Systems Approaches for Sustainable Agricultural Development

Transcription

1 FOOD FROM DRY LANDS

2 Systems Approaches for Sustainable Agricultural Development Volume 1 The titles published in this series are listed at the end of this volume.

3 Food from dry lands An integrated approach to planning of agricultural development Edited by Th. ALBERDA Formerly DW- Centre for Agrobiological Research (CABO-DW), Wageningen, The Netherlands H. van KEULEN DLO - Centre for Agrobiological Research (CABO-DW), Wageningen, The Netherlands N.G. SELIGMAN Agricultural Research Organization (ARO), Bet Dagan, Israel C.T. de WIT Emeritus Professor Wageningen Agricultural University (WAU), Wageningen, The Netherlands Springer-science+Business Media, B.V.

4 Library of Congress Cataloging-in-Publication Data Food frol dry lands : an lntegrated approach to plannlng of agricultural developllent / edlted by Th. Alberda... [et a1.j. p. CI. -- (Systell approaches for sustalnable agrlcultural developlent ; v. 1) Includes blbllographlcal references. ISBN ISBN (ebook) DOI / Arid reglons agrlculture. 2. Agropastoral systems. 3. Pastures. 4. Sheep. 1. Alberda, Th. II. Serles. S613.F '763' dc ISBN printed on acidfree paper AII rights reserved 1992 Springer Science+Business Media Dordrecht Originally published by Kluwer Academic Publishers in 1992 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, includ ing photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owners.

5 Contents Contributors IX Foreword xi Acknowledgements xm 1. Introduction C.T. de Wit and N.G. Seligman 1.1. In the current of change I 1.2. The natural environment Agro-pastoral systems Perspectives for development 4 2. Structure and dynamics of grazing systems on seasonal pastures 7 I. Noy-Meir 2.1. Introduction Types of plants Questions to be dealt with Plant attributes relevant to animal production Within-season plant biomass dynamics under grazing Leaf area dynamics Deferred grazing Interactions with water, nitrogen and other factors (see also Chapter 3) Growth under grazing in semi-arid annual grasslands in Israel Between-season plant population dynamics and the effects of grazing I. Initial seedling biomass Plant population dynamics Conclusions Moisture, nutrient availability and plant production in the semiarid region 25 H. van Keulen and N.G. Seligman 3.1. Introduction The water balance Rainfall 26 v

6 VI Interception Runoff Infiltration Redistribution and drainage Soil surface evaporation Transpiration The soil nitrogen balance Aridity and the nitrogen cycle Soil-nitrogen transformations The soil nitrogen balance at equilibrium Experimental study of some nitrogen transformations in a semi-arid environment Plant production limited by weather, mainly water availability The relation between biomass production and water use The simulation model ARID CROP Plant production limited by weather and nitrogen availability Plant growth and nitrogen supply The simulation model PAPRAN Grain production in a semi-arid environment Short description of the wheat model Performance of the model Application of the model Conclusions Sheep husbandry for lamb production in a semi-arid mediterranean environment 83 R. W. Benjamin 4.1. The grazing environment Breeds of sheep in Israel Reproduction and breeding practice Definition of terms The breeding season and sheep fertility Out-of-season breeding and lambing Ewe nutrition Maintenance requirements Flushing Breeding Early pregnancy Late pregnancy and 'steaming up' Lactation- first four weeks Lactation -later stages Lamb production Importance of lamb in the production system Pre-weaning nutrition up to sixty days of age 92

7 Vll Artificial rearing Pre-weaning nutrition after sixty days of age Post-weaning nutrition from pasture Lamb fattening from concentrates in feedlots 4.6. Flock management Culling and replacements Ewe hogget breeding Pasture productivity and systems of utilization System intensification Agro-pastoral systems 5. Description of a pasture system generator (PSG) N.G. Seligman 5.1. General outline Range of system variation Technical characteristics of the system Some general comments 5.2. Calculation of system inputs and outputs Pasture Flock Feed balance and supplementary feeding Supplementary feeds Pasture allocation Labour requirements Capital requirements Running (or current) costs Cropping systems 5.4. PSG activity table 5.5. Input and output values calculated by the PSG Appendix 6. Management of agro-pastoral systems at the farm level E.D. Ungar 6.1. Introduction Objectives The agro-pastoral system Why integrated systems? Measures of system performance Long-term and short-term decisions 6.2. Short-term decisions The grazing schedule of the ewe Grazing deferment Early-season grazing of green wheat Late-season grazing of green wheat Lamb feeding Lamb rearing

