Soil Facts?
Soil is an unconsolidated organic material on Earth’s surface, used for land plant growth. The environment, including genetic and environmental factors such as climate, macro- and microorganisms, significantly influences the development of this species. Soil consists of solids, liquids, and gases and is characterized by horizons or layers that differentiate from the initial material.
Soil is not considered soil if the surface is too deep for rooted plant growth. The lower boundary separates soil from non soil, which consists of horizons altered by climate, relief, and living organisms. Soil at its lower boundary is classified as hard rock or earthy materials without any biological activity, including animals, roots, or other organisms. The product-soil varies in physical, chemical, biological, and morphological properties from its derived material, highlighting the influence of these factors on the parent material over time.
Write about Soil Surveys?
Soil surveys are systematic examinations of soils in an area, classified based on field intensity. The National Cooperative Soil Survey program develops and implements standards for describing, classifying, mapping, writing, and publishing information about specific soils.
Explanation and Uses:
Soil survey or soil mapping is a method of classifying soil types and properties in an area, using principles of soil science and geomorphology. Primary data is obtained through field sampling and remote sensing, primarily using aerial photography and LiDAR. Today, soil scientists often use a rugidized tablet computer and GPS to carry digital aerial photos, LiDAR, topography, soil geo-data-bases, and mapping keys. This approach allows for more accurate and efficient soil surveying, enhancing the understanding of soil formation, vegetation, and land use patterns.
Soil survey information is valuable for various sectors, including farmers, ranchers, architects, engineers, and homeowners. Farmers can determine soil suitability for crops and livestock, while engineers can assess soil properties for construction. Homeowners can use this information to maintain their gardens, yards, or homes. The scientific community and the public can benefit from this valuable data.
Components of Soil Survey:
County Geography Overview
General soil map describing major soil types and characteristics.
Detailed aerial photographs of specific soil types.
Photographs of typical soils in the area.
Tables providing information on soils, including total area, crop production comparisons, and land use planning interpretations.
Tables detailing physical, chemical, and engineering properties of soils.
Soil surveys, once published in book form for individual counties, are now available online for users to create custom surveys. The rapid flow of latest soil information is enabled by this, as publishing a paper survey was often challenging and nearly obsolete. Many published manuscripts have been scanned for historical purposes, making the process more efficient and accessible.
Understanding the Value
Soil surveys identify soil characteristics that determine its limitations and qualities, warning of potential hazards. A classification system, called soil taxonomy, is used to apply this information to engineering and agricultural uses of soil. This information helps assess risks and hazards in land use decisions. Soil inventory helps understand the connection between landscape features and soil geography, strengthening interpretations, hydrology, and landscape stability. The separation of geology and soils is not a clear division, but rather enhances information delivery by connecting soils to the landscape and corresponding geology.
Soil Formation and Classification
The Cooperative Soil Survey maps over 20,000 soil types, with most given names originating from the initial mapping location, forming soil series, which are referred to as soil series.
Soil survey reports, published by the Cooperative Soil Survey, include maps and descriptions of soils in a report area, accessible to all.
Soils are classified based on physical and chemical properties in their layers, using “Soil Taxonomy” to classify soil based on color, texture, structure, and other two-meter-deep surface properties, aiding in soil information use and providing a common language for scientists.
Soil scientists utilize five soil factors to explain soil formation and predict soil occurrences. They also consider daily activities and changes within the soil, including additions, removals, and daily changes, to predict the differences between soils and their horizons.
Factors of Soil Formation:
Parent Material Factor:
Soils are formed from materials that have moved from other areas, such as windblown loess in the Midwest and glacial till in many areas. These “parent material” may have moved many miles or a few feet, and the lower part of the soils may remain relatively unchanged from their deposit, with the same general chemistry as the original rocks.
River sediments vary in texture based on the stream’s speed, with fast-moving water leaving gravel, rocks, and sand, and slow-moving water and lakes leaving fine textured clay and silt.
Climate Factor:
Soils are influenced by climate, with temperature and moisture causing weathering and leaching patterns. Wind redistributes sand, especially in arid regions. Precipitation intensity, timing, and type influence soil formation. Seasonal and daily temperature changes affect moisture effectiveness, biological activity, chemical reactions, and vegetation types.
Topography Factor:
Soil moisture and temperature are influenced by slope and aspect. Steep slopes facing the sun are warmer, while steep soils may be thinner due to erosion and loss of topsoil. Deeper, darker soils are expected on the bottom land.
Biological factors
Soil formation is influenced by a variety of factors including plants, animals, micro-organisms, and humans. Animals mix soils, creating burrows and pores. Plant roots open channels, with different types having different effects. Grass roots decompose easily, while taproots create dense layers. Micro-organisms play a crucial role in influencing the chemical exchanges between roots and soil. Humans can mix soil extensively, making it the parent material.
Native vegetation is influenced by various factors such as climate, topography, biological factors, soil density, depth, chemistry, temperature, and moisture. Plant leaves decompose, while organisms mix them with the soil, and trees and shrubs have deep roots.
Time Factor:
Soil formation processes are continuous, with features reflecting other forming factors over time. Recently deposited material, like flood deposition, doesn’t show development features, and the previous soil surface and horizons become buried.
Soil scientists map soils by identifying areas with similar soil-forming factors, describing their colors, texture, structure, and other properties. For example, a Midwest soil with a thick, nearly black surface layer is called a “mollic epipedon” due to its temperate climate and native prairie vegetation. Subsurface horizons, such as those in forested areas, are also used in soil classification.
Soil Orders: Soil taxonomy identifies 12 soil orders, with names derived from Greek or Latin root words. There are 64 suborders, with over 2,400 subgroups. The soil classification system comprises 300 great groups and 2,400 subgroups, with soils within subgroups forming families based on similar physical and chemical properties.