Fósforo e enxofre no desenvolvimento inicial da soja

Abstract

Phosphorus (P) and sulfur (S) are essential elements for plants and are found in low amounts in tropical soils. It is extremely important to apply these nutrients via fertilizer to ensure high yields. When applied to the soil, fertilizers can be absorbed by the crop, but they can also enhance the absorption and favor the leaching of other nutrients. Through leaching columns, the objective was to quantify macronutrient absorption, initial crop development, and macronutrient content in the leached solution after 15 and 30 days of soybean cultivation. The experiment was carried out in a greenhouse with samples of Yellow Red Latosol conditioned in PVC tubes. The experimental design was completely randomized, with 4 sources of fertilizers and 2 modes of application, in a 4x2 factorial scheme plus an additional treatment as control, totaling 36 plots. The treatments used were: 940 kg ha-1 of SSP superficial; 308 kg ha-1 of MAP superficial; 308 + 40 kg ha-1 of MAP + Sulfurgran superficial; 308 + 2000 kg ha-1 of MAP + Plaster superficial; 940 kg ha -1 of SSP incorporated; 308 kg ha-1 of MAP incorporated; 308 + 40 kg ha -1 MAP + Sulfurgran incorporated; 308 + 2000 kg ha-1 MAP + Plaster incorporated; and witness. Leached solutions were collected after 15 and 30 days of cultivation for macronutrient analysis and at 30 days, stomatal conductance, electron flow, chlorophyll content, number of trifoliums, plant height were quantified. Plants were collected for green and dry matter mass quantification, and aerial macronutrient analysis. Data were analyzed using the R (Core Development Core Team) statistical program. Analysis of variance (ANOVA) and F test were performed. The incorporated application mode of fertilizers favored Ca leaching, but also favored the higher initial development of soybean with higher leaf concentrations of macronutrients.