Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 8 of 8
Full-Text Articles in Entire DC Network
Urban Agriculture And Small Farm Water Use: Case Studies And Trends From Cache Valley, Utah, Tyler Pratt, L. Niel Allen, David E. Rosenberg, Andrew A. Keller, Kelly Kopp
Urban Agriculture And Small Farm Water Use: Case Studies And Trends From Cache Valley, Utah, Tyler Pratt, L. Niel Allen, David E. Rosenberg, Andrew A. Keller, Kelly Kopp
Publications
The landscape of water in Utah is changing due to population growth, conversion of agricultural land to urban development, and increasing awareness of water scarcity. At the same time, Utah is experiencing a growing number of urban and small farms, but knowledge of water use in this sector is limited. Better understanding of what occurs at the field level on urban and small farms can aid state water use estimates and conservation efforts, and assist farmers in moving towards wiser water management. For the 2015 growing season, we performed irrigation evaluations for 24 urban and small farms in Cache Valley, …
Double-Ended High Pressure Sodium Fixtures Decline Less Than 6% Over 2 Years And 5000 Hours, Jakob Johnson, Bruce Bugbee
Double-Ended High Pressure Sodium Fixtures Decline Less Than 6% Over 2 Years And 5000 Hours, Jakob Johnson, Bruce Bugbee
Publications
Double-ended (DE) high pressure sodium (HPS) lights with electronic ballasts are reported to age more slowly than the old mogul base technology with magnetic ballasts, but aging has not been well studied in a greenhouse environment. Both dirt accumulation and age can decrease output.
Analysis Of Environmental Effects On Leaf Temperature Under Sunlight, High Pressure Sodium And Light Emitting Diodes, Jacob A. Nelson, Bruce Bugbee
Analysis Of Environmental Effects On Leaf Temperature Under Sunlight, High Pressure Sodium And Light Emitting Diodes, Jacob A. Nelson, Bruce Bugbee
Publications
The use of LED technology is commonly assumed to result in significantly cooler leaf temperatures than high pressure sodium technology. To evaluate the magnitude of this effect, we measured radiation incident to and absorbed by a leaf under four radiation sources: clear sky sunlight in the field, sunlight in a glass greenhouse, and indoor plants under either high pressure sodium or light emitting diodes. We then applied a common mechanistic energy-balance model to compare leaf to air temperature difference among the radiation sources and environments. At equal photosynthetic photon flux, our results indicate that the effect of plant water status …
Effect Of Silicon On Plant Growth And Drought Stress Tolerance, Kaerlek W. Janislampi
Effect Of Silicon On Plant Growth And Drought Stress Tolerance, Kaerlek W. Janislampi
Publications
Silicon is not considered an essential nutrient, but it is typically abundant in soils and can be taken up in large amounts by plants. Silicon is known to have beneficial effects when added to rice and several other plants. These effects include disease and insect resistance, structural fortification, and regulation of the uptake of other ions. In this study, the effect of silicic acid fertilization on the growth and drought tolerance of four crop plants (corn, wheat, soybean, and rice) was analyzed. Plants were studied using three cultivation techniques: 1) hydroponic solution and subjected to salt stress, 2) low-silicon soil-less …
Optimizing The Physical And Nutritional Environment Of Unleached Root-Zones, Curtis B. Adams
Optimizing The Physical And Nutritional Environment Of Unleached Root-Zones, Curtis B. Adams
Publications
Unleached root-zones represent an environmental ideal by eliminating wasteful leaching of nutrients and water. NASA grows plants in space in unleached root-zones, incorporating polymer-coated fertilizer (PCF) into a ceramic media (Turface or Profile). However, lack of growth productivity in space has led to the need for research to improve the nutritional and physical environment of the root-zone, which is the objective of this research. PCF types are diverse in release characteristics and the effects of temperature and substrate water content have not been well characterized. In spite of widespread use, studies on chemical properties and applied studies to verify soil …
Ethylene Synthesis And Sensitivity In Crop Plants, Joseph F. Romagnano
Ethylene Synthesis And Sensitivity In Crop Plants, Joseph F. Romagnano
Publications
The gaseous plant hormone ethylene is a small molecule that regulates developmental change. Research was conducted in three areas: sensitivity, synthesis, and alterations to synthesis. Vegetative pea plants were more sensitive than radish plants to atmospheric ethylene. Light intensity did not affect ethylene sensitivity. Ethylene synthesis rates were measured for unstressed cotton, corn, soybean, and tomato plants. The per-plant ethylene synthesis rate ranged from 0.1-80 pmol plant-1 s-1. However, when normalized to net photosynthetic rate, this range was 1-4 µmol of ethylene synthesis per mol of CO2 uptake. Diurnal cycles in ethylene synthesis were present in all crops studied. These …
Use Of Ground-Based Canopy Reflectance To Determine Radiation Capture, Nitrogen And Water Status, And Final Yield In Wheat, Glen L. Ritchie
Use Of Ground-Based Canopy Reflectance To Determine Radiation Capture, Nitrogen And Water Status, And Final Yield In Wheat, Glen L. Ritchie
Publications
Ground-based spectral imaging devices offer an important supplement to satellite imagery. Hand-held, ground-based sensors allow rapid, inexpensive measurements that are not affected by the earth’s atmosphere. They also provide a basis for high altitude spectral indices. We quantified the spectral reflectance characteristics of hard red spring wheat (Triticum aestivum cv. Westbred 936) in research plots subjected to either nitrogen or water stress in a two year study. Both types of stress reduced ground cover, which was evaluated by digital photography and compared with ten spectral reflectance indices. On plots with a similar soil background, simple indices such as the normalized …
Comparison Of Tolerance To High Moisture Conditions Of The Soil Among Crop Plants: Studies On The Comparative Plant Nutrition [English Translation], Toshiaki Tadano, Kiyokazu Kirimoto, Isao Aoyama, Arika Tanaka
Comparison Of Tolerance To High Moisture Conditions Of The Soil Among Crop Plants: Studies On The Comparative Plant Nutrition [English Translation], Toshiaki Tadano, Kiyokazu Kirimoto, Isao Aoyama, Arika Tanaka
Publications
Tolerance to high moisture conditions in the soil was compared for eighteen crop species, and factors causing differences among species were studied: 1) When the moisture content of a soil was kept high, the soil air contained 10.5 - 17.5% of O2 and 5.0 - 9.8% of CO2, and the soil solution was not very high in Fe, Mn or NO2-N. 2) Cruciferae, Solanaceae, sugar beet, field bean, pea, cucumber and Chrysanthemum coronarium were very susceptible to this condition, but maize, soybean, and onion were tolerant. Rice grew better under this condition than under ordinary upland conditions. 3) Tolerance to …