Quantitative phosphate fertilizing for sugar cane

This paper presents the results obtained in 1952 in a fertilizing experiment on sugar cane, at the Usina Tamôio, Araraquara. Five levels of phosphorus (in the presence of nitrogen and potash) using a randomized blocks design with six replicates were studied. The formula used contained always 45 kg/ha of K(2)0 and 30 kg/ha of N, the amount of phosphorus being variable as follows: 0, 60, 120, 180 and 240 kg/ha. Phosphorus, nitrogen and potash were applied under the form of simple superphosphate, Chilean nitrate and potash muriate, respectively. An exponential Mitscherlich curve of the form y = 66,23 [1 - 10 - 1,032(x + 0,3978)] was the best fit for the results. It is concluded that for the conditions of the experiment 120 kg/ha of P2O5- is the best dose to be recommended.