Phosphorus fractions in different management systems in the Cerrado Goiano

Abstract

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.