Physical and chemical methods of soil and water analysis [antikvár]

- ix - INTRODUCTION In all the 117 member countries of FAO agricultural and other researcb is being carried out and the field activities of FAO and UN Agencies and of many national organizations are designed to facilitate, strengthen and make more effective the practical application of our knowledge in the general process of development. This work involves a large number of institutes and laboratories which use, for similar purposes, very different methods of investigation and analysis, the results of which cannot normally be compared directly and easily. Coordination and standardization would obviously facilitate matters, save precious time and make results and conclueions useful for much larger regions of the world than is the case now. To take steps in this direction is obviously one of the functions of international organizations. Soil research and soil testing laboratories spread all over the world are typical of the situation described. Their purpose is practically the sams^averywhere but the analytical methods employed vary widely and direct comparison of results from one laboratory to another or from one country to another is often difficult or even impossible. In order to obtain basic information on the actual situation concerning typos of soil laboratories and analytical methods, FAO made a world-wide survey and the results are published in Soil Bulletin No. 3, entitled "A Survey of Soil Laboratories In Sixty-Four FAO Member Countries". Among much useful information, this survey brought out clearly which of the analytical methods are being used on the widest scale. Methods varied with climatic regions and, therefore, with soil groups, as was expected; and it is recognized that variations in analytical procedures of this type are inevitable and fully justified. Related information from the survey also showed how a greater uniformity of analytical methods and more standardization and coordination is practically feasible in the future. The present publication is a practical guide in soil and water analysit which includes all those methods which, according to the FAO Survey, are employed moat widely. Laboratories following these methods will, in the end, belong to a large group "talking the same language" and comparing their results directly. Explanations, descriptions, procedures and calculations of results are arranged systematically in easy language so that this guide can be used by laboratory personnel with a wide range of educational level. Also basio values and factors needed fov calculating results are given in each method eo that no extra books and tables are normally required, although some exceptione could not be avoided. This Guide, together with FAO Soil Bulletin No. 3 ("Guide un General and Specialized Equipment for Soil Laboratories"), should be valuable for budgeting, designing and operating a modern soil and water analytical laboratory with up-to-date methods suitable for most developing countries.