With recent developments allowing increased planter speeds, improving spatial uniformity of crop emergence will continue to be an important focus of research. Vertical vibration during planting usually interferes with the seed metering and delivery process, and thereby affects seeding quality. Two different row crop planters were instrumented with accelerometers to monitor vertical vibration of planter row units in five fields with a total area of 220 ha in both no-till and strip-tilled conditions. The test results showed that the row unit vibration linearly increased with planting speeds. The R 2 of each fitting equation was more than 0.90. The main frequencies of the vibration were concentrated in a low-frequency band of 3 Hz to 10 Hz. These frequencies did not show an increasing trend with the planter speed. However, the amplitude clearly increased when the planter speed increased. For the John Deere MaxEmerge™ 5 planter, the manually measured average plant spacing was close to the target plant spacing with a maximum error of 21 mm, and a max coefficient of variation (CV) of 24.3%; the standard deviation (SD) increased with travel speed and row unit vibration. For the John Deere ExactEmerge™ planter, the plant spacing was closer to the target plant spacing with a maximum error of only 5 mm and a max CV of 14.3%; the SD remained almost constant, at lower values than that of the MaxEmerge™ 5, at different speeds. For both planters, overall, the row unit vibration increased planting spatial variability. The quality of feed index decreased with increased vertical acceleration on the row unit while the miss index increased. However, the multiples index was generally unaffected by row unit vibration.
Recent advances in the ability to capture high spatial resolution images by unmanned aerial vehicles (UAVs) have shown the potential of this technology for a wide range of application including exploring the effects of different external stimuli when monitoring environmental and structural variables. In this paper, we show the application of UAV technology for crop height monitoring and modelling to provide quantitative crop growth data and demonstrate the remote sensing and photogrammetric capabilities of the technology to the farming industry. This study was carried out in a field trial involving a combination of six wheat varieties and three different fungicide treatments. The UAV imagery of the field trial site was captured on five occasions throughout crop development. These were used to create digital surface models from which crop surface models (CSMs) were extracted for the cropped areas. Crop heights are estimated from the photogrammetric derived CSMs and are compared against the reference heights captured using Real-Time Kinematic Global Navigation Satellite System (GNSS) to validate the CSMs. Furthermore, crop growth differences among varieties are analysed; and crop height correlations with grain yield as well as with independently estimated vegetation indices are evaluated. These evaluations show that the technology is suitable (with average bias range 2-10 cm depending on wind conditions relative to GNSS height) and has potential for quantitative and qualitative monitoring of canopy and/or crop height and growth. Keywords Crop monitoring • Crop surface model • Digital surface model • Low-cost sensor system • Unmanned aerial vehicles • UAV in agriculture Zusammenfassung Überwachung von Getreidehöhen mit einer handelsüblichen Kamera und UAV Technologie. Jüngste Fortschritte bei der Erfassung von Bildern mit hoher Auflösung durch unbemannte Luftfahrzeuge (Unmanned Aerial Vehicles, UAV) haben das Potenzial dieser Technologie für einen breiten Anwendungsbereich aufgezeigt, einschließlich der Untersuchung der Auswirkungen verschiedener externer Reize bei der Überwachung von Umgebungs-und Strukturvariablen. In diesem Artikel zeigen wir die Anwendung der UAV-Technologie zur Überwachung und Modellierung von Getreidehöhen, um quantitative Getreidewachstumshöhen bereitzustellen und die Fernerkundungs-und photogrammetrische Fähigkeiten der Technologie für die Landwirtschaft zu demonstrieren. Diese Studie wurde in einem Feldversuch mit einer Kombination von sechs Weizensorten und drei verschiedenen Pilzbehandlungen durchgeführt. Die UAV-Bilder des Feldversuchsgeländes wurden während der gesamten Ernteentwicklung fünfmal aufgenommen. Diese Bilder wurden verwendet, um digitale Oberflächenmodelle (Digital Surface Models-DSMs) zu erstellen, aus denen Getreideoberflächenmodelle (Crop Surface Models-CSMs) für die Versuchsflächen extrahiert wurden. Die Erntehöhen werden aus den photogrammetrisch abgeleiteten CSMs geschätzt DGPF
Yellow poplar (Liriodendron tulipifera) was chosen as the woody biomass for the production of charcoal for use in a liquid fuel slurry. Charcoal produced from this biomass resulted in a highly porous structure similar to the parent material. Micronized particles were produced from this charcoal using a multi-step milling process and verified using a scanning electron microscope and laser diffraction system. Charcoal particles greater than 50 µm exhibited long needle shapes much like the parent biomass while particles less than 50 µm were produced with aspect ratios closer to unity. Laser diffraction measurements indicated D10, D50, and D90 values of 4.446 µm, 15.83 µm, and 39.69 µm, respectively. Moisture content, ash content, absolute density, and energy content values were also measured for the charcoal particles produced. Calculated volumetric energy density values for the charcoal particles exceeded the No. 2 diesel fuel that would be displaced in a liquid fuel slurry.
BOAZ, ROBERT DALE. Design of a Pneumatic Baling System for Burley and Fluecured Tobacco. (Under the direction of Michael D. Boyette.) Current tobacco baling technology utilizes hydraulic power to press tobacco into bales. The high system pressures at which hydraulic systems operate pose a risk to workers. Hydraulic systems are costly and hydraulic oil leaks contaminate baled tobacco. A pneumatically driven, vertically oriented, multi-stroke baler was designed as an affordable alternative to current hydraulic balers. Pneumatics was chosen due to the lower system operating pressure and absent risk of tobacco bale contamination. The transmission of power was achieved through a reversible pneumatic gearmotor turning left and right hand acme threaded rods coupled together to form a powerscrew. The plunger was driven by a scissor-jack design and was used to take advantage of the non-linear force response of tobacco. The scissor-jack was driven by acme nuts traveling along the acme rod of the powerscrew. The baler was tested with burley tobacco grown during the 2007 season at the Central Crops Research Station in Clayton, NC. The compressive force and plunger displacement was measured for each bale produced. These readings were used to determine the compressive force as a function of plunger travel and the compressive force as a function of bale density. The baler required 3-4 presses to produce burley bales roughly 42 inches cubed and weighing approximately 500-600 pounds.
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