Citation
Chan K.S., . and Goh K.J., . (1997) Characterisation of phosphate rock reactivity and implications on management practices in Malaysia. [Proceedings Paper]
Abstract
The reactivity of four phosphate rocks PR finely ground to 100 mesh were estimated by their solubilities in 2 citric acid 2 formic acid and by incubation in two Malaysian soils. In the incubation experiment the PR at equivalent rates of 125 250 500 and 1000 mg P kg E-1 soil were incubated in soil thoroughly wetted at ambient temperature for over eight weeks. The dissolution of PR was determined by measuring the difference in extractable calcium between treated and untreated soils using BaCl2 triethanolamine this being commonly called the delta calcium Ca technique. Results of the incubation experiment showed that dissolution of PR decreased exponentially with increasing application rates. Using logarithmic transformation of the PR rates a linear relationship was obtained. PR dissolution was generally better in the more acidic Rengam series soil. However when high rate of a reactive rock was used the soil C.E.C became the dominant factor controlling the dissolution rate. The PR dissolution rate was also found to be better correlated to formic acid solubility than to citric solubility. Formic acid-P was found to provide a good index of the reactivity of PR. These experiments also indicated that the choice of PR for plantation crops depended on the soil properties and application rate. At high rate the PR should be applied evenly and broadly to improve its dissolution rate.
Download File
Full text available from:
|
Abstract
The reactivity of four phosphate rocks PR finely ground to 100 mesh were estimated by their solubilities in 2 citric acid 2 formic acid and by incubation in two Malaysian soils. In the incubation experiment the PR at equivalent rates of 125 250 500 and 1000 mg P kg E-1 soil were incubated in soil thoroughly wetted at ambient temperature for over eight weeks. The dissolution of PR was determined by measuring the difference in extractable calcium between treated and untreated soils using BaCl2 triethanolamine this being commonly called the delta calcium Ca technique. Results of the incubation experiment showed that dissolution of PR decreased exponentially with increasing application rates. Using logarithmic transformation of the PR rates a linear relationship was obtained. PR dissolution was generally better in the more acidic Rengam series soil. However when high rate of a reactive rock was used the soil C.E.C became the dominant factor controlling the dissolution rate. The PR dissolution rate was also found to be better correlated to formic acid solubility than to citric solubility. Formic acid-P was found to provide a good index of the reactivity of PR. These experiments also indicated that the choice of PR for plantation crops depended on the soil properties and application rate. At high rate the PR should be applied evenly and broadly to improve its dissolution rate.
Additional Metadata
| Item Type: | Proceedings Paper |
|---|---|
| AGROVOC Term: | ROCK PHOSPHATE |
| AGROVOC Term: | PHOSPHATES |
| AGROVOC Term: | PHOSPHORUS |
| AGROVOC Term: | DISSOLVING |
| AGROVOC Term: | SOLVENTS |
| AGROVOC Term: | INORGANIC ACID SALTS |
| AGROVOC Term: | SOIL |
| AGROVOC Term: | SOIL CHEMICOPHYSICAL PROPERTIES |
| AGROVOC Term: | SOIL BIOLOGY |
| AGROVOC Term: | MALAYSIA |
| Geographical Term: | MALAYSIA |
| Depositing User: | Ms. Norfaezah Khomsan |
| Last Modified: | 24 Apr 2025 05:27 |
| URI: | http://webagris.upm.edu.my/id/eprint/16214 |
Actions (login required)
 |
View Item |
