Straw is the dried stem of certain grasses, especially cereals commonly called "reed" (wheat, oats, rye, barley, rice, etc.), once cut and discarded, after separating the grain or seed by threshing .These products crop cereals are used in areas of good forage production almost exclusively as a bed or couch.

in regions that lack constantly forage, or years of poor agricultural production in general use as food is much higher and especially in those areas where, on the weather and soil quality, are not suitable for the cultivation and harvesting of hay (dry or very dry).

When food very fibrous its nutritional value is low compared, so it should always be supplemented with energy and protein foods, such as vitamins and minerals essential for proper growth.

it is also used as prote ction soil, especially in horticulture, used to keep moisture after sowing grass.

Straw is therefore more alternatives within the group of protective materials of the wet soil layer, adjacent to the pine bark, or even plastic sheeting material.

can also be used as material construcciónLa straw composition depends largely on the leaf and stem, stem diameter, height plant, so that there are variations linked to the species, its composition also depends upon its definition -for collecting straw comes from the plant at the time of maximum maturation, but mowing anticipate that cereal or the we delay, the composition will be distinta-.

the most abundant straws in Spain by extending your growing area and ease of collection are wheat and barley and to a lesser extent oats. < br>
Most of the components of the cereal straws (including protein and minerals) are associated with the cell wall.

average, contain 71% neutral detergent fiber, distributed in 40% of cellulose, 23% hemicellulose, and lignin 8%.

in general cereal straws contain from 3% to 4% crude protein that is practically mostly indigestible, other part presents marked deficiencies in most minerals, except potassium chloride and iron containing 1.5%, 0.46% and 180 mg / kg respectively.

as macrominerales, calcium and phosphorus we can say that the content of both as the relationship between them is acceptable.