This book is a modification of the book “Fertile Soil” published by AgAccess in 1990, which itself was an updated version of the book “Organic And Inorganic Fertilizers” published by Woods End Laboratory in 1985.

During the many years since it has been out of print, it seems to have attracted some popularity, judging by the resale market. Also in this interval, AgAccess kindly mailed me the original masters. Furthermore, noone seems to have picked up the main message in the book. The last straw was prodding (nagging may be closer to the mark) by a friend to “get up and do something”.

The result is what you see: an online version freely available to the public under a creative commons license.

The book arose during the years that I ran the soil testing facility at Woods End Laboratory. Its specialty was to offer recommendations for organic fertilizers and had a working arrangement with certifying organizations in Vermont and California. The research conducted in an effort to understand the distinctions among fertilizers led to the book.

What is the main message? Actually it has two messages. One is to state as fairly as possible, subject to an occasional bias, differences among the fertilizers commonly available. I am not currently aware of any other publication with that goal.

The second message is to emphasize the need in the soil for energy required to maintain soil fertility. The book accomplishes this by identifying a value of the energy in organic residues.

The book has four parts. The first part discusses the importance of organic residues to soil fertility and proposes an energy index for comparing organic and inorganic fertilizers; addresses the controversy regarding the effect of organic and inorganic fertilizers on food quality; and discusses options for determining fertilizer applications.

The second part covers the range of organic fertilizers including unprocessed locally available residues and compost as well as cover crops; processed wastes; and commercial organic fertilizers. The third part has a chapter for each soil nutrient, except for a single chapter on trace elements. Each chapter describes the importance of the nutrient to the plant; its behavior in the soil; and common organic and inorganic fertilizers and application rates.

The final part consists of four appendices which contain the only use of chemical and mathematical equations in the book. Appendix A. Conversion Factors is a collection of conversion factors which may be useful. Appendix B. The Energy Index presents the details of the argument behind the energy credit proposed for organic matter in chapter 2. Essentials of Soil Fertility . Appendix C. Acid and Basic Nature of Fertilizers offers calculations on the liming value and acidity of various fertilizers. Appendix D. Changes in Compost contains a derivation of graphs in figure Figure 2. Loss of Humus showing the loss of organic matter in a compost process under different conditions.

A perhaps controversial issue of this modified version of the book is that no tables and few references were updated; in particular, the energy index is still based on 1990 prices and oil valued at $1 per gallon. This issue may manifest itself in a claim of laziness on my part, to which I have no defense.

Nevertheless, there is a rationale for leaving prices alone. An update value for fuel oil is likely to be in the range of $3 and change. At some future time another update may occur, requiring a further and doubtless significant increase. But no one knows when that will happen; in the meantime readers will have to do their own update. Doing so will be much easier if updating from a base price of $1 than from an odd number like, say, $3.25.

A second rationale is that costs of fertilizers against which the book compares organic fertilizers are likely to have risen by a comparable amount.

Another problem with this edition is that people to whom the earlier editions referred may no longer be accessible at the address noted.

Robert Parnes
May 2013.

© 2013 Robert Parnes

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