Soil Science Simplified. 6e.

eashRating: ★★★★☆

Neil S Eash, Thomas J Sauer, Deb O’Dell and Evah Odoi. 2016. Soil Science Simplified. 6e. Wiley Blackwell. ISBN 978 1 118 54069 5

One of the more difficult ideas with students is getting them to appreciate the value of soil. Synonyms don’t help – “dirt” being the least useful! It’s just stuff to grow things in, wipe off the shoes and generally get an indifferent, if not actually bad, press. It makes a difference to see it as a vital ecosystem, a crucial link in the biogeochemical cycle or a key interdependency between terrestrial ecosystems. Of course, that leaves out its role in hydrology and the more applied uses such as agriculture. Once its role as an ecosystem can be established, it’s time to add some basic science to the mix. This is where it can become slightly more difficult for the educator. Soil texts tend to be small chapters in books or highly complex issues of physics, chemistry and biology. There’s a need to find a text that links enough science to the basics so that the lay reader can appreciate the complexity of what’s beneath their feet. Here’s where this text might well come in. A 6th editionĀ  tending to highlight its utility in a rapidly-changing publishing scene, its aim is to provide a detailed yet understandable overview of this field.

Essentially, the book can be divided into two. The first section looks at soils and their properties whilst the second examines applied uses of soil management. We start with a very brief chapter defining soil, its uses and the conversions of acre/hectare. The real work of understanding soil starts in the next chapter, looking at soil formation or pedogenesis. We not only have a logical starting point but the way in which the text aims to set out the information. Starting with the rock cycle (producing the basic mineral material for soil), the chapter examines rock types, weathering and erosion, soil-forming factors (a link to Jenny’s CLORPT, although not mentioned specifically). Next, soil horizons but here, the authors take the useful step of linking soil formation and horizon development – not a common approach but a useful one for the beginner, who often needs such explicit understanding.

The next three chapters take each of the sciences in turn to explore their impact on soils. Soil physics is a key element because it defines the drainage and engineering capabilities of the soil. There’s the usual soil tri-plot and the key physical properties although it’s the briefest of the three and could have been usefully expanded especially in the area of soil colour and its significance. Students tend to find soil colour a tricky issue and greater explanation here would have been useful. The biological and chemical properties have greater coverage with all the key points mentioned. The next three chapters take the picture further. We now have a basic soil with its attendant properties so how does it interact with other aspects of the abiotic environment? Water is crucial and links to the movement of water in the soil are made clear. There’s much work on the use of water by plants and the impacts of too little water with clear links to irrigation. A chapter on soil temperature is an unusual but welcomed addition. Next, we have the longest of the three chapters with a comprehensive look at soil fertility and nutrition. The focus is on which nutrients, where and what aids/slows their use and progress in soil. There’s work on soil sampling, soil testing and the study of nutrient supply (both natural and artificial). The last section of this chapter moves firmly into agricultural settings with information linking to soil fertility and fertilizer applications.

The remainder of the book, the second part, focusses on applied topics and the use of soil as an agricultural resource. Soil management looks at ploughing (and its alternatives), crop nutrients and crop productions. Soil conservation tackles the increasingly important topic of looking after soils. The text might be brief but there are numerous examples highlighted from water management to erosion control. This conservation theme is carried on to the next chapter which looks at conservation agriculture. Looking very much like a scaled-up version of permaculture (with which it shares several features in common), the authors describe the principles of minimal disturbance, permanent cover and crop rotation as the key to success. Soil classification is the next topic. The value of classification is discussed but in the context of the USDA classification which might need some local adaptation outside the US. The concepts are sound but the specifics would need changing (e.g. UK system, Australian system). A final chapter outlines a range of uses for soil – urban areas, engineering, waste treatment and land reclamation.

This is a very useful text for the beginner. Its strengths lie in the very clear layout of the text, that the coverage of the topics in such a small text is comprehensive and that there is a constant focus on applied issues which helps bring the topic to life for the student. Its agricultural focus might be seen as less useful for ecological purposes and its US-centric approach means that those readers outside the area might need to adapt some of the points mentioned. These points need to be made explicit for the reader because they won’t have the background but these days, a small amount of web-surfing will remedy any deficits.

What is seeks to do is to bring together all the key parts of soil science and present them to the lay reader in an orderly fashion with enough technical detail to inform and not overwhelm. In this regard, this small book does an excellent job! It would be difficult to find a text with such a mix of depth and brevity to help the student better understand the topic.

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