
TY  - JOUR
A1  - Kanabo, IAK 
A1  - Gilkes, RJ 
T1  - A comparison between plant response and chemical measurements of the dissolution of reactive phosphate rock in soils of different pH and phosphorus retention
JF  - Soil Research
JO  - Soil Res.
Y1  - 1987
VL  - 25
IS  - 4
SP  - 451
EP  - 460
KW  - 
UR  - https://doi.org/10.1071/SR9870451 
N2  - Chemical measurements of the dissolution of reactive North Carolina phosphate rock (PR) in a lateritic podzolic soil adjusted to different pH values or amended to different P retention capacities were compared with plant response data. Soil pH adjustment consisted of incubating soil mixed with dilute HCl or solid SrCO3. The P retention capacity was adjusted by adding different amounts of synthetic goethite. Clover was grown as a test crop under glasshouse conditions on soils treated with no P and 800 µg Pg-1 soil as PR. The dissolution of PR, measured as the increase in soil exchangeable Ca (ÄCa) at harvest time, increased by 46% for a decrease in soil pH from 5.78 to 4.55. Both dry weight and P content of clover tops showed no response to the greater PR dissolution at low soil pH, although twice as much P was bicarbonate-soluble at pH 4 55 compared with pH 5.78. This increase in bicarbonate-soluble P was only partly due to the greater dissolution of PR. Increasing the goethite content of the soil by 9% resulted in a 107% increase in PR dissolution but induced a 54% decrease in the bicarbonate-soluble P level compared with the control soil and consequently reduced both dry weight yield and P content of clover tops by 19% and 34% respectively. 
ER  -

