IMPACT OF CATTLE TREADING ON HILL LAND 1 - SOIL DAMAGE PATTERNS AND PASTURE STATUS

An experiment was conducted on steep hill land in New Zealand to descr ibe the pattern of cattle treading that occurred from a single damage event during winter. The experiment also measured some of the conseque nces of treading and sought to define the subsequent grazing managemen t which promoted the most rapid recovery of pasture. In hill paddocks of mixed topography, damage of the soil surface was greatest on animal tracks/camps and easy contoured areas (<25 degrees) where cattle pref er to walk. Evidence of this initial winter impact disappeared over sp ring, most rapidly on easy contoured areas and under continuous sheep grazing. To promote rapid recovery of damaged paddocks continued grazi ng of cattle during spring should be avoided. At high levels of damage (>50% soil surface), puddling on tracks/camps and skid damage on stee p inter-tracks became frequent. These processes are significant becaus e animal tracks/camps act as important channels for surface water flow in hill lands; and disturbed, inter-track areas are an important sour ce of sediment runoff. During spring, pasture growth rates were reduce d by treading damage. From a systems context this could represent loss es of 5-10 kg DM ha(-1) d(-1) during early-mid spring. Pasture cover a nd growth rates had fully recovered by early December.