In:
Biogeosciences, Copernicus GmbH, Vol. 15, No. 1 ( 2018-01-08), p. 105-114
Abstract:
Abstract. The exchange rate of inorganic phosphorus (P) between the
soil solution and solid phase, also known as soil solution P turnover, is
essential for describing the kinetics of bioavailable P. While soil solution
P turnover (Km) can be determined by tracing radioisotopes in a
soil–solution system, few studies have done so. We believe that this is due
to a lack of understanding on how to derive Km from isotopic exchange
kinetic (IEK) experiments, a common form of radioisotope dilution study.
Here, we provide a derivation of calculating Km using parameters
obtained from IEK experiments. We then calculated Km for 217 soils from
published IEK experiments in terrestrial ecosystems, and also that of 18
long-term P fertilizer field experiments. Analysis of the global compilation
data set revealed a negative relationship between concentrations of soil
solution P and Km. Furthermore, Km buffered isotopically
exchangeable P in soils with low concentrations of soil solution P. This
finding was supported by an analysis of long-term P fertilizer field
experiments, which revealed a negative relationship between Km and
phosphate-buffering capacity. Our study highlights the importance of
calculating Km for understanding the kinetics of P between the soil
solid and solution phases where it is bioavailable. We argue that our
derivation can also be used to calculate soil solution turnover of other
environmentally relevant and strongly sorbing elements that can be traced
with radioisotopes, such as zinc, cadmium, nickel, arsenic, and uranium.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-15-105-2018
DOI:
10.5194/bg-15-105-2018-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2158181-2
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