Evaluation of Two Industrial By-products as Soil Conditioners for Reducing Potential Aluminium Toxicity and Acidity in a Palexerult of Western Spain

Abstract

A field experiment evaluated the effects of surface applications of two industrial by-products (sugar foam and phosphogypsum) to an acidic Ultisol of the temperate zone in Spain to ameliorate topsoil and subsurface acidity and potential aluminium (Al) toxicity. The by-products were applied in single and combined amendments and at two different rates. Two years after their application, it was determined that applications at a low rate of sugar foam and sugar foam + phosphogypsum increased the pH and the exchangeable calcium (Ca) and reduced the exchangeable Al in the surface horizon of the soil while only a significant reduction of exchangeable Al was obtained in the subsurface horizon. Long-term amelioration of acidity and potential Al toxicity were only achieved upon the addition of these treatments at high rate. The addition of sugar foam at a high rate provides an effective practice for long-term acidity amelioration from the surface downward.

Keywords:

• Aluminium toxicity
• industrial by-products
• soil acidity
• Ultisols

Acknowledgments

This work was supported by the Spanish Ministry of Science and Innovation, within the framework of the research project AGL2005‐07017‐C03‐03. We are especially grateful to Laura Barrios for her assistance in the statistical analysis of the data. Fertiberia S.A. and Ebro S.A. are acknowledged for supplying the waste samples studied.