Dando prosseguimento ao estudo da eficiência de diversos fosfatos para a cultura da cana-de-açúcar, neste trabalho são relatadas mais cinco experiências, realizadas entre 1961 e 1963 (três em terra-roxa-misturada, uma em solo massapé-salmourão e uma em solo derivado do arenito Bauru), nas quais foram empregados, na presença de NK, 50. 100 e 150 kg/ha de P2O5 total. Tôdas apresentaram produções satisfatórias e respostas significativas ao fósforo. Em média das cinco experiências e das três doses usadas, foram os seguintes os aumentos porcentuais, na produção de cana-planta, proporcionados pelos fosfatos estudados: termofosfato, 49; fosfato bicálcico, 39; farinha de ossos degelatinados, 38; superfosfato simples, 35; fosfato Alvorada, 28; fosforita de Olinda, 26; fosfato de Araxá, 20; bauxita fosforosa, 10. Houve consideráveis diferenças no comportamento dos fosfatos nas experiências individuais, mas os autores preferem deixar para estudá-las em conjunto com outras conduzidas anterior e posteriormente, quando procurarão associá-las às características dos solos estudados.

Five experiments were conducted in the State of São Paulo to study the efficiency of different sources of phosphorus for the production of sugar cane on three types of soil, using 50, 100 and 150 kilograms of total P2O5 per hectare in the presence of NK. The soil pH varied from 4.8 to 5.6. Phosphorus significantly increased the yields in all of the experiments. As an average of the five experiments and the three rates of application, the per-cent yield increases caused by the studied phosphorus carriers were the following: thermophosphate, 49; dicalcium phosphate, 39; bone meal, 38; ordinary superphosphate, 35; Alvorada-phosphate, 28; Olinda-phosphate, 26; Araxá-phosphate, 20; phosphorous bauxite, 10. The four latter sources are natural phosphates from different regions of Brazil.

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).

No presente trabalho são apresentados resultados preliminares, obtidos em quatro ensaios de adubação da cana de açúcar de 18 meses, instalados na Usina Tamôio, Município de Araraquara, em 1951. O objetivo foi obter dados sobre as adubações mais adequadas, para os diversos tipos de solo daquela Usina. Estudaram-se quatro níveis de fósforo e de potássio, em presença e ausência de nitrogênio protêico, utilizando-se um delineamento fatorial 2x4x4 (NPK). Os níveis dos fertilizantes empregados, em kg/ha, foram 0 e 30 de nitrogênio e 0,30, 60 e 90 de p2o5 e de K2O. O nitrogênio foi empregado sob a forma de torta de algodão e o fósforo e o potássio, sob as formas de superfosfato simples e cloreto, respectivamente. A adubação foi realizada nos sulcos, por ocasião do plantio, e a variedade de cana empregada a Co. 290. Os resultados mostraram que o nitrogênio sob a forma proteica elevou significativamente a produção nos quatro ensaios. O fósforo em três ensaios apresentou aumento significativo de produção, proporcional aos níveis de P2O5 empregados, o mesmo se verificando com relação ao potássio, em dois dêsses ensaios.

Four fertilizer experiments were planted at the Usina Tamôio, Araraquara, São Paulo. Two of the trials were located in the "terra roxa misturada" type of soil (Sections Serra D'Água and Sede) ; one in sandy soil (Mantuana Section), and one in "terra roxa legítima" (Bela Vista Section). A 2x4x4 factorial design was used in the four tests, and the fertilizer levels per hectare were as follows : Nitrogen, 0 and 30 kg of N ; Phosphorus and Potassium, 0, 30, 60 and 90 kg of P2O5 and K2O, respectively. Nitrogen was used as cotton seed meal, and phosphorus and potassium were employed as superphosphate and potassium chloride. The fertilizers were added to the furrows before planting, and the variety used was Co. 290. Harvesting was done after 18 months. The statistical analysis of the data from the four trials gave the following indications : a) Nitrogen applied as cotton seed meal at, the rate of 30 kg of N per hectare prior to planting gave a significant increase in yield in the three types of soil; b) yield increases due to phosphorus application were recorded in three'of the tests; the rate of 60 kg/ha of P2O5 is indicated for the Bela Vista Section, whereas for the Serra D'Água and Mantuana Sections the rate of 90 kg/ha was better; c) Potassium should be employed at the rate of 60 kg/ha in the Mantuana Section, and at the rate of 90 kg/ha in the Sede Section.

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.