Footprints in the Soil, edited by Benno Peter Warkentin, is a journey through the history of soil science, led by a distinguished group of writers who explore the progression of concepts about soil's nature, its components and processes, and its importance to societies over the ages. It encompasses this history in four sections: “Early Understanding of Soils,” “Soil as a Natural Body,” “Soil Properties and Processes,” and “Soil Utilization and Conservation.” Together, they cover the entire range of components that constitute the discipline of soil science.
The first section alone makes Footprints in the Soil indispensable reading for soil scientists who may not be familiar with the early beginnings and sources of the concepts related to soil's importance to agriculture and society. Written by members of the archaeological and anthropological communities, the section traces the history and development of the early concepts of the soil and earth, beginning with the ancient Romans, whose husbandry derived from their coupling of Greek ideas with their own practical knowledge of soils. The discussion moves on to the additions that other cultures have made to the body of knowledge about soils, to those cultures' understanding of the interrelationships between soil and agriculture, and to the incorporation of concepts about soil into their religious and ethical thinking. These early concepts are the basis for present-day holistic approaches to environmental ethics and ecology in natural ecosystems.
A note about the progression of chapters in the first section: Chapter 3,“The Heritage of Soil Knowledge among the World's Cultures,” is a good overview of indigenous people's knowledge of soil and land-use systems. Readers may want to begin the section with that chapter, follow with chapters 1 and 2 (on the ancient Romans and pre-Colombian Mesoamerica, respectively), and then move to chapters 4 (“Some Major Scientists [Palissy, Buffon, Thaer, Darwin and Muller] Have Described Soil Profiles and Developed Soil Survey Techniques before 1883”) and 5 (“Souls and Soils: A Survey of Worldviews”).
The next section of Footprints in the Soil moves to the West (as does the focus of the book) by way of Russia, where Dokuchaev, in the late 19th century, was developing his concepts of soil genesis to explain soil diversity. Dokuchaev's ideas resonated with soil scientists in the United States, but divergence in approaches soon arose. One chapter in the second section describes the clash between Eugene Hilgard and Milton Whitney, two US scientists with very different backgrounds who advocated two very different approaches to advancing knowledge of soil fertility: Hilgard believed soil chemistry was the appropriate route, whereas Whitney thought that soil physics research was. Both of them were right.
Chapter 9, “A History of Soil Geomorphology in the United States,” describes the introduction of pedological concepts into geomorphology, an important science for reconstructing past landscapes and environments. It is a fascinating look into how current approaches to geomorphology developed, and into the roles of the soil scientists who contributed to that development in the United States. For a soil scientist, this chapter is as compelling as a novel: the pages turn faster and faster as the history unfolds.
“Soil Properties and Processes,” the third section, begins with an interesting description of how concepts from soil science and from ecology cross-fertilized each other. Soil scientists incorporated emerging ecological concepts about the interactions between the biotic and abiotic features of an ecosystem to explore the interrelationships among soil-forming factors, whereas from soil science, Warkentin says, “ecology found a new object of investigation that extended beyond the limits of individual organisms.” Understanding soil dynamics and changes in varied ecosystems is incomplete, despite important developments in soil chemistry and soil physics. The material in the second and third sections of Footprints in the Soil will help advance that understanding, however, by pointing the way for graduate students and beginning scientists to integrate basic sciences with the applied and social sciences.
The fourth section returns to a theme developed at the beginning of the book—the value of soil to society—but from the perspective of soil conservation and sustainable agriculture. The chapters in this section point to the need for soil-science applications—physical, chemical, biological, and ecological—to meet the challenges related to conserving land quality, preventing soil erosion and loss of nutrients, and sustaining soil fertility for long-term food production. The discussion of agricultural terracing brings the concerns of ancient indigenous peoples full circle to those of present-day agricultural producers: the aim then was, and is now, to conserve resources. It is up to soil scientists today to provide the research and quantitative information that will enable the conservation and optimal management of soil, an essential resource for providing food security for global populations.
Although Footprints is an extremely useful textbook for upper-level undergraduates as well as professors, researchers, and scientists working in the relevant sciences, it could also serve as a valuable reference for others. Any reader can appreciate the historical integration of biology, physics, chemistry, philosophy, and ethics that led to our reliance on soil and our understanding of its complexity. Notable scientists have contributed excellent overviews on aspects of soil science that cover the discipline from the beginnings of soil concepts to the current state of knowledge. As a result, the book includes a comprehensive collection of references ranging from ancient documents (many of them difficult to find) to papers published in the 21st century. The bibliographic information is extensive and detailed. Moreover, the sidebars that expand on the biographies and major findings of early soil researchers add a pleasing, personal touch.
I do have a couple of quibbles. With regard to production, the publisher chose a paper that is too thin, and there are a few editorial oversights in some chapters (information missing from a figure, e.g.). I wish there had been more chapters in which authors pointed out knowledge gaps in soil-science research and challenged and encouraged future scientists to fill them.
Nonetheless, I found the book excellent overall. By presenting the evolution of soil science in a way that relates key concepts to specific individuals, Footprints leaves readers more inclined to appreciate the wide range of disciplines integrated into the field and perhaps more capable of understanding its present-day challenges. The book also reminds soil scientists that the history of their discipline is still being formed, and their legacy is still evolving.