Replacing cheatgrass by reseeding with perennial grass on southern Idaho ranges

Cheatgrass, an aggressive winter annual native to southern Europe, appeared in Idaho before 1900. It is well adapted to climatic conditions in southern Idaho and invades on ranges wherever native vegetation has been disturbed. Undisturbed cheatgrass stands average about 570 plants per square foot. Current studies indicate that if this number can be reduced to 50 plants per square foot (80 plants per square foot if reduction is by burning and 100 if by lister drill) for one season, perennial grass seedlings can become established and occupy the area. The best season for reducing the number of cheatgrass plants through cultural treatments is in the spring before seed forms; the next best, after fall germination. The most effective but a costly method of eliminating cheatgrass and getting good stands of reseeded grass is moldboard plowing at any season of the year followed by fall drilling. A good alternative is wheat land plowing or heavy disking in spring, or in late fall if cheatgrass has germinated vigorously, followed by fall drilling. Early summer burning, usually in June, followed by fall drilling is a cheap method and data in four consecutive years indicate that good results may be expected. Deep-furrow lister drilling in late fall gives good results when cheatgrass has germinated. Crested wheatgrass is the most universally recommended species for seeding on cheatgrass areas and should form the major part of all reseeding mixtures for southern Idaho. Bulbous bluegrass is well suited for poor sites and as an understory species on some areas of southwestern Idaho. Other species which may be used on the drier cheatgrass areas are bearded bluebunch, beardless bluebunch, stiffhair, and intermediate wheatgrasses. Species for the better and moister sites are smooth and mountain brome, tall oatgrass, intermediate and tall wheatgrass, Russian wildrye, and big bluegrass. Seeds should be drilled wherever possible. Drill furrows are best spaced from 6 to 8 inches apart with seed covered from 1/2 to 3/4 inch deep. Wherever feasible, drill furrows should be cut to 1 1/2 inches or more deep, with very light covering of soil on the seed in the bottom of the drill furrow. Where fall moisture is dependable, seedings in cheatgrass areas may be done in September or early October. Where fall moisture is not dependable, seeding should be delayed until late October or early November.