Chapter 14 Techniques for assessing nutrient bioavailability in soils: Current and future issues

• Published in: Developments in Soil Science Vol. 32; pp. 283 - 327
• Main Author: Hedley, M.J.
• Format: Book Chapter
• Language: English
• Published: Elsevier Science & Technology 2008
• ISBN: 0444521690; 9780444521699
• ISSN: 0166-2481
• DOI: 10.1016/S0166-2481(07)32014-X

This chapter discusses some selected techniques used to quantify nutrient acquisition by plant roots. In terms of developing techniques to assess nutrient availability, most attention in past years has been directed at developing soil tests through extensive studies correlating the amounts of nutrients released to weak chemical extractants with crop yield, or with the amounts of nutrients taken up by crop plants. A number of conclusions can be drawn from this research, which is pertinent to the dogma driving development of techniques for assessing nutrient bioavailability. The chapter briefly covers computer simulation of dynamic nutrient cycling processes. Conceptual models of nutrient availability in soil are explained. A description of actual or potential nutrient bioavailability is given. Also, applied tools for assessing and removing soil mineral constraints to crop production are discussed. An overview of applied tools for assessing soil management threats to water quality is presented and research tools for building a fundamental understanding of the quantity, form and dynamics of plant-available nutrients in soils are described. This chapter presents a section on isotope exchange studies and rhizosphere studies.