SYSTEMS APPROACHES FOR AGRICULTURAL DEVELOPMENT Systems Approaches for Sustainable Agricultura! Development VOLUME 2 Scienti/ic Editor F.W.T. Penning de Vries, CABO-DLO, Wageningen, The Netherlands International Steering Committee An international steering committee wiIl support the series Aims and Scope The book series Systems Approaches for Sustainable Agricultural Development is intended for readers ranging from advanced students and research leaders to research scientists in developed and developing countries. It wiIl contribute to the development of sustainable and productive systems in the tropics, subtropics and temperate regions, consistent with changes in population, environment, technology and economic structure. The series will bring together and integrate disciplines related to systems ap proaches for sustainable agricultural development, in particular from the technical and the socio-economic sciences, and presents new developments in these areas. Furthermore, the series wiIl generalize the integrated views, results and experiences to new geographical areas and will present alternative options for sustained agricultural development for specific situations. The volumes to be published in the series wiIl be, generally, multi-authored and result from multi-disciplinary projects, symposiums, or workshops, or are invited. AH books will meet the highest possible scientific quality standards and wiIl be up to-date. The series aims to publish approximately three books per year, with a maximum of 500 pages each. The titles published in this series are listed at the end ofthis volume. Systems approaches for agricultural development Proceedings of the International Symposium on Systems Approaches for Agricultural Development, 2-6 December 1991, Bangkok, Thailand Edited by FRITS PENNING DE VRIES DLO Centre for Agrobiological Research, Wageningen, The Netherlands PAULTENG International Rice Research Institute, Manila, Philippines and KLAAS METSELAAR DLO Centre for Agrobiological Research, Wageningen, The Netherlands Springer Science+Business Media, B.V. Library of Congress Cataloging-in-Publication Data Systeas approaches for agrlcultural developaent I edlted by F.H.T. Pennlng de Vries. P.S. Teng. K. Metselaar. p. ca. -- (Systeas approaches for sustainable agrtcultural developaent ; v. 2) Includes tndex. ISBN 978-0-7923-1881-1 ISBN 978-94-011-2842-1 (eBook) DOI 10.1007/978-94-011-2842-1 1. Agrtcultural systeas--Congresses. 2. Crops--Congresses. 3. Crops--Matheaatlcal aOdels--Congresses. 4. Agricultural systeas -Research--Congresses. 6. Rlce--Congresses. 1. Pennlng de Vrles. F. H. T. II. Teng. P. S. III. Meuelaar. K. IV. Seriss. S494.6.S96S96 1992b 338.1--dc20 92-20496 ISBN 978-0-7923-1881-1 printed on acid-free paper AII rights reserved @ 1993 Springer Science+Business Media Dordrecht Originally published by Kluwer Academic Publishers in1993 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanica1, inc1uding photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owners. Contents Preface ix SESSION 1. CROP PRODUCTION: GENOTYPIC CONSTRAINTS Designing improved plant types: a breeder's viewpoint L.A. Hunt 3 Improvement of rice plant type concepts: systems research enables interaction of physiology and breeding M. Dingkuhn, F.W.T. Penning de Vries and K.M. Miezan 19 Designing improved plant types for the semiarid tropics: agronomists' viewpoints R.C. Muchow and P.S. Carberry 37 Simulation in pre-testing of rice genotypes in Tamil Nadu S. Palanisamy, F.W.T. Penning de Vries, S. Mohandass, T .M. Thiyagarajan and A.A. Kareem 63 Genetic specific data for crop modeling J. T. Ritchie 77 SESSION 2. CROP PRODUCTION: WEATHER CONSTRAINTS Agro-ecological zoning using crop growth simulation models: characterization of wheat environments of India P .K. Aggarwal 97 An agroclimatic approach to agricultural development in India R.K. Singh and D.N. Singh 111 Optimising harvest operations against weather risk G.Y. Abawi 127 v vi The impacts of climate change on rice yield: evaluation of the efficacity of different modeling approaches D. Bachelet, J. van Sickle and C.A. Gay 145 Rice production and climate change F.W.T. Penning de Vries 175 SESSION 3. CROP PRODUCTION: SOIL CONSTRAINTS A systems approach to the assessment and improvement of water use efficiency in the North China Plain Tian-Duo Wang 193 Soil data for crop-soil models J. Bouma, M.C.S. Wopereis, J.H.M. W6sten and A. Stein 207 Root ventilation, rhizosphere modification, and nutrient uptake by rice G.J.D. Kirk 221 Adjustment of nitrogen inputs in response to a seasonal forecast in a region of high climatic risk B.A. Keating, R.L. McCown and B.M. Wafula 233 Maize modeling in Malawi: a tool for soil fertility research and development U. Singh, P.K. Thornton, A.R. Saka and J.B. Dent 253 SESSION 4. CROP PRODUCTION: BIOLOGICAL CONSTRAINTS Pest damage relations at the field level