Pasture renovation. I. Seedbed preparation, seedling establishment, and subsequent yields

Renovation trials were started in 1942 and 1943 on an old unproductive pasture on Dunmore silt loam at State College, Pa., to determine the adaptability of various farm implements and the factors involved in preparing a seedbed for several of the deeper rooted and higher yielding grasses and legumes. The implements used included the mold board plow, disk plow, two types of field cultivators, ordinary disk harrow, cover crop disk, cutaway disk, and sod cutter (sweep). Additional plots of the existing sod were weakened by close clipping before seeding. Lime and heavy rates of phosphate and potash fertilizer were applied so that soil fertility would not be a limiting factor. The following species were seeded in late winter on frozen ground in various combinations: Alfalfa, red clover, Ladino clover, birdsfoot trefoil, orchard grass, bromegrass, and timothy. The results of these trials indicated that the farm implements used differed somewhat in their adaptability in preparing a seedbed for pasture grasses and legumes. On land that is plowable the use of a mold board plow was slightly more rapid and as economical as any of the other implements and was more effective for killing the old sod. The organic matter of the old sod was turned under, however, with little or no surface mulch to prevent puddling, runoff, and erosion. The other implements used were all approximately equal in power requirements and in the type of seedbed prepared. The heavy disk, and particularly the cutaway type, appeared to be adaptable to the widest range of land and sod conditions. With the use of any surface tillage implement it was essential to rework the land at least once and sometimes twice after the initial tillage to turn up those sods which had rooted down so they would be killed by desiccation. The sod cutter or sweep was least adaptable since it cannot be easily used on stony land; in addition, it cut the sod underground and left it in place where it could easily root again. On areas which were not tilled but were severely clipped to weaken the existing sod and limed, fertilized, and seeded, a fair stand of Ladino clover and red clover became established. Only scattered plants of alfalfa, birdsfoot trefoil, and the seeded grasses were found. The response from top-dressing on this unproductive sod with lime, phosphate, and potash was delayed until the third year by which time a sufficient amount of white clover and Kentucky blue grass had become established to increase herbage yields.