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

SOIL INDICATORSPresence of a tillage pan under <strong>cropping</strong> Examine the lower part of the topsoil <strong>and</strong> compare with the uppertopsoil. This can be done in situ or by removing a spade slice fromthe side of the hole exposed by removing the 20 cm cube extractedfor the structural assessment. Compare against the three photographs opposite.WELL-DEVELOPED TILLAGE PANS can impede the movement of water,air <strong>and</strong> oxygen through the profile, increasing the susceptibility to waterlogging <strong>and</strong> erosion by rilling <strong>and</strong> sheet wash. Well-developed tillagepans are difficult for roots to penetrate, <strong>and</strong> can cause roots to growsidewards, restricting vertical root growth <strong>and</strong> development. Thisreduces the ability of the root system to take up water <strong>and</strong> nutrients.26 VISUAL SOIL ASSESSMENT: Volume 1