40 Questions
Which soil class is characterized by being unfit for cultivation and having severe limitations for pasture or forestry use?
Class VI
Which soil class is characterized by being very wet, usually found in small and nearly level drainageways, and not subject to erosion but having drainage problems and frequent flooding?
Class V
Which soil class is only suited for wildlife or recreation purposes and is usually extremely stony, sandy, or wet?
Class VIII
Which soil class requires extensive management of conservation practices to control erosion and has major hazards of severe erosion and/or slope?
Class VII
How is slope calculated?
By dividing the amount of vertical change in elevation by the horizontal distance and multiplying by 100
What does the term 'erosion' refer to in land evaluation?
The harmful effects of water and wind on a percentage of the original topsoil
What is the surface texture of the topsoil determined by?
The proportion of sand, silt, and clay in the topsoil
What does the term 'permeability of subsoil' refer to in land evaluation?
The ability of air and water to move through the subsoil
How many land capability classes are there?
Eight
What does the classification of erosion depend on?
Percentage of original topsoil remaining
How is topsoil texture determined?
By the proportion of sand, silt, and clay
What does permeability rate measure?
Movement of water or air through the soil
What does effective depth refer to?
Depth to which plant roots can easily penetrate
Which land capability class is very good for crop production with ideal soils and no restrictions?
Class I
What are the two groups into which land capability classes are divided?
Crop production and permanent vegetation
How many slope categories does Texas have?
Six
What does drainage influence after rainfall?
Soil's tillability
What does the classification of Class IV land indicate?
Borderline cultivatable land with severe limitations
What is the classification of land capability classes with higher numbers?
Less suitable for crop production
What influences the soil's tillability after rainfall?
Drainage
Class V soils are subject to severe erosion and slope hazards
False
Class VI soils may be suitable for cultivation with extensive management of conservation practices
False
Class VII soils require extensive management of conservation practices to control erosion
True
Class VIII soils are suitable for crop production with ideal soils and no restrictions
False
Is slope determined by estimating the number of feet the land rises or falls over 100 feet and expressed as a percent?
True
To calculate slope, you divide the amount of vertical change in elevation by the horizontal distance the change takes place over, and then multiply that number by 100 to get a percentage.
True
Erosion refers to a percentage of the original topsoil which has suffered the harmful effects of water and wind.
True
The permeability of subsoil refers to the ability of air and water to move through the subsoil.
True
Land capability classes are divided into three groups for crop production, permanent vegetation, and wildlife habitat.
False
Class II land is very good for crop production, with ideal soils and no restrictions.
False
There are six slope categories in Texas, ranging from nearly level to very steep.
False
Erosion is classified based on the percentage of original topsoil remaining, ranging from none to slight, to very severe.
True
Permeability rates the movement of water or air through the soil as rapid, moderate, or slow, based on the topsoil type.
False
Class IV land is borderline cultivatable land with severe limitations.
True
Topsoil texture is determined by the proportion of sand, silt, and clay, with fine, medium, and coarse textures having specific characteristics.
True
Drainage is categorized as excessive, well-drained, moderate, somewhat poor, poorly drained, or wet, influencing the soil's tillability after rainfall.
True
Effective depth refers to the depth to which plant roots can easily penetrate and is classified as deep, moderately deep, shallow, or very shallow.
True
Land capability classes are a system designed to classify land based on its best use and are divided into two groups for crop production or permanent vegetation.
True
There are eight land capability classes, with higher numbers indicating less suitability for crop production.
True
Class V-VIII are suited only for permanent vegetation as pasture or forest and have increasing limitations for crop production.
True
Study Notes
Soil Classification and Land Capability
- Slope categories are based on the percentage of elevation change over a given distance, with Texas having six categories ranging from nearly level to very steep.
- Erosion is classified as none to slight, moderate, severe, or very severe based on the percentage of original topsoil remaining.
- Topsoil texture is determined by the proportion of sand, silt, and clay, with fine, medium, and coarse textures having specific characteristics.
- Permeability rates the movement of water or air through the soil as rapid, moderate, or slow, based on the subsoil type.
- Drainage is categorized as excessive, well-drained, moderate, somewhat poor, poorly drained, or wet, influencing the soil's tillability after rainfall.
- Effective depth refers to the depth to which plant roots can easily penetrate and is classified as deep, moderately deep, shallow, or very shallow.
- Land capability classes are a system designed to classify land based on its best use and are divided into two groups for crop production or permanent vegetation.
- There are eight land capability classes, with higher numbers indicating less suitability for crop production.
- Class I land is very good for crop production, with ideal soils and no restrictions, while Class II has some limitations but is suitable for crop production.
- Class III may be used for crop production with certain conservation practices, and Class IV is borderline cultivatable land with severe limitations.
- Class V-VIII are suited only for permanent vegetation as pasture or forest and have increasing limitations for crop production.
- Each land capability class has specific characteristics related to slope, topsoil thickness, erosion, texture, permeability, drainage, and effective depth.
Soil Classification and Land Capability
- Slope categories are based on the percentage of elevation change over a given distance, with Texas having six categories ranging from nearly level to very steep.
- Erosion is classified as none to slight, moderate, severe, or very severe based on the percentage of original topsoil remaining.
- Topsoil texture is determined by the proportion of sand, silt, and clay, with fine, medium, and coarse textures having specific characteristics.
- Permeability rates the movement of water or air through the soil as rapid, moderate, or slow, based on the subsoil type.
- Drainage is categorized as excessive, well-drained, moderate, somewhat poor, poorly drained, or wet, influencing the soil's tillability after rainfall.
- Effective depth refers to the depth to which plant roots can easily penetrate and is classified as deep, moderately deep, shallow, or very shallow.
- Land capability classes are a system designed to classify land based on its best use and are divided into two groups for crop production or permanent vegetation.
- There are eight land capability classes, with higher numbers indicating less suitability for crop production.
- Class I land is very good for crop production, with ideal soils and no restrictions, while Class II has some limitations but is suitable for crop production.
- Class III may be used for crop production with certain conservation practices, and Class IV is borderline cultivatable land with severe limitations.
- Class V-VIII are suited only for permanent vegetation as pasture or forest and have increasing limitations for crop production.
- Each land capability class has specific characteristics related to slope, topsoil thickness, erosion, texture, permeability, drainage, and effective depth.
Test your knowledge of soil classification and land capability with this quiz. Explore slope categories, erosion classifications, topsoil texture, permeability, drainage, effective depth, and land capability classes. Understand the characteristics and best uses of different land capability classes for crop production or permanent vegetation.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
