<b>Land cover changes affect soil chemical attributes in the Brazilian Amazon

Abstract

ABSTRACT. Forest plantations may minimize the effects of deforestation in the Amazon. However, there are differences among species in terms of their influences on soil recovery. The effects of monospecific plantations of Acacia mangium, Dipteryx odorata, Jacaranda copaia, Parkia decussata,and Swietenia macrophylla, and areas of pasture and native forest on the chemical soil attributes of the Brazilian Amazon were evaluated. One bulked soil sample was collected per plot (0.00-0.05, 0.05-0.10, and 0.10-0.30 m; three plots of 128 m 2 ) in each area. No significant differences in most of the soil attributes were observed among the forest plantations. However, soil K + and P were higher in the Swietenia macrophylla plantations, while higher values of Ca 2+ , sum of bases, and pH occurred in Jacaranda copaia plantations. In the native forest, the pH, and P content were lower, whereas the soil organic matter (SOM) content, soil organic carbon (SOC) content, cation exchange capacity (CEC), N content, H+Al content, and Al 3+ content were higher than in the plantations. The lowest values of SOM, SOC, CEC, K

Chemical and physical attributes of an Ultisol under sustainable agricultural production systems

“…Means followed by the same letter does not differentiate from each other by the Tukey test at 5%. Pasture showed higher pH, base saturation, and higher Ca and Mg contents in the 0.10-0.20 and 0.40-1.00 m layers, among all treatments, and lower potential acidity in the 0-0.20 and 0.40-1.00 m layers, corroborating with Machado et al (2017), who also found lower potential acidity content under pasture.…”

Silvicultural performance of five forest species in the central Brazilian Amazon

“…The better performance of Dipteryx odorata and Jacaranda copaia was correlated with the higher soil fertility (higher availability of calcium and magnesium, which influenced the highest values of pH and sum of bases at the depth of 0.00-0.30 m; Machado et al 2017). On the other hand, the worst performance of Acacia mangium and Swietenia macrophylla was influenced by higher values of exchangeable aluminum in the soil, which can be toxic and compromise the growth and survival of most plants.…”

“…According to the latter authors, Parkia decussata and Jacaranda copaia both have high retranslocation rates of phosphorous. In monospecific plantations, Swietenia macrophylla is able to enrich the soil availability of potassium and phosphorous, while the soil under Jacaranda copaia presents high values of calcium, sum of bases and pH, up to the depth of 0.30 m (Machado et al 2017). In rural properties in the Brazilian Amazon region, Acacia mangium has been planted for the production of wood for export (Barros et al 2009), whereas Jacaranda copaia has been used to provide thermal comfort for cattle due to shading, and also for the future obtaining of wood, and Dipteryx odorata has been planted for medicinal purposes (Santos and Mitja 2010).…”

“…Principal component analysis was performed with the purpose of identifying the biometric variables that correlated with the monospecific plantations. In this latter analysis, we also considered the mean values of soil chemical attributes that were provided by Machado et al (2017), and excluded the variables or soil attributes that had low correlation (< 0.70%) with the principal axis 1 or axis 2. Multivariate analyses were carried out using version 2.17c of the PAST program (Hammer et al 2001).…”

<b>Depth distribution of exchangeable aluminum in acid soils: A study from subtropical Brazil

“…The effects of lime, management system/land use practices, and organic residue addition on Al KCl levels have been widely evaluated (Brunetto et al, 2012;Barcellos, Motta, Pauletti, Silva, & Barbosa, 2015;Costa, Crusciol, Ferrari Neto, & Castro, 2016;Baquy, Li, Xu, Mehmood, & Xu, 2017;Barbosa et al, 2017b;Machado, Camara, Sampaio, Pereira, & Ferraz, 2017;Rocha et al, 2017). These data were obtained from the most superficial soil layers, excluding less weathered deep horizons with organic matter contents close to zero.…”