Use of Alternative Fertilizers and Phosphorus Content and Accumulation in Maize Plants.

The phosphate fertilizers used in agriculture are water soluble and require elementary sulfur and concentrated of apatite during its production, leading to large losses of P during industrial process. The P fertilizers are applied in large amounts in Brazil due the low availability of this nutrient  associated with its strong capacity to react with many soil components and  to become unavailable. The aim of this work is to study new management techniques in the use of alternative sources of P and the impact in phosphorus content and accumulation. The experiment was conducted in São Paulo, Brazil, and was carried out in pots of 20 L in a greenhouse. The treatments consisted of applying four sources of phosphorus: Triple superphosphate (TSP) (reference), Bayovar (reactive phosphate), phosphate precipitate 1 and 2 phosphate precipitate, and a treatment without P and five kind of soils, Alfisol ferrudalfs, two Typic Quartzipsamment,  Rhodic hapludox clayey and medium texture. The P level was 120 mg dm^-3. The variables of concentration and accumulation of P were evaluated 55 days after plant emergence. The P sources showed positive interaction with soil types. The precipitate source 1 and 2 showed higher levels of P in plants in all soils. When comparing the values of P uptake is observed that the reference source obtained the highest accumulated P. However, the alternative sources showed large amount of P uptake, mainly precipitated source 2, becoming very useful like fertilizer.