It is the surface area to volume ratio ( specific surface area ) of soil particles and the unbalanced ionic charges within those that determine their role in the fertility of soil, as measured by its cation exchange capacity.
12.
One theory states that the fertility of loess soils is due largely to cation exchange capacity ( the ability of plants to absorb nutrients from the soil ) and porosity ( the air-filled space in the soil ).
13.
Montmorillonite is a subclass of smectite, a 2 : 1 phyllosilicate mineral characterized as having greater than 50 % octahedral charge; its cation exchange capacity is due to isomorphous substitution of Mg for Al in the central alumina plane.
14.
This work was key to identifying the principle of cation exchange capacity and facilitating William Albrecht's later work on the Base Cation Saturation Ratio ( BCSR ), which is a method of interpreting soil test results that is now widely used in sustainable agriculture.
15.
Once the litterfall has settled, decomposition of the litter layer, accomplished through the leaching of nutrients by rainfall and throughfall and by the efforts of detritivores, releases the breakdown products into the soil below and therefore contributes to the cation exchange capacity of the soil.
16.
The rates of application of borate to produce an adequate alfalfa crop range from 15 pounds per acre for a sandy-silt, acidic soil of low organic matter, to 60 pounds per acre for a soil with high organic matter, high cation exchange capacity and high pH.
17.
Properties include having an argic horizon, which has a specific cation exchange capacity; a predominantly alic properties zone between 250mm and 1000 mm from the soil surface; and no diagnostic horizons other than an ochric, umbric, albic, andic, ferric, nitic, plinthic or vertic horizon.
