Some Effects of Simulated Acid Rain on Cool Season Turfgrasses

Six varieties of cool season turfgrasses were exposed to simulated acid rainfall with treatments consisting of a sulfuric acid solution, a nitric acid solution, and a 50-50 mixture of both. Each solution was used to make acid rain of pHs 3.0, 2.5, 2.0, and 1.5. Height measurements showed decreases in growth throughout the experiment for all treatments except the nitric and 50-50 acid treatments at pHs of 2.0 and 1.5, which maintain fairly constant growth. Analysis of nitrate, phosphorous, and potassium levels in the soil indicated heavy leaching of the nitrates and potassium from most soil samples, which probably account for the reduced growth observed. There appeared to be an increase in leaching of potassium from samples recieving the more acidic treatments. Grasses with little decrease in growth showed greater foliar injury than did the stunted plants. Greater foliar injury was also observed at the beginning of the experiment when all the plants were fairly uniform in height. Soil pH showed little change except for the pH 1.5 sulfuric acid treatments, which caused some increase in acidity. There was no correlation between the soil pH and turfgrass height or foliar injury. A separate, related experiment was conducted to investigate a new chlorophyll extraction procedure reported in the literature for obtaining chlorophyll concentrations expressed as mg chlorophyll per gram dry weight. Chlorophyll extracts from the injured plants showed a reduction in chlorophyll A, chlorophyll B, and total chlorophyll. Injured plants also showed a decrease in chlorophyll A to B ratios. In addition, higher percentages of chlorophyll were extracted from uninjured tissue than from injured tissue. Length of storage studies indicated that chlorophyll extracts were stable for at least ten days when stored in the dark

Some Effects of Simulated Acid Rain on Cool Season Turfgrasses

Six varieties of cool season turfgrasses were exposed to simulated acid rainfall with treatments consisting of a sulfuric acid solution, a nitric acid solution, and a 50-50 mixture of both. Each solution was used to make acid rain of pHs 3.0, 2.5, 2.0, and 1.5. Height measurements showed decreases in growth throughout the experiment for all treatments except the nitric and 50-50 acid treatments at pHs of 2.0 and 1.5, which maintain fairly constant growth. Analysis of nitrate, phosphorous, and potassium levels in the soil indicated heavy leaching of the nitrates and potassium from most soil samples, which probably account for the reduced growth observed. There appeared to be an increase in leaching of potassium from samples recieving the more acidic treatments. Grasses with little decrease in growth showed greater foliar injury than did the stunted plants. Greater foliar injury was also observed at the beginning of the experiment when all the plants were fairly uniform in height. Soil pH showed little change except for the pH 1.5 sulfuric acid treatments, which caused some increase in acidity. There was no correlation between the soil pH and turfgrass height or foliar injury. A separate, related experiment was conducted to investigate a new chlorophyll extraction procedure reported in the literature for obtaining chlorophyll concentrations expressed as mg chlorophyll per gram dry weight. Chlorophyll extracts from the injured plants showed a reduction in chlorophyll A, chlorophyll B, and total chlorophyll. Injured plants also showed a decrease in chlorophyll A to B ratios. In addition, higher percentages of chlorophyll were extracted from uninjured tissue than from injured tissue. Length of storage studies indicated that chlorophyll extracts were stable for at least ten days when stored in the dark

Environmental and cultural considerations for growth of potatoes in CELSS

The white potato (Solanum tuberosum) was evaluated for use in the Closed Ecology Life Support System (CELSS) because of its high ratio of edible to inedible biomass and highly nutritious tuber that consists of readily digestible carbohydrates and proteins. Results are given for conditions that will produce the highest yields. The results, given in tabluar form, indicate the optimum temperatures, irradiance, carbon dioxide concentration, root environment, plant spacing, root and stolen containment, and harvesting times

Making Plant-Support Structures From Waste Plant Fiber

Environmentally benign, biodegradable structures for supporting growing plants can be made in a process based on recycling of such waste plant fiber materials as wheat straw or of such derivative materials as paper and cardboard. Examples of structures that can be made in this way include plant plugs, pots, planter-lining mats, plant fences, and root and shoot barriers. No chemical binders are used in the process. First, the plant material is chopped into smaller particles. The particles are leached with water or steam to remove material that can inhibit plant growth, yielding a fibrous slurry. If the desired structures are plugs or sheets, then the slurry is formed into the desired shapes in a pulp molding subprocess. If the desired structures are root and shoot barriers, pots, or fences, then the slurry is compression-molded to the desired shapes in a heated press. The processed materials in these structures have properties similar to those of commercial pressboard, but unlike pressboard, these materials contain no additives. These structures have been found to withstand one growth cycle, even when we

