Sampling under tree sprinklers

Take three cores from 0-15cm from under a tree starting from beside the sprinkler and evenly spaced to 1/3 in from the drip line of the canopy. Ensure that there is good sprinkler coverage over the whole sampling area under each tree. Sample from 8-10 sites within the block, keeping to the main soil type for the block and avoiding excessively wet or dry areas.