SOIL TAXONOMY Review And Use InThe Asian And Pacific Region Food and Fertilizer Technology Center for the Asian and Pacific Region Agriculture Building, 14 Wen Chow Street, Taipei Taiwan, Republic of China June 1985 TABLE OF CONTENTS Page Foreword ........................................................... I Preface .............................................................. ii 1. Review of workshop sessions - Hari Eswaran .................................. 1 2. A decade of soil taxonomy - HariEswaran ................................... 2 3. Diagnostic horizons, properties and features in soil taxonomy - John H. Kimble .......... 17 4. Agro-ecological zones and agricultural land use in Malaysia: The potential contribution of soil taxonomy - V.Sooryanarayana ..................................... 19 5. Experiences, problems and prospects in the adoption of soil taxonomy in the Philippines - M.E. Raymundo ................................................... 30 6. Grouping soils for management practice - S.S. Wann and T.C. Juang .................. 41 7. A study of the fertility characteristics of Taiwan paddy soils by numerical taxonomy methods - ChangJong-Min and Chen Zueng.Sang .................................... 55 8. Classification of cultivated soils and its use in Japan - YoiAmano ................... 75 9. Testing proposed changes in soil taxonomy with soils in the tropics - M.R. Recel ......... 88 10. Fertility Capability Classification (FCC) as a guide to PK-fertilization of lowland rice -C.F. Lin ....................................................... 103 1]. Soil temperature classes in soil taxonomy - H.Ikawa and L. Kourouma .............. 121 12. Paddy soils in Japan and their classification - M. Otowa ......................... 126 13. Soil fertility and management implications of soil taxonomy - B.G. Cagauan, Jr. ......... 135 Discussion raised on soil taxonomy (Answers to questions on papers not printed) ........ 144 Plenasy Session - General discussion chaired by H. Eswaran and H.Ikawa ............. 148 List of Workshop Participants .......................................... 153 FOREWORD Caught up in the excitement of advanced agro-technical development it is possible to forget our ultimate purpose of serving the farmer. In FFTC we have a par­ ticular mission of serving the Small farmers of the Asian and Pacific region, many of whom depend for their livelihoods on small farm budgets with no tolerance for crop failure. Under such conditions we, the scientists, planners and extension workers have a duty to be virtually certain of success in implementing new agro-technology for one mistake can cause the small farmer's family years of poverty. It was with this in mind that I have come to enthusiastically accept the concept of Soil Taxonomy. It can, provided the information is assembled carefully and treated thoroughly, give us greater assurance of Lucce:s in implementing agro-technological developments throughout the scattered parts of our chosen region. I wish to thank all who took part in the International Workshop On Soil Taxonomy and Characterization Of Tropical Soils from which the following papers and discussion have been drawn for a very fine contribution to our knowledge of Soil Taxonomy, I believe it is ultimately a great service to the farmers and scientists whom we serve. T.C. Ju g Director, FFTC PREFACE Soil Taxonomy has become an international system of soit classification, and its proponents would have it become the main means of communication for soil scientists in international forums. It has a lot to offer in providing a standardized terminology and system of categorization suitable for the evaluation of situations in which technology can be transfered within or beyond national boarders. Soil Taxonomy was developed in America and is now facing a critical test in being applied to soils of the Asian and Pacific tropical areas. Scientists ofthe Soil Conservation Service in America ask critics of its short comings to be constructive. They stress that Soil Taxonomy has been more than thirty years in development and changes made to adapt it to the tropic condition should be well considered, and be the results -f extensive investigation. Explaining the possible value to farmers and decision 'makers of subsequent systems developed using Soil Taxonomy, its supporters say that it can be adapted for computeriz?:1ion in a way that will make it potentially useful for local and national planning of new agricultural technology implementaLion. Assimilating this information to a data base is only in its early stages but for the future there is the promise that trial and error agricultural extension will be eliminated and replaced by Model Simulation Techniques and Expert Systems. Soil Taxonomy is faced with