Sustainable Soil Management

Glossary

F

FALLOW. Cropland left idle in order to restore productivity, mainly through accumulation of nutrients, water, and/or organic matter.
FAMILY, SOIL. In Soil Taxonomy, one of the categories intermediate between the great group and the soil series. Families are defined largely on the basis of physical and mineralogical properties of importance to plant growth.
FERTILITY, SOIL. The quality of a soil that enables it to provide essential chemical elements in quantities and proportions for the growth of specified plants.
FERTILIZER. Organic or inorganic material added to a soil to supply one or more nutrients essential to plant growth.
FERTILIZER ANALYSIS. The composition of a fertilizer, expressed as a percent of total nutrients; for example, total nitrogen, available phosphoric acid (P2O5), and water-soluble potash (K2O).
FERTILIZER SUSPENSION. A fluid fertilizer containing dissolved and undissolved plant nutrients. The undissolved nutrients are kept in suspension, usually by swelling-type clays.
FIELD CAPACITY. The amount of water a soil holds after free water has drained because of gravity.
FIXATION. For other than elemental nitrogen: the process or processes in a soil by which certain chemical elements are converted from a soluble or exchangeable form to a much less soluble or to a nonexchangeable form.
FLOCULATE. To aggregate or clump together individual, tiny soil particles, especially fine clay, into small clumps or floccules. Opposite of deflocculate or disperse.
FLOOD PLAIN. Land near a stream that is commonly flooded when the water levels are high. Soil is built from sediments deposited during flooding.
FOLIAR FERTILIZATION. Application of a dilute solution of fertilizer to plant foliage, usually made to supplement soil-applied nutrients.
FOOD WEB. The community of organisms that relate to one another by sharing and passing on food substances. They are organized into trophic levels such as producers that create organic substances from sunlight and inorganic matter, to consumers and predators that eat the producers, dead organisms, waste products and each other.
FRIABLE. The ease by which a moist soil can be crumbled.
FURROW SLICE. The uppermost layer of an arable soil to the depth of primary tillage; the layer of soil sliced away from the rest of the profile and inverted by a moldboard plow.