The investigation herein reported was undertaken as part of a cooperative project on the biology of forest trees at Duke University. It represents an attempt to add a contribution to knowledge of the mineral nutrition of certain forest trees, in the hope that ultimately it may be possible to correlate the findings with studies of soil composition and with the local distribution of these tree species. Loblolly pine (Pinus taeda L.) was selected as a species that is relatively cosmopolitan, and yellow poplar (Liriodendron tulipifera L. ) as a species that is relatively specific in environmental requirements. The present paper is a preliminary report on loblolly pine only. For the purposes of this investigation, sand cultures were regarded as the most desirable method. Of the extensive work with sand cultures by many investigators within the past few years, little has been concerned with woody plants, and very little with forest trees. Mitchell 's (4) experiments on Scotch pine and white pine in the Black Eock Forest represent the most fruitful work of the kind that has been done with forest trees.