Soil clay loam that begins at 43% water by weight to a field capacity of 22% is six days, whereas a sand loam that is flooded to its maximum of 22% water will take two days to reach field capacity of 11% water. The available water for the clay loam might be 11% whereas for the sand loam it might be only 8% by weight. The above are average values for the soil textures as the percentages of sand, silt and clay vary. Water moves through soil due to the force of gravity, osmosis and capillarity. At zero to one-third bar
Soil released as ammonium by the processes of mineralisation. Protein material is easily broken down, but the rate of its decomposition is slowed by its attachment to the crystalline structure of clay and when trapped between the clay layers. The layers are small enough that bacteria cannot enter. Some organisms can exude extracellular enzymes that can act on the sequestered proteins. However, those enzymes too may be trapped on the clay crystals. Ammonium fixation occurs when ammonium pushes potassium ions from between the layers of clay such as illite or montmorillonite. Only a small fraction of soil nitrogen is held this