Soil Properties

Available water capacity

an estimate of how much water a soil can hold and release for use by plants measured in inches of water per inch of soil

cation exchange capacity (CEC)

a measure of the ability of soil to hold and exchange cations

Drainage class

refers to the frequency and duration of periods of saturation or partial saturation during soil formation

Erosion Factor (K)

a relative index of the susceptibility of bare, cultivated soil to particle detachment and removal and transport by rainfall

Erosion Factor (T)

the soil loss tolerance used in the RUSLE. It is defined as an estimated maximum rate of annual soil erosion that will permit crop productivity to be sustained economically and indefinitely

High water table

the highest average depth of free water during the wettest season

Permeability

is saturated hydraulic conductivity. Saturated hydraulic conductivity is influenced by texture, structure, bulk density, and large pores. Soil structure influences the rate of water movement through saturated soil, in part, by the size and shape of pores

Organic matter

One percent organic matter is equivalent to 0.6 organic carbon. It encourages granulation and good tilth, increases porosity, lowers bulk density, promotes water infiltration, reduces plasticity and cohesion and increases available water capacity. It has a high cation adsorption capacity and its decomposition releases nitrogen, phosphorus, and sulfur. 

Reaction

Soil pH is an expression of the degree of acidity or alkalinity of a soil. It influences plant nutrient availability. A very acid soil (pH <5.0) typically has lower levels of nitrogen, phosphorus, calcium, and magnesium available for plants, and higher levels of availability for aluminum, iron, and boron than a neutral soil at pH 7.0. At the other extreme, if the pH is too high, availability of iron, manganese, copper, zinc, and especially phosphorus and boron may be low.

Salinity

Salts, mainly sodium, magnesium, calcium, and chloride or sulfate, may interfere with the absorption of water by plants. They also create a nutrient imbalance in some plants. Soils that have more than 2 mmhos/cm of electrical conductivity in soil solution are considered saline

Slope

the gradient of the elevation change