We have been fortunate to be the primary researcher and developer of crabgrass forage information. This writing is a brief summary of some of our work with the high-quality forage.

Crabgrass, Digitaria spp., is an annual warm-season grass with many species: large crabgrass, D. sanguinalis, and hairy crabgrass, D. ciliaris, are the primary species discussed. The two are relatively large types from the North American continent and can produce high levels of upper-quality forage and abundant seed for volunteer stands if they are managed appropriately.

The information presented is a brief summary of some of crabgrass's forage attributes and related characteristics and is based upon our research and demonstration and client interaction information. We hope it will help make other forage managers aware of the many ways the forage can be used for stocker cattle and other livestock. Crabgrass is increasingly chosen as a forage.

Crabgrass may have evolved in Africa (Ball et al., 1991) and is found in many other subtropic to temperate regions. It has been used as a grain crop as well as a forage crop, was introduced into the United States in 1849 (Anon., 1988) for stock feed, and may have been introduced as a component in immigrant's seed and food supplies. It was very successful and spread throughout every state in the contiguous United States, but it is used as a forage primarily in the southeastern one-third of the country in the mild to temperate areas.

Use of crabgrass as a forage declined gradually because graziers found that other forage crops were produced easily and crabgrass was invasive. However, some graziers always have used the forage.

Geographic adaptation of crabgrass far exceeds that of bermudagrass, Cynodon dactylon. It is present in similar climatic regions throughout the world. Researchers in the southeastern United States as well as in other parts of the world have become interested in the forage.

These crabgrasses produce best on well-drained soils such as sands, sandy loam, loamy fine sand, loam, and silt loam that do not crack much when parched and are moist enough to keep the grass green; irrigation is necessary in dry climates. Stands have produced well on good moist clay loam soils but only moderately on clay, clay loam, and silt soils. Crabgrass grows best at about 27°C to over 38°C. Production can exceed 125 kilograms per hectare¹ per day in moist, fertile conditions and optimum temperatures. Crabgrass does not tolerate extremely saline, alkaline, or basic (pH 8 or higher) soils well.

Crabgrass is used in both tilled and untilled forage production approaches. Without a doubt, the best production and the longest green season for both initial plantings and planned volunteer stands come from appropriate dormant-season tillage, which may be minimal. For best yields the tillage should be moderately deep, resulting in a relatively firm soil, and completed before spring seed germination.

Forage yields from untilled areas (orchard understory pasture, crabgrass mixture in bermudagrass pasture, crabgrass volunteer stands after small grains or ryegrass pasture, and cool-season legume and crabgrass mixtures) have been good. These untilled pastures develop early-spring pasture about one to two months later than the best single-crop crabgrass pastures. However, they are very effective pastures from summer to winter (about three to six months) and yields during that period are excellent: about 3,400 to 5,600 kilograms per hectare in our research.

1. 1 Kilogram per hectare = 0.89 lbs./ac.

Crabgrass is a nitrophilous plant and, therefore, responds to nitrogen fertilization very well like a good winter annual grass or lush forage from bermudagrass (Dalrymple et al., 1991; Huneycutt, personal communication). Well-managed crabgrass produces about 25 kilograms of grass per kilogram of nitrogen when the latter is applied with a balanced amount of phosphorus and potassium as needed. Crabgrass prefers an acidic to slightly basic soil and sometimes responds negatively to lime application. Usual nitrogen rates for moderate level dry-land production range from 50 to 100 kilograms per hectare. Rates of 1 to 2 kilograms of actual nitrogen per hectare per day of expected good growth are realistic.

An appropriate approach to a flexible form of rotational grazing is imperative for successful crabgrass pastures because the grass is among the most palatable of all summer forages (Dalrymple, 1976) and must be managed to control quality for stock performance goals, forage production, area performance goals, and seed production for planned volunteer stands. Crabgrass sometimes will fail under continual stocking because stock overgraze it and prevent good production.

Crabgrass is relatively easy to produce from planned volunteer stands: the manager simply must control grazing or conservation harvests to allow adequate seed drop the prior season or two and then either apply the proper shallow dormant-season tillage or tread the seed in under nontillage approaches. We have one volunteer pasture that was excellent for eighteen consecutive years at this writing, and it was replanted only to add a new variety component. Without a doubt, that pasture could have continued as it was for another seven years.