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The soil color components of 127 samples from five Arizona Agricultural Research Centers and 52 WEPP samples occurring in various parts of the U.S.A. were evaluated using a Minolta Chroma Meter. This instrument is designed to minimize the variability in color determination utilizing a built-in light source to generate a primary source of radiation. Simple and multiple linear regression equations relating Hue, Value, and Chroma color components were obtained to predict the organic carbon and iron content of these soils. The results show that using global data is less reliable than specific groupings of soils. Moist value and moist chroma moist are the two most important color components in estimating the organic carbon content of soils. Chroma and Hue were highly correlated to iron at all moisture levels. Chroma was least affected by soil moisture, but Value and Hue consistently decreased for all soils.

The hydraulics, water use, and energy use of a two year old subsurface drip irrigation system installed at the Maricopa Agricultural Center in southern Arizona were examined to evaluate the performance of typical subsurface drip irrigation systems. Although the pressure distribution was better than expected due to the effect of the looped network, the average discharge rate of the drip tape decreased by 20% as reflected by the change in the discharge coefficient from 0.45 to 0.36 over two years and emitter plugging resulted in the statistical uniformity being only 64.6%. Water use was higher than expected at 50.76 and 41 inches during the two years of use. The total annual energy requirements for the system including direct, 7593 megajoules/hectare/year, and indirect, 12965 megajoules/hectare/year, inputs was 24318 megajoules/hectare/year.

A study of electro-osmotic draft reduction was conducted to determine the effectiveness of electro-osmosis content and apparent resistivity, tillage speed, and electrical voltage and current were measured to determine a relationship which predicts the effectiveness of electro-osmosis in reducing draft force. The application of electro-osmosis resulted in a reduction in draft force for all tested conditions in the loam soil, with a maximum reduction of 39.4 percent. Water content was a good predictor of resistivity with a regression coefficient of 0.944. Resistivity was a significant predictor of draft force for all test configurations with an average regression coefficient of 0.8173. A comparison of water content and resistivity regression coefficients indicates that the difference between the coefficients is not large enough to choose one variable as a better predictor than the other of the effects of electro-osmosis on draft force.

Balancing of rotating machinery involves a wide spectrum of applications including low and high speed rotors. Systems which continuously monitor machines for vibration have made it possible to develop other systems that continually correct for instabilities such as unbalance. This research provides an initial examination of the use of an Electro-Rheological Fluid as correction weight to alleviate unbalance in a rotating machine. Vibrations not associated with balancing were dampened by solidifying ER Fluid used as a correction weight in a balancer prototype. However, optimal apportionment of ER Fluid to achieve rotary balancing was not achieved in prototype tests.