- Author: Marcy Sousa
What is a State Soil?
A state soil is a soil that has special significance to a particular state. Each state in the United States has selected a state soil, twenty of which have been legislatively established. These “Official State Soils” share the same level of distinction as official state flowers and birds. Also, representative soils have been selected for Puerto Rico and the Virgin Islands. California's State Soil is the “San Joaquin” soil. It was designated the official state soil of California in 1997. California's central valley has more than half a million acres of San Joaquin soils.
A little about soil profiles and textures
Soil is made up of distinct layers, called horizons. Each layer has its own characteristics that make it different from all of the other layers. These characteristics play a very important role in what the soil is used for and why it is important.
A HORIZON- This is the layer that we call “topsoil” and it is located just below the O Horizon. This layer is made up of minerals and decomposed organic matter and it is also very dark in color. This is the layer that many plants roots grow in.
B HORIZON- This is the layer that we call “subsoil” and it is located just below the A Horizon. This layer has clay and mineral deposits and less organic materials than the layers above it. This layer is also lighter in color than the layers above it.
C HORIZON- This is the layer that we call “regolith” and it is located just below the B Horizon. This layer is made up of slightly unbroken rock and only a little bit of organic material is found here. Plant roots are not found in this layer.
Three types of particles are found in soil: sand, silt and clay. Soil texture is classified by the type of particle that makes up the majority of the soil. Each soil type has a distinctive textural feel and holding a sample of your garden soil in your hand may help you determine the type of texture that makes up your garden soil.
Sandy Soil: Sand is the largest of the particles found in soil. It is a sharp-edged material, giving the soil a gritty feel. When wet, it remains course and breaks apart easily. Beach sand is at the extreme end of sandy soils. Sandy soil holds almost no nutrients and does not retain moisture. Plants do not grow well in this type of soil.
Silty Soil: Silt particles are smooth and smaller than sand particles. When wet, a silty soil feels mud-like; it's smooth and has a silky texture. It's rich in nutrients but retains moisture to the point where garden plants are unable to access oxygen. In a silty soil, plants wilt because they can't breathe.
Clay Soil: Clay is the smallest of the particles and a clay soil will clump and feel sticky when wet. Air flow between
Loamy Soil: Loam is a combination of all three particles– sand, silt and clay–in nearly-equal proportions. The large sand particles promote drainage and air flow within the soil. The smaller silt particles are rich in nutrients and aid in moisture retention. Clay, also rich in nutrients, balances the poor soil retention of the sand and the excessive moisture of the silt.
If you would like to see what kind of soil you have, click here to start NRCS's web soil survey.
If you are curious to see all of California's state symbols from fish to gemstone, click here.