Impact of Calcareous Amendments on Rye Production and the Exchange Complex in a Palexerult in Northwestern Spain

Abstract

A Typic Palexerult from northern Spain was subjected to acidity correction field tests over a period of 2 years. The experimental crop was a local rye variety and the amendments included gypsum, dolomite, limestone, and sugar foam waste, all at a 6000 kg ha^–1 rate as calcium carbonate (CaCO₃). General analyses were integrated with specific tests for soluble and easily exchangeable aluminum (Al) forms (Al-CaCl₂) in addition to potassium chloride (KCl)–, barium chloride (BaCl₂)–, and copper chloride (CuCl₂)–extracted Al and adsorbed and amorphous Al. Two types of multiple linear regression models for production each year were established; some encompassed all studied variables and others the six Al forms only. As shown here, Al-KCl, Al-CaCl₂, base saturation, and exchangeable Ca were the individual variables most strongly correlated with production, with R ² = 0.865, within the topmost 12 cm. A principal component analysis exposed a substantial share of pH-dependent charge in organic matter on the cation exchange capacity of the soil.

Keywords:

• Acidity
• biomass
• CEC
• OLS equation
• ΔpH
• pH-dependent charge

Acknowledgments

The authors are grateful to the Education and University Council of the Castilla y León regional government for award of Project LE-04/01, the framework for the conduct of this research, and to the Neighbor Council of Rioseco de Tapia (León, Spain) for providing the land for the experimental plots.