S

Salinity

A measure of salt concentration. See “dS/m.”

Saturate

A saturated soil contains the maximum amount of moisture that it can hold.

Scabrous

Rough to the touch.

Scarify

To etch or scratch the hard seed coat of a seed (e.g. a cicer milkvetch seed) so that it will absorb water, enabling it to germinate. The process usually involves mechanical abrasion, but may be done chemically.

Seed Bank

Un-germinated seeds present in the soil, generally from forage crops that have produced seed that has shattered onto the ground.

Seed Cover

Grasses have a lemma (outer seed cover) and palea (inner seed cover), which protect the seeds. They are sometimes called hulls.

Self-pollinated

Fertilization of the ovary of a plant with the pollen of the same plant.

Semi-arid

A climate where evaporation exceeds precipitation.

Senescence

The natural aging process of plant tissues and the ultimate deterioration of the plant tissue functions, i.e. as a leaf matures, it senesces and dries up.

Serrate

Having sharp teeth pointing forward.

Sheath

In grasses, the sheath is the tubular, lower portion of the leaf that arises from a node and surrounds the stem. Opposing sheath margins may be separated (open), grown together (closed) or overlapping.

Shoot

See “tiller.”

Simulated Grazing

To use machine harvesting to estimate the potential of pasture production, usually involving multiple cuttings per season.

Sod

Surface soil permeated by and held together by forage roots and/or rhizomes.

Sod Bound

Grass sod that is unproductive due to lack of available nitrogen. Generally, the upper soil profile is filled with live and dead roots, making it impermeable to water and low in productivity due to that lack of available nitrogen.

Soil Texture

Relative proportions of soil, clay, silt and sand in combination comprises the texture of the soil.

Spike

A grass seed head where the spikelets are attached directly to the stem (the rachis) without a stalk, e.g. wheatgrasses, cereal wheat.

Spikelet

A secondary spike. In grasses, this is a structure with one or more florets that usually have a pair of glumes at the base where they are attached to the stem (rachis).

Stalk

A common term for a stem or similar structure that supports a plant part such as a flower, etc.

Stem

The plant structure that supports the branches and leaves of a plant.

Stocking Period

The duration of time that livestock are grazing in a paddock or pasture.

Stocking Rate

The number of livestock per area of pasture, usually expressed as animals or animal units per hectare or acre, but may be expressed as hectares or acres per animal unit.

Stockpile

The accumulation of the growth of a forage crop that can then be grazed at another time during the year, e.g. ungrazed summer regrowth to be grazed in the fall or winter.

Stolon

A prostrate stem on or just below ground level, which produces shoots and roots at its nodes, enabling the plant to spread. White clover has stolons.

Subspecies

Subdivision or sub-member of a species, e.g. Flemish or Siberian alfalfa is a subspecies of the species alfalfa.