The Rhizosphere

This volume in the Ecological and Applied Microbiology series of monographs, incorporates recent work by a number of contributors concerning the rhizosphere and its importance to developments in biotechnology and molecular biology.

Below the soil surface, the rhizosphere is the dynamic interface among plant roots, soil microbes and fauna, and the soil itself, where biological as well as physico-chemical properties differ radically from those of bulk soil. The Rhizosphere is the first ecologically-focused book that explicitly establishes the links from extraordinarily small-scale processes in the rhizosphere to larger-scale belowground patterns and processes. This book includes chapters that emphasize the effects of rhizosphere biology on long-term soil development, agro-ecosystem management and responses of ecosystems to global change. Overall, the volume seeks to spur development of cross-scale links for understanding belowground function in varied natural and managed ecosystems. First cross-scale ecologically-focused integration of information at the frontier of root, microbial, and soil faunal biology Establishes the links from extraordinarily small-scale processes in the rhizosphere to larger-scale belowground patterns and processes Includes valuable information on ecosystem response to increased atmospheric carbon dioxide and enhanced global nitrogen deposition Chapters written by a variety of experts, including soil scientists, microbial and soil faunal ecologists, and plant biologists

The Plant Root and the Rhizosphere was a major topical feature of the first International Symposium on Factors Determining the Behavior of Plant Pathogens in Soil held at the University of California, Berkeley in 1963. The symposium was edited by K. F. Baker and W. C. Snyder and published under the title Ecology of Soil-Borne Plant Pathogens. Since that time, several other international efforts, either on the root-soil interface specifically or on topics relating to the root environment, have provided"a wealth of valuable information basic to promoting the culture of healthier, more productive plants. For the writing of this book, inspiration has come, in large part, from 10 years of cooperative rhizosphere research in association with leading scientists participating in a regional effort within the southern United States. We have attempted to bring together in this work the major aspects of rhizosphere research and the principles of rhizosphere ecology for the benefit of developing young scientists and technologists, as well as for the established professional researcher and teacher. A prime objective and hope is that this volume might generate ideas that will bring forth new approaches and methodology leading to further advances in our understanding of rhizosphere interactions and their implications for agriculture. ' Because of the enormous complexity of the chemical, physical, and microbiological environment of roots, the methods used by various workers are rarely standardized, but must be devised or modified for each experiment.

The rhizosphere is a very complex environment in which the effects of the plant on soil microorganisms and the effects of the microorganisms on the plant are interacting and are interdependent. Plant root exudates and breakdownproducts attract microbes and feed them and, in turn, the plants often bene?t from the microbes. Interactions among microorg- ismsandplantrootsareessentialfornutritionalrequirementsoftheplant. Plant growth, development and productivity are largely dependent on the soil environment in the root region rhizosphere. The new techniques of studying the rhizosphere enables us to get a much better understanding of the dynamics of the rhizosphere population, such rhizosphere studies beingofinteresttoagriculturists,soilbiologists,chemists,microbiologists andmolecularbiologists. The rhizosphere microbes in?uence the root environment in several ways. They may change the oxidation-reduction potential, in?uence the availabilityofmoistureandnutrients,producegrowthinhibitingorgrowth promoting substances in the form of exudates, provide competition and possiblyinducemanyothereffects.Mycorrhizalassociationsarebene?cial in mineral uptake and in increasing root surface area for effective ion absorption. Antagonism,competitionandsynergisminsoilandtherhizoplane(r- zosphere) are the most important microbial interactions to consider in the study of rhizosphere biology. With the growing information on the production of growth regulators, competitiveness of the microbes in the rhizosphere, microsymbionts, and other factors, their effect upon plant growth will become more evident. Experiments on the introduction of microbes or their products in the rhizosphere will help to improve our understandingofthebiologyoftherhizosphere.

In the rhizosphere, exudates from plants and microorganisms as well as stable soil organic matter influence processes that can control plant growth, microbial infections, and nutrient uptake. As the chemistry and biochemistry of these substances becomes more and more clear, their study promises to shed light on the complex interactions between plan

This book presents a detailed discussion on the direct interactions of plants and microorganisms in the rhizosphere environment. It includes fifteen chapters, each focusing on a specific component of plant-microbe interactions, such as the influence of plants on the root microbiome, and the downstream effects of rhizosphere microbial dynamics on carbon and nutrient fluxes in the surroundings. As such, the book helps readers gain a better understanding of diversity above the ground, and its effect on the microbiome and its functionality.

The first book devoted to the complex interactions between trace elements, soils, plants, and microorganisms in the rhizosphere, Trace Elements in the Rhizosphere brings together the experimental, investigative, and modeling branches of rhizosphere research. Written by an international team of authors, it provides a comprehensive overview of the mechanisms and fate of trace elements in the rhizosphere and the application of this information to phytoremediation technologies and sustainable agriculture and forestry. With ecological and environmental issues moving to the forefront, the focus of rhizosphere research has increasingly shifted to studying the effect of plant-microbial association on the bioavailability, uptake, and transformation of inorganic and organic contaminants in soils. Contaminant-rhizosphere interactions have attracted renewed attention as plants have been proposed for use in the remediation of contaminated soils. Trace Elements in the Rhizosphere provides an in-depth look at rhizosphere processes and leads the way to further understanding and developments in this field.

Rhizosphere Engineering is a guide to applying environmentally sound agronomic practices to improve crop yield while also protecting soil resources. Focusing on the potential and positive impacts of appropriate practices, the book includes the use of beneficial microbes, nanotechnology and metagenomics. Developing and applying techniques that not only enhance yield, but also restore the quality of soil and water using beneficial microbes such as Bacillus, Pseudomonas, vesicular-arbuscular mycorrhiza (VAM) fungi and others are covered, along with new information on utilizing nanotechnology, quorum sensing and other technologies to further advance the science. Designed to fill the gap between research and application, this book is written for advanced students, researchers and those seeking real-world insights for improving agricultural production. Explores the potential benefits of optimized rhizosphere Includes metagenomics and their emerging importance Presents insights into the use of biosurfactants