Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 5 of 5

Full-Text Articles in Engineering

Determining Agricultural Chemical Transport Through The Vadose Zone Using A Large Borehole Cavity , Dean Ivan Olson Jan 1995

Determining Agricultural Chemical Transport Through The Vadose Zone Using A Large Borehole Cavity , Dean Ivan Olson

Retrospective Theses and Dissertations

A large borehole cavity designed to investigate agricultural chemical transport through the vadose zone was installed at the Agronomy-Agricultural Engineering Research Center near Ames, Iowa. The system consisted of a culvert installed vertically in the soil profile with stainless steel suction lysimeters installed radially from the cavity wall. Suction lysimeters were installed at five depths in the soil profile with five replications at each depth to monitor changes in water quality in the vadose zone and below the water table. Electronic tensiometers and a data logger system were installed to continuously monitor matric potential and used to automatically collect water ...


Knowledge And Decision Support For Variable Rate Application Of Materials In Prescription Farming , Jack Robert Ambuel Jan 1995

Knowledge And Decision Support For Variable Rate Application Of Materials In Prescription Farming , Jack Robert Ambuel

Retrospective Theses and Dissertations

One major goal of prescription farming is to optimize application rates for seed fertilizer, and other agricultural inputs as a function of location within a field. There are four main components of a variable rate application system: (1) A method of determining the location of farm equipment (e.g. combines, tractors) within a field. (2) A system for controlling the application rate of materials (seeds, fertilizers, pesticides). (3) The capability to measure the results using a real time yield monitor. (4) An algorithm or prescription for determining what rates of materials to apply at each location. In this dissertation it ...


Measuring And Modeling Alachlor Dissipation In Soil , Dee Anna Jo Weed Jan 1995

Measuring And Modeling Alachlor Dissipation In Soil , Dee Anna Jo Weed

Retrospective Theses and Dissertations

Field and laboratory experiments evaluated the overall dissipation of alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide) and the effect of no-till and chisel-plow tillages on alachlor leaching and dissipation. In the top 30-cm layer of field soil, the time to 50% dissipation (half-life) was 2 to 3 d, and the time to 90% dissipation ranged from 17 to 30 d. In no-till soil, alachlor dissipated slightly faster, and more was transported into the 10-to-30-cm soil layer. The tillage effect depended on weather that favored movement into and dissipation within the soil, rather than dissipation on plant residues and the soil ...


Air Cleaning Systems For Livestock Buildings , Atta Elmanan Mustafa Atia Jan 1995

Air Cleaning Systems For Livestock Buildings , Atta Elmanan Mustafa Atia

Retrospective Theses and Dissertations

The objective of this study was to design an ionization system for maximum collection efficiency. The laboratory studies were conducted to test the system and evaluate the performance of the prototypes. Two ionization systems were designed and tested in an air quality laboratory chamber. In the first system a high voltage negative ionization electrode and a neutral collector were used to charge and collect the dust from the air. Samples were obtained with the systems on and off. Samples were also obtained to compare the effectiveness of the second ionization system and an ionization system manufactured by Alpine. Two methods ...


Seed Furrow Sidewall Smearing By Double Disk Openers , Muhammad Iqbal Jan 1995

Seed Furrow Sidewall Smearing By Double Disk Openers , Muhammad Iqbal

Retrospective Theses and Dissertations

Seed furrow sidewall smearing by planter double disk openers in clay loam and loam soils was investigated in field and growth chamber experiments. Treatment variables were row preparation, soil moisture, and planting period. Evaluation parameters were soil bulk density, air permeability, cone index, emergence rate index and total emergence, and plant dry matter weight. The experiments were conducted in somewhat poorly drained soils near Ames, Iowa. The fields were not cultivated before planting and the residue from the previous year's corn was removed. Experiments were conducted in two cropping seasons. Each experiment consisted of a factorial design of three ...