8 Vlll Supplementary feeding of the ewe Straw baling Wheat hay cutting The agro-pastoral system model Results of the agro-pastoral system model The standard run Wheat grazing and utilization Lamb rearing Weaning lambs on sown legume pasture Economic efficiency and technical efficiency Modelling agricultural development strategy 159 I. Spharim, R. Spharim and C. T. de Wit 7.1. Introduction The multi period regional development model Activities and constraints Animal production activities Interactions with the socio-economic environment outside the region Interactions between activities within the region Capital formation Cash flow budget and time preference Model output Testing model performance Interactive multiple-goal planning Background A graphical illustration of Interactive Multiple-Goal Programming (IMGP) An example of the application The initial conditions The goals The policy views Results Discussion Conclusions 190 Appendix 190 Model activities and constraints by categories Summary 193 C.T. de Wit 8.1. Introduction Primary production Secondary production The matrix of production techniques Management under uncertainty Regional development 198 References 201

9 Contributors Alberda, Th. formerly DLO- Centre for Agrobiological Research (CABO-DLO), Wageningen, The Netherlands. Benjamin, R. W. Agricultural Research Organisation, Bet Dagan, Israel. Keulen, H. van Noy-Meir, I. Seligman, N.G. Spharim, I. Spharim, R. Ungar, E.D. Wit, C.T. de DLO- Centre for Agrobiological Research (CABO-DLO), Wageningen, The Netherlands. Department of Evolution, Systematics and Ecology, Hebrew University of Jerusalem, Jerusalem, Israel. Agricultural Research Organization (ARO), Bet Dagan, Israel. Agricultural Research Organization, Bet Dagan, Israel. Bahat - Examination and Evaluation of Technologies Ltd., Jerusalem, Israel. Agricultural Research Organization, Bet Dagan, Israel. Emeritus Professor Wageningen Agricultural University (WAU), Wageningen, The Netherlands. lx

10 Foreword In the early seventies, scientists in Israel and The Netherlands started a cooperative project on actual and potential production under semi-arid conditions. In Israel research concentrated on primary production of natural pastures and small grain crops, and on the associated secondary production of small ruminants. Most of the experimental work was carried out at the Migda Experimental Farm in the semi-desert of the northern Negev where the longterm average annual rainfall is 250 mm. In The Netherlands existing facilities in Wageningen were used for measuring growth, photosynthesis and transpiration of Negev pasture plants and small grains under controlled conditions, both as individual plants and as simulated swards and crops. The joint research program was initiated by the late N.H. Tadmor and A. Dovrat from Israel and by C.T. de Wit and Th. Alberda from The Netherlands and conducted by various scientists from both countries, some of whom are among the authors of this book. The experimental results first served as a basis for the development, calibration and validation of simulation models of the growth and water use of pasture and crops. Subsequently, additional models were developed, allowing incorporation of socio-economic considerations, both at the farm and regional level, so harnessing the research results for analysis of regional development possibilities. The methodologies developed within the present project served as a basis for the initiation of projects in Mali, Egypt and Peru. Although none of these projects were as all-encompassing as that in Israel, they have demonstrated the possibilities of applying the tools developed in one region for extrapolation and prediction in others, provided that the relevant input parameters for the local conditions are available. This book presents the results of the Netherlands/Israeli project, with emphasis on the methodology for exploring different regional development options. It starts with a summary of the experimental results on primary and secondary production and illustrates how these results can be integrated in simulation programs and optimization techniques as a basis for development planning of a farm or of a region. To improve readability, the models have not been included in the text, but are given in appendices or in relevant references. The book is intended for biologists, agricultural scientists and planners xi

11 xii involved in the development planning, particularly of semi-arid regions. It describes a method for estimating the socio-economic effectiveness of technological innovation in a realistic multiple-goal context. This method can provide 'early warning' of pitfalls in development schemes and so improve development planning in a world where this is becoming more complicated by the day.

12 Acknowledgements The editors wish to thank: - the authors, not only for writing their chapters, but also for their continuous efforts in realizing the book in the form it is presented; - the directors of the participating research institutes: the Agricultural Research Organisation (ARO), Bet Dagan, Israel, and the Centre for Agrobiological Research (CABO-DLO), Wageningen, The Netherlands; - the Vice-Chancellor of the Hebrew University of Jerusalem, Jerusalem, Israel and the Rector of the Agricultural University Wageningen (WAU), Wageningen, The Netherlands; - the Directorate General of International Cooperation (DGIS) of the Dutch Ministry of Foreign Affairs, The Hague, The Netherlands, for financial support to conduct both the research and the preparation of this book. Thanks are also due to the following persons, who participated in the research, but, for various reasons, did not contribute to this book: E. Dayan, A. Dovrat, Y. Harpaz, R. Jonathan, H. Lof, G. Orshan and the late N.H. Tadmor. xiii