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Concentration of phosphorus and sulphur at soil ped surfaces
Author(s) -
QURESHI R. H.,
JENKINS D. A.
Publication year - 1987
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1987.tb02143.x
Subject(s) - microanalysis , pedogenesis , mineralogy , electron probe microanalysis , nutrient , phosphorus , geology , metasomatism , soil horizon , chemistry , environmental chemistry , soil science , soil water , geochemistry , electron microprobe , organic chemistry , mantle (geology)
SUMMARY Pedogenesis involves reorganization of a soil's components and thus relocation of nutrients within the microfabric. This has particular relevance to P which, being relatively immobile, is needed within the immediate root environment. The spatial distribution of P and S in four profiles (haplaquepts, eutrochrept, ochraqalf) with well developed prismatic structure has been investigated at the 1 mm scale, by physical sampling of successive ped surface zones, and at the 1 μm scale by electron probe microanalysis. Results reveal distinct though variable patterns of concentration of P and S at ped surfaces (0.1–3 mm depth) in certain profile horizons; correlation with extractable Ca, Al & Fe proved obscure by macroanalysis, but microanalysis showed specific associations variously interpreted as detrital grains (apatite, monazite, etc.), organic debris or adsorbed phosphate. Such heterogeneity in distribution is mostly consistent with the microfabric seen in thin‐section, although some remains cryptic. This is important since plant roots selectively sample the differentiated ped surfaces and not the bulk homogenized soil analysed in the routine assessment of nutrient availability.