Potential phosphorus losses from organic and podzol soils: prediction and the influence of soil physico-chemical properties and management.

Autor:	Simmonds, BM, McDowell, RW, Condron, LM, Jowett, T
Předmět:	PHOSPHORUS in soils SOIL chemistry CHEMICAL potential ORGANIC compound content of soils CALCIUM chloride SOIL permeability
Zdroj:	New Zealand Journal of Agricultural Research; Jun2015, Vol. 58 Issue 2, p170-180, 11p
Abstrakt:	Organic and podzol soils may have properties that exacerbate phosphorus (P) loss to surface water following development for pastoral agriculture, including high porosity and hydraulic conductivity, and poor P retention. Soil samples (from depths of 0–7.5cm and 30–37.5cm) were taken (80 sites) within a catchment to quantify the impacts of land use development on the potential for P loss. Water-extractable P (WEP) and dilute CaCl2-extractable P (CaCl2-P), representing surrogates for surface and subsurface runoff potential, were two and 66 times greater for organic soils compared with podzols, respectively. Variables such as Olsen P and P retention could predict WEP (R2= 0.52–0.75), but not CaCl2-P. A mass balance estimated that mean P losses with time since development for organic soils (c. 38 kg P ha−1yr−1) were nearly double those of podzol soils. With such high losses, we recommend using these tests to help identify organic and podzol soils that pose a risk to surface water quality. [ABSTRACT FROM AUTHOR]
Databáze:	Complementary Index
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