difference between SAND and CLAY?
Answers
Clay is the tiniest soil particle. Compared to sand particles, which are generally round, clay particles are thin, flat and covered with tiny plates. Clay particles tend to stick together and make very little movement through soil.
Explanation:
As every gardener knows, not all soils are made the same. Humus-rich soils are naturally friable, clay soils are tight and almost impenetrable when dry, and sandy soils are loose and coarse and need frequent watering to maintain plant growth. Each of these soils resulted from parent material and climatic effects. An ideal soil contains all three of these different soil types.
The best combination these common soil types is called "loam," allowing plants to get the right amount of both air and water, according to Utah Education Network.
About Soil Formation
Soil genesis began with parent material – such as volcanic ash, bedrock, sediments and windblown materials. Climatic forces of water, temperature and other elements broke down the parent material to form the Earth's upper mantle, or life-supporting outer crust. The type of soil naturally occurring in your garden depends upon climate and forces of nature, such as glacial movement and flooding.
Sand, the Largest Soil Particle
Sand is a very basic soil, made of particles of rock and hard minerals, such as silicon dioxide. The largest of the different types of soil particles, one grain of sand is visible to the naked eye. According to a comparison made by Penn State Extension, if a particle of clay were a BB, a grain of sand would be the size of a chair. Although sand supports very few plant life forms in comparison with other soil types, sand is a valuable component of an optimal soil mixture. The large, relatively stable sand-particle size increases soil aeration, improves drainage in tight soils and creates plant-growth supporting qualities, or tilth.
Clay, the Smallest Soil Particle
Clay is the tiniest soil particle. Compared to sand particles, which are generally round, clay particles are thin, flat and covered with tiny plates. Clay particles tend to stick together and make very little movement through soil. Negatively charged, clay particles attract positively charged nutrients – such as potassium, calcium, magnesium and certain types of nitrogen, providing valuable nutrients to plants.
Clay also tends to hold moisture, improving water retention qualities of soil but reducing drainage potential. The color of clay soil depends upon minerals attached to the particles and the amount of water in the soil. Yellow and red clay contain varying amounts of iron oxide and drain more freely than blue or gray clay soils. The colors blue and gray indicate the soil stays wet most of the year and very little iron, if any, is attached to the particles.