Kochia - a Forage with Winter Grazing Potential
Dave Koch, Extension Agronomy Specialist, University of WyomingForage for winter grazing in Wyoming is usually in short supply and/or poor in
nutrient content. Drought and other factors accentuate this shortage. Forage kochia
(Kochia prostrata), not to be confused with the weedy Kochia scoparius, is adapted to
regions of the Western U.S. with annual precipitation of 6 to 16 inches, it can be grown
on a wide range of soil textures and it is very tolerant of salinity. Forage kochia shows
very little aggressiveness and no tendency to cross with weedy kochia. The appearance
and growth habit also is different. It is a semi-evergreen half shrub, growing to a height
of 1 to 3 feet. It develops a very deep tap root, as well as an extensive fibrous root
system. Individual plants can live 10 to 15 years and the plant readily reseeds.
Forage use. Forage kochia has been used for year-round grazing. Perhaps its best use is
in winter, when range and pasture forage is low in nutritive value. At the Archer
Research & Extension Center, forage kochia was included among 16 improved forages in
a test to evaluate winter forage availability and nutritive value after season-long
stockpiling (Table 1). In 1998, a normal rainfall year (9.4 in. of spring-summer
precipitation), it produced the greatest amount of forage among 16 entries, 3035 lb of dry
matter/acre; in 1999, a wet year (16.0 inches of spring-summer precipitation), it produced
2220 lb of d.m./acre, about average among the 16 forages; and in 2000, a dry year (
inches from June through Aug.), it produced 821 lb/acre.
Forage quality. Forage kochia tested 7.7% crude protein on Feb. 26, higher than the 12
perennial grasses and three legumes in the test. Neutral detergent fiber (NDF), which is
related to forage intake and acid detergent fiber (ADF), which is related to forage
digestibility, were lower than for all other forages, indicating superior forage nutritive
value during the winter.
Forage kochia was planted in a pure stand in this study, although it is generally
planted in a mixture with grasses and other species. In its natural habitat it will comprise
up to 20% of total production and can be cut for hay.
During the winter of 2000-01, 300 beef cows grazed kochia on the Broadbent Ranch
in Uinta County. Cows grazed from early January until mid-March, a period in which
there was 10 inches of snow cover. Cows were given a high-energy grain supplement
(13% protein) at 2 lb/day. Cows improved about two points in body condition score
during the kochia-grazing period and calved in late March-early April. Kochia near the
end of the grazing period still tested over 7 1/2% crude protein. Although it appears
unpalatable, cows readily eat kochia. A seed crop had been harvested the previous fall,
leaving most of the kochia below the snow.
The ranch is located in an area that receives only 6 to 10 inches of precipitation and
2000 was a dry year. Yet the kochia produced an estimated 800 lb/acre of forage dry
matter. Adjacent range produced an estimated 80 lb/acre of grass. A total of about 1500
acres was grazed and was cross-fenced to graze 200-300 acres at once. Carrying capacity
was about 0.5 AUM/acre.
Other uses. Forage kochia competes well with annual weeds such as downy brome,
Russian thistle and halogeton. It is used for soil conservation, establishing on very
disturbed and droughty soils. Since it maintains as much as 40% moisture in its stems,
even in the winter, it has been used as a fire break.
Establishing the stand. The seedbed should be prepared as with any other forage
seeding. The seed is very small (>400,000 seeds/lb) and must not be planted more than
1/16 inch deep. Therefore, it is commonly broadcast on the soil surface in winter or early
spring. Spreading on top of snow is a good practice.
The seed loses viability after one year, or earlier if improperly stored. Seed is
expensive, however, only ½ to 1-lb per acre in mixtures with grasses is needed.
‘Immigrant’ is the only released variety.
Grazing management. At this time, definitive recommendations on grazing
management is not possible because grazing trial information is very limited.
References:
Gade, A.E. and F.D. Provenza. 1986. Nutrition of sheep grazing crested wheatgrass
versus crested wheatgrass-shrub pastures during winter. J. Range Management 39:527-
530.
Harrison, R.D., et al. 2000. Forage kochia - Its compatibility and potential
aggressiveness on intermountain rangelands. Utah Agric. Exp. Sta. Research Report 162.