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Prediction of Water‐Extractable Phosphorus Content of Soil Following a Phosphorus Addition
Author(s) -
Sharpley A. N.
Publication year - 1982
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1982.00472425001100020004x
Subject(s) - soil water , surface runoff , phosphorus , chemistry , sorption , water content , environmental chemistry , zoology , soil test , soil science , environmental science , geology , ecology , biology , geotechnical engineering , organic chemistry , adsorption
The effect of time on the water‐extractable P content ( P X ) of surface soil (0–10 cm) following a P addition ( P A ) was investigated in the laboratory using 20 soils from 14 states. The soils were incubated with P equivalent to 0‐, 25‐, 50‐, and 100‐kg/ha additions and the water‐extractable P content and soluble P concentrations of runoff from the soils determined at frequent intervals. Water‐extractable P decreased in the first 2 weeks after P addition; following this P X remained fairly constant. Water‐extractable soil P content was linearly related to P A at any given time after the addition. The slope of this relationship decreased logarithmically with time after a P addition. In the first 2 weeks after P addition, the slope of the relationship between P X and P A could be predicted from percent clay content or P sorption capacity of the soil. Using these simple relationships, an improved prediction of the amount of soluble P available for transport in surface runoff from fallow soil can be made from limited extractable soil P data.