Soil: Texture vs. Structure
Exploring the differences between each.
When it comes to discussing the texture and structure of soil, the two terms may sound like they mean the same thing. Even though these terms related to each other, this is not the case. The texture of a soil refers to the relative proportions of sand, silt, and clay in a given soil. The structure of a soil refers to the grouping of soil particles into porous compounds.
Soil texture can be determined using a soil texture triangle. Based on the percentages of sand, silt and clay in a soil, a soil texture triangle can help classify a soil as one of twelve textures. Soil with relatively even proportions of sand, silt, and clay are referred to as a loam and lie in the middle of the triangle. These soils are the most ideal for agriculture.
Soil texture triangle (https://www.pinterest.com/pin/202450945724695687/)
Soil Drainage Based on Texture and Structure
Soil texture and structure are important because they control the amount of water and water-borne nutrients that can be stored in a soil and they control how much water can pass through the grains of a soil. The living atlas map and the legend below show the different levels of soil drainage across the United states.
USA Soil Drainage (https://centralmichigan.maps.arcgis.com/home/webmap/viewer.html?webmap=e09b094d808a40a2b380628440edd272)
Distribution of Sand, Silt and Clay Across the World
This express map shows areas on Earth where sand, silt, and clay can be found and explains the size limitations of each.
Different Types of Soil Structure:
- A granular soil structure consists of small, spherical shaped peds that are less than 0.5cm in diameter. This structure is good for agriculture because it offers an ideal structure for root penetration.
- A blocky soil structure consists of peds that are irregularly shaped into chunks. These soils cause problems like poor tilth, limited root penetration, and limited permeability.
- A prismatic (or columnar) soil structure comes apart into tall, column shaped fragments. These are most commonly found in arid climates because the soil dries out ant cracks, forming these columnar fragments.
- A platy soil has peds that are compacted into horizontal plates. The cause of this soil structure is usually compaction due to the weight of overlying materials.
- A single-grained soil is one of two soils that are classified as structureless. Most common in sandy environments, single-grained soils are very infertile due to the lack of organic material to bond into peds or to provide nutrients.
- A massive soil structure is also a structureless soil because there is no arrangement of the soil particles into any specific fragment or shape. These soils do not allow water or root penetration so they can be a challenge to plant life.
(https://www.pinterest.ch/pin/102527328993021257/)
