Nitrogen fertilisers in establishing Pinus radiata plantations on sandy soils: an evaluation of their use

Summary

Results from experiments with Pinus radiata (D. Don) at several locations raise serious doubts about the benefits of current nitrogen fertilisation practices on sandy soils in South Australia and western Victoria. Intensive silvicultural practices appear to exert a major influence on the rate of nitrogen supply to young trees and until the mechanisms involved are clearly understood, the benefits of nitrogen fertiliser will remain uncertain. The control of weeds and the organic matter left after site preparation seem to be the two most important factors determining nitrogen availability, and hence the responses of trees to applied nitrogen. Methods of applying fertilisers should take account of potential leaching losses and the root distribution of the young pines.