In 2010 Decagon awarded seven individuals instrumentation through the GA Harris Research Instrumentation Fellowship. Those winners were:
Ginger Allington, Saint Louis University
Influence of Soil Properties on the Reversal of Desertification
The desertification of arid grasslands around the world is seen a largely irreversible. However, recent work has documented recovery of perennial grasses in long-term livestock enclosures at four desertified sites. At one such site, changes in vegetation were concomitant with increased water infiltration and soil nutrients. Based on these data I proposed the following mechanism for reversal of desertification: in the long-term absence of livestock, water infiltration rates increase via release from compaction, which decreases erosion and allows soil nutrients accumulate to a level that is favorable to perennial grass re-establishment. To test this model, I am collecting data from additional long-term livestock enclosures, at sites with and without grass recovery. These data will allow us to draw more comprehensive conclusions about the dynamics of desertified systems, and the potential for restoration of arid range lands.
Kendall DeJong, Colorado State University
Quantification of Consumptive Use and Return Flows in Irrigated Agriculture
As rapid municipal growth occurs in the Colorado Front Range and other water-limited areas of the United States, increasing pressure is put on farmers to transfer water rights. As an alternative to permanent water rights transfers, Kendall's research investigates the ability of producers to reduce seasonal consumptive use and optionally lease unused water to cities. Kendall will use the Decagon Watershed Characterization Package to monitor three sensor arrays in a furrow irrigated corn field. Data collected at these sites will help compute all components of the water balance. This sampling method could potentially be used by individual producers as a low-cost method to quantify both evapotranspiration and return flows.
Michael Wine, Oklahoma State University
Effects of Marginal Land Conversion to Bio-energy Feedstock Production on the Water Cycle
Recent government mandates requiring increased production of bio-fuels to improve sustainability of the nation's fuel supply and reduce carbon emissions could affect the water cycle both during and after energy crop establishment. Switchgrass, a leading choice for biomass production has deeper roots than dominant mixed-grass prairie species. We will use paired watersheds in Woodward, Oklahoma to determine how switchgrass establishment and production will affect each component of the water cycle. The GA Harris Fellowship will provide Decagon Drain Gauge Lysimeters to determine deep drainage on each watershed and improve our understanding of both the baseline water cycle of this landscape and the water budget associated with a switchgrass monoculture.
Jill Sherwood, Iowa State University
Climate Change Effects on Trophic Interaction in Montane Meadow Systems
Climate change is likely to impact many biological systems. This study will quantify how modification in the timing of key biological events could affect a montane meadow ecosystem. In this project, Jill will manipulate snow cover and temperature to mimic the effects of predicted climate change. She will then test the interactions between soil moisture, soil temperature, and air temperature on emergence and survival of Parnassius clodius butterflies and their host plants, Dicentra uniflora. The results will provide insight into the interactions of butterflies and their host plants and will be used as a proxy for understanding climate change impacts in other ecological systems.
Camila Tejo Haristoy, University of Washington
Water-holding Capacity and Temperature Patterns of Canopy Soils in an Old-growth Sitka Spruce Forest of Washington State
Sitka Spruce tree crowns contain large accumulations of organic matter known as "canopy soil". These accumulations provide substrate and habitat for a broad community of plants, insects, and other arboreal species. Using tree-climbing techniques, moisture and temperature sensors will be installed in the canopy soils of spruce trees of an old-growth stand of the Olympic Peninsula, Washington. This study will Characterize for the fist time environmental conditions associated with soil mats within the crown of spruce trees, providing a framework for understanding the distribution and activity of epiphytic plants, nutrient dynamics and associated canopy organisms.
Tracy Rowlandson, Iowa State University
Investigation into the Spatial Variability of Dew at Field Scale
Investigations into the spatial and temporal variability of dew have implications for both plant disease management and remote sensing of soil moisture. In this study, the process of scaling point measurements of dew to canopy scale will be investigated by determining the contribution of LAI for regions in the canopy with the highest and lowest dew amounts to the total LAI of the canopy. Leaf wetness sensors will be used to determine where in a soybean canopy the greatest dew duration (and amount) occurs. Investigation at locations around a field will be examined for variation of dew within a field.
Nikki Woodward, University of Wisconsin
Thermal Conduction Phenomena of Compacted Fill for Sustainable Energy Practice
Maximizing heat flow around high voltage, high ampacity cables in wind energy collector trenches and in shallow geothermal exchange trenches is necessary for efficient cyclic heating and cooling processes in compacted, engineered trench back fill soil. Research into the physical structure of compacted fill and theoretical constraints as related to heat input rate and thermally driven moisture flow is limited in the unsaturated state. To transition from establishing soil thermal values for design by rules of thumb to using empirical correlations based on science and thermal measurements, a database of measured thermal properties for a comprehensive collection of soil types at variable compaction conditions will be compiled and investigated for correlations of soil thermal properties with physical properties.
Lafe Conner, Brigham Young University
Measuring Deep Drainage in the Soil as a Response to Grazing and Rainfall Manipulation
Climate change in the western United States is predicted to cause longer intervals between rainfall events and greater volume of rainfall in single events. Grazing will likely interact with climate change to influence the soil water balance. The instruments provided by this grant will measure changes in deep drainage related to rainfall manipulation in paired grazed and ungrazed treatments. Rainfall manipulation and grazing may result in greater water loss through deep drainage or may improve water availability in the root zone. The amount of water available for plants and soil bio-geochemical processes in a single year, may change even if total annual precipitation remains constant.
Sruthi Narayanan, Kansas State University
Canopy Architecture and Radiation Use Efficiency in Sorghum
This study investigates the influence of canopy architecture on sorghum radiation use efficiency. RUE was calculated as the ratio of above-ground biomass accumulation to cumulative intercepted photosynthetically active radiation (IPAR). Accupar LP-80 ceptometer measurements of PAR above and below a crop canopy provide measures IPAR and leaf area index. Preliminary results showed 1) lines differed in apparent RUE, which increased with average internode length; 2) positive correlation between RUE and water use efficiency (biomass produced per unit crop water use); 3) the increased productivity was due to increased radiation use efficiency rather than capture considering the similarity among lines in IPAR.
Andres Olivos, University of California, Davis
Modeling Root Distribution and Nutrient Uptake in Almonds
To optimize nutrient use efficiency in fertigated almond it is essential that fertilizers injected into the irrigation system are provided at the optimal concentration and time to ensure that deposition patterns coincide with maximal root nutrient uptake. The objective of the project is to instrument almond trees with 5TE water content devices to monitor ion and water movement to provide almond specific data to input in Hydrus 2D/3D model. The goals are to determine root distribution, water and solute movement and dynamics of plant nutrient uptake. These parameters, and the subsequent optimization of Hydrus performance, will be used to develop best fertilization management tools for almond growers.