Bioresource and Agricultural Engineering Commons^™

Evaluation Of Gamma Ray Attenuation For Measuring Soil Bulk Density Part I. Laboratory Investigation, Xiwen Luo, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

Gamma ray attenuation was evaluated as a means of determining soil bulk density. Experiments were conducted using clay, silt, and sandy loam soils wherein samples were compacted to uniform densities at various moisture contents. We determined the attenuation characteristics of dry soil to be independent of soil texture while being significantly different from that of water. Comparison of gamma density measurements with known soil sample densities indicated that the gamma gauge provided reliable measurement of soil bulk density, provided that the effect of soil moisture on attenuation was accounted for and the manufacturer-prescribed calibration procedure was followed daily. Further, we …

Evaluation Of Gamma Ray Attenuation For Measuring Soil Bulk Density Part Ii. Field Investigation, Larry G. Wells, Xiwen Luo

Biosystems and Agricultural Engineering Faculty Publications

A field investigation was conducted at sites near Lexington and Central City, Kentucky, to evaluate the use of gamma ray attenuation for measuring soil bulk density. Experiments were conducted whereby the gamma gauge was calibrated by various means and compared with volumetric cores collected from the field soils. Calibration by the manufacturer’s recommended procedure was determined to be as accurate as more rigorous laboratory calibration or calibration via regression of soil bulk density data, provided that the effect of soil water on gamma attenuation is correctly considered. We also developed a linear regression equation to correct for the occurrence of …

Comparison Of Four Infiltration Models In Characterizing Infiltration Through Surface Mine Profiles, Larry G. Wells, A. D. Ward, I. D. Moore, R. E. Phillips

Biosystems and Agricultural Engineering Faculty Publications

A laboratory infiltrometer system was used to evaluate the infiltration process through reconstructed surface mine profiles. Six different profiles were subjected to constant simulated rainfall intensities for selected test conditions. Surface runoff rates were monitored and transient soil moisture contents in the profiles were measured with a gamma density gauge. Unsaturated hydraulic conductivity relationships were determined using Campbelfs method and the "zero-flux" procedure. The infiltration process was modeled by the SCS curve number method, a form of Holtan's equation, the Green-Ampt model and Richards' equation. SCS curve numbers were determined by fitting the method to the observed results. Richards' equation …

Traction Characteristics Of Prepared Traffic Lanes, Eddie C. Burt, James H. Taylor, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

Traction characteristics of lugged and smooth tires were compared on prepared traffic lanes and on conventional seedbed conditions. Results indicated that elevated traffic lanes offer important traction advantages over seedbeds in wet soil conditions. In dry soil conditions, traction on elevated traffic lanes was sometimes less than on the seedbed conditions. A timeliness advantage in mobility for the elevated traffic lanes was found to be up to 2 days in extremely wet conditions. A non-elevated traffic lane showed no traction advantage in wet conditions.

Characterizing Soil Deformation By Direct Measurement Within The Profile, Randall K. Wood, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

A unique feature of the University of Kentucky soil bin enables deformation to be characterized by studying a cross-sectional soil profile grid pattern. Modular sections of the bin are laterally removed to expose the cross-section after passes of a pneumatic tire.

The measured displacements of the grid points were converted to values of volumetric strain and then compared to soil density as measured by a dual probe gamma-ray density gauge following tests at various soil conditions. Final soil bulk density determinations using the two methods were not statistically different..

Salinity Control In Northern China, G A. Robertson

Journal of the Department of Agriculture, Western Australia, Series 4

China has vast areas of saline land, perhaps as much as six million hectares. Some of this saline land is a result of marine influence in coastal areas and some is the resultof soil formation in areas with saline geological deposits and inadequate rainfall to leach out the salts at that time.

However, most saline soils in China are as a result of secondary salinisation processess induced by a hydrological imbalance resulting from over-clearing of the land or irrigation. This imbalance has produced rising watertables bringing the salt closer to the soil surface.

In this article, G..A. Robertson, Commissioner …

Water Supplies : Dams And Roaded Catchments, W J. Burdass, T. R. Negus, A. L. Prout, I. A. F. Laing

Journal of the Department of Agriculture, Western Australia, Series 4

Western Australia's Upper and Lower Great Southern statistical areas include most of the broad-scale agricultural land south of a line from Perth to Hyden. Much of the area is well-developed and carries 13.4 million sheep, 203 00 cattle and 95 000 pigs, almost half the State's livestock.

