Other Civil and Environmental Engineering Commons^™

Runoff, Erosion, And Soil Quality Characteristics Of A Former Conservation Reserve Program Site, John E. Gilley, John W. Doran, Douglas Karlen, T. C. Kaspar

Department of Agricultural and Biological Systems Engineering: Faculty Publications

No-till and moldboard plow tillage systems were established on a former Conservation Reserve Program (CRP) site in southwest Iowa. Runoff rates from simulated rainfall events were significantly greater on sites returned to crop production than from adjoining, undisturbed CRP areas. Substantial soil loss was measured from the moldboard plow treatments, but no significant differences in erosion rates were found between the undisturbed CRP and no-till management systems. No-till management maintained levels of soil quality similar to those of CRP by preserving soil structural integrity and reducing losses of soil organic matter (SOM) associated with tillage. Conservation tillage systems which maintain …

Variability In Volume Metering Devices, Leonard L. Bashford, Abdeljabar Bahri, K. Von Bargen, Michael F. Kocher

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The inherent variability of seed and fertilizer application from volumetric metering devices is not readily recognized. The Canadian Prairie Agricultural Machinery Institute (P AMI) suggests a maximum coefficient of variation (CV) of 15% among outlets for seeding grain or applying fertilizer. P AMI does not report down-the-row variability of individual outlets. Parameters that influence variability of volumetric measuring external fluted wheels such as rotational speed of the metering wheel, product delivery rate, seed size, and cell collection lengths were examined.

In the first study, external fluted wheel meters on four grain drills were tested for seed delivery variability for wheat …

Metering Characteristics Accompanying Rate Changes Necessary For Precision Farming, A. Bahri, K. Von Bargen, Michael F. Kocher, L. L. Bashford

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Agricultural machines used in precision fanning must adjust application rates according to the needs of each cell within a field. Changing from an initial application rate to a new rate while the machine travels from one cell to another in the field is accompanied with some misapplication. The severity of this misapplication depends on the down-the-row delivery characteristics of the metering system and the magnitude of the rate change from cell to cell.

On-the-go rate change tests evaluated the down-the-row performance of an operator controlled metering system when increasing and decreasing wheat seeding rates by 10 and 20 kg/ha steps. …

Spatial Patterns Analysis Of Field Measured Soil Nitrate, Farida Shaukat Goderya, Mohamed F. Dahab, Wayne E. Woldt, Istvan Bogardi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The purpose of this study was to assess the spatial variability of residual soil nitrate, measured in three contiguous 16 ha fields. Available data for residual soil nitrate were examined using conventional statistics. Data tended to be skewed with the mean greater than the median. Geostatistical methods were used to characterize and model the spatial structure. Three dimensional spatial variability was examined using two semivariograms: horizontal-spatial and vertical. Two dimensional horizontal-spatial semivariograms were also computed for each 0.3m (1ft) layer. Semivariogram analysis showed that there were similarities in the patterns of spatial variability for all fields. The results suggest that …

Impact Of Erosion, Mass Wasting, And Sedimentation On Human Activities In The Río Grande Basin, Jujuy Province, Argentina, Waldo Chayle, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Nearly all dry mountainous regions are affected by severe erosion, floods, and debris flows during times of intense precipitation. The lithology, geologic structure, and climate in Jujuy Province, Argentina combine to place at serious risk the people who live along the Río Grande, the major river that drains the east side of the Cordillera Oriental and the west side of the Sierras Subandinas. Nearly all precipitation falls during summer (January–March) with little during the remainder of the year; most of the basin is semiarid to arid, although the southern end has a humid subtropical climate. Relief is great, as much …

Solid Waste Disposal Site Characterization Using Non-Intrusive Electromagnetic Survey Techniques And Geostatistics, Gary N. Kuhn, Wayne E. Woldt, David D. Jones, Dennis D. Schulte

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Prior to the research reported in this paper, a site-specific hydrogeologic investigation was developed for a closed solid waste facility in Eastern Nebraska using phased subsurface characterizations. Based on the findings of this prior investigation, a surface based geoelectric survey using electromagnetic induction to measure subsurface conductivity was implemented to delineate the vertical and horizontal extent of buffed waste and subsurface contamination. This technique proved to be a key non-intrusive, cost-effective element in the refinement of the second phase of the hydrogeologic investigation.

Three-dimensional ordinary kriging was used to estimate conductivity values at unsampled locations. These estimates were utilized to …

Method And Apparatus For Objective Evaluation Of Patent Ambulation, Balance And Weight Bearng Status, Eric B. Lancaster, Michael F. Kocher

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A walker is provided which is equipped with detectors for measuring various loads and torques placed thereon by a user including right side and left side loads as well as torque loads on the handles of the walker and having time and distance detectors to allow the ambulation status of a user to be progressively monitored by medical personnel.

Sol Probe And Method Of Obtaining Moisture,Temperature And Root Distribution Of A Soil Profile, Marvin Twersky, William E. Splinter, Bruce C. Sandhorst

Department of Agricultural and Biological Systems Engineering: Faculty Publications

To provide a profile of simultaneous moisture, temperature and root density characteristics at different depths of soil, a soil probe is inserted in the soil with a viewing and camera section extending above the soil. Similarly, the probe provides a profile of simultaneous moisture, temperature and presence of molds, insects or other foreign matter in grain or similar media including liquid as well as solid granulated material. The portion of the probe that is in the soil or other media includes a source of light or light conveyance and windows which transmit an image of the soil at various depths …

A History Of The Board Of Engineers For Rivers And Harbors, Richard G. Waugh, Judith M. Hourigan

United States Army Corps of Engineers, Omaha District

CHAPTER I: THE BOARD IS ESTABLISHED
Theodore F. Burton • Constituting the Board

CHAPTER II: STARTING BUSINESS
First Board Members • Location • The First Reviews • Early Board Reviews • Public Hearings • Board Meetings • Expenses • Staff

CHAPTER III: THE MISSIONS OF THE BOARD
The Primary Mission • The Review Process • Assigned Missions • Planning Associates Program • Waterborne Commerce Statistics • Permanent International Association of • Navigation Congresses (PIANC) • Foreign Trade Zones • Processing Reports for State and • Washington-Level Agency Review • Former Missions • Marine Design • Transportation Economics • National Capital …

Pollution Of Surface Irrigation Waters By Plant Pathogenic Organisms, James R. Steadman, C. R. Maier, H. F. Schwartz, E. D. Kerr

Department of Plant Pathology: Faculty Publications

Systematic sampling of waterways and irrigation runoff from agricultural lands in the North Platte Project of Nebraska in July and August of 1972–1974 demonstrated that phytopathogenic organisms were disseminated. The organisms monitored included the bean common blight bacterium Xanthomonas phaseoli, the bean white mold fungus Whetzelinia sclerotiorum and various nematodes. Although many types of nematodes often were recovered from irrigation water, Heterodera sp. cysts which cause significant disease problems in the valley were found infrequently. Patterns of movement of the bacterial and fungal organisms were correlated with previous or current season infection of bean plants. The short-term survival of X. …