scope:

Preface

For over 150 years, scientists have studied plant nutrition with goals of understanding the acquisition, accumulation, transport, and functions of chemical elements in plants. From these studies, much information has been obtained about the growth and composition of plants in response to soilborne elements and to fertilization of crops in the soil or in soil-less media, as in hydroponic culture of plants. A compilation of elements known as plant nutrients and beneficial elements has also been developed from this work.

Plant nutrients are chemical elements that are essential for plant growth. For an element to be essential, it must be required for a plant to complete its life cycle, it must be required by all plants, and no other nutrient can replace this requirement fully. If an element does not meet all of these requirements, for example, being required by some plants or only enhancing the growth of plants, the element may be a beneficial element. Much interest in plant nutrition lies in the development and use of diagnostic techniques for assessment of the status of plants with respect to plant nutrients and beneficial elements.

Soil testing is a common approach to assessments of soil fertility and plant nutrition. With correlation to plant growth, development, and yield, soil testing indicates the capacity of soils to supply plant nutrients and suggests appropriate corrective measures. Plant analysis, used in conjunction with plant symptoms and soil testing, is another common tool for assessment of the nutritional status of plants.

This handbook covers principles of plant nutrition from a historical standpoint to current knowledge of the requirements of crops for certain elements and the beneficial effects of others. Its layout owes much to Homer D. Chapman's 1966 book Diagnostic Criteria for Plants and Soils and, as with that book, presents contributions from eminent plant and soil scientists from around the world. The purpose of this handbook is to provide a current, readily available source of information on the nutritional requirements of world crops.

In the Introduction, the editors provide an overview of plant nutrients and beneficial elements and note diagnostic criteria and research approaches used by current investigators who are interested in plant nutrition.

Each of the chapters dealing with plant nutrients starts with historical information of each nutrient, including the demonstration of essentiality and functions in plants. Each of these chapters will include diagnosis of the nutritional status of plants through assessments of plant appearance and composition. Tabulated data will help correlate plant appearance and composition with regard to nutritional needs. A discussion of the value of soil tests for assessment of the nutritional status of plants will be provided in each chapter. Each chapter will conclude with fertilizers that can be applied to remedy nutritional deficiencies in plants.

Chapters concerning beneficial elements will discuss the history of the relation of the beneficial effects of these elements to crop growth and yield and will relate the benefits to growth stimulation and plant metabolism for particular plant species.

A separate CD-ROM containing all the photographs and some line drawings in color is included with the book, because color versions of the illustrations offer details not obvious in black-andwhite pictures.

With the world population increasing rapidly, and projected to do so for some time, and with improved plant nutrition remaining as one of the major factors increasing crop yields, use of our knowledge of plant nutrition to maximize agricultural yields grows in importance. However, public interest in minimizing the use of chemical inputs in agriculture also is increasing with emphasis on less use of chemical fertilizers and more use of alternative fertilizers. Attention to precision agriculture, in which plant nutrition is controlled or monitored carefully, has grown in research and practice. All of these situations require knowledge of plant nutrition.

The handbook is intended to be a practical reference work for anyone who needs to know the requirements of the world's major crops for essential or beneficial elements. It will also give information on how to assess and govern the nutritional status of crops. It should be of use to farmers, agricultural advisers, soil scientists, and plant scientists