There are few natural rivers and lakes to water livestock in summer and much of the bore water is salty. On-farm waterr conservation, therefore, consits mainly of excavated earth tanks (dams) which are filled by surface runoff or shallow seepage. In the drier areas and in the sandplain roaded catchments have neen built …

Infiltration Through Reconstructed Surface Mined Spoils And Soils, A. D. Ward, Larry G. Wells, R. E. Phillips

Biosystems and Agricultural Engineering Faculty Publications

An extensive series of tests involving reconstructed profiles of spoil and topsoil material from a Western Kentucky surface mine site was conducted with a laboratory infiltrometer system. Infiltration through the reconstructed spoil profiles was very slow despite the coarse nature of the material. Low infiltration rates could be attributed to the material having a well-graded texture and to the high densities of the profiles. Infiltration through topsoil horizons was controlled, for the most part, by conditions at the surface. Following wetting, infiltration rates were primarily controlled by the hydraulic characteristics of the less permeable sub horizon of the spoil material. …

Effect Of Herbicides On Performance Of Aerobic Dairy Lagoons, John D. Bottom, Joseph L. Taraba

Biosystems and Agricultural Engineering Faculty Publications

The herbicides glyphosate, bromacil, and dalapon were assessed for their affect on the oxygen uptake of microorganisms from an aerated dairy lagoon at 20 °C. The maximum recommended addition of herbicide active ingerdient to a lagoon is: glyphosate (isopropyl amino salt)—0.42 mg/L; bromacil—3.70 mg/L; and dalapon (85.8 percent Na salt and 14.2 percent Mg salt)—1.95 mg/L. In addition, microorganism isolates from the aerobic dairy lagoon were incubated under aerobic and anerobic conditions at room temperature to assess the effects of the herbicides. Under aerobic incubation, it was found that neither herbicide type nor herbicide concentration affected isolate growth. Under anaerobic …

Ground Driven Powered Tillage, Larry G. Wells, E. M. Smith, D. E. Hammett, H. J. Thompson Jr.

Biosystems and Agricultural Engineering Faculty Publications

A ground driven powered tillage device is described which utilizes a passive rolling coulter propelled through the soil by a prime mover. The reaction torque imparted by the soil to the coulter is delivered via a torque transfer unit to a powered tillage blade. The tillage blade rotates counter to the direction of the passive rolling coulter and prepares a tilled furrow of some predetermined depth for seed placement and coverage.

Analysis is presented in which the torque developed by a passive rolling coulter engaging the soil is predicted. A relationship is presented for determining the velocity ratio between the …

Predicted And Measured Drainable Porosities For Field Soils, R. W. Skaggs, Larry G. Wells, S. R. Ghate

Biosystems and Agricultural Engineering Faculty Publications

Experiments were conducted on large field cores to determine the relationship between drainage volume and water table depth for five soils. The measured drainage volumes were less than predicted from the soil water characteristics for three soils, but were in good agreement for the other two. Drainable porosities were calculated from both theoretical and experimental drainage volume-water table depth relationships by assuming that the unsaturated zone is essentially 'drained to equilibrium, with the water table. The experimental drainable porosities thus obtained were less than predicted.

Drainable porosities for drainage in two-dimensions were calculated from experimental results for one-dimension by assuming …

The Response Of Various Soil Strength Indices To Changing Water Content And Bulk Density, Larry G. Wells, O. Treesuwan

Biosystems and Agricultural Engineering Faculty Publications

Various soil strength parameters were measured in the laboratory using a bevameter and a recording soil cone penetrometer. Measurements were made at various levels of soil bulk density and water content. Results were discussed in terms of similar published analyses. Two dissimilar methods of predicting vehicular tractive performance were compared and evaluated in terms of potential utility with respect to prediction of soil trafficability.

Vertical Drainage In Field Cores, Larry G. Wells, R. W. Skaggs

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.

Upward Water Movement In Field Cores, Larry G. Wells, R. W. Skaggs

Biosystems and Agricultural Engineering Faculty Publications

No abstract provided.

Nutrient And Energy Composition Of Beef Cattle Feedlot Waste Fractions, C. B. Gilbertson, J. A. Nienaber, J. R. Ellis, T. M. Mccalla, T. J. Klopfenstein, S. D. Farlin

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

This bulletin describes nutrient and energy composition of beef cattle waste fractions as a function of the ration roughage level and type of feedlot. Results can be used to plan engineering system approaches and research to develop handling and processing equipment necessary for recovery of the most valuable portion of waste.

Drought Effects On Wheat Cultivars Using Trickle Irrigation, R N. Weir

Experimental Summaries - Plant Research

Trial 74M32 - The trial was aimed at - 1. Looking for cultivar differences in drought tolerance: particularly involving Gamenya and Insignia. 2. Considering trickle irrigation as a means of controlled water application. Four cultivars were sown at the end of July in salmon gum soil at Merredin. Drought effects on four wheat cultivars in controlled environment Trial 74GL8 - This work was aimed at assessing the performance of the cultivars Gamenya, Gambee, Darkan and Insignia under controlled moisture stress.