Maize Growth and Biomass Production with the Use of Alternative Phosphorus Fertilizers.

Brazilian soils have low fertility due to the high acidity, toxicity of some chemical elements and low availability of P. The production of phosphate fertilizers generates a lot of intermediate materials considered like waste, but riches in P yet, whose use is not possible by current industrial methods, representing therefore a P source not used and capable to generate a big environmental problem due to the large volumes involved. . The aim of this work is to study new uses and management  of alternative P sources. 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 soil types. The P level was 120 mg dm^-3. The variables of growth and biomass production were evaluated 55 days after plant emergence. The P sources showed positive interaction with soil types while the Alfisol ferrudalfs showed the highest values of height and diameter in all sources studied followed by sandy soils Typic Quartzipsamment the medium texture and Rhodic hapludox clay. Only for biomass production, Alfisol ferrudalfs soil showed lower biomass production. Among the sources, the precipitate 1 when compared to (TSP) was the source from which it obtained the highest values of growth and production of dry matter.