Critical foliage concentrations of nitrogen and phosphorus as a guide to the nutrient status of araucaria underplanted to pinus

Abstract

The growth ofAraucaria cunninghamii Ait. planted in lateritic podzolic soils on dry sclerophyll forest sites in southern Queensland is known to be limited primarily by lack of nitrogen; phosphorus is a secondary deficiency. However, Araucaria can be grown without fertilizers on these sites by underplanting to Pinus. A factorial fertilizer trial was used to establish critical levels of foliage nitrogen and phosphorus in Araucaria. The critical level of nitrogen depends