Soil Survey Trends in Java

Soil science and soil survey in Java are making marked progress and some description of them may be pf interest to this Association, particularly because the literature describing the methods and the results arc largely unavailable to American soil surveyors. The developments are particularly interesting because there are two distinct organizations which have been studying and mapping the soils of the Netherland Indies. The Institute of Soil Technology of the Department of Agriculture, originally developed under Dr. E. C. Jul. Mohr, is now under the able administration of Dr. J. Th. White. This organization during the last three years has made a very excellent start in the actual classification and mapping of the Soils of Java and Madoera. Detailed soil surveys of certain areas have commenced to appear in print. Dr. White has given a very interesting description of the map features and principles employed in mapping^) from which the following has been condensed: It is the U. S. Bureau of Soils system which has been adopted for the use in the governmental soil survey of Java, although with perhaps some slight change in emphases, as may be seen from the following description: The system as adopted for use in Java is a classification of the soil according to the physical properties and the chemical and mineralogical composition of the several horizons of the profile, and the relation of the soil to the parent rock. Field observations are recorded on color, texture, structure, density, weight, viscosity, water holding capacity, and the drainage. In addition, Atterberg numbers are obtained on samples. Besides the determination of the mineralogical composition, chemical analysis include the percentages of P, K, Ca and Mg in cold 25 per cent HC1 and in 2 per cent citric acid; percentages of N, and organic matter, and the reaction or pH in aqueous and KC1 suspensions are determined. Great attention is paid to any concretions or cemented layers which may be in the soil, noting particularly their nature, and the horizon or horizons in which they are found. The different soil types are indicated on the map in full colors and briefly characterized on the map legend and more fully in the report. The choice of colors and their intensity, the nomenclature of the soil types and the legend depend more or less on the genetic relations as for the time being they are understood. This has nothing to do with the real system of classification, which is based on absolute facts and is indicated by separate colors. In spite of the desirability of using a purely genetic classification for the soils of the East Indies, Dr. White feels since not nearly enough is yet known about the weathering processes it is not yet possible to use a truly genetic system. Attention is called to 'the fact that