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The economics of organic farming: An international perspective
Book reviews with basic soil environment parameters are adequately described. Regarding soil moisture, however, the use of units that are not comparable (i.e., % instead of water suction units) largely impedes comparison among data. In general, this chapter is well documented, as is the rest of the book, but synthesis is often limited; this is partly explained by a total lack of standardisation of the methods that have been used by the different authors. Chapters on soil organic matter dynamics, nutrient cycling and micro-organims are excellent compilations of a large number of recent research done on this topic. Information on relationships with microflora are well summarised; nonetheless there is a need for a conceptual model that integrates all this information that is contradictory in many respects, in a logical way, taking into consideration scales involved. For example, the importance given to microorganisms as food for earthworms that may be true for epigeics like Eisenia fetida seems to be exagerated in many cases since the rate of assimilation of organic matter is often greater than the proportion of C as microbial biomass in this organic matter. A comprehensive approach that would consider separately large groups of microorganisms, and discriminate among earthworm ecological categories is clearly needed. The next chapter describes the favourable effects of earthworms on soil structure and plant growth. This is an important chapter for people interested in the management of earthworms in agriculture practices, although most data are restricted to European Lumbricidae, and a large proportion of results have been obtained in short-term pot experiments. The last four chapters provide a very food evaluation of the importance of earthworms as a resource for soil and waste management, and the effects of cropping practices and chemicals on their activities. A large amount of information is given on several "positive" and "negative" effects of earthworms. Thorough literature reviews are given on their use and as biostimulators in land restauration, as bioindicators of soil pollution, or trasformers of organic wastes into compost. The section on vermicomposting is well informed and gives a reasonable assesment of these techniques. However, the economic evaluation of these practices is missing. The last chapter contains a series of information on the con-
79
sequences of agricultural practices and chemicals on earthworms, and a very useful appendix on the evaluation of toxicity of a wide range of chemicals on earthworms. This book that reviews more than 1300 articles both ancient and recent, gives an excellent up to date account of the research made on earthworm biology and ecology, using a logical plan. Among the few weak points are the limited number of figures and tables, most of them being taken from old papers written at times when statistical treatments were not as much used as now. The basic ecological sections would have also benefited from better comparing these results with the mainstream paradigms and theories. This would have facilitated the consideration of these organisms in the elaboration of general ecological theories that continue to mainly focus on above-ground organisms. In conclusion, this book is definitely an excellent basis for students, researchers and engineers interested in earthworms. PATRICK LAVELLE Laboratoire d'Ecologie des Sols Tropicaux Centre de Bondy ORSTROM, 93143 Bondy Cedex France
Economics of organic farming The Economics of Organic Farming: An International Perspective. Edited by N.H. Lampkin and S. Padel, CAB International, Wallingford, 1994, xix + 468 pp., hardback, £49.95, ISBN 085198 911. This book is a very useful contribution to the discussion of the economics of organic farming. Furthermore, it highlights areas where more research and additions to knowledge are needed from natural science, if rational social and private choices between organic and chemically based agriculture are to be made. It focuses on the economics of organic farming in more developed countries with the main emphasis being on European countries, although Canada, USA
80
Book reviews
and Australia are given consideration. After providing background on concepts, history and research issues involved in organic farming, interesting reviews of the actual economics of organic farming in selected countries are presented. The following sections deal with the economics of changing over from non-organic to organic agriculture (that is, the economic experiences of farmers during the transition process), the possible regional impacts of widespread conversion to organic farming and the consequences for agricultural policy of the adoption of organic farming. Particular attention is given to the possible implications of Common Agricultural Policy (CAP) for the adoption of organic agriculture given the recent emphasis of CAP on reducing agricultural production in the European Union. As observed by Lampkin in the opening chapter of this book and as further elaborated by Tate, organic farm produce still only accounts for a small proportion of the total food market, typically less than 0.5% in most countries, but its share is growing. However, in Germany and Austria it accounts for 2-3% of the food market. Market penetration depends upon several factors but the willingness of large supermarkets to stock organic produce is a significant factor in Western countries. Studies in this book show that the profitability of organic farming differs considerably between countries. In Germany, organic farming is just as profitable as conventional agriculture (Padel and Zerger, p. 113) but on average less so in the UK where returns are quite variable between organic farming enterprises (Lampkin, p. 87). The market for organic produce is less well developed in Britain than in Germany and this influences relative returns from conventional and organic agriculture. Anderson (p. 101) finds that in the United States "under current government policies, organic farming enterprises generally are slightly less profitable than comparable conventional enterprises". These estimates are made by contrasting the farms which have made the transition to organic farming with the remaining conventional farms. However, if organic enterprises are as profitable as conventional ones or even slightly more profitable, profit-maximizers might have no incentive to switch to organic farming because of the high costs of transition. Contributions to these books indicate that the prof-
