| Summary, etc |
"Conceptual Approach<br/>This sixth edition of Soil Science and Management continues the primary objectives of earlier editions, with the following four main purposes: (1) to acquaint the reader with the soil and water resources of the United States to enable a full appreciation of the importance of these resources; (2) to present soil science theory tied to the practice of those who use soil, mainly for growing plants; (3) to stress the sustainable management of soil and water resources by devoting detail to such subjects as soil and water conservation, conservation tillage, nutrient management, Best Management Practices, and sustainable agriculture; and (4) to relate soils to natural ecosystems.<br/>New to the Sixth Edition<br/>The major change to the sixth edition is an enhanced focus on horticultural soil use, particularly landscape horticulture. This change results from reviewer comments. Recognizing that many of the readers of this text do attend horticulture and landscaping programs, and that the majority of Americans live in cities and experience urban horticulture, I decided to follow the reviewer's request. Examples include coverage of landscape irrigation and drainage practices, expansion of greenhouse fertilization practices, and many others. Several mentions have also been made to LEED certification, a system for certifying "green" building construction that influences the landscape trade. It is hoped that the alterations will clarify the applicability of soil science to horticulture and engage student interest.<br/>Since I did not wish this sixth edition to achieve doorstop weight, some coverage of agronomic practices has been condensed to make room for the new material. I feel this was achieved by deleting unnecessary details rather than weakening coverage of important ones.<br/>Other, smaller changes are scattered liberally throughout the text. This includes updating various bits of data, expanding coverage of soil biology and geology, and providing more information on soils in the natural world. Also, since the effects of climate change have become even more pronounced, a bit more is added to that topic.<br/>A more detailed chapter-by-chapter summary of changes follows: <br/>Chapter 1: The section on soil uses was reworked to put greater emphasis on horticulture and landscape soil use, including an introduction to LEED certification, a third-party certification program for energy- and resource- efficient construction relevant to landscapers and landscape architects. It is also referred to elsewhere in the text. The section also introduces urban agriculture as a soil use, a topic of growing interest for many.<br/>Chapter 1 includes a lot of data on land use and other details, most of these have been updated. Other smaller alterations appear throughout the chapter, including a bit more about Best Management Practices (BMPs) and soil's relationship to climate. An image of a rain garden was added to illustrate a BMP and an image of a staked palm to illustrate the concept of anchorage; to make room, the figure of the earth's cross section was dropped. There were minor changes in the review questions and enrichment activities.<br/>Chapter 2: Chapter 2 now features an expanded discussion of rocks and minerals and their weathering, including an illustrative sidebar about weathering of Mount Rushmore. The accompanying drawing demonstrating the rock types was replaced by photos of actual rocks. Also new is a drawing of slope effects on soil. There are also several new review questions.<br/>Chapter 3: There are no major changes. A sidebar was added about Histosols and climate, and a paragraph warning about some problems with published soil surveys. Some data on lands of the United States are updated, and some review and enrichment activities have been modified.<br/>Chapter 4: Chapter 4 now exhibits more examples of soil physical properties related to horticultural soil use, including a sidebar about protecting soil from compaction around trees and a new photograph of what the soil in a yard looks like during building construction-such an indignity for soil to suffer. The section on soil temperature has been expanded because it is so important in horticulture. For example, frost heaving of plants and preventing it has been added. Also included in this section is the effect of fire on soil temperatures in natural ecosystems with an accompanying new figure; I felt it was timely given the great increase in wildfire incidence climate change is imposing on nature.<br/>Numerous other smaller additions appear in this edition. The chapter calls out important simple practices for managing physical conditions of the soil, referring to them as axioms or cardinal rules, like "avoid bare soil." The intent is to focus student attention on certain simple, almost universal sustainable practices. There are several new review questions, including a couple applying soil science to the landscape industry.<br/>Chapter 5: I reworked the coverage of the soil food web, expanding it and aligning it more with classical ecological knowledge of trophic levels. A well-known United States Department of Agriculture (USDA) graphic of the soil food web has been added to illustrate the principles, and the student is invited to refer back to it as a context for the rest of the chapter.<br/>This edition puts more emphasis on the rhizosphere, even including material on rhizosphere effects on natural plant communities. That discussion continues with the effects on soil biology from the invasion of natural ecosystems by exotic plants like buckthorn. Numerous other smaller changes are also scattered throughout the chapter, like the introduction of intercropping as a practice to increase biological diversity in a garden or field. A couple of new enrichment activities are also added, as well a couple of new figures.<br/>Chapter 6: There are no major changes in this chapter. A sidebar was added of some interest to those who work with plants in containers concerning the water- holding capacity of their growing media. I have expanded the concept of allelopathy, adding examples from landscaping and nature. The value of permanent vegetative cover for improving soil organic matter content is stressed a bit more, as well as its use in permaculture.<br/>There are a couple of new images and little additions scattered throughout the chapter, especially of matters related to horticulture. One reviewer asked for a photo of an organic soil profile to augment the drawing I have, and I was lucky to find a photo of peat harvesting in Ireland that shows a profile.<br/>Chapter 7: The main change to this chapter is the addition of material on elevation contours on the land and how they affect overland water flow. I added this partly because it is very important information for a diligent landscape designer, but also because it helps understand the soil conservation practices presented in Chapter 18. There are also several new review questions.<br/>Chapter 8: In the past, this chapter has been pretty focused on water conservation in agricultural settings. In this edition, I have added some new basic material on water conservation in urban settings. To make room, the coverage of conservation in agricultural areas is slightly less detailed.<br/>There is some updating of data used in the chapter and a couple of new images as well.<br/>Chapter 9: In this edition, Chapter 9 expands coverage of drainage and irrigation in landscape settings. The new material certainly cannot substitute for classes dedicated to those subjects, and anyone wanting to design and install landscape irrigation needs to take a class on the subject. The same for stormwater management. This new material should help prepare for such classes.<br/>To make room for this new material, I condensed the material on agricultural irrigation, which probably has been more detailed than needed in a basic text. Other bits were also edited out to avoid chapter size growing larger. This also meant losing a few figures and adding a few new ones.<br/>I also expanded the discussion on controlled drainage, with a new drawing.<br/>Chapter 10: This edition of Chapter 10 has relatively few changes. A photomicrograph of kaolinite clay particles has been added to assist students in visualizing clay structure.<br/>Chapter 11: The biggest alteration is the treatment of soil acidification. This topic has been expanded to accommodate those who need to acidify soils-often landscapers and gardeners who want to grow acid-loving plants. Soil acidification is a less well-developed practice than liming.<br/>As in many chapters of this edition, there are additional examples of the chapter topic applied to horticulture and natural ecosystems; for example, effects of acid rain on some forests, seaside salt issues, or natural plant communities that grow on salted soil. To make room, I slightly condensed material on salted and sodic soils. I hope this does not inconvenience some readers too much.<br/>There are several new review questions, all using horticultural examples.<br/>Chapter 12: Numerous smaller additions have been made to this chapter. The subject of nitrogen leakage into the environment has been introduced in greater detail, and will be developed more in later chapters. This topic also introduces the dramatic nature of the discovery of the Haber-Bosch process. More detail is added about phosphorus, and iron and manganese toxicities are discussed in more depth-these are common problems in some horticulture applications. Many of the changes relate to horticulture.<br/>Chapter 13: In this edition, only a few minor changes were made to this chapter. I added some references to practices in horticulture, and stressed a bit more the importance of soil testing to avoid applying fertilizers in excess of plant needs. <br/>Chapter 14: I expanded the material on slow-release fertilizers and the Haber- Bosch process. There are new comments about materials suitable or not suitable for organic growing. As in most chapters, there are more horticultural references. To keep the text from growing ever larger, I deleted or condensed some material, including that on blending calculations and pop-up fertilizers. There is a new image of a greenhouse injector and fewer images of field application equipment. There are also a few changed review questions.<br/>Chapter 15: The material on manure has been modified with some information added and some deleted. The benefits, and potential problems, of these amendments have been stressed more. I condensed the material on manure handling systems while emphasizing manure's potential for phosphorus loading into the environment. Composting and anaerobic digestion are mentioned as ways to handle manure. I condensed the treatment of biosolids, mainly to save space. A new brief mention of small-scale composting appears. This edition also expands on the topic of human alteration of the nitrogen cycle and its effect on the environment and human health. <br/>Chapter 16: In keeping with my desire to keep this text from developing gigantism, I condensed this chapter. Some detail and a couple of figures have been deleted. I added a section on the concept of intercropping as a cropping system. <br/>Chapter 17: The sections of this chapter on fruit, vegetable, and nursery production are largely unchanged. The sections on greenhouse production and landscaping have been altered with changes scattered throughout. A major addition is a sidebar on the use of fertilizer injectors, including fertilizer calculations that are different from those standard calculations in Chapter 14. Minor changes include such matters as drawbacks of horticultural peat, water-quality issues, the use of low-ammonia and low-phosphorus feeds in container production, and others.<br/>Chapter 18: This new edition updates some erosion data. I altered the text mainly in the section on water erosion control practices, with additional material throughout. Here I also refer back to the new material in Chapter 6 on the direction of water flow over land. There are also new references to soil conservation in landscape settings, including observing that landscaping is a soil conservation practice. The use of polyacrylamide polymers as a soil protectant is also mentioned for the first time. There are several new review questions.<br/>Chapter 19: Some data are updated. There is additional new material on managing urban soils, like some detail about practices for LEED certification. Two new side-bars compare and contrast two ways of installing pavers: the traditional compacted base method and the newer permeable paving method. These provide examples of both purposeful compaction and a low-impact practice. Both also illustrate what is really an engineering use of soil.<br/>Chapter 20: To make room for other additions in the text, I condensed this chapter. It also updates content for a couple of changes in the 2008 farm bill. Unfortunately, the 2012 farm bill was sitting in Congress at the time this edition was being prepared, so the content should be augmented by the instructor when the bill is passed. <br/>In the Enrichment Activities section at the end of the chapters, some old or defunct Web sites have been deleted or updated, and I have a added a few sites of interest that I encountered while preparing this edition. I, along with the publisher, can affirm that the Web site URLS referenced were accurate at the time of printing. However, due to the fluid nature of the Internet, we cannot guarantee their accuracy for the life of the edition. Each activity attempts to provide the user with enough information to locate the Web site even if the link becomes out of date." |
