Discusses the destabilizing influences that affect feedback systems in the earth and trigger disorganization. Presents information that integrates mantle degassing with feed-back systems, and the Sun-Earth-Space energy flow system which is the primary source of energy that drives the Earth's biosphere. (RT)

Presents a model for demonstrating soil mass stabilization. Explains how this approach can assist students in understanding the various types of soil reinforcement techniques, their relative contribution to increased soil strength, and some of their limitations. A working drawing of the model and directives for construction are included. (ML)

Describes an experiment simulating heat transfer and overall energy loss in upper layers of soil surfaces. (SL)

The structure, execution, uses, and software specifications for this spreadsheet file are discussed. Availability and modifications of this program are described. (CW)

Proposes an analog circuit for use in sedimentation analysis of finely divided solid materials. Discusses a method of particle size distribution analysis and provides schematics of the circuit with list of components as well as a discussion about the operation of the circuit. (JM)

Two implanted slide techniques are described by which activity of proteolylic bacteria and the growth of algae in the soil can be readily studied by school students using simple apparatus and methods. Variations are suggested for studying the effects of agricultural practices and environmental conditions on the soil bacteria and algae. (Author/DS)

Described is a slide set which is designed to illustrate the entire range of soils found in the arid regions of the earth's surface. Information on physical and chemical soil properties, soil classification, and related soil management considerations for agricultural development are included. (CW)

Stressed is the interrelationship among the three major groups of sedimentary rocks and the potential benefits in understanding of sedimentary processes to be gained by a petrosynthesis. Listed are 59 references. (CW)

Discusses magnetic polarity stratigraphy as a tool for correlation of fossiliferous terrestrial deposits. Explains the strengths, weaknesses, limitations, preferred conditions, sampling, laboratory analysis, and applications of this technique. A table of paleomagnetic studies on vertebrate-bearing terrestrial sections arranged by age and locality…

Offers perspectives and an overview of 35 years of teaching an elementary course in soils at Mississippi State University. Discusses the nature of and changes over the years in course content, teaching methods, and student characteristics. Explains the principles that guided instruction in the course. (ML)

Describes a computer program, Residue Management, which is designed to supplement discussions on the Universal Soil Loss Equation and the impact of tillage on soil properties for introductory soil courses. The program advances the user through three stages of residue management. Information on obtaining the program is also included. (ML)

Describes the organization of a crop production systems course for undergraduates in agriculture. Emphasis is placed on problem solving and student interaction and co-operation while working on grain farms and in the classroom. Samples of student evaluations of the course are included. (ML)

The advantages and disadvantages of poster sessions vs. oral talks are reviewed. Front-end and secondary planning, materials, and follow-up needed for poster sessions are outlined. An example session and a check list are included. (Author/CW)

Presented is a successfully implemented active learning project and results of a survey to assess the success of the project. Materials and methods are discussed, and an example of one project is provided. (Author/CW)

Reviews the numerical gains that women have made in employment in the agricultural sciences in the last five years, and the career opportunities that currently exist. Discusses trends in recruiting women into the agricultural sciences, the increase in doctoral degrees conferred upon women, and the need for more women in agronomy and soil science.…