Phosphorus fractions in different management systems in the Cerrado Goiano

Frações de fósforo em diferentes sistemas de manejo no Cerrado Goiano

Phosphorus (P) is an essential macronutrient for plant development. Cerrado soils have a high P adsorption capacity, and conventional management can increase fixation, losses and reduce its availability in the soil. This study assesses the influence of different management practices on soil P fractions in cultivated areas in the Cerrado of Goiás. Deformed samples were collected at depths of 0-5 and 5-10 cm in two areas (Boa Vereda - BV and Mata do Lobo - ML). The total organic carbon content, pH, and phosphorus fractions (soluble, available, inorganic, organic, calcium-bound, occluded, and total) were quantified. The design was entirely randomized. Principal component analysis (PCA) was carried out. In BV, available and inorganic P levels were higher at 0-5 cm in the Cerrado area, while at 5-10 cm, available P was more prominent in soybean and Cerrado. The crop-livestock-forestry integration system showed high levels of occluded P. In ML, occluded P was predominant, except in the agroforestry system at 0-5 cm, where available, inorganic, calcium-bound, and total P levels were higher, while occluded and organic P levels were more prominent in soybean and pasture. At 5-10 cm, available P was lower in the cerrado, while occluded and total P levels were higher in soybean. The PCA confirmed the difference between the areas and management systems. Less intensive management systems promote higher levels of P fractions that are more available to plants.

Keywords:
Cerrado crops; conservation systems; phosphorus lability; soil quality