A cation is a positively charged ion, e.g. hydrogen H+, calcium Ca++.
Cation exchange capacity is a measure of the ability of soil (or organic matter) to retain positively charged ions (cations) on particle surfaces, primarily influencing nutrient availability and exchange.
Any substance that acts to supplement osmotic pressure in plant cells and help to retain water in the cell.
Cemented or hardpan layers refer to the layers of soil, where soil particles are held together by a binding agent that may be naturally present or introduced into the soil. Cemented soils do not crumble into individual soil particles when squeezed between the fingers. Cemented layers can impair drainage and plant growth.
Cover crops generally refer to either:
1. growing plants between two main crops, generally during the winter or summer. Cover crops are sown after the main crop has been harvested and before the next crop is sown. They cover the soil during the intercropping period, preventing erosion and nutrient loss as well as limiting weeds.
2. using your main crop or pasture phase as a green manure crop and returning all biomass to the soil as opposed to harvesting (normally returned at, or just prior to flowering)
Cover crops add organic matter and boost biological activity. Cover crops can also be used to fix nitrates in the soil to limit leaching.
The movement of molecules or ions (not water) from an area of higher to lower concentration without the use of energy.
Dispersion causes micro-aggregates to collapse and release clay, silt and sand particles. Smaller particles move to block soil pores, which slows internal drainage and contributes to an increased risk of waterlogging. Typically, dispersion is associated with sodic soils. Dispersion is the collapse of soil aggregates into single particles, causing water to appear cloudy or milky as the clay disperses.
Dispersion is a process that occurs in soils that are particularly vulnerable to erosion by water. In soil layers where clays are saturated with sodium ions (“sodic soils“), soil can break down very easily into fine particles and wash away.
The ecosystem is the living and non-living components of an environment functioning as an interconnected system.
A term relating mainly to the topsoil, where the structure may at first look massive or be composed of large aggregates, but these break up easily (with little effort) into fine aggregates that are stable and resistant to further disturbance.