4.2.3 Total Phosphorus
The total phosphorus dissolved in water in T1 (Figure 3E), presented values ​​higher than those recommended by CONAMA Resolution 20/86, which is 0.025 mg l-1), compared to T2 (Figure 3F). The values ​​of phosphorus for T2 of 0.10, 0.16 and 0.16 mg l-1, for February, October, and December, respectively, were below the values ​​of 0.21, 0.13 and 0, 21 mg l-1, except for October, the values ​​observed in T1 were higher than those recorded in T2, except for the peaks recorded in December 2010 and October 2009 and 2012, which reached more than 0.30 mg l-1, even below the peaks that occurred in T1 in 2001, 2002, 2003 and 2005, which reached 0.50 mg l-1, in December 2005 (Figure 3E).
The results show lower values ​​than the values ​​obtained by Donadio et al. (2005) who evaluated the water quality in a Watershed in Taquaritinga, SP, whose predominant soil is the Ultisol and the average values ​​of phosphorus in the water for the dry period of the year was 1.58 mg l-1and for the rainy season was 4.32 mg l-1.
The results of phosphorus, found by Pinheiro et al. (2014), who studied the use and occupation of soil and the relation to water quality in two sub-areas of Rio Duas Mamas Watershed in Santa Catarina, were 27.3 and 41.6 mg l-1 and, were higher than the results found in the present study. This was because in SW2 there were banana cultivation and cultivation areas for annual cycle crops, despite the large percentage of remaining natural forest, in both cases.