N-P-K FERTILISATION OF TEAK (TECTONA GRANDIS) PLANTATIONS: A CASE STUDY IN COSTA RICA

Despite the international importance of teak (Tectona grandis) plantations, very few studies have been published on fertilisation, generally with inconsistent conclusions. To evaluate the effect of N-P-K fertilisation on teak stands of different ages and related factors, four N-P-K fertilisation trials were analysed over an 11-year chronosequence (1, 3, 6 and 10 year-old plantations) in northern lowlands of Costa Rica. The site has a humid climate (with 3 dry months) and low fertility clayey acidic red soils (typic hapludults). ANOVA and Tukey-LSD mean differences tests (alpha = 0.05) were conducted to determine the best fertilisation treatment at each age. No evidence of growth improvement, related to fertilisation, was observed in the 3 and 10-year-old plantations, while a positive (but low) effect of fertilisation was recorded in the 1 and 6-year-old plantations. The present study highlighted the need for further research with greater scope, both spatial and temporal, to gain a clearer understanding of the fertilisation requirements of teak, an important pantropical species.