Montana State University Soil Fertility Web Site

This Web site provides accesses to publications from the Montana State soil fertility program, which focuses on soil management for agriculture. Much of the information is very relevant for Wyoming agriculture.

Web Soil Survey

The NRCS Web Soil Survey is the official internet access to soil survey information. The National Cooperative Soil Survey is the long-term and comprehensive mapping effort by NRCS. It provides excellent reference information on soils and vegetation for assessing soil health, but is often mapped at large scale, especially for “extensive” management areas like Wyoming. This means that large map units contain several different soil types with descriptions of where they lay on the landscape within the map unit. The Web Soil Survey is kept up-to-date with current mapping efforts, ecological site descriptions, changes in soil classification, and other updates, but it is slower and more cumbersome to use than the SoilWeb apps described below. It allows you to build a comprehensive report for a selected “area of interest”, such as a ranch. A good approach is to use the SoilWeb Apps to rapidly explore a larger area, and then use the Web Soil Survey to generate a report for the area you define.

SoilWeb Apps

This Web site from from the California Soil Resource Lab at UC Davis provides several user-friendly tools for accessing NRCS soil survey maps and information. The SoilWeb internet site provides a seamless soil survey for all the areas map across the US, along with access to all the soil survey and ecological site information. SoilWeb Earth downloads a layer for Google Earth that provides access to all the soil survey maps and information. The iPhone Apps link describes an excellent tool that uses GPS to access soil survey information for the location where you’re standing when you open it.

These are excellent, fast, and user-friendly tools with two drawbacks for Wyoming: 1) the soil survey is not complete everywhere in the state; and 2) we don’t have cell phone access everywhere. But both of these are improving rapidly.

NRCS Soil Health for Educators

This site contains a great deal of basic information about simple soil tests. The Soil Quality Test Bucket recommends simple equipment and resources for field tests, including pH and EC probes, nitrate and phosphate test strips, and others, and lists where they can be ordered.

Soil Texture

A simple test for estimating proportions of sand, silt, and clay in the soil. Texture is one of the most important properties and affects the soil’s potential water and nutrient supplying potential. It is needed to estimate soil water content by the method below.

NRCS Soil Moisture by Feel

This site gives guidelines, including photographs, about how to estimate the amount of water a soil is holding as a proportion of it’s water holding potential, split up by soil textural classes (sandy loam, silt loam, etc.). It is also available as a printable brochure. For rangelands, this method can be useful for comparing where in the landscape and vegetation patterns soil moisture is being held or lost in the hours after a rain.

Soil health assessment

The Comprehensive Assessment of Soil Health manual from Cornell University describes many soil tests and what they mean in terms of soil health. Reading this requires wearing Wyoming goggles because it is generally written from the perspective of regions with higher precipitation, and therefore higher productivity and soil organic matter contents.