Various combinations of NPKCa fertilizer were applied to a Pinus nigra var. laricio stand in Sologne, on poor acid sandy soils with little organic matter. One year after fertilizer application, needles of trees which had received 200 kg/ha N had significantly higher N contents than in other treatments, but 2 yr after treatment N contents were n.s.d. None of the other treatments showed significant differences from the unfertilized control. Plots which received combined N and P showed a significant increase in girth increment, but this effect only lasted 3 yr.