Spatialization of chemical attributes, penetration resistance and magnetic susceptibility of the soil in a Cerrado area

Abstract

Knowledge on the spatial variability of chemical and physical attributes and magnetic susceptibility of the soil is important for precision agriculture, especially in Cerrado areas, which have limitations due to low natural fertility and acidity. The objective was to analyze the spatial variability of chemical attributes, penetration resistance, and magnetic susceptibility in a Cerrado area. The experiment was carried out in the municipality of Corrente-PI. A sampling grid was defined, with points spaced every 20 m, totaling 50 points, and soil was collected at a depth of 0.00-0.20 m. pH in water, phosphorus (P), organic matter (OM), potassium (K + ), calcium (Ca 2+ ), magnesium (Mg 2+ ), H + Al (potential acidity), and aluminum (Al 3+ ), sand, silt, clay (Texture), penetration resistance (PR) and magnetic susceptibility (MS) were analyzed and the sum of bases (SB), cation exchange capacity (CEC) and percentage of base saturation (V%) were calculated. The values of chemical attributes had positive and negative relationships with pH. Penetration resistance showed that the area is under adequate management conditions and the magnetic susceptibility was considered low, reflecting the parent material, sandy rock. The Cerrado area has more than 50% of its extension with medium to high acidity and low fertility levels. The Cerrado area, in all aspects, has adequate values of soil penetration resistance and low magnetic susceptibility, probably resulting from the sandy soil, proven by the textural analysis.