Tropical plantations are an important source of forest products both to meet the growing demand for wood, and to facilitate the transition from native forests to more sustainably produced forest resources. Management of these plantations for optimal productivity and resource-use efficiency is vitally important, and nutrient management is a critical component of sustainable plantation production. In this study, we explored the response of Acacia mangium plantations in South Sumatra, Indonesia, to fertiliser and their requirement for fertiliser, focusing on phosphorus (P) at establishment. Almost all plantations across a series of 11 sites were highly responsive to P fertiliser, with nine of the 11 sites having more than double the productivity in P-fertilised treatments at age 1 year compared with control treatments. However, the quantity of P required for 90% of maximum growth was generally low by age 2 or 3 years, and 10 kg P ha -1 at establishment was sufficient to ensure that at least 90% of maximum growth was captured across all the experimental sites. At a 12 th site, we explored the interactions between genotype and weed control, and found that both effects were additive in the response of the plantations to P, and thus there was no substitutability between management types: weed control, genotype and P needed to be managed in combination to achieve maximum productivity.
ARTICLE HISTORY