itability of farming is much reduced during the transition period to organic farming because yields fall substantially and price premiums are unavailable in the transition period. It may of course be that the social net value of organic farming is higher than that of conventional fanning. In this respect, Bateman discusses the possibility that organic farming promotes soil conservation, yields landscape and wildlife benefits, results in less leaching of nitrate than conventional farming and fosters greater national self-sufficiency in food supplies. Bateman argues that there is a lack of scientific evidence about these consequences of organic fanning even though he believes that a number of these points have substance. He states that "a major research effort is needed by environmental scientists before economists can begin to make reliable assessments of the case for organic farming or of the policies that might be most appropiate" (Bateman, p. 62). Given recent directions in agricultural policy, it is clearly important that these issues be carefully researched. For example, recent emphasis in agricultural policy in Europe and the USA has been on reducing excess supplies of agricultural produce. One instrument for attempting to achieve this has been set asides, land set aside from agriculture and used for conservation purposes. Another possible method is to provide greater encouragement to organic farming because yields with this type of fanning are lower than for conventional farming. To decide on the relative benefits of these alternative approaches from a social farming view, more information is needed about the effects mentioned by Bateman. As Lampkin reports in the first chapter of this book, there are other systems of 'conservation' or 'sustainable' agriculture, such as low input agricultural systems and integrated ones. Ideally, a comparative economic assessment across the board should be done. The relative sustainability of the alternative systems and their consequences for the variability of returns on farms should also be considered. We are still a long way from such an analysis. Nevertheless, this book, edited by Larnpkin and Padel, has significantly added to our knowledge about the economics of organic farming and highlights areas where solid research is urgently needed. It can be observed from this book that many policy-makers seem quite pre-
Book reviews
pared to implement agricultural policies on very frail scientific evidence. The material in this book is presented in a scientific manner and can be read with profit by all interested in the private and social evaluation of alternative agricultural systems. CLEM TISDELL
Department of Economics The University of Queensland Brisbane 4072 Australia
Climate change and rice
Climate Change and Rice, edited by S. Peng, K.T. Ingram, H.-U. Neue and L.H. Ziska. Springer, Berlin, and International Rice Research Institute, Philippines, 1995, 374 pp., price DM 148.00, ISBN 3-540-58906-6. Rice crops contribute to climate change, and a changing climate will affect the rice crop and rice ecosystems. During a symposium in March 1994, organised by IRRI and supported by the US environmental Protection Agency, top level scientists from all over the world gathered in Los Banos to present and review research and insights related to climate change and rice. This book resulted from the meeting. It presents a large step forward in understanding how and how much climate change may affect rice ecosystems, and to what extent rice crops are also a cause of climate change. The book comes at a very appropriate moment, when the existence of a global wanning has been accepted widely among scientists. The first and largest part of the book deals with methane ( C H 4) and nitrous oxide (NO 2) emissions from rice fields, both important greenhouse gasses. Field observations of emission rates during the rice growing season are presented from several countries. The primary source of CH 4 is the rice crop itself and any organic matter added to the soil; the higher crop productivity, the larger the potential C H 4 release. C H 4 is formed in anaerobic conditions. It is shown how 02 in the soil or paddy water oxidises C H 4 and reduces emission. Pathways of C H 4 emission to the ambient air (through soil, stems) are discussed, and
81
their relations to soil structure and composition reviewed. In a logical follow up to these explanations, ways to mitigate CH 4 production and emission (rice variety, soil management) are critically discussed. One paper estimates that 10% of the annual global CH 4 production originates from irrigated rice. But while methods exist to cut this in half, concomitant yield reduction may prevent adoption of such measures. Further research on this trade off is encouraged. The second part of the book deals with the effects of UV~ radiation, the intensity of which is expected to increase as one of the aspects of climate change. Models to compute levels of UV B are discussed. Experimental setups are presented to impose specific UV B levels in greenhouse and field. The book describes the effects of plants, crops and diseases. It was observed that field crops hardly suffer from UV B levels that retard plant growth in greenhouses significantly. The mutagenic effect of UV B on diseases is hypothesised to be more important than its lethality. The effect of climate change on arthropods should not be studied using individual