This study evaluated the spatial variability of magnetic minerals and the potential of mass-specific magnetic susceptibility (χ_lf) to recognize minimum areas of phosphorus adsorbed (P_ads). In an area of 443 ha cultivated with sugar cane in the state of São Paulo, 84 soil samples were collected at a depth range of 0.0–0.20 m. Analysis of mass-specific magnetic susceptibility at low (χ_lf) and high (χ_hf) frequencies was performed in all soil samples. Characterization of ferrimagnetic minerals was carried out by X-ray diffraction (XRD) and the chemical distinction between lithogenic (magnetite-Mt) and pedogenic (maghemite-Mh) ferrimagnetic minerals was determined by χ_lf before and after chemical reduction by citrate-bicarbonate-dithionite (CBD), with subsequent determination of P_ads. The analytical results were evaluated by descriptive analysis and the spatial pattern was assessed by applying the geostatistical technique. χ_lf differentiated soils from their respective parent material even under conditions of high weathering and lithologic complexity. Positive linear correlations between P_ads and clay (R² = 0.77; p < 0.01), P_ads and χ_lf (R² = 0.86; p < 0.01), and P_ads and Mh (R² = 0.84; p < 0.01) indicated the use of χ_lf as a component of pedotransfer functions (PTF) for indirect quantification of P_ads in the soil. Quantification of Mh and Mt by χ_lf was more sensitive than by XRD. The spatial pattern of ferrimagnetic minerals indicated that Mh originated from the direct oxidation of Mt. Soil χ_lf was sensitive to the spatial variability of P_ads and might have assisted with the identification of minimum areas of phosphate fertilization in soils under lithologic complexes.

_{本研究评估了磁性矿物的空间变异性和质量比磁化率 (χ lf} ) 识别磷吸附最小面积 (P _ads )的潜力。在圣保罗州 443 公顷的甘蔗种植区，在 0.0–0.20 米的深度范围内采集了 84 个土壤样本。对所有土壤样品进行了低频 (χ _lf ) 和高频 (χ _hf )的质量比磁化率分析。通过 X 射线衍射 (XRD) 对亚铁磁性矿物进行表征，并通过 χ lf 确定成岩（磁铁矿-Mt）和成土（磁赤铁矿-Mh）亚铁磁性矿物之间的化学_区别用柠檬酸盐-碳酸氢盐-连二亚硫酸盐 (CBD) 进行化学还原之前和之后，随后测定 P _ads。通过描述性分析评估分析结果，并通过应用地质统计学技术评估空间格局。即使在高度风化和岩性复杂的条件下，χ _{lf也能将土壤与其各自的母质区分开来。}P _ads和粘土 (R ²  = 0.77; p  < 0.01)、P _ads和 χ _lf (R ²  = 0.86; p  < 0.01) 以及 P _ads和 Mh (R ²  = 0.84; p < 0.01) 表示使用 χ _lf作为土壤传递函数 (PTF) 的一个组成部分来间接量化土壤中的磷_{广告。通过 χ lf}对 Mh 和 Mt 进行量化比通过 XRD 更灵敏。亚铁磁性矿物的空间格局表明，Mh 起源于山的直接氧化。土壤 χ _{lf对 P ads}的空间变异性敏感，可能有助于识别岩性复合体下土壤中磷肥的最小面积。