Ward's World + McGraw Hill's AccessScience

Ward's World+McGraw Soil Chemistry w/ Questions

Issue link: https://wardsworld.wardsci.com/i/1305211

Contents of this Issue


Page 0 of 4

Soil Chemistry Article by: Garrison Sposito, College of Natural Resources, Department of Plant and Soil Biology, University of California, Berkeley, California. Content • Elemental composition • Minerals • Ion exchange • Soil solution Key Concepts • Chemical processes, including hydrolysis, ion-exchange, and hydration, change the chemical composition of soil (such as ion and mineral content) over time. • Soils can be divided into organic soils and mineral soils. The main elements of organic soils are carbon, oxygen, hydrogen, nitrogen, phosphorus, and sulfur, whereas the main elements of mineral soils are silicon, aluminum, and iron. • Soils' cation- and anion-exchange capacities describe the degree to which soils can adsorb and exchange cations or anions, respectively. • Mineral stress occurs when soil suffers from nutritional deficiencies and toxicities, which limit its plant growth potential. • On a large scale, the nutrient content of soils impacts both plant and animal production; deficiencies in certain miner- als can impact plant growth and development as well as animal health. Access to this content is available to Ward's World readers for free from McGraw Hill's AccessScience, an award-winning, digital STEM resource containing exclusive articles written by expert scientists and engineers; biographies of well-known scientific figures; science news, videos, and animations; and much, much more. Instructors can use AccessScience to guide students on their research project journeys, to help students understand scientific concepts, to support distance learning efforts, in flipped classroom approaches, and in countless other ways. Ward's World and AccessScience have partnered to offer educators a no-obligation, free trial subscription to AccessScience. Request your free trial today to discover how valuable AccessScience can be for you and your students! Get your free trial now. The study of the composition and chemical properties of soil. Soil chemistry involves the detailed investigation of the nature of the solid matter from which soil is constituted and of the chemical processes that occur as a result of the action of hydrological, geological, and biological agents on the solid matter. Because of the broad diversity among soil components and the complexity of soil chemical processes, the application of concepts and methods employed in the chemistry of aque- ous solutions, of amorphous and crystalline solids, and of solid surfaces is required. In addition, soil chemistry controls the availability of plant nutrients within the soil and thus influenc- es plant growth (Fig. 1), yield, and nutritional value for human or animal consumption. Elemental composition The elemental composition of soil varies over a wide range, permitting only a few general statements to be made. Those soils that contain less than 12–20% organic carbon are termed mineral. (The exact percentage to consider in a specific case depends on drainage characteristics and the clay content of the soil.) All other soils are termed organic. Carbon, oxygen, hydrogen, nitrogen, phosphorus, and sulfur are the most important constituents of organic soils and of soil organic + ward ' s science Fig. 1: Proper soil chemistry helps a green seedling to sprout out from the soil. Soil chemistry controls the availability of plant nutrients within the soil and thus influences plant growth. (Credit: amenic181/Shutterstock)

Articles in this issue

Links on this page

Archives of this issue

view archives of Ward's World + McGraw Hill's AccessScience - Ward's World+McGraw Soil Chemistry w/ Questions