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Agricultural residues as fuel in the third world
Energy in Agriculture, 6 (1988) 353-359 ElsevierSciencePublishersB.V., Amsterdam-- Printed in The Netherlands
353
Book reviews
AGRICULTURALRESIDUES AS FUEL IN THE THIRD WORLD Agricultural Residues as Fuel in the Third World. Geoffrey Bernard and Lars Kristoferson. Technical Report 4, International Institute for Environment and Development, Beijer Institute, Royal Swedish Academy of Sciences Energy Information Programme. Earthscan, London, 1985. 178 pp., £10.00/US$20.00, softcover. ISBN 0-905347-59-5.
Many people from the developing world have been forced to turn to crop residues and animnal dung for cooking and heating as alternatives to replace woodfuel resources which have become scarce. Consequently, concern is frequently expressed that burning residues diverts essential nutrients and organic matter that would otherwise be returned to the soil, leading to crop-yield loss. This book is an attempt to look at agricultural residue-burning from a broad perspective. It pieces together data that exist of the complex role that agricultural residues play at the village level, effect on soil, and the impacts of the burning of residues. The content include four main parts reviewed in the following, in addition to appendices, acknowledgements, and an extensive bibliography. The first part (General Appraisal) includes information and maps on the geographical distribution of the use of dung and agricultural residues as fuel in the developing countries. There are also discussions on general topics: availability of residues, their properties, importance in soil, recycling of organic matter, limitations on recycling, implications of their burning, risks, new uses and technolgoes, and conclusions. Recycling of organic matter is recommended for the benefit of soil and agricultural environment. Examples are given of Nepal, northern India, and Ethipia, where recycling has traditionally played a key role in maintaining agriculture. Switching to residue burning, however, threatens the stability of the whole agricultural system. It thus becomes crucial that local factors have to be carefully analysed before conclusions are reached regarding residue use and risks involved. However, more information is required for the debate. The second part (Role of Residues as Fuel) is documented with maps and photographs about the use of residues in different parts of the third world including India, Nepal, Bangladesh, and many other Asian, African, and Latin American countries. Availability, properties and uses are discussed in the third part of the book. Diagrams and tables are provided to represent statistics of residue production related to main crops, and per caput. Diversities are observed where a Bolivian
354
peasant may get 2 tons of wheat straw per ha, while another from the Philippines may get as much as 15 tons of rice straw, depending on the productivity of the crop. On the other hand, annual dung production ranges from 0.1 ton for sheep and goats to as much as 0.7 ton per one buffalo. On the national level, Latin American countries such as Argentina, Colombia, and Costa Rica stand among the greatest residue-producing countries, while Malawi, from Africa, and Indonesie, from Asia, produce least. The same part of the report shows that most dry crop residues have a fairly similar heat content. Gross calorific values usually fall within the range 15-20 MJ/kg, compared with a typical value of about 20 MJ/kg for wood; calorific values for different crop residues are given in an extensive table. Other interesting applications for plant residues reviewed from various countries include: feeding to animals, thatching and handicrafts, house roofing, in addition of course to use as fuel. On the other hand, dung is used in house-wall plastering ( Ghana, Sudan, Agrwal, etc. ) in addition to cooking and fertilization. Other utilizations include cremating the dead, smoking with tobacco, goldsmithing, glass industry, lighting, and even as pesticide or pest deterrent. In the fourth part (Residues in the Soil), studies deal with the presence of organic matter in soil, its breakdown, balance, addition rates, its role, the nitrogen cycle and fixation, and losses from soil. Organic recycling is reviewed in Asia and Africa with discussions on the constraints faced. Residue burning implies reduction of organic-matter recycling. The problem is graphically illustrated by an example showing severe drops in the carbon content of soil with time when manure has not been applied since 1852. Another threat to soil comes from erosion when organic matter levels drop. The last sections make recommendations regarding the identification of high risk areas, and stresses the need for local analysis. The book is a comprehensive collection of data and information about the distribution and utilization of agricultural residues in the Third World. Although the reports does not strictly lay down solutions for the urgent problems of energy and soil fertility, it contains considerable reference material useful to policy makers and planners interested in the affairs of the developing countries, for aid programmers, and for scientific and technical advisors and researchers in the relevant fields of energy, soil fertility, rural societies, economy, and other allied fields. M.N. E1AWADY
College o/Agriculture, A. Shams University Shobra El Kheima, Misr, Egypt
353
Book reviews
AGRICULTURALRESIDUES AS FUEL IN THE THIRD WORLD Agricultural Residues as Fuel in the Third World. Geoffrey Bernard and Lars Kristoferson. Technical Report 4, International Institute for Environment and Development, Beijer Institute, Royal Swedish Academy of Sciences Energy Information Programme. Earthscan, London, 1985. 178 pp., £10.00/US$20.00, softcover. ISBN 0-905347-59-5.
