Neste trabalho são apresentados os resultados preliminares obtidos em terra massapê-salmourão da Usina Itaiquara, município de Tapiratiba, em três ensaios com diferentes fertilizantes fosfatados. No ensaio instalado em 1950, em presença de nitrogênio e potássio foram estudados oito tipos de adubos fosfatados, na dose de 120 kg/ha de P2O5 verificando-se que, estatísticamente, deram os mesmos resultados: superfosfáto'simples, serranafosfato, farinha de ossos degelatinados, farinha de ossos autoclavados, hiper-fosfato, fosfato argeliano e fosfato do Morro do Serrote. A bauxita fosforosa mostrou-se inferior ao superfosfáto e às duas farinhas de ossos. Em outros dois experimentos, instalados em 1952, foram estudados cinco tipos de fertilizantes fosfatados, nos níveis de 0, 40, 80 e 120 kg/ha de P2O5. e os resultados mostraram que não houve diferença entre o superfosfato simples, farinha de ossos degelatinados, fosfato bicálcico (fertifós) e hiperfosfato; o fosfato do Morro do Serrote foi inferior a êsses fertilizantes.

The application of various types of phosphate fertilizers to sugar cane was compared in 3 experiments carried out in soil of the "massape-salmourao" type at the Usina Itaiquara, Tapiratiba. In a first trial, nitrogen and potassium were applied uniformly to all plots receiving fertilizers, and 8 different types of phosphates were compared at the rate of 120 kg of P2O5 per hectare. In two other tests a uniform rate of NK was applied, and four levels, 0, 40, 80 and 120 kg per hectare, of 5 phosphate fertilizers were compared. The results obtained in the three tests permitted the following conclusions: a) In a "massape-salmourao" soil with high acidity, a good increase in cane tonnage was obtained by the application of NK alone, when this treatment was compared with control plots receiving no fertilizer. The yield increase was considerably greater when phosphate in any of the forms was applied. There was no statistical difference in the cane yields obtained with the use of superphosphate, degelatinated and steamed bone meal, "serranafosfato", "hiperfosfato", Argelian phosphate, and a local rock phosphate (Morro do Serrote). Superphosphate and the two types of bone meal were statistically better than a type of phosphorated bauxite, but there was no difference between this and the remaining treatments. b) In "massapê-salmourão" soils of low acidity there was no statistical difference between the applications of phosphorus as superphosphate, degelatinated bone meal, "fertifós", and "hiperfosfato"; all these treatments were better than rock phosphate (Morro do Serrote).

This paper relates the results of an experiment designed to study the comparative effects of several phosphates applied to corn crops. The following phosphates were applied to a latin square of 6x6: Latif (a rock phosphate), fospal, superphosphate, fertifos, hiperfosfato and serranafosfato (a fusion phosphate). The nutrients were employd at the rates of 200 kg of N (as Chilean nitrate), 200kg of K2O (as muriate of potash) and 200 kg of P205. To correct the acidity and to improve the poor physical conditions of the sandy soil studied limestone (450 kg/Ha) and cotton seed meal (900 kg/Ha) were added to all plots; liming was made one month in advance to the planting. In the second year, in the same place, the split-plot technique was used: half plot received only N and K20 whereas the other half received the same treatment as the year before. The results can be summarized as follows: 1. in the first year, superphosphate of lime, produced better results than the other phosphates; there was no significant difference among fertifos, serranafosfato, and hiperfosfato but these phosphates proved to be superior to fospal and Latif; 2. in the second year, superphosphate, fertifos and serranafosfato produced practically the same effect, being better than hiperfosfato, fospal, and Latif which did not differ signicantly; 3. the increase in yield due to the reapplication of phosphates to the half plots was not advantageous under an economic point of view; however, it is interesting to note that the yield was still benefited in spite of the heavy doses of phosphates applied the year before.