Soil Types and Identification

 soil core

Photo by Mission Resource Conservation District

Soil is more than dirt! Soil is a mixture of minerals, air, water, and microorganisms that forms at the surface of land. Soil supports, either directly or indirectly, all life. It provides the nourishing medium plants need to grow. Healthy soils are the foundation of productive farms. Soil type, texture, and nutrient availability are key components to crop production. High quality soil, or soil that is healthy, provides the essential nutrients that plants need to survive, while poor, infertile soils require amendments to sustain production. Healthy soil has the correct physical, chemical and biological properties to sustain plants and animals. Soil Scientists have used these properties to classify the soils of the United States.

 

Determining soil texture can help you learn about possible restrictions and advantages of the soil. Soil texture is related to weathering and the parent material. The three basic texture classes are sand, silt, and clay, though many soils are a combination of these textures. Soil texture can be determined in the field by feeling the particles and observing their flexibility and stickiness. Use the Soil Texture by Feel flow chart and Soil Textural Triangle to determine the property’s soil texture.

 Soil Textural Triangle

Chart by USDA NRCS

 OLYMPUS DIGITAL CAMERA

Photo by Vic Smothers

A soil’s water holding capacity is another important factor when it comes to managing crops. The available water holding capacity (AWC) is the portion of water in a soil that can be readily absorbed by a plant’s roots. The soil’s AWC can be determined by using the feel and appearance method. Knowing the AWC can help with scheduling irrigation events based off of the crop’s needs and the amount of water that can be stored in the soil in the crop’s root zone.

Knowing what soil(s) are on the property can help with making informed management decisions such as proper nutrient and water application rates. To find out what soil is on a specific property, use the USDA’s interactive Web Soil Survey.

Soil Resources