Influence of trace-element deficiencies on plantation forestry in New Zealand

Abstract

Bush sickness in animals (only much later recognised as cobalt deficiency) led to large areas of the volcanic plateau in the North Island being planted in pine forests. Some forests in this district have since suffered from dieback and malformation; in a few, but in by no means the majority of cases, Boron deficiency has been responsible. Boron deficiency is much more widespread in forests in the South Island, particularly in low-rainfall areas. In relatively restricted areas in the northern part of the North Island, copper and zinc deficiencies have affected tree growth in plantations and one nursery. In one sand-dune forest, molybdenum deficiency severely restricted lupin growth. Once corrected, the lupins were able to play their essential role of N fixation. High soil pH's found associated with limestone cause manganese and iron deficiencies. Under nursery conditions, acidification with high applications of sulphur have proved very effective, but in plantations this would be uneconomic.