Phosphate Fertilisation of Mature Pinus radiata Stands

SYNOPSIS The response of mature Pinus radiata (16–20 years old) to phosphate fertilisation was highly significant, resulting in a potential increase in volume at 35 years of age of between 44 and 130 m3 per hectare, depending on site Conditions. These responses have been recorded on different soil forms and types. Gains from phosphorus application were economically viable and it appears that between 35–60 kg per hectare P applied to P-deficient mature P. radiata is the optimum economic application rate. Further growth responses are expected on the better Sites With a subsequent nitrogen top dressing.