enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. 1938 USDA soil taxonomy - Wikipedia

    en.wikipedia.org/wiki/1938_USDA_soil_taxonomy

    Hydromorphic soils form in wetland conditions. There are two sub-types: Gley soils - These occur when the pore spaces between the grains become saturated with water and contain no air. This lack of oxygen leads to anaerobic conditions which reduce the iron in the parent rock. This gives the soil a characteristic grey/blue colour with flecks of red.

  3. Acid sulfate soil - Wikipedia

    en.wikipedia.org/wiki/Acid_sulfate_soil

    The term ‘acid sulfate soils’ (ASS) was coined by the Working Party on Nomenclature and Methods for the first International Symposium on Acid Sulfate Soils (1972, Wageningen) to mean soils that contain, or have the potential to produce, sulfuric acid in quantities that cause significant and long-lasting changes in key soil properties. [22]

  4. USDA soil taxonomy - Wikipedia

    en.wikipedia.org/wiki/USDA_soil_taxonomy

    A soil family category is a group of soils within a subgroup and describes the physical and chemical properties which affect the response of soil to agricultural management and engineering applications. The principal characteristics used to differentiate soil families include texture, mineralogy, pH, permeability, structure, consistency, the ...

  5. Soil formation - Wikipedia

    en.wikipedia.org/wiki/Soil_formation

    Soil formation is influenced by at least five classic factors that are intertwined in the evolution of a soil. They are: parent material, climate, topography (relief), organisms, and time. [9] When reordered to climate, organisms, relief, parent material, and time, they form the acronym CLORPT. [10]

  6. Soil pH - Wikipedia

    en.wikipedia.org/wiki/Soil_pH

    Elemental sulfur (90–99% S) has been used at application rates of 300–500 kg/ha (270–450 lb/acre) – it slowly oxidises in the soil to form sulfuric acid. Acidifying fertilizers, such as ammonium sulfate, ammonium nitrate and urea, can help to reduce the pH of soil because ammonium oxidises to form nitric acid.

  7. Soil acidification - Wikipedia

    en.wikipedia.org/wiki/Soil_acidification

    Soil acidification is the buildup of hydrogen cations, which reduces the soil pH. Chemically, this happens when a proton donor gets added to the soil. The donor can be an acid , such as nitric acid , sulfuric acid , or carbonic acid .

  8. Soil in the United States - Wikipedia

    en.wikipedia.org/wiki/Soil_in_the_United_States

    Soils are the product of climate, organisms and topography, acting on parent (geologic) material over time. Thus the great diversity of geologic materials, geomorphic processes, climatic conditions, biotic assemblages and land surface ages in the United States is responsible for the presence of an enormous variety of mineral and organic soils.

  9. Parent material - Wikipedia

    en.wikipedia.org/wiki/Parent_material

    Parent material is the underlying geological material (generally bedrock or a superficial or drift deposit) in which soil horizons form. Soils typically inherit a great deal of structure and minerals from their parent material, and, as such, are often classified based upon their contents of consolidated or unconsolidated mineral material that has undergone some degree of physical or chemical ...