Many people from the developing world have been forced to turn to crop residues and animnal dung for cooking and heating as alternatives to replace woodfuel resources which have become scarce. Consequently, concern is frequently expressed that burning residues diverts essential nutrients and organic matter that would otherwise be returned to the soil, leading to crop-yield loss. This book is an attempt to look at agricultural residue-burning from a broad perspective. It pieces together data that exist of the complex role that agricultural residues play at the village level, effect on soil, and the impacts of the burning of residues. The content include four main parts reviewed in the following, in addition to appendices, acknowledgements, and an extensive bibliography. The first part (General Appraisal) includes information and maps on the geographical distribution of the use of dung and agricultural residues as fuel in the developing countries. There are also discussions on general topics: availability of residues, their properties, importance in soil, recycling of organic matter, limitations on recycling, implications of their burning, risks, new uses and technolgoes, and conclusions. Recycling of organic matter is recommended for the benefit of soil and agricultural environment. Examples are given of Nepal, northern India, and Ethipia, where recycling has traditionally played a key role in maintaining agriculture. Switching to residue burning, however, threatens the stability of the whole agricultural system. It thus becomes crucial that local factors have to be carefully analysed before conclusions are reached regarding residue use and risks involved. However, more information is required for the debate. The second part (Role of Residues as Fuel) is documented with maps and photographs about the use of residues in different parts of the third world including India, Nepal, Bangladesh, and many other Asian, African, and Latin American countries. Availability, properties and uses are discussed in the third part of the book. Diagrams and tables are provided to represent statistics of residue production related to main crops, and per caput. Diversities are observed where a Bolivian
354
peasant may get 2 tons of wheat straw per ha, while another from the Philippines may get as much as 15 tons of rice straw, depending on the productivity of the crop. On the other hand, annual dung production ranges from 0.1 ton for sheep and goats to as much as 0.7 ton per one buffalo. On the national level, Latin American countries such as Argentina, Colombia, and Costa Rica stand among the greatest residue-producing countries, while Malawi, from Africa, and Indonesie, from Asia, produce least. The same part of the report shows that most dry crop residues have a fairly similar heat content. Gross calorific values usually fall within the range 15-20 MJ/kg, compared with a typical value of about 20 MJ/kg for wood; calorific values for different crop residues are given in an extensive table. Other interesting applications for plant residues reviewed from various countries include: feeding to animals, thatching and handicrafts, house roofing, in addition of course to use as fuel. On the other hand, dung is used in house-wall plastering ( Ghana, Sudan, Agrwal, etc. ) in addition to cooking and fertilization. Other utilizations include cremating the dead, smoking with tobacco, goldsmithing, glass industry, lighting, and even as pesticide or pest deterrent. In the fourth part (Residues in the Soil), studies deal with the presence of organic matter in soil, its breakdown, balance, addition rates, its role, the nitrogen cycle and fixation, and losses from soil. Organic recycling is reviewed in Asia and Africa with discussions on the constraints faced. Residue burning implies reduction of organic-matter recycling. The problem is graphically illustrated by an example showing severe drops in the carbon content of soil with time when manure has not been applied since 1852. Another threat to soil comes from erosion when organic matter levels drop. The last sections make recommendations regarding the identification of high risk areas, and stresses the need for local analysis. The book is a comprehensive collection of data and information about the distribution and utilization of agricultural residues in the Third World. Although the reports does not strictly lay down solutions for the urgent problems of energy and soil fertility, it contains considerable reference material useful to policy makers and planners interested in the affairs of the developing countries, for aid programmers, and for scientific and technical advisors and researchers in the relevant fields of energy, soil fertility, rural societies, economy, and other allied fields. M.N. E1AWADY
College o/Agriculture, A. Shams University Shobra El Kheima, Misr, Egypt