Effect of citrate and tartrate on phosphate adsorption by amorphous ferric hydroxide
- 82 Downloads
Curves for P adsorption by ferric hydroxide in the presence of citrate and tartrate were prepared. From the curves, it appeared as though tartrate at 10−4M has no effect on P adsorption up to 750µmol P g−1 ferric hydroxide adsorbed. However, observation of flocculation patterns show that even when the curves are identical, there is a difference in the way P is adsorbed in the presence of tartrate and citrate in terms of the type of site that is attacked.
Assessment of phosphate - citrate competition using32P and14C showed that citrate is less readily adsorbed by ferric hydroxide than tartrate and that citrate dissolves adsorption sites more readily than tartrate.
The implications of this study are that root exudates containing a greater amount of tartrate would cause more efficient use of added P by plants since tartrate occupies the high affinity sites and therefore reduces phosphate fixation. Plants which produce root exudates high in citrate content would be able to utilize more fixed P than plants which produce exudates lower in citrate content because citrate dissolves sites at which P is held.
Key wordsadsorption citrate organic phosphate tartrate
Unable to display preview. Download preview PDF.
- Appelt H, Coleman N T and Pratt P F (1975a) Interactions between organic compounds, minerals and ions in volcanic-ash-derived soils.In: Adsorption of benzoate, salicylate and phthalate ions. Soil Sci. Soc. Am. Proc. 39: 623–627Google Scholar
- Appelt H, Coleman N T and Pratt P F (1975b) Interactions between organic compounds, minerals and ions in volcanic-ash-derived soils. II. Effect of organic compounds on the adsorption of phosphate. Soil Sci. Soc. Am. Proc. 39: 628–630Google Scholar
- Deb D L and Datta N P (1967a) Effect of associated anions on phosphorus retention in soil. I. Under variable phosphorus concentrations. Plant and Soil 26: 303–316Google Scholar
- Deb D L and Datta N P (1967b) Effect of associated anions on phosphorus retention in soil. II. Under variable anion concentration. Plant and Soil 26: 432–444Google Scholar
- Earl K D, Syers J K and McLaughlin J R (1979) Origin of the effects of citrate, tartrate and acetate on phosphate sorption by soils and synthetic gels. Soil Sci. Soc. Am. J. 43: 674–678Google Scholar
- Murphy J and Riley J P (1962) A modified single solution method for the determination of phosphate in natural waters. Anal. Chim. Acta 27: 31–36Google Scholar
- Nagarajah S, Posner A M and Quirk J P (1970) Competitive adsorption of phosphate with polygalacacturonate and other organic anions on kaolinite and oxide surfaces. Nature 228: 84Google Scholar
- Posner A M and Bowden J W (1980) Adsorption isotherms. Should they be split. J. Soil Sci. 31: 11–24Google Scholar
- Ryden J C, McLaughlin J R and Syers J K (1977) Mechanisms of phosphate sorption by soils and hydrous ferric oxide gel. J. Soil Sci. 28: 72–92Google Scholar
- Sposito G, Kafkaki U, Bar-Yosef B and Rosenberg R (1988) Phosphorus adsorption by kaolinite and montmorillonite: Organic anion competition. Soil Sci. Soc. Am. J. 52: 1585–1589Google Scholar
- Struthers P H and Sieling P H (1950) Effect of organic anions on phosphate precipitation by Fe and Al as influenced by pH. Soil Sci 69: 205–213Google Scholar
- Swenson R M, Cole C V and Sieling D H (1949) Fixation of phosphate by iron and aluminium and replacement of organic and inorganic anions. Soil Sci 67: 3–22Google Scholar
- White R E (1979) Retention and release of phosphate by soil and soil constituents. In: Tinker P B (Ed.) Critical reports on applied chemistry. II. Soils and agriculture: 78. Blackwell, OxfordGoogle Scholar