Soil Quality Glossary

agroecology - the science of ecology, or the branch of biology dealing with the relations and interactions between organisms and their environment, applied to the design, development, and management of agriculture.

allelopathic - refers to the suppression of growth of one plant species by another due to the release of toxic substances.

biomass - as simple as 'above and below-ground vegetative material'; or more complex to include microbial contributions or specific uses, such as for fuel.

Capability Classification System - a system developed by the USDA Natural Resources Conservation Service of grouping soils based on their inherent suitability for intensive uses.

denitrification - a process occurring naturally in soil, where bacteria break down nitrates to give nitrogen gas, which returns to the atmosphere.

disturbance - an ecosystem disturbance can be natural or human induced stress. An example of a natural disturbance is a hurricane or a tornado. An example of a human-induced disturbance is tillage or pesticide application.

dynamic properties - soil characteristics that can change in response to land use changes.

ecosystem - a functioning system of interacting parts of the physical environment and biological community in a geographic region.

ecosystem function - refers to the services performed by the organisms in the system such as energy flow, nutrient cycling, filtering and buffering of contaminants, and regulation of populations.

eutrophication - a process where water bodies receive excess nutrients, primarily nitrogen and phosphorus, that stimulate excessive plant growth.

green manure - young and succulent plant material turned into the soil to improve its organic matter and nutrient content.

inherent properties - soil properties that do not change with land use.

Intermediate Disturbance Hypothesis - a theory in ecology which states that the highest levels of diversity are supported at intermediate levels of disturbance (frequency or intensity).

minimum data set (MDS) - a limited number of biological, chemical and physical indicators that together give an overall measure of soil quality.

population - a group of individuals of the same species that live in the same geographic region

resilience - a component of ecosystem stability, is the ability of an ecosystem to recover after disturbance.

resistance - a component of ecosystem stability, is the ability of an ecosystem to remain stable in the face of disturbance.

soil properties - chemical, physical, or biological characteristics of soil which can indicate its level of function of ecosystem services. Properties can be dynamic or inherent characteristics. Also see soil quality indicator.

soil quality indicator - a chemical, physical or biological property of soil that is sensitive to disturbance and represents performance of ecosystem function in that soil of interest. These are dynamic soil properties.

soil quality, soil health, soil condition - these phrases are used in various ways and sometimes interchangeably. Soil quality sometimes refers to the inherent potential of soil, in contrast to soil health or soil condition

synergistic - is when separate elements produce a greater effect when acting together than would be produced if they acted separately.