%0 Research Notes %T Effect of apatite and phlogopite application on the needle nutrient concentrations of Pinus sylvestris (L.) on drained pine mires %A Kaunisto, Seppo %A Moilanen, Mikko %A Issakainen, Jorma %D 1999 %J Suo - Mires and peat %V 50 %N 1 %U http://suo.fi/article/9780 %X Pine nutrition was monitored after the application of phosphorus and potassium fertilisers of different solubility in 12 experiments on drained mires in northern Central Finland. Ten experiments involved the following three treatments: (i) control, (ii) fertilisation with rock phosphate and potassium chloride, and (iii) fertilisation with apatite ore or enriched apatite and phlogopite. Two experiments focused on the fertiliser amount. In seven experiments needle samples were collected three times: 3-7, 11-14 and 16-19 years after fertilisation and in the others once or twice (after 10-17 years). The stands suffered from phosphorus and potassium shortage on the unfertilised plots. Rock phosphate had raised the needle phosphorus concentrations slightly more than apatite by 5-7 and 11-14 years after fertilisation. By the last sampling apatite (16-19 years after) had raised the concentrations to about the same or to a higher level than rock phosphate. Potassium chloride raised the concentrations more than phlogopite during the first few years after fertilisation but the situation had reversed by 11-14 years. Five years later the change was even more pronounced. The needle potassium concentrations increased slightly with the increasing application amounts on the nitrogen-rich sites. Fertilisation with PK lowered the needle zinc, manganese, copper and boron concentrations especially on the nitrogen-rich sites.