species alone, but at the community level. The third part of the book deals with tile effects of increased temperature and CO 2 level on rice crops. It presents physiological and morphological studies to reveal plant responses to the individual factors, and some extrapolations to wider areas. The studies are sound and valuable, particularly those with open-top chambers in field crops. Sufficient variability among rice varieties in these physiological traits is found to serve a breeding program. The specific results confirm the positive response of yield and of water use efficiency to increasing CO 2, and the negative response to increasing temperature above the threshold of 26°C. The last part of the book presents simulations of climate change on potential production of irrigated rice across Asia. Models of the rice crop are briefly presented (SIMRIW, CERES-rice and ORYZAI), validated, and applied for the usual climate change scenarios. Results for different tropical countries are presented. No adaptation of future rice crops to the changed climate has been anticipated, so the negative effects must be overestimated and positive effects underestimated. Only for China has the area of irrigated rice been related to climate change. As a
79
sequences of agricultural practices and chemicals on earthworms, and a very useful appendix on the evaluation of toxicity of a wide range of chemicals on earthworms. This book that reviews more than 1300 articles both ancient and recent, gives an excellent up to date account of the research made on earthworm biology and ecology, using a logical plan. Among the few weak points are the limited number of figures and tables, most of them being taken from old papers written at times when statistical treatments were not as much used as now. The basic ecological sections would have also benefited from better comparing these results with the mainstream paradigms and theories. This would have facilitated the consideration of these organisms in the elaboration of general ecological theories that continue to mainly focus on above-ground organisms. In conclusion, this book is definitely an excellent basis for students, researchers and engineers interested in earthworms. PATRICK LAVELLE Laboratoire d'Ecologie des Sols Tropicaux Centre de Bondy ORSTROM, 93143 Bondy Cedex France
Economics of organic farming The Economics of Organic Farming: An International Perspective. Edited by N.H. Lampkin and S. Padel, CAB International, Wallingford, 1994, xix + 468 pp., hardback, £49.95, ISBN 085198 911. This book is a very useful contribution to the discussion of the economics of organic farming. Furthermore, it highlights areas where more research and additions to knowledge are needed from natural science, if rational social and private choices between organic and chemically based agriculture are to be made. It focuses on the economics of organic farming in more developed countries with the main emphasis being on European countries, although Canada, USA
80
Book reviews
and Australia are given consideration. After providing background on concepts, history and research issues involved in organic farming, interesting reviews of the actual economics of organic farming in selected countries are presented. The following sections deal with the economics of changing over from non-organic to organic agriculture (that is, the economic experiences of farmers during the transition process), the possible regional impacts of widespread conversion to organic farming and the consequences for agricultural policy of the adoption of organic farming. Particular attention is given to the possible implications of Common Agricultural Policy (CAP) for the adoption of organic agriculture given the recent emphasis of CAP on reducing agricultural production in the European Union. As observed by Lampkin in the opening chapter of this book and as further elaborated by Tate, organic farm produce still only accounts for a small proportion of the total food market, typically less than 0.5% in most countries, but its share is growing. However, in Germany and Austria it accounts for 2-3% of the food market. Market penetration depends upon several factors but the willingness of large supermarkets to stock organic produce is a significant factor in Western countries. Studies in this book show that the profitability of organic farming differs considerably between countries. In Germany, organic farming is just as profitable as conventional agriculture (Padel and Zerger, p. 113) but on average less so in the UK where returns are quite variable between organic farming enterprises (Lampkin, p. 87). The market for organic produce is less well developed in Britain than in Germany and this influences relative returns from conventional and organic agriculture. Anderson (p. 101) finds that in the United States "under current government policies, organic farming enterprises generally are slightly less profitable than comparable conventional enterprises". These estimates are made by contrasting the farms which have made the transition to organic farming with the remaining conventional farms. However, if organic enterprises are as profitable as conventional ones or even slightly more profitable, profit-maximizers might have no incentive to switch to organic farming because of the high costs of transition. Contributions to these books indicate that the prof-
