Neste trabalho são apresentados os resultados obtidos era três experimentos para verificar possíveis deficiências de micronutrientes e de magnésio em solos tipos terra-roxa-misturada e massapê-salmourão, cultivados há mais de quinze anos com cana. Foram feitas aplicações de sulfato ferroso, tetraborato de sódio, sulfato de magnésio, sulfato de manganês, sulfato de cobre, sulfato de zinco e molibdato de amônio, nos sulcos de plantio, na presença de NPK. Nos solos massapê-salmourão, os micronutrientes boro, molibdênio, ferro e cobre determinaram aumentos na produção de cana.
In this paper are presented the results obtained with three experiments on the application of minor elements and magnesium to sugar cane, on soils known as "terra-roxa-misturada" and "massapê-salmourão" which for many years had been cultivated with this graminea. The treatments with four replications, in randomized blocks, were as follows: 1) NPK (control), 2) NPK + Fe, 3) NPK + B, 4) NPK + Cu, 5) NPK + Mn, 6) NPK + Zn, 7) NPK + Mo, 8) NPK + Mg and 9) NPK + (Fe + B + Cu + Zn + Mg + Mn + Mo). The nitrogen, phosphorus and potassium were applied as ammonium sulfate, superfosfate and potassium chloride at the rates of 150 kg/N, 100 kg/P2O5 and 150 kgK2O per hectare. The elements were applied in the furrows in addition to the basic fertilization: iron, magnesium, manganese, copper and zinc, as sulfates; boron, as borax and molybdenum as ammonium molybdate. The results indicated that boron, iron, copper and molybdenum gave a yield increase in the soil massapê salmourão, whereas ou "terra-roxa-mistura da", effects were not significant.