Fertiliser Applications for Growing <I>Cryptomeria japonica</I> and <I>Pinus patula</I> Container Seedlings

Abstract

For container-growing both Cryptomeria japonica and Pinus patula seedlings it is recommended to mix 300 g of ammonium sulphate, plus 1,300 g super phosphate plus 400 g sulphate of potash to each m^{3 of soil-less potting mix. An additional 4 mg Nand 1 mg K per seedling should be applied every two weeks. Alternatively a slow-release, complete fertiliser could be used. This recommendation stems from N, P, K factorial experiments using 150 ml root trainers, which clearly showed applying only one of the three nutrients by itself elicited almost no response and applying any combination of two, an intermediate response. Applying N+P+K produced 86% and 155% responses in height over the control; for C. japonica and P. patula, respectively. Applying a substantially higher rate of N, P, K increased growth by only a further 10%. The N+P+K fertiliser treatments produced satisfactory planting stock in 6 months.}