31.2 The Soil

31.2 The Soil

  • Ray Wheeler checks onions being grown.
    • Two plants are left and right.
  • Hydroponics is a method of growing plants in water.
    • Hydroponics has become a growing process that researchers often use.
    • Under strictly controlled conditions, scientists can use Hydroponics to study the effects of different nutrient combinations.
  • Growing flowers, vegetables, and other crops in greenhouse environments has become a way to grow Hydroponics.
    • Hydroponically grown produce can be found at your local grocery store.
    • Many lettuces and tomatoes in your market have been grown indoors.
  • Plants get elements from the soil, which is a natural medium for land plants.
    • Climate and soil quality are related to plant distribution and growth.
    • The chemical composition of the soil is only one of the factors that affect the quality of the soil.
    • The history of the soil can affect the fertility and characteristics of that soil.
  • Natural and environmental forces acting on mineral, rock, and organic compounds are what lead to the formation of soil.
    • Mineral soils are usually found in the middle of the year or exposed to the atmosphere.
  • A healthy soil has enough air, water, minerals, and organic material to support plant life.
  • The components of the soil are shown.
  • When soil is compressed, it can result in soil compaction.
  • Plants get water and minerals from humus.
    • The soil is made of rock that is broken down into smaller particles.
  • A combination of biological, physical, and chemical processes leads to soil formation.
    • Solid material should make up 50 percent of the soil.
    • Half of the space should be water and the other half should be air.
    • The organic component of the soil is used as a cementing agent, returns nutrients to the plant, allows soil to store water, makes soil tillable for farming, and provides energy for soil organisms.
    • The majority of soil organisms are active once the soil is dry.
  • There are zones called horizons within the soil profile.
    • The five factors that account for soil formation are parent material, climate, topography, biological factors and time.
  • Sand and glaciers form in other soils.
    • The deposited material is different from the materials located in the depth of the soil.
    • Depending on how quickly or slowly the stream moves, there may be different characteristics for the silt in the river.
    • A fast moving river could have sand and rocks, while a slow moving river could have clay.
  • The soil's characteristics are affected by temperature, humidity, and wind.
    • A key component of a quality soil is the presence of the elements.
  • The lay of the land can have a big influence on the fertility of a soil.
    • Water flow is affected by topography, which strips away parent material.
    • The soils that are steep are more prone to erosion and may be thinner.
  • The presence of living organisms affects the structure of the soil.
    • Plants can penetrate into crevices and animals can produce crevices.
    • The leaves that fall from plants contribute to soil composition.
  • soils develop over long periods because time is an important factor.
    • The process of soil formation is changing.
  • Living organisms can use materials deposited onto the surface of the soil.
  • The soil is classified based on their horizons.
    • There are four distinct layers to the soil profile: O horizon, A horizon, B horizon, and C horizon.
    • The humus improves the soil's hydration retention.
    • The top layer of soil is usually two to three inches deep.
  • Deep layers of topsoil can be found in the Mississippi River Delta.
    • Topsoil is rich in organic material, and it is the "workhorse" of plant production.
    • The horizon is usually darkly colored due to the presence of organic matter.
    • Rainfall trickles through the soil and carries materials from the surface.
    • Some soils have a layer of calcium carbonate in the B horizon.
    • The parent material can either be created in its natural place or transported somewhere else.
    • Beneath the horizon lies bedrock.
  • The O horizon, A horizon, B horizon, and C horizon are found in typical soils.
  • Some soils have more than one layer.
    • The thickness of the layers varies depending on the factors that influence soil formation.
    • In general, immature soils may have O, A, and C horizons, whereas mature soils may display all of these, plus additional layers.
  • The O horizon, A horizon, B horizon, and C horizon are found in the San Joaquin soil profile.