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| Titel |
Changes in soil carbon, nitrogen, and phosphorus due to land-use changes in Brazil |
| VerfasserIn |
J. D. Groppo, S. R. M. Lins, P. B. Camargo, E. D. Assad, H. S. Pinto, S. C. Martins, P. R. Salgado, B. Evangelista, E. Vasconcellos, E. E. Sano, E. Pavão, R. Luna, L. A. Martinelli |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 15 ; Nr. 12, no. 15 (2015-08-07), S.4765-4780 |
| Datensatznummer |
250118058
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| Publikation (Nr.) |
 copernicus.org/bg-12-4765-2015.pdf |
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| Zusammenfassung |
| In this paper, soil carbon, nitrogen and phosphorus concentrations and stocks
were investigated in agricultural and natural areas in 17 plot-level paired
sites and in a regional survey encompassing more than 100 pasture
soils In the paired sites, elemental soil concentrations and stocks were
determined in native vegetation (forests and savannas), pastures and
crop–livestock systems (CPSs). Nutrient stocks were calculated for the soil
depth intervals 0–10, 0–30, and 0–60 cm for the paired sites and
0–10, and 0–30 cm for the pasture regional survey by sum stocks
obtained in each sampling intervals (0–5, 5–10, 10–20, 20–30, 30–40, 40–60 cm). Overall, there were significant differences in soil element
concentrations and ratios between different land uses, especially in the
surface soil layers. Carbon and nitrogen contents were lower, while
phosphorus contents were higher in the pasture and CPS soils than in native
vegetation soils. Additionally, soil stoichiometry has changed with changes
in land use. The soil C : N ratio was lower in the native vegetation than in
the pasture and CPS soils, and the carbon and nitrogen to available
phosphorus ratio (PME) decreased from the native vegetation to the
pasture to the CPS soils. In the plot-level paired sites, the soil nitrogen
stocks were lower in all depth intervals in pasture and in the CPS soils when
compared with the native vegetation soils. On the other hand, the soil
phosphorus stocks were higher in all depth intervals in agricultural soils
when compared with the native vegetation soils. For the regional pasture
survey, soil nitrogen and phosphorus stocks were lower in all soil intervals
in pasture soils than in native vegetation soils. The nitrogen loss with
cultivation observed here is in line with other studies and it seems to be a
combination of decreasing organic matter inputs, in cases where crops
replaced native forests, with an increase in soil organic matter
decomposition that leads to a decrease in the long run. The main cause of
the increase in soil phosphorus stocks in the CPS and pastures of the
plot-level paired site seems to be linked to phosphorus fertilization
by mineral and organics fertilizers. The findings of this paper illustrate
that land-use changes that are currently common in Brazil alter soil
concentrations, stocks and elemental ratios of carbon, nitrogen and
phosphorus. These changes could have an impact on the subsequent vegetation,
decreasing soil carbon and increasing nitrogen limitation but alleviating soil
phosphorus deficiency. |
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