Environmental factors and land use changes controlling the availability of phosphorus in dryland soils
2022
Oliveira Filho, José de Souza | Barrozo, Marcus Vinicius da Silva | Pereira, Marcos Gervasio
The wide climatic and lithological variability observed in drylands form soils with peculiar characteristics, whose phosphorus (P) dynamics is poorly understood. In this study, we used 93 samples from the surface layer of soils located in tropical drylands in northeastern Brazil, to estimate the effects of climate, land use, parent material, topography and altitude on soil P availability. Our results indicated that the climate affected the availability of P in the soil by its effect in the dynamics of pH values. The increase in pH values in the most arid environments explained 21.9% of the increase in P availability in the soils. We observed that the P available content in soils originated from river sediments was 286, 202 and 168% higher than those found in soils from sedimentary, igneous and metamorphic rocks, respectively. We observed that agricultural cultivation (>20 years) and pasture (>20 years) increased the available P content in the soil by 60 and 51%, respectively, when compared to the reference native forest. We observed that soils located in flat and gently wavy topography had the highest contents of P. The results of our study can be useful for the sustainable use of soils in tropical drylands.
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