22 dryer sites, it is thus prone to damage during extended dry periods. Even in better forestry areas this tree is usually planted on the worst sites (Shallow, north facing, and rocky) and therefore may show signs of damage before compartments planted to other species. On clay/ loam to clay soils this tree can grow successfully on soils as shallow as 35 to 40 cm, however on sandier soils depths of 50 to 60cm are required. • Soil texture plays an important role in determining ERD, soils with higher clay contents have a better moisture holding capacity. BRUSH MANAGEMENT & SILVICULTURE Plantation residues can be used to buffer the effects of dry periods. A mulch acts as an insulator keeping soils cooler during hot spells and reducing evaporation from the soil. Because surface soils remain cooler and moister, roots grow up to the surface and into the mulch thus increasing the volume of soil and moisture available to roots. Brush retention also results in increases in soil organic matter which helps to retain moisture and nutrients in the soil. Ideally residues should be mulched to form a compact layer of organic matter that can protect soils. However, this is an expensive operation and spreading brush, or even stacking it in brush piles, will improve soil protection and moisture retention. SITE PREPARATION & PLANTING TECHNIQUE Correct site preparation and planting technique can help to minimise seedling mortality. On regeneration sites, small well prepared (no clods and minimum depth of 30cm) pits are sufficient (quality rather than quantity). Intensive site preparation will result in soils drying out. At planting a litre of water should be poured into the planting pit, mixed with mineral soil to form a porridge (remove any clods), and the seedling planted into the porridge. Dry soil (or mulch) should then be scraped back to cover the wet soil and break the capillary action between the soil moisture and surface air. Alternatively, seedling can be planted into hydrogels using the same principle. Hydrogels are particularly effective in sandy soils that rapidly dry out. In dry times seedlings should be planted deeper at a depth of four to eight centimetres (to the top of the root plug). Drought stress in a wattle compartment on shallow soil Thinning plantations reduces competition for moisture Weeds compete with young trees for moisture
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