various practical problems which must be over­ come. These in nature are of two kinds; there are those where the system itself is at fault, for example criteria which do not adapt well to classify paddy soils, and, then there are those problems which arise from misunderstandings of the concept, for example some soil scientists seem to miss the point that Soil Taxonomy does not primarily seek to describe the fertility of any soil but describes only its nature in terms of taxonomy and climate. It cannot pretend to specify the fertility status of a vegetable patch soil, but through taxonomic classification it can say where you can put a similar vegetable patch. Another problem is that the concepts of Soil Taxonomy must be spread inter­ nationally, this is being done through the International Benchmark Sites Network, and other channels. It must be taught, included in the discussion is a suggestion for ii the structure of an undergraduate course teaching the principles of Soil Taxonomy, in which it can be related to the basics of soil geneis. The papers included here are selected from the papers presented by their authors at the International Workshop On Soil Taxonomy And Characterization Of Tropical Soils, held at the National Chung Hsing University, Taichung, Taiwan, ROC in March 1985. Also included is discussion that arose from the papers, and a record of secticns of a talk with discussion given by Dr. John Kimble. The first chapt2r is a record of Dr. Hari Eswaran's review of sessions prior to the Plenary Session, and is intended to act as an introduction to the extent of the workshop. The discussion in the Plenary Session is far ranging and appears as the final chapter. Sponsoring agencies for the workshop were the National Chung Hsing Uni­ versity, the Council Of Agriculture, ROC, the Soil Management Support Services, US AID, the International Benchmark Site Network for Agrotechnology Transfer US AID, the Food and Fertilizer Technology Center for the Asian and Pacific Region. (FFTC) Peter W. MacGregor Information Officer iii REVIEW OF WORKSHOP SESSIONS Hari Eswaran In the these six sessions over these two days we have heard first , a series of lectures on Soil Taxonomy which for some of us acted as a review and for others as an introduction to Soil Taxonomy; whichever it remains incomplete. second, we heard examples of applications of Soil Taxonomy in the Philippines, Thailand and Malaysia. third , we have heard discussion and papers on related areas of soil classification the work of agri­ cultural colleges in Taiwan, the application of the Fertility Capability Classification, and classification systems used in Japan and Korea. fourth , Dr. Ikawa has spoken on the work of the Benchmark Soil Project and the International Benchmark Sites Network (IBSN). In his talk he described three means of technologic transfer 1. trial and error 2. analogy 3. Simulation Technique Simulation Technique This has become a new area of scientific discussion. In this era of scientific development there seem to be two catch phrases I repeatedly hear; these are Simulation Technique and Expert Systems. In the future we will have to be able to deal with these concepts to call ourselves scientists. These techniques seem to offer the promise to assimilate a large amount of information, put it together and digest it, presenting it in a useful and reliable form for use by decision makers, and, in our case the farmers. That is where the computer similation technique will be of use. The personnel computer has now become relatively cheap and accessible, about U.S.$1,000 for a serviceable unit, on which the extension worker or even farmer can do many things himself. The soil Management IBSNAT project took up the task of putting Soil Taxonomy into a simulation technique form. The new field emerging called Expert Systems, I don't fully understand as yet, but it seems to be one way by which technology can be transfered both by -analogy and simulation techniques. - 1­ A DECADE OF SOIL TAXONOMY Hari Eswaran Soil Management Support Service P. 0. Box 2890, Washington, D.C. 20013, U.S.A. ABSTRACT The U.S. system of soil classification - Soil Taxonomy - is the basis for the soil survey program in the United States. It was for this purpose - the making and interpretingof soil surveys ­ that it was created. The system has received the most criticism from countries that place a heavy emphasis on theoreticaland genetic approaches to soil classification. Consequently, in these countries there is little appreciationfor the utilitarianvalue of the system. The paper attempts to examine the impact the system hashad worldwide since its publication in 1975. In the decade since its appearance,Soil Taxonomy has emerged as the de facto international soil classificationsystem.