepaper
not dated

Soil and water relationships can be described by soil porosity, water infiltration, permeability, and available water capacity

This page reviewed by Liz Schultheis, Joe Rorick, and Walt Sell.

Last reviewed 10/1/19