Technical Abstract: To protect habitat in the Everglades, legislation mandates a reduction of at least 25% in the P content of water discharged from the Everglades Agricultural Area (EAA). The objective of this study was to compare two soil-tests for basing P fertilizer recommendations for sugarcane grown on organic soils in the EAA. Three yield characteristics were measured at four field locations with no added P, an often recommended commercial rate of 24 kg P per ha, and 48 kg P per ha for the plant-cane, first-ratoon, and, at three locations, the second-ratoon crop. One group of eight genotypes was planted at two locations, and two other groups of eight genotypes were each planted at one of two other locations. An acetic acid-extractable P soil test predicted yields better than the historically used water-extractable P test. However, unexpected responses in sugar and cane yield characteristics were noted for both P extraction procedures. Further knowledge of the effects of soil pH, factors affecting P mineralization, and sugarcane genotype response to P may explain some of the unexpected results. Accurate P fertilizer recommendations for sugarcane in the EAA are critical to optimize farm profits and the ecologic health of the Everglades.