itability of farming is much reduced during the transition period to organic farming because yields fall substantially and price premiums are unavailable in the transition period. It may of course be that the social net value of organic farming is higher than that of conventional fanning. In this respect, Bateman discusses the possibility that organic farming promotes soil conservation, yields landscape and wildlife benefits, results in less leaching of nitrate than conventional farming and fosters greater national self-sufficiency in food supplies. Bateman argues that there is a lack of scientific evidence about these consequences of organic fanning even though he believes that a number of these points have substance. He states that "a major research effort is needed by environmental scientists before economists can begin to make reliable assessments of the case for organic farming or of the policies that might be most appropiate" (Bateman, p. 62). Given recent directions in agricultural policy, it is clearly important that these issues be carefully researched. For example, recent emphasis in agricultural policy in Europe and the USA has been on reducing excess supplies of agricultural produce. One instrument for attempting to achieve this has been set asides, land set aside from agriculture and used for conservation purposes. Another possible method is to provide greater encouragement to organic farming because yields with this type of fanning are lower than for conventional farming. To decide on the relative benefits of these alternative approaches from a social farming view, more information is needed about the effects mentioned by Bateman. As Lampkin reports in the first chapter of this book, there are other systems of 'conservation' or 'sustainable' agriculture, such as low input agricultural systems and integrated ones. Ideally, a comparative economic assessment across the board should be done. The relative sustainability of the alternative systems and their consequences for the variability of returns on farms should also be considered. We are still a long way from such an analysis. Nevertheless, this book, edited by Larnpkin and Padel, has significantly added to our knowledge about the economics of organic farming and highlights areas where solid research is urgently needed. It can be observed from this book that many policy-makers seem quite pre-
Book reviews
pared to implement agricultural policies on very frail scientific evidence. The material in this book is presented in a scientific manner and can be read with profit by all interested in the private and social evaluation of alternative agricultural systems. CLEM TISDELL
Department of Economics The University of Queensland Brisbane 4072 Australia
Climate change and rice
Climate Change and Rice, edited by S. Peng, K.T. Ingram, H.-U. Neue and L.H. Ziska. Springer, Berlin, and International Rice Research Institute, Philippines, 1995, 374 pp., price DM 148.00, ISBN 3-540-58906-6. Rice crops contribute to climate change, and a changing climate will affect the rice crop and rice ecosystems. During a symposium in March 1994, organised by IRRI and supported by the US environmental Protection Agency, top level scientists from all over the world gathered in Los Banos to present and review research and insights related to climate change and rice. This book resulted from the meeting. It presents a large step forward in understanding how and how much climate change may affect rice ecosystems, and to what extent rice crops are also a cause of climate change. The book comes at a very appropriate moment, when the existence of a global wanning has been accepted widely among scientists. The first and largest part of the book deals with methane ( C H 4) and nitrous oxide (NO 2) emissions from rice fields, both important greenhouse gasses. Field observations of emission rates during the rice growing season are presented from several countries. The primary source of CH 4 is the rice crop itself and any organic matter added to the soil; the higher crop productivity, the larger the potential C H 4 release. C H 4 is formed in anaerobic conditions. It is shown how 02 in the soil or paddy water oxidises C H 4 and reduces emission. Pathways of C H 4 emission to the ambient air (through soil, stems) are discussed, and
81
their relations to soil structure and composition reviewed. In a logical follow up to these explanations, ways to mitigate CH 4 production and emission (rice variety, soil management) are critically discussed. One paper estimates that 10% of the annual global CH 4 production originates from irrigated rice. But while methods exist to cut this in half, concomitant yield reduction may prevent adoption of such measures. Further research on this trade off is encouraged. The second part of the book deals with the effects of UV~ radiation, the intensity of which is expected to increase as one of the aspects of climate change. Models to compute levels of UV B are discussed. Experimental setups are presented to impose specific UV B levels in greenhouse and field. The book describes the effects of plants, crops and diseases. It was observed that field crops hardly suffer from UV B levels that retard plant growth in greenhouses significantly. The mutagenic effect of UV B on diseases is hypothesised to be more important than its lethality. The effect of climate change on arthropods should not be studied using individual species alone, but at the community level. The third part of the book deals with tile effects of increased temperature and CO 2 level on rice crops. It presents physiological and morphological studies to reveal plant responses to the individual factors, and some extrapolations to wider areas. The studies are sound and valuable, particularly those with open-top chambers in field crops. Sufficient variability among rice varieties in these physiological traits is found to serve a breeding program. The specific results confirm the positive response of yield and of water use efficiency to increasing CO 2, and the negative response to increasing temperature above the threshold of 26°C. The last part of the book presents simulations of climate change on potential production of irrigated rice across Asia. Models of the rice crop are briefly presented (SIMRIW, CERES-rice and ORYZAI), validated, and applied for the usual climate change scenarios. Results for different tropical countries are presented. No adaptation of future rice crops to the changed climate has been anticipated, so the negative effects must be overestimated and positive effects underestimated. Only for China has the area of irrigated rice been related to climate change. As a