LITERATURE REVIEW 



Some of the earliest work on reducing tillage in relation to renovating 

 non-plowable permanent pastures was conducted by Sprague (1952, 1960). Es- 

 tablishment of orchardgrass and Ladino clover was equally successful with 

 only two discings of a chemically-killed sod as with 10-12 discings, which 

 was considered necessary for preparing a conventional seedbed. A mixture of 

 amitrole and dalapon, applied to a closely grazed sward, effectively killed 

 bluegrass, poverty grass, sweet vernalgrass, and many perennial broadleaf 

 species. 



More recently, the availability of non-selective herbicides has 

 improved the control of sod competition, especially competitive weedy species, 

 without residual effect on introduced seedlings. Triplett, et al. (1975) 

 summarized the work of several researchers who have effectively changed the 

 composition of pasture swards with such materials. Other workers have 

 attempted to reduce competition from existing species in order to favor 

 conditions for introduced species (Cullen, 1970; Newman, 1966; and White, 

 1970) . Herbicide use has improved the reliability of no-till legume es- 

 tablishment (Linscott, 1979; Mueller-Warrant and Koch, 1979). 



The development of specialized equipment with the capability of 

 placing small-seeded forages in contact with soil without burying surface 

 mulch or residues from previous crops has provided new opportunities 

 (Decker, et al . , 1964; Decker, et al . , 1969; Taylor, et al . , 1969). Forage 

 species which are more responsive to fertility and which are higher in 

 quality than those of the previously existing sod were introduced and with 

 less time, labor and energy than with tilled seedbeds. 