Physiological Disorders in Closed, Controlled Environment Crops

This slide presentation reviews some of the physiological disorders that affect crops grown in closed controlled environments. A physiological disorder is understood to be a problem resulting from the influence of environmental and horticultural factors on plan development other than a problem caused by a pathogen or some other abiotic cause. The topics that are addressed are: (1) Calcium-Related Disorders (2) Oedema (Intumescence) (3) Long-Photoperiod Injury (4) Light Spectral Quality Effects (5) Super-Elevated CO2 Injuries (6) Ethylene (7) Other Disorders (8) Considerations for Closed Space Environments. Views of plant with the disorders are shown

Solid Freeform Fabrication of Transparent Fused Quartz using a Filament Fed Process

Glass is a critical material for many scientific and engineering applications including optics, communications, electronics, and hermetic seals. Despite this technological relevance, there has been minimal research toward Additive Manufacturing (AM) of glass, particularly optically transparent glass. Additive Manufacturing of transparent glass offers potential advantages for lower processing costs for small production volumes, increased design freedom, and the ability to locally vary the optical properties of the part. Compared to common soda lime glass, fused quartz is better for AM since it has lower thermal expansion and higher index homogeneity. This paper presents a study of additive manufacturing of transparent fused quartz by a filament fed process. A CW CO2 laser (10.6 µm) is used to melt glass filaments layer by layer. The laser couples to phononic modes in the glass and is well absorbed. The beam and melt pool are stationary while the work piece is scanned using a standard lab motion system. Representative parts are built to explore the effects of variable laser power on the properties of printed fused quartz. During printing the incandescent emission from the melt pool is measured using a spectrometer. This permits process monitoring and identifies potential chemical changes in the glass during printing. After deposition, the printed parts are polished and the transmission measured to calculate the absorption/scattering coefficient. Finally, a low-order thermal analysis is presented and correlated to experimental results, including an energy balance and finite volume analysis using Fluent. These results suggest that optical quality fused quartz parts with low absorption and high index of refraction uniformity may be printed using the filament-fed process

Large Plant Growth Chambers: Flying Soon on a Space Station near You!

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species, and those capabilities continue to grow. The Veggie vegetable production system will be deployed to the ISS in Spring of 2014 to act as an applied research platform with goals of studying food production in space, providing the crew with a source of fresh food, allowing behavioral health and plant microbiology experimentation, and being a source of recreation and enjoyment for the crew. Veggie was conceived, designed, and constructed by Orbital Technologies Corporation (ORBITEC, Madison, WI). Veggie is the largest plant growth chamber that NASA has flown to date, and is capable of growing a wide array of horticultural crops. It was designed for low energy usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nanometers), blue, (455 nanometers) and green (530 nanometers) light emitting diodes. Interfacing with the light cap is an extendable bellows baseplate secured to the light cap via magnetic closures and stabilized with extensible flexible arms. The baseplate contains vents allowing air from the ISS cabin to be pulled through the plant growth area by a fan in the light cap. The baseplate holds a Veggie root mat reservoir that will supply water to plant pillows attached via elastic cords. Plant pillows are packages of growth media and seeds that will be sent to ISS dry and installed and hydrated on orbit. Pillows can be constructed in various sizes for different plant types. Watering will be via passive wicking from the root mat to the pillows. Science procedures will include photography or videography, plant thinning, pollination, harvesting, microbial sampling, water sampling, etcetera. Veggie is one of the ISS flight options currently available for research investigations on plants. The Plant Habitat (PH) is being designed and constructed through a NASA-ORBITEC collaboration, and is scheduled to fly on ISS around 2016. This large plant chamber will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional monitoring capabilities include leaf temperature sensing and root zone moisture and oxygen sensing. The PH light cap will have red (630 nanometers), blue (450 nanometers), green (525 nanometers), far red (730 nanometers) and broad spectrum white light emitting diodes. There will be several internal cameras to monitor and record plant growth and operations

Growth Chambers on the International Space Station for Large Plants

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED (Light Emitting Diodes) lighting, and those capabilities continue to expand. The Veggie vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nanometers), blue, (455 nanometers) and green (530 nanometers) LEDs. Interfacing with the light cap is an extendable bellowsbaseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals