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Shifting ground—the changing agricultural soils of China and Indonesia
Geoderma 107 (2002) 143 – 149 www.elsevier.com/locate/geoderma
Book reviews Shifting ground—the changing agricultural soils of China and Indonesia by P.H. Lindert. MIT Press, Cambridge. Hardbound, 351 pp. ISBN 0 262 12227 8. GBP30.95 ‘‘Shifting Ground’’ is a unique and controversial addition to the discussion on soil degradation due to human activities and of interest to a broad audience including soil scientists, agronomists, agricultural economists, geographers, and even policy makers. The core of this book is an analysis of historical soil trends in China and Indonesia during the past 60 years using regression techniques commonly used in agricultural economics. Results from China have been previously published by Lindert et al. in several journal papers, but the book provides an extended analysis, much more background information, and adds Indonesia as another case study. Contrary to many other studies, Peter Lindert’s investigation concludes that human activities did not on average worsen the quality of agricultural soils in China and Indonesia. He suggests that soil erosion was not the major force shaping nutrient trends in agricultural soils since the 1930s, but more subtle trends in organic matter, pH, potassium and phosphorus appear to have occurred. In Chapter 1, Lindert sets the tone with a summary of the major concerns addressed, his approach, and the key results found. He also explains the use of soil organic matter, pH, total P, and total K as the four key indicators of soil quality and its changes over time in China and Indonesia. Obviously, choosing properties such as total P and K raises questions of agronomic relevance as well as consistency of the chemical digestion methods used during a period of roughly 60 years. This is followed by a critical discussion of previously conducted studies on global soil degradation (Chapter 2), which is probably one of the highlights of the book. As an agricultural economist, he approaches these issues from a different perspective than most soil scientists would do and provides an entertaining discussion of exaggerations often found in the (global) soil degradation literature. Many questions are raised about the accuracy and subjectivity of estimates of cultivated land area, land loss and erosion. We are also reminded that economic progress may force that soils go out of cultivation. Chapter 3 describes the origin of the data sets used and the general statistical approach to account for at least some uncertainties and controls. The critical soil scientist will question many of the conclusions drawn because of the uncertainties that are associated with any empirical statistical analysis of historical soil data. Geographic coverage at different time periods is uneven, repeated samples of the same locations are not available, historical differences in sampling depths and bulk density are unaccounted for, only soil properties in the ‘‘upper root zone’’ are considered, the relevance of the soil properties chosen may be questioned, and the consistency and accuracy of laboratory methods used
144
Book reviews
is unknown. Throughout the book, Lindert discusses some of these issues, but concludes that this should not stop us from drawing at least preliminary conclusions. Chapters 4 – 8 provide thorough discussions of historical soil trends and their interactions with agriculture for both China and Indonesia. There are differences between the two countries and data for Indonesia appear to be of better quality, but the author also unravels similarities. Perhaps the most surprising discovery is the apparent increase in total soil P and K contents in parts of both China and Indonesia (Java). Where have these nutrients come from, particularly at times when the use of fertilizer was low (China during 1930– 1950)? Lindert suggests that use of manure and fertilizers may have caused such increases, but most agronomic nutrient balance studies suggest almost universally negative K input –output balances for both countries, particularly on intensively used agricultural land. How could fertilizer use explain the apparent increase in total soil K on fallow land in Java (p. 185)? The book cannot fully explain these apparent discrepancies and the choice of total soil P or K as indicators, possible shifts in laboratory procedures (see p. 173 for Indonesia) and the unavailability of re-sampled locations leaves the reader with some hesitation to accept these trends as real. Production functions fitted to the China data (Chapter 5) also suggested inconsistent relationships between the soil properties chosen and yield trends. Chapter 6 discusses the quality and quantity of China’s cultivated soils. Contrary to what many like to believe, Lindert’s analysis suggest that China as a whole may have gained in cultivated area and has maintained its average soil quality. The chapters on Indonesia (Chapters 7 and 8) follow similar formats as used for China, with particular emphasis given to differences between Java and the out islands. Chapter 9 (What have we done the land?) is a well-written summary of everything discussed, the limitations involved in such an analysis, and issues to be looked at in the future. I recommend reading this chapter first to get the right appetite for the rest of the book. The book is well produced in the familiar format of MIT books on global issues. At times the writing style is a bit wordy and repetitive, but, overall, the book is well structured and will keep your attention. Most chapters start with a brief summary of the major results followed by more detailed elaborations. Of particular value is the extensive Appendix (80 pp.) containing all detailed statistical results, numerous notes, and references. All data sets can be obtained on CD or by downloading them from the internet (http://aghistory.ucdavis.edu). With all this and at a price of US$45, the book is good value, particularly for those who wish to try out their own approaches or expand on the analysis that Lindert et al. have done so far. Overall, this study of rare data is an optimistic alternative to the predominantly pessimistic views on soil quality and soil degradation. Clearly, many uncertainties are associated with using existing soil databases for thematic soil monitoring to reveal shifts in agricultural soils due to human activities. Are the regressions used by Lindert appropriate in soil science? Would there have been other statistical or non-statitistical ways to investigate the change in soil properties? How much sense does the study make taking into account the variability in the data and the large number of uncertainties? Whatever the real trends in soil chemical properties of China and Indonesia are, studies like this point out many open questions to be answered. Hopefully, other researchers will be encouraged to conduct similar investigations for other countries and exploring other techniques for
Book reviews
145
comparison. As a challenge to agricultural scientists, the work of Lindert et al. calls for the collection of better socio-economic and biophysical data through monitoring systems that allow a more quantitative assessment of agricultural soils and their changes over time. A. Dobermann Department of Agronomy and Horticulture, University of Nebraska, 253 Keim Hall, P.O. Box 830915, Lincoln, NE 68583-0915, USA E-mail address: [email protected] PII: S 0 0 1 6 - 7 0 6 1 ( 0 1 ) 0 0 1 3 4 - 3
Soils and environmental quality 2nd edition, by GP Pierzynski, JT Sims and GF Vance. CRC Press 2000. Hardbound, ISBN 0 849300223. GBP30 The task that the authors set themselves in covering the subject matter of this book is an important one, yet soils and environmental quality is a vast interdisciplinary subject, making it a difficult task. There is a requirement for a book synthesising the aspects of soil science central to environmental quality. Such a synthesis is key to discussing the importance of soils for ecosystem and economic health. Soils are a resource that have been heavily impacted by anthropogenic activity (through acidification, climate change, pollution with industrial and agronomic chemicals, sewage sludge disposal, development of land for housing, erosion etc). Highlighting the resilience of soils, and how to manage soil structure and composition (biological, chemical and physical) with respect to improving environmental quality, is extremely important. Knowledge of carbon sequestration in soils is key to predicting the impacts of global climate change, and to come up with strategies for increasing sequestration. Gases emitted from soils (NOX’s and methane) are deleterious to the ozone layer. Soil acidification has had severe impacts on forest productivity around the globe, while atmospheric deposition of nitrogen and sulphur, and phosphate fertilisation has, in many environments irreversibly, changed the ability of soils to support flora and fauna indigenous to nutrient deficient soils. Many industrial pollutants released into soils have severe impacts on soil quality, and will be persist in soils for decades (chlorinated aromatic compounds), or in the case of many metals, persist in soil indefinitely. Soils will, therefore, act as a source of these chemicals to the environment. Percolation of pollutants to groundwater is contaminating aquifers. Slash and burn agriculture is denuding vast areas of the globe of its forests, and in some areas it subsequently leads to nutrient mining and soil erosion. These are the issues that should be addressed directly in a book dealing with soils and environmental quality. While many of these issues are raised in this book, not all are central to its focus. The book contains many good examples of problems relating to the role of soils in environmental quality. However, it tries to condense the subject areas of soil and environmental sciences relating to environmental quality, rather than synthesising the key properties of soils that are central to environmental quality. I realise that both approaches are valid, but
Book reviews Shifting ground—the changing agricultural soils of China and Indonesia by P.H. Lindert. MIT Press, Cambridge. Hardbound, 351 pp. ISBN 0 262 12227 8. GBP30.95 ‘‘Shifting Ground’’ is a unique and controversial addition to the discussion on soil degradation due to human activities and of interest to a broad audience including soil scientists, agronomists, agricultural economists, geographers, and even policy makers. The core of this book is an analysis of historical soil trends in China and Indonesia during the past 60 years using regression techniques commonly used in agricultural economics. Results from China have been previously published by Lindert et al. in several journal papers, but the book provides an extended analysis, much more background information, and adds Indonesia as another case study. Contrary to many other studies, Peter Lindert’s investigation concludes that human activities did not on average worsen the quality of agricultural soils in China and Indonesia. He suggests that soil erosion was not the major force shaping nutrient trends in agricultural soils since the 1930s, but more subtle trends in organic matter, pH, potassium and phosphorus appear to have occurred. In Chapter 1, Lindert sets the tone with a summary of the major concerns addressed, his approach, and the key results found. He also explains the use of soil organic matter, pH, total P, and total K as the four key indicators of soil quality and its changes over time in China and Indonesia. Obviously, choosing properties such as total P and K raises questions of agronomic relevance as well as consistency of the chemical digestion methods used during a period of roughly 60 years. This is followed by a critical discussion of previously conducted studies on global soil degradation (Chapter 2), which is probably one of the highlights of the book. As an agricultural economist, he approaches these issues from a different perspective than most soil scientists would do and provides an entertaining discussion of exaggerations often found in the (global) soil degradation literature. Many questions are raised about the accuracy and subjectivity of estimates of cultivated land area, land loss and erosion. We are also reminded that economic progress may force that soils go out of cultivation. Chapter 3 describes the origin of the data sets used and the general statistical approach to account for at least some uncertainties and controls. The critical soil scientist will question many of the conclusions drawn because of the uncertainties that are associated with any empirical statistical analysis of historical soil data. Geographic coverage at different time periods is uneven, repeated samples of the same locations are not available, historical differences in sampling depths and bulk density are unaccounted for, only soil properties in the ‘‘upper root zone’’ are considered, the relevance of the soil properties chosen may be questioned, and the consistency and accuracy of laboratory methods used
144
Book reviews
is unknown. Throughout the book, Lindert discusses some of these issues, but concludes that this should not stop us from drawing at least preliminary conclusions. Chapters 4 – 8 provide thorough discussions of historical soil trends and their interactions with agriculture for both China and Indonesia. There are differences between the two countries and data for Indonesia appear to be of better quality, but the author also unravels similarities. Perhaps the most surprising discovery is the apparent increase in total soil P and K contents in parts of both China and Indonesia (Java). Where have these nutrients come from, particularly at times when the use of fertilizer was low (China during 1930– 1950)? Lindert suggests that use of manure and fertilizers may have caused such increases, but most agronomic nutrient balance studies suggest almost universally negative K input –output balances for both countries, particularly on intensively used agricultural land. How could fertilizer use explain the apparent increase in total soil K on fallow land in Java (p. 185)? The book cannot fully explain these apparent discrepancies and the choice of total soil P or K as indicators, possible shifts in laboratory procedures (see p. 173 for Indonesia) and the unavailability of re-sampled locations leaves the reader with some hesitation to accept these trends as real. Production functions fitted to the China data (Chapter 5) also suggested inconsistent relationships between the soil properties chosen and yield trends. Chapter 6 discusses the quality and quantity of China’s cultivated soils. Contrary to what many like to believe, Lindert’s analysis suggest that China as a whole may have gained in cultivated area and has maintained its average soil quality. The chapters on Indonesia (Chapters 7 and 8) follow similar formats as used for China, with particular emphasis given to differences between Java and the out islands. Chapter 9 (What have we done the land?) is a well-written summary of everything discussed, the limitations involved in such an analysis, and issues to be looked at in the future. I recommend reading this chapter first to get the right appetite for the rest of the book. The book is well produced in the familiar format of MIT books on global issues. At times the writing style is a bit wordy and repetitive, but, overall, the book is well structured and will keep your attention. Most chapters start with a brief summary of the major results followed by more detailed elaborations. Of particular value is the extensive Appendix (80 pp.) containing all detailed statistical results, numerous notes, and references. All data sets can be obtained on CD or by downloading them from the internet (http://aghistory.ucdavis.edu). With all this and at a price of US$45, the book is good value, particularly for those who wish to try out their own approaches or expand on the analysis that Lindert et al. have done so far. Overall, this study of rare data is an optimistic alternative to the predominantly pessimistic views on soil quality and soil degradation. Clearly, many uncertainties are associated with using existing soil databases for thematic soil monitoring to reveal shifts in agricultural soils due to human activities. Are the regressions used by Lindert appropriate in soil science? Would there have been other statistical or non-statitistical ways to investigate the change in soil properties? How much sense does the study make taking into account the variability in the data and the large number of uncertainties? Whatever the real trends in soil chemical properties of China and Indonesia are, studies like this point out many open questions to be answered. Hopefully, other researchers will be encouraged to conduct similar investigations for other countries and exploring other techniques for
Book reviews
145
comparison. As a challenge to agricultural scientists, the work of Lindert et al. calls for the collection of better socio-economic and biophysical data through monitoring systems that allow a more quantitative assessment of agricultural soils and their changes over time. A. Dobermann Department of Agronomy and Horticulture, University of Nebraska, 253 Keim Hall, P.O. Box 830915, Lincoln, NE 68583-0915, USA E-mail address: [email protected] PII: S 0 0 1 6 - 7 0 6 1 ( 0 1 ) 0 0 1 3 4 - 3
Soils and environmental quality 2nd edition, by GP Pierzynski, JT Sims and GF Vance. CRC Press 2000. Hardbound, ISBN 0 849300223. GBP30 The task that the authors set themselves in covering the subject matter of this book is an important one, yet soils and environmental quality is a vast interdisciplinary subject, making it a difficult task. There is a requirement for a book synthesising the aspects of soil science central to environmental quality. Such a synthesis is key to discussing the importance of soils for ecosystem and economic health. Soils are a resource that have been heavily impacted by anthropogenic activity (through acidification, climate change, pollution with industrial and agronomic chemicals, sewage sludge disposal, development of land for housing, erosion etc). Highlighting the resilience of soils, and how to manage soil structure and composition (biological, chemical and physical) with respect to improving environmental quality, is extremely important. Knowledge of carbon sequestration in soils is key to predicting the impacts of global climate change, and to come up with strategies for increasing sequestration. Gases emitted from soils (NOX’s and methane) are deleterious to the ozone layer. Soil acidification has had severe impacts on forest productivity around the globe, while atmospheric deposition of nitrogen and sulphur, and phosphate fertilisation has, in many environments irreversibly, changed the ability of soils to support flora and fauna indigenous to nutrient deficient soils. Many industrial pollutants released into soils have severe impacts on soil quality, and will be persist in soils for decades (chlorinated aromatic compounds), or in the case of many metals, persist in soil indefinitely. Soils will, therefore, act as a source of these chemicals to the environment. Percolation of pollutants to groundwater is contaminating aquifers. Slash and burn agriculture is denuding vast areas of the globe of its forests, and in some areas it subsequently leads to nutrient mining and soil erosion. These are the issues that should be addressed directly in a book dealing with soils and environmental quality. While many of these issues are raised in this book, not all are central to its focus. The book contains many good examples of problems relating to the role of soils in environmental quality. However, it tries to condense the subject areas of soil and environmental sciences relating to environmental quality, rather than synthesising the key properties of soils that are central to environmental quality. I realise that both approaches are valid, but