K.J. Boote, W.D. Batchelor, J.W. Jones, H. Pinnschmidt and G. Bourgeois 277 Quantification of components contributing to rate-reducing resistance in a plant virus pathosystem F.W. Nutter, Jr. 297 The rice leaf blast simulation model 'Epiblast' C.K. Kim and C.H. Kim 309 SESSION 5. FARMING SYSTEMS Potential for systems simulation in farming systems research? J.B. Dent 325 vii Making farming systems a more objective and quantitative research tool L. Stroosnijder and T. van Rheenen 341 Options for agricultural development: a new quantitative approach H. van Keulen 355 Options for agricultural development: a case study for Mali's fifth Region H. van Keulen and F.R. Veeneklaas 367 Multicriteria optimization for a sustainable agriculture E.C. Alocilja and J.T. Ritchie 381 Simulation of multiple cropping systems with CropSys R.M. Caldwell and J.W. Hansen 397 Optimization of cropping patterns in tank irrigation systems in Tamil Nadu, India K. Palanisami 413 Agricultural development in Thailand N. Chomchalow 427 A methodological framework to explore long-term options for land use H.C. van Latesteijn 445 SESSION 6. EDUCATION, TRAINING AND TECHNOLOGY TRANSFER Decision support systems for agricultural development J.W. Jones 459 Constraints in technology transfer: a user's perspective with a focus on IPM, Philippines T .H. Stuart 473 Postgraduate education in agricultural systems: the AIT experience J .A. Gartner 485 The IBSNAT project G. Uehara and G.Y. Tsuji 505 Building capacity for systems research at national agricultural research centres: SARP's experience H.F.M. ten Berge 515 Subject index 539 Preface The symposium In the next decades, agriculture will have to cope with an ever-increasing demand for food and raw basic materials on the one hand, and with the necessity to use resources without further degrading or exhausting the environment on the other hand, and all this within a dynamic framework of social and economic conditions. Intensification, sustainability, optimizing scarce resources, and climate change are among the key issues. Organized thinking about future farming requires forecasting of consequences of alternative ways to farm and to develop agriculture. The complexity of the problems calls for a systematic approach in which many disciplines are integrated. Systems thinking and systems simulation are therefore indispensable tools for such endeavours. About 150 scientists and senior research leaders participated in the symposium 'Systems Approaches for Agricultural Development' (SAAD) at the Asian Institute of Technology (AIT), Bangkok, Thailand, in December 1991. The symposium had the following objectives: - to review the status of systems research and modeling in agriculture, with special reference to evaluating their efficacy and efficiency in achieving research goals, and to their application in developing countries; - to promote international cooperation in modeling, and increase awareness of systems research and simulation. The symposium consisted of plenary sessions with reviews of major areas in systems approaches in agriculture, plus presentations in two concurrent sessions on technical topics of systems research. Subjects of studies were from tropical and temperate countries. The plenary sessions with eight invited presentations were aimed at senior research leaders. These broad papers dealt with (i) agricultural research, (ii) education, training and technology transfer, (iii) agricultural policy and (iv) practical applications. These contributions, plus five review papers from technical sessions, are published in three special issues of the journal Agricultural Systems (1992). The second group of presentations was aimed at systems scientists. Half of the 36 contributions were invited papers, half were selected. In five sessions, they dealt with the following features: (i) crop production under genotypic ix x constraints, (ii) crop production under weather-related constraints, (iii) crop production with soil constraints, (iv) crop production with biological constraints; farming systems (v). A separate session (vi) dealt with training and technology transfer. These contributions form the contents of this book. There are five papers in the first session, five in the second, five in the third, three in the fourth, nine in the fifth and five in the last session. All papers were reviewed. The models presented in the first four of the technical sessions are generally mechanistic, explanatory and process-based, often with a one-day time interval of integration and simulate a single, cropped field. They are particularly suited for research and research applications. As there are many valid goals for systems research, many models are possible, and a discussion of which one is 'best' is futile. Several of the 'farming systems' papers explore the possibility of combining agrotechnical models with socio-economic considerations; they