Attributes of Neosols associated with agricultural uses in the Semi-arid Region of Rio Grande do Norte, Brazil

The integrated study of soil properties allows the establishment of appropriate management practices in the Brazilian Semi-arid region. This study aimed at evaluating the physical and chemical attributes in Neosols under different agricultural uses in different landscape positions. The evaluations were carried out in five areas in the city of Martins, RN: Consortium of corn/bean/cassava (CON), monoculture of corn (MM) and banana (BN) all in Lithic Neosol; monoculture of sugarcane (SC) and elephant grass (EG) in Fluvic Neosol and native forest area (NF). For chemical and physical analysis, samples were collected from layers of 0.00-0.10, 0.10-0.20 and 0.20-0.30 m. Data were analyzed using multivariate analysis. The main results of the principal components analysis, CP1, CP2, CP3 and CP4, explained 87.16% of data variance: CP1 represented by pH and exchangeable cations (Ca2+, Mg2+), base saturation (SB), and the contrast represented by the potential acidity (H+Al) and aluminum (Al3+). In CP2 electrical conductivity (EC), sodium (Na+), aluminum (Al3+) and acidity by aluminum (m) were responsible for the differentiation of uses, highlighting the importance of maintaining crop residues as responsible for the reduction of exchangeable Al3+ content and the increase in pH and release of exchangeable bases. It is concluded that agricultural systems that favored the maintenance of the total organic carbon were the grass-Elephant grass (EG), followed by the consortium of corn, beans and cassava (CON). The attributes (pH, Ca2+ and Mg2+), sum of bases (t, V, EG, Na+ and PST) were indicators of separation of environments, and the most sensitive (Al3+and H+Al). The chemical attributes in agricultural uses of banana monoculture (BN), consortium of corn, beans and cassava (CON), monocultures of Elephant grass (EG) and native forest (NF) had stood, reflecting higher weights in module, following the order of importance of the components: CP1>CP2>CP3>CP4.