Agro-Ecosystems, 7 (1981) 271--275 271 Elsevier Scientific Publishing Company, Amsterdam -- Printed in The Netherlands

Book Reviews

AGRICULTURAL SYSTEMS

An Introduction to Agricultural Systems. C.R.W. Spedding, Applied Science Publishers, Barking, 1979, 169 pp., 59 tables, 47 figures, U.S. $8.50. ISBN 0.85334.823.5.

It is rumoured that some students embark on the study of a foreign lan- guage with the attitude, "it can't be that complicated; after all, the natives don't seem to have any difficulty with it". Too often the study of agriculture is approached with a similar outlook. Although the language student quickly receives a rude awakening, those whose studies involve an aspect of agriculture are often never similarly enlightened.

Much excellent work has been done in related disciplines premised only on a vague notion of what agriculture entails. On this basis the physical sciences have provided a vast array of technical inputs for use in the agricultural sec- tor. Yet workers in these fields have occasionally been disheartened that their innovations have not been enthusiastically welcomed by farmers, disappointed when their particular ideas have refused to perform under real-world condi- tions and dismayed when unforseen adverse side effects become apparent. In the social sciences, phenomena resulting from change in the agricultural sys- tems are thoroughly analysed by economists, geographers and sociologists. Where incomplete or inaccurate information about the nature of agricultural production persists, such studies are necessarily a posteriori. Misconceptions about agriculture become dangerous as public policy increasingly impinges on the agricultural sector in the form of price manipulation, quotas, acreage restrictions, energy subsidies and the like.

Against this backdrop, "An Introduction to Agricultural Systems" fills a pressing need. It attacks the root of many problems by providing a functional definition of agriculture. The applicability of the systems approach to the study of agriculture is then justified on the grounds that the multi-disciplinary nature of the subject renders alternative methodologies inadequate. In the first section, the systems view is briefly explained using deceptively simple examples and then applied in basic agricultural situations.

The systems approach is used to advantage in discussion of two fundamen- tal aspects of the agricultural production process -- biological and economic efficiency. In both instances, the application of simple solutions to complex problems is admirably illustrated. Throughout the book an array of alter- natives is presented, and the implications of adopting different criteria in the process is outlined. Two very important but often disregarded features of agriculture are introduced in these chapters. The first is the dependence of modern agriculture on 'support energy' -- the use of non-renewable energy sources. The second is the law of diminishing returns where implications for agriculture are too often denied.

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Such a short volume on a very broad topic is obviously susceptible to criticism on the grounds that something of importance has been omitted. Given the constraint of space, material has been carefully selected and is con- sistent with the stated objective of providing a "useful introductory text". This is equally true of the bibliography and recommendations for further reading which are comprehensive without being overwhelming. If criticism of content is to be levelled, it would take the form of a sin of inclusion rather than a sin of omission. To my mind, one of the longer chapters, Chap- ter 6, "The Contribution of Science", represents an unfortunate digression from the overall theme. Much of the relevant material from this chapter appears elsewhere and the remainder does not add appreciably to the volume.

In the second half of the book a systems framework is used, first to provide a tentative classification of agricultural production modes and second to ex- plore the constraints on the location of production imposed by the physical and economic environments. By way of illustrating this, four agricultural systems -- subsistence, shifting cultivation, pastoral nomadism and mixed farming -- are described in Chapters 8--10. The descriptive nature of these chapters and their brevity precludes any systematic analysis. Instead the reader is left with a rather cursory indication of the positions of these exam- ples in the agricultural scheme.

From exemplary systems, attention is shifted in Chapters 11, 12 and 13 to agricultural subsystems. The first two subsystems, crop production and animal production, are well known, but the application of systems theory facilitates a more complete appreciation of the constituent cyclical interrela- tionships. The third, industrial production, involves the production of food- stuffs from single,celled protein and processes burdened with such unappetiz- ing terminology as "meat analogue" and "green crop fractionation". Here the brief overview not only serves to introduce the student to a rapidly ex- panding area of food production but also informs the teacher about non- traditional modes of production.

The penultimate chapter entitled "The Related Efficiency of Production Systems in Agriculture" underlines some of the choices that will have to be made in the future to sustain our food supply in the face of dwindling re- sources. On reaching the concluding chapter a student who might have re- garded the discussion of a definition of 'agriculture' at the outset as being unnecessarily condescending will have a fresh perspective on the subject and will applaud the closing plea for a citizenry better informed on agricultural matters.

Spedding has sorted out the essential elements of agriculture and presented them in an informal style which maintains interest yet challenges the reader. "An Introduction to Agricultural Systems" provides a valuable first step towards a holistic view of agricultural problems which will help avoid the "bullet" solutions of the past. The next decades will pose serious questions relating to the energy efficiency and environmental appropriateness of agricul- tural systems. The possibility of making intelligent choices will be enhanced

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as more students are introduced to the study of agriculture using the approach outlined in "An Introduction to Agricultural Systems".

ANDREW REED (Toronto, Canada)

TIRURAY SUBSISTENCE

Tiruray Subsistence: From Shifting Cultivation to Plow Agriculture. Stuart A. Schlegel, Ateneo de Manila University Press, Quezon City, 1979. 219 pp., 3 tables, 16 figures, 12 appendices, US $25.00 (cloth), $18.00 (paper- back).

The Tiruray people, numbering under 30,000 live in a small area of moun- tainous country bordering the Celebes Sea in south-west Mindanao, in the Philippines. Dr Schlegel, an anthropologist at the University of California, has lived and worked among the Tiruray for some years and has written about many aspects of their culture. In his latest book he compares and contrasts their tribal type of shifting cultivation with the more recent settled sub- sistence form of tenant-farming which is inexorably taking its place. This account is the 'general' one, the other and more technical version being lodged at Manila University. Because it includes much socioeconomic materi- al as well as information on crop and other resources, the book is addressed as much to students of contemporary anthropology as to students of agro- ecosystems.

The opening chapter sets the scene and briefly traces the history of outside influences on the Tiruray way of life, especially during this century with the American and latterly the Philippine Government. Chapters two to six de- scribe the traditional shifting cultivation as practised in a small but represen- tative community, with the social and physical environments, the cycle of operations involved in running the swidden agriculture, and the associated and complementary activities of hunting, fishing, and gathering of wild plants Which form an integral part of the subsistence. Many of the activities, in- cluding the organisation of labour, site selection and preparation, planting, the range of crops grown, crop tending and harvesting, the methods of hunt- ing and fishing, and the relatively small dependence on trading with the coastal peoples, are described in considerable detail. Where possible the author assesses the labour content of various activities along with estimates of productivities. Chapters seven to nine then describe, in a similar sequence, the features of another area, that has been deforested through deliberate felling and commercial exploitation of the native forest, and is now given over to a settled plough agriculture, with considerable dependence on the marketing of a small number of cultivated crops. These chapters, together with the final one, document the dramatic upheaval to the traditional subsistence economy