Field Guide. cropping and pastoral grazing on flat to rolling country.

PLANT INDICATORSPasture composition Assess the botanical composition of the pasture (the proportion ofeach species present) in the winter or early spring.PASTURE SPECIES vary in their tolerance to poor soil aeration,waterlogging <strong>and</strong> pugging. Consequently, their nitrogen uptake, drymatter production <strong>and</strong> survival ability also vary markedly. Phalarisaquatica, tall fescue, meadow fescue, meadow foxtail, Poa trivialis,timothy, creeping bent, sweet grass, pennyroyal, buttercup, duckweed<strong>and</strong> dock are tolerant of waterlogging due to pugging or poor drainage.Perennial ryegrass, white clover, chewing fescue, browntop, Poa annua,<strong>and</strong> crested dogstail are moderately tolerant of waterlogging. Matuaprairie grass, cocksfoot, sweet vernal, Poa pratensis, ratstail, meadowrice grass <strong>and</strong> yarrow are sensitive to waterlogging <strong>and</strong> will die out ifwet conditions persist.Pasture composition will also change according to the degree of treadingdamage. Ryegrass <strong>and</strong> Poa pratensis resist treading damage betterthan many other species, <strong>and</strong> often become more common in puggedpastures. Poa trivialis, brown top, white clover <strong>and</strong> timothy aremoderately tolerant to treading. Cocksfoot, red clover <strong>and</strong> yorkshirefog, <strong>and</strong> many low fertility pasture species such as sweet vernal <strong>and</strong>chewing fescue are sensitive to intensive treading <strong>and</strong> disappear underprolonged pugging. Treading damage <strong>and</strong> the exposing of bare groundwill also allow invasion by opportunist species such as white clover <strong>and</strong>Poa annua, more vigorous weeds, <strong>and</strong> less desirable pasture species.White clover, being stoloniferous, can rapidly colonise bare ground <strong>and</strong>become dominant in severely pugged pasture.70 VISUAL SOIL ASSESSMENT: Volume 1