Zinc and Cu nutrition of corn (Zea mays L) was studied both under controlled and field environments on soils low in DTPA extractable Zn and/or Cu. The influencee of fertilizer P on the extent and severity of Zn and Cu deficiencies in corn was also investigated. Application of as little as 2 ppm Zn as ZnSO4.7H2O increased dry matter yield of eight-week old corn shoots when grown under controlled environment on an Almasippi loamy very fine sand containing 0.51 ppm DTPA extractable Zn... Corn did not respond to applied Cu either in the field on an Almasippi loamy fine sand containing 1.1 ppm DTPA extractable Cu or under controlled environment on an Almasippi loamy very fine sand containing 0.23 ppm Cu although Cu concentrations and/or uptake into corn shoots were increased significantly by Cu fertilization both in the field and greenhouse. Corn was found to be Zn deficient in the greenhouse regardless of P level when the Zn concentration in mature leaf blades just prior to silking was less than 7.0 ppm... Levels of Fe and Mn in plant tissue were adequate in all cases for optimum growth but N, K and S levels were often not quite adequate, particularly in the greenhouse... The influence of soil volume on Zn response under controlled environment was also studied... The uptake of all macronutrients into corn shoots increased with increasing soil volume because of increasing dry matter yield. However in the case of P and K plant concentrations also increased, suggesting that expanding soil volume increased plant uptake of P and K. The increase in yield with increasing soil volume may have resulted at least partially from correction of P and/or K deficiencies since plant concentrations of these nutrients were marginal.