SOIL-ROOT INTERACTIONS AND PHOSPHORUS NUTRITION OF PLANTS

Authors: Kovar, John; CLAASSEN, N - GEORG-AUGUST UNIVERSITAT

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 8/10/2004
Publication Date: 7/1/2005
Citation: Kovar, J.L., Claassen, N. 2005. Soil-root interactions and phosphorus nutrition of plants. Book Chapter. In: Sims, J.T. and Sharpley, A.N., editors. Phosphorus: Agriculture and the Environment. Madison, WI: ASA-CSSA-SSSA. p 379-414.

Interpretive Summary: One of the major functions of plant roots is that of supplying the plant with phosphorus (P) and most other essential nutrients. In this capacity, roots provide an interface for P moving from one living system - the soil - and into another living system - the plant. In this chapter, we discuss the reactions of P at the interface of plant roots with the soil, including the means by which soil P moves to the surface of active roots, the characterisctics of the soil that affect plant uptake of P, and the mechanisms used by plants to enhance P availability. Much has been learned about P dynamics within the soil-root interface during the past two decades, so a significant amount of relatively new information is presented. We hope that the information presented in this chapter will stimulate new research and ultimately lead to more effective use of both inorganic and organic P fertilizers, so that environmental quality is maintained and protected.

Technical Abstract: One of the major functions of plant roots is that of supplying the plant with phosphorus (P) and most other essential nutrients. In this capacity, roots provide an interface for P moving from one living system - the soil - and into another living system - the plant. Phosphorus moving through the soil-root interface during the process of absorption is subject to the chemical and biological reactions occurring in this zone. These reactions, therefore, play an important role in determining P flux into the root. In this chapter, we discuss the processes and mechanisms involved in both the soil supply of P to plant roots and absorption of P by the growing root system. These processes are interrelated and complex. Given that a plant root is not simply a sink for P, and can alter the physical, chemical, and biological properties of the soil adjacent to it, the extent of these changes and their influence on P flux into the root are considered. Because food and fiber production are vital, the majority of the research has been conducted with agronomic species. Some of the basic concepts presented in this chapter were discussed in the previous edition of this monograph. Much has been learned about P dynamics within the soil-root interface during the past two decades, so a significant amount of new information is presented. We hope that the information presented in this chapter will stimulate new research and ultimately lead to more effective use of both inorganic and organic P fertilizers, so that environmental quality is maintained and protected.