Marion L. Jackson

Bio: Marion L. Jackson is an academic researcher from University of Wisconsin-Madison. The author has contributed to research in topics: Kaolinite & Quartz. The author has an hindex of 33, co-authored 94 publications receiving 7456 citations. Previous affiliations of Marion L. Jackson include Virginia Tech & Academia Sinica.

Chemical Weathering of Minerals in Soils

Abstract: Publisher Summary As agriculture is intensified in particular areas, the proportion of nutrients supplied by weathering becomes relatively small, compared to that added as fertilizers. Even in areas of well-developed agriculture, both in temperate and tropical regions, the weathering release of nutrient elements is of major importance in soil fertility and crop production. It is found that the inherent fertility of soils is related to their mineral content. As the weathering stage advances, soils gradually change, first toward increased productivity and finally, to extremely low productivity. The release of the major and minor elements can be correlated with mineral composition of the soil. In backward areas, agriculture has been directed toward maximum use of the native mineral source of nutrients by systems such as patch agriculture and paddy culture. Even in areas of intensive agriculture, it is clear that the addition of ground rocks (such as ground limestone) and minerals to soils is a reversal of the weathering scheme, with extremely beneficial effects on crop productivity. The chapter examines the processes and products of chemical weathering of minerals in soils from the standpoint of each of these phases and highlights the relative stability of minerals; weathering sequences and indexes. The chapter also lists out the factors affecting the reaction rates of chemical weathering and their distribution frequency.

Study and Interpretation of the Chemical Characteristics of Natural Water

Abstract: The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from human activities. Broad interrelationships among these processes and their effects can be discerned by application of principles of chemical thermodynamics. Some of the processes of solution or precipitation of minerals can be closely evaluated by means of principles of chemical equilibrium, including the law of mass action and the Nernst equation. Other processes are irreversible and require consideration of reaction mechanisms and rates. The chemical composition of the crustal rocks of the Earth and the composition of the ocean and the atmosphere are significant in evaluating sources of solutes in natural freshwater. The ways in which solutes are taken up or precipitated and the amounts present in solution are influenced by many environmental factors, especially climate, structure and position of rock strata, and biochemical effects associated with life cycles of plants and animals, both microscopic and macroscopic. Taken together and in application with the further influence of the general circulation of all water in the hydrologic cycle, the chemical principles and environmental factors form a basis for the developing science of natural-water chemistry. Fundamental data used in the determination of water quality are obtained by the chemical analysis of water samples in the laboratory or onsite sensing of chemical properties in the field. Sampling is complicated by changes in the composition of moving water and by the effects of particulate suspended material. Some constituents are unstable and require onsite determination or sample preservation. Most of the constituents determined are reported in gravimetric units, usually milligrams per liter or milliequivalents

The Chemistry of Submerged Soils

Abstract: Publisher Summary This chapter discusses the chemistry of submerged soils. The chemical changes in the submerged materials influence: (a) the character of the sediment or soil that forms, (b) the suitability of wet soils for crops, (c) the distribution of plant species around lakes and streams and in estuaries, deltas, and marine flood plains, (d) the quality and quantity of aquatic life, and (e) the capacity of lakes and seas to serve as sinks for terrestrial wastes. The single electrochemical property that serves to distinguish a submerged soil from a well-drained soil is its redox potential. The redox potential of a soil or sediment provides a quick, useful, semiquantitative measure of its oxidation–reduction status. Two recent developments have stimulated interest in the chemistry of submerged soils: the breeding of lowland rice varieties, with a high yield potential, and the pollution of streams, lakes, and seas, by domestic, agricultural, and industrial wastes. The chemistry of submerged soils is valuable: (a) in understanding the soil problems, limiting the performance of high-yielding rice varieties, and (b) in assessing the role of lake, estuarine, and ocean sediments as reservoirs of nutrients for aquatic plants and as sinks for terrestrial wastes.