Developments in soil science 

About: Developments in soil science is an academic journal. The journal publishes majorly in the area(s): Soil water & Soil organic matter. It has an ISSN identifier of 0166-0918. Over the lifetime, 592 publications have been published receiving 9672 citations.

Geomorphometry : concepts, software, applications

Abstract: Geomorphometry is the science of quantitative land-surface analysis. It draws upon mathematical, statistical, and image-processing techniques to quantify the shape of earth's topography at various spatial scales. The focus of geomorphometry is the calculation of surface-form measures (land-surface parameters) and features (objects), which may be used to improve the mapping and modelling of landforms to assist in the evaluation of soils, vegetation, land use, natural hazards, and other information. This book provides a practical guide to preparing Digital Elevation Models (DEM) for analysis and extracting land-surface parameters and objects from DEMs through a variety of software. It further offers detailed instructions on applying parameters and objects in soil, agricultural, environmental and earth sciences. This is a manual of state-of-the-art methods to serve the various researchers who use geomorphometry. Soil scientists will use this book to further learn the methods for classifying and measuring the chemical, biological, and fertility properties of soils and gain a further understaing of the role of soil as a natural resource. Geologists will find value in the instruction this book provides for measuring the physical features of the soil such as elevation, porosity, and structure which geologists use to predict natural disasters such as earthquakes, volcanoes, and flooding.

Chapter 1 Humic Substances: Chemistry and Reactions

Abstract: Publisher Summary This chapter deals with humic substances and discusses its chemistry and reactions. Humic substances, major organic constituents of soils and sediments, are widely distributed over Earth's surface, occurring in almost all terrestrial and aquatic environments. Humic substances arise from the chemical and biological degradation of plant and animal residues and from synthetic activities of microorganisms. The products so formed tend to associate into complex chemical structures that are more stable than starting materials. Important characteristics of humic substances are their ability to form water-soluble and water-insoluble complexes with metal ions and hydrous oxides and to interact with clay minerals and organic compounds such as alkanes, fatty acids, dialkyl phthalates, and pesticides. The capacity of humic substances to adsorb water and plant nutrients was one of the first observations. Humic substances were thought to arise from the prolonged rotting of animal and plant bodies. The chapter also describes the synthesis of humic substances.

Land-Surface Parameters Specific to Topo-Climatology

Abstract: Publisher Summary This chapter presents a brief overview of climate regionalization approaches. It introduces land-surface parameters relevant to assessing the short- and long-wave radiation flux of the surface. The chapter also deals with land-surface parameters, suitable to assessing the orographic effects on thermal conditions and cold air flow. The influences of the land-surface on near-ground thermodynamics, on wind velocities and the closely related precipitation distribution are discussed, emphasizing the passive effects of terrain in particular. The land-surface parameters, discussed in this chapter are either physically proved expressions or measures suitable to parameterize the multitude of orographically induced or affected atmospheric processes in the boundary layer. Land surface is one major control within the scope of atmosphere surface interactions, however, land use pattern, type and state of natural or managed vegetation cover likewise significantly affect the topo-climatic settings. Relevant surface properties, such as the meteorological roughness and vegetation/land cover, require consideration of the nature of underlying ground and its influence on the regional climate modeling applications.

Chapter 4 - Spatial Variability and Pedology

Abstract: Soil variability is no stranger to a pedologist. In fact, landscape variability is the very essence of the discipline and dates to antiquity. The development and implementation of Soil Taxonomy have furthered pedogenic quantification. The transfer of technology from laboratory models to field conditions presents serious difficulties. Models are material specific but soils as landscape bodies contain wide ranges of physical, chemical, morphological and mineralogical properties, laterally and vertically. In addition, many parameters are not single valued but vary with transient soil features. Many do not vary randomly in space and thus are not normally distributed. Inability to adequately cope with spatial variability remains a major obstacle to interpretations of field research. The chapter provides an overview to identify the magnitude and loci of spatial variability, its systematic versus random origin and the pedologist's role in communicating such information to users of soil surveys.

Chapter 7 Physical Characteristics of Volcanic Ash Soils

Abstract: Publisher Summary Volcanic ash soils have many unique physical properties that are attributable directly to the properties of the parent material, the noncrystalline materials formed by weathering, and the soil organic matter accumulated during soil formation. These properties include dark soil color, difficult clay dispersion, unique consistence, low bulk density, and high water holding capacity. Soil color is the most striking feature observed for volcanic ash soils, especially for their A horizons. Andisols typically display a large difference in texture when comparing field and laboratory determination methods. Noncrystalline materials play an important role as cementing agents and react with an excess amount of sodium hexametaphosphate. Furthermore, each of the inorganic colloids shows a different point of zero net charge, so that complete dispersion of mineral particles is virtually impossible. Andisols generally have low bulk densities that are attributable to the development of highly porous soil structure. Andisols usually show low degrees of stickiness, plasticity, and hardness that result from the abundance of noncrystalline materials and/or soil organic matter. These physical properties also provide an excellent environment for root growth. Andisols have well-developed soil structure resulting in high porosity with a range of pore sizes that retain a large amount of water with varying tensions.