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

PLANT INDICATORSThe size <strong>and</strong> development of the crop root system Determine size <strong>and</strong> development of the root system, ideally at plantmaturity, by carefully prizing the plant out of the soil <strong>and</strong> gentlyshaking it to remove adhering soil from the roots. Compare the rootsystem against the three photographs opposite.CONSOLIDATION AND COMPACTION of the seedbed restrict plantgrowth <strong>and</strong> vigour by restricting root development (rooting depth <strong>and</strong>root density), owing to increased mechanical resistance <strong>and</strong> impededsoil aeration. High mechanical resistance to roots limits plant uptake ofwater <strong>and</strong> nutrients, restricts the production of several plant hormonesin roots necessary for growth, <strong>and</strong> increases the susceptibility of thecrop to windthrow.38 VISUAL SOIL ASSESSMENT: Volume 1