520 Revista Agrogeoambiental, Pouso Alegre, v. 13, n. 3, p. 520-529, set. 2021. DOI: http://dx.doi.org/10.18406/2316-1817v13n320211639 1 Embrapa Soils, Researcher. ademir.fontana@embrapa.br 2 Rural Federal University of Rio de Janeiro. Professor. mgervasiopereira01@gmail.com 3 jaqueline_jjss@hotmail.com 4 Embrapa Soils. Researcher. guilherme.donagemma@embrapa.br 5 Rural Federal University of Rio de Janeiro. Graduate Student. otavioqueiroz7@hotmail.com Received in: July 22, 2021 | Accepted in: November 24, 2021 Abstract The specific adsorption of phosphorus in minerals from the clay fraction of the soil, such as Fe and Al oxyhydroxides, is responsible for the decrease in the availability of this element for plants. In Brazil, this condition is studied substantially in medium to very clayey textured soils, whose adsorption activity is expressive. The aim of this study was to evaluate the maximum phosphorus adsorption capacity (CMAP) in sandy-textured soils with fertility built in the Cerrado biome. Areas with representative soils were selected in the cities Luís Eduardo Magalhães (LEM / BA) and Guaraí (TO), with the following vegetation cover: a) LEM: natural vegetation and cotton; b) Guaraí: natural vegetation and soybean. Soil samples were collected in the 0-20 cm and 60-80 cm layers, in which chemical and physical analyzes were performed periodically, as well as analyzes related to phosphorus adsorption such as Prem and CMAP and PESN. Prem contents are higher in the 0-20 cm layer for the LEM region. The CMAP is not very expressive in the soils of the two studied regions, with the Guaraí soils having higher relative adsorption potential due to the higher values of the CMAP/clay ratio. Keywords: Phosphate retention. Prem. CMAP. Sandy soils. Introduction The expansion of Brazilian agriculture has been taking place preferentially in areas that present a favorable terrain for cultivation operations, low cost per unit of area and in regions with established agriculture. There are soils with the textural classes as sandy, loamy sandy and sandy loam, which are called “light textured soils” (DONAGEMMA et al., 2016) or simply ‘’sandy soils’’ (HUANG; HARTEMINK, 2020). With these characteristics, the most expressive soil classes are the Neossolos Quartzarênicos, Latossolos Vermelhos, Amarelos and Vermelho-Amarelos psamíticos e Argissolos Vermelho-Amarelos and Amarelos with a sandy/ medium texture (DONAGEMMA et al., 2016). The greatest occurrence of these soils is verifed in the west of Bahia, north and northeast of Tocantins, northwest of Minas Gerais, southwest of Goiás, northeast of Pará, northwest of Paraná, Center-south of Rio Grande do Sul, west of São Paulo and several regions of Mato Grosso and Mato Grosso do Sul. These soils can be listed as main limitations to cultivation the low levels of organic matter, the poor stability of aggregates, and especially the low capacity of water retention, retention and availability of nutrients. On the other hand, the low buffering capacity favors corrections by fertilizers and correctives, mainly phosphorus (P), since it is unavailable for crops in tropical soils. From this point of view, aiming to evaluate the availability of P as a function of specifc adsorption, fxation or precipitation, the studies focus on the evaluation of the remaining phosphorus (Prem), which is used in the evaluation of the buffer capacity of the soil in relation to P, S and Zn. This analysis assesses the availability and affnity of P after a soil sample is subjected to contact with a solution with known P content (ALVAREZ V. et al., 2000). From the Phosphorus adsorption capacity in sandy textured soils with built fertility Ademir Fontana 1 , Marcos Gervasio Pereira 2 , Jaqueline Jesus Santana dos Santos 3 , Guilherme Kangussu Donagemma 4 , Otavio Augusto Queiroz dos Santos 5