"It seems that science progress has taken an exponential course with new ideas and new techniques breaking new grounds not yearly, but at monthly pace. This is reflected in the increasing speed of online publications and even not yet reviewed stories that are coming in on a daily basis making it hardly possible for a human being to stay informed in the own scientific discipline. Therefore, we are happy to realize that a large group of scientists still appreciate the value of textbooks overviewing a broad field of research such as the study of the below ground parts of the plant. This 5th edition of Plant Roots: The Hidden Half presents the great developments that have taken place in this field of research in the last decade, since the publication of its preceding 4th edition. Things which were never thought possible became everyday tools leading to new and exciting discoveries. At the same time research focus also changed with new topics taking center stage while others had drawn less attention. The recognition of the role of root-based processes in determining plant development and productivity cast new light on all aspects of root biology. This together with the ecological considerations regarding fertilization and atmosphere composition emphasize the importance of this field. Results of recent studies shape new breeding strategies taking into account root physiological characteristics"