RECENT EXPERIMENTS ON FERTILIZER WITH BLACK WATTLE

Abstract Results of a comprehensive experiment laid down in 1949 comparing superphosphate and raw phosphate, potash and lime, are described, together with a number of subsidiary fertilizer experiments. Lime and nitrogen are concluded to be of no benefit to wattle, while there are weak responses to potash on certain sandy soils only. Superphosphate is highly beneficial on all wattle soils, while raw phosphate is disappointing. The function of the superphosphate is to act as a “starter fertilizer”: its effect is the same whether applied in powdered, granular or tabletized form. Two hundred lb./acre is recommended as a standard dressing of superphosphate for soils derived from Table Mountain Sandstone, applied by placement in the soil within six months of regeneration, and 400 lb. for all other soils.