Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Agriculture, Ecosystems & Environment 144 (2011): 281–289, doi:10.1016/j.agee.2011.08.016.
Description:
Clearing for large-scale soy production and the displacement of cattle-breeding by
soybeans are major features of land-use change in the lowland Amazon that can
alter hydrologic properties of soils and the runoff generation over large areas. We
measured infiltrability and saturated hydraulic conductivity (Ksat) under natural
forest, pasture, and soybeans on Oxisols in a region of rapid soybean expansion in
Mato Grosso, Brazil. The forest-pasture conversion reduced infiltrability from 1258 to
100 mm/h and Ksat at all depths. The pasture-soy conversion increased infiltrability
from 100 to 469 mm/h (attributed to shallow disking), did not affect Ksat at 12.5 cm,
but decreased Ksat at 30 cm from 122 to 80 mm/h, suggesting that soybean
cultivation enhances subsoil compaction. Permeability decreased markedly with
depth under forest, did not change under pasture, and averaged out at one fourth the
forest value under soybeans with a similar pattern of anisotropy. Comparisons of
permeability with rainfall intensities indicated that land-use change did not alter the
predominantly vertical water movement within the soil. We conclude that this
landscape is well buffered against land-use changes regarding near-surface
hydrology, even though short-lived ponding and perched water tables may occur
locally during high-intensity rainfall on pastures and under soybeans.
Description:
This research was supported by the US National Science Foundation (NSF) grant
DEB-0640661 and the Fundação de Amparo à Pesquisa do Estado de São Paulo
(FAPESP).
Keywords:
Land-cover change
;
Tropical forest
;
Pasture
;
Infiltrability
;
Saturated hydraulic conductivity, Ksat
;
Hydrological flowpaths
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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