Distribution & Habitat
Due to the aggressiveness of this invasive plant it can now be found across the continental U.S. and in most warm regions of the world. It is readily found in climates ranging from boreal moist or wet to tropical, dry or moist forests. Barnyard grass prefers sandy, loamy or clay, soils that are well drained. Furthermore it can persist in acidic, neutral and alkaline soils with a ph range of 4.8-8.2. It is common to find these in ditches, along roadsides, croplands and other disturbed areas. This weed is adapted best to temperatures ranging from 14-16°C, but can survive in temperatures between 5.7 -27.8°C. Temperatures for germination range from 5 -40°C with 35°C being the optimum. Water requirements span a wide range with the plant persisting with 31-250cm annual precipitation.
Characteristics
Barnyard grass has long thick coarse stems that can reach up to 1.5m in height. One of the defining characteristics is that it lacks ligules and auricles. It has flat glabrous leaves, rolled in the shoot with keeled sheaths. The leaves tend to b 30-50cm in length and 1-2cm in width with a prominent midrib, and are usually have a reddish tint toward the base. The stems are thick and smooth, and usually branch at multiple points; they also tend to be reddish toward the base. Panicles composed of spikelets can be from 4-16mm in length and tend to be green or purple in color.
Barnyard grass is an annual with primary vegetative growth between May and July if planted in the spring. Barnyard grass matures in the fall between August and October. It is a self pollinating hermaphrodite that can produce up to one million seeds per plant, with seed distribution primarily via wind or water. Seed viability varies widely, but has been reported that seeds can remain viable up to 13 years in soil.
Importance
Barnyard grass has many uses. It can be used for cattle fodder and is widely grazed in Arizona and Virginia. However, the low protein content, as can be seen in nutritive chart, makes it less than optimal for a first choice. The seeds are fed on by birds and the grass is eaten by water fowl. However there is some danger as it can accumulate harmful levels of nitrate which can be toxic to animals. Barnyard grass can also be erosion control and in Egypt it has been used for reclamation of saline and alkaline areas. Furthermore, the seeds can be died to make a coffee substitute.