demonstrate that this integration is still in an early stage. In the 'training and technology transfer' session, one might note the contrast between the IBSNAT approach that emphasizes development of tools for predictive purposes, and the SARP-approach that emphasizes trainee's understanding of the mechanisms involved. They reflect the extremes of the range of modeling skills mentioned by Spedding in 'The study of Agricultural Systems': operate, repair, improve, construct models. Systems research Where systems research is often thought of as computer work, and personal computers have become a very visible tool for research and planning in all countries, a symposium on systems research may appear to result from that technological development. Indeed, much of the work presented here is carried on a wave of new technology. However important and fascinating these new toys are, their presentation was not the key issue of SAAD. SAAD's key issues were the need to think about entire agricultural production systems, the observation that optimizing subsystems has lead to unsustainable agriculture, and the recognition that improving agricultural systems implies satisfying several, partially conflicting goals. The real world is complex, and to think about it and handle it, we must divide it into parts. In our science, large parts are 'systems', that can often be divided into several 'subsystems'. We use the term 'system' for 'a part of the real world with many interacting components and processes, but with few interactions with the environment'. Systems Research comprises an analytic and a synthetic phase. The tool Systems Analysis has been around for a while. It guides us to identify systems, subsystems and key processes. By taking systems analysis very far, one can dissect systems and identify relevant research problems at a disciplinary level. In this manner, systems analysis guides us to optimize our often traditionally xi approach of monodisciplinary research, and to derive conclusions and recommendations. Model building is the inverse of the analysis. Since systems are not just conglomerates of subsystems, special attention is given to the interactions of susbsystems. Only for subsystems without feedback, an optimum system is obtained by putting together optimized subsystems. But this is rare in agriculture. We must, therefore, look at the entire system and not stop at subsystems. Reaching an optimum for one or two subsystems, in fact, might be counterproductive for the total. Two examples illustrate initially promising developments, based on optimized subsystems, that turned wrong at the systems level: (i) Elimination of insect pests with insecticides initially appeared attractive: all bugs could be killed so that yield loss would be history. We know now that this was short-sighted: natural enemies get killed as well, so that previously harmless insects can become new pests; persistent pesticides accumulate in soil, groundwater, ecological food chains, farmers, and are a serious problem. Killing all insect pests was an optimum solution in a too narrowly defined system. We are starting to learn that insect ecology is part of the agricultural system, as is the soil, the groundwater and the fauna. (ii) Too narrow a focus at fertilizer use efficiency has lead to practices of applying fertilizer at high levels where the response of the crop is small (but economically still positive), but with emissions of large quantities of nutrients to the environment. Pollution of ground and surface water has become a world-wide problem. There are many examples of subsystems optimization leading to malfunctioning of the entire system of agricultural production. These subsystem optimizations make the entire production system look good for some time, but then the total becomes unsustainable. Indeed, sustainability requires systems research. We hope that this volume of SAAD papers will make you more aware of the point that one should not look too narrowly at problems, and that agricultural production and land use have many features that should be studied together. There is also another emerging feature that has lead to SAAD: the possibility to handle quantitatively the common knowledge that yield is generally only one objective out of many. Farming can have several goals such as yield and yield stability, income, product diversity, an attractive landscape. Governments have goals regarding water and fertilizer use, absence of pollution, employment. In any system of crop production, all goals are reached at a certain level. We could not compare these goals and their implications objectively and quantitatively, or indicate how the degree of realization of goals can be traded, so that the full systems view was lacking. New developments make this possible, thereby opening ways to define and explore explicitly alternative options for the development of agriculture.