THE USE OF FERTILISER IN WATTLE CULTURE

Summary A COMPREHENSIVE series of replicated and other experiments laid out between 1927 and 1938 on the estates of the Natal Tanning Extract Company to test the efficacy of artificial fertilisers in wattle culture are described and the results thereof are analysed. It is concluded that it is possible to increase the yields of wattle plantations materially and profitably by the use of artificial fertilisers, provided that optimum sylvicultural practices are adopted and overcrowding and suppression during youth are avoided. The response to fertiliser varies with soil depth, rainfall and humidity, and soil constitution. On shallow soils response is negligible, but on soils of moderate to good depth it is satisfactory and in such cases is much greater in dry areas than in moist. On sandstone soils between 100 and 200 lb. of superphosphate per acre at the start of each rotation may be expected to increase yields by about 10% on the average, gaining say ¾ ton of green bark per acre, but greater applications of...