Physical Sciences and Mathematics Commons^™

Modelling Water Uptake Provides A New Perspective On Grass And Tree Coexistence, Michael G. Mazzacavallo, Andrew Kulmatiski

Wildland Resources Faculty Publications

Root biomass distributions have long been used to infer patterns of resource uptake. These patterns are used to understand plant growth, plant coexistence and water budgets. Root biomass, however, may be a poor indicator of resource uptake because large roots typically do not absorb water, fine roots do not absorb water from dry soils and roots of different species can be difficult to differentiate. In a sub-tropical savanna, Kruger Park, South Africa, we used a hydrologic tracer experiment to describe the abundance of active grass and tree roots across the soil profile. We then used this tracer data to parameterize …

Estimation Of The Effects Of Climate Variability On Crop Yield In The Midwest Usa, Ruoyu Wang

Ruoyu Wang

Soil Water Potential Control Of The Relationship Between Moisture And Greenhouse Gas Fluxes In Corn-Soybean Field, Dinesh Panday, Nsalambi V. Nkongolo

Dinesh Panday

Analyzing The Relationship Of Soil Moisture And Biophysical Variables In Wet And Dry Seasons At A Rainfed And Irrigated Field In Eastern Nebraska, Eric Hunt

School of Natural Resources: Dissertations, Theses, and Student Research

Agriculture production, particularly of maize and soybeans, is a major component of Nebraska’s economy and identity. However, agricultural production in Nebraska faces increasing challenges. One of the challenges is the potential for excessive groundwater depletion due to increased demand for food and fuel from irrigated Nebraska crops and increasing risks of water stress due to climate change. Therefore, it is has become essential for a deeper understanding of the soil-plant-atmosphere continuum to help producers make more informed management decisions. One of the most important variables is soil moisture. Soil moisture is an integral part of the hydrologic cycle and an …

Hydrologic Mediation Of The Spatial And Temporal Variability Of The Soil Carbon Dioxide Stable Isotopic Composition Of A Subalpine Watershed, Theresa Marie Lorenzo

School of Natural Resources: Dissertations, Theses, and Student Research

The stable carbon isotopic composition of CO₂ (δ¹³C-CO₂) has been studied as an indicator of changes in ecosystem CO₂ exchange. Soil moisture is an important factor in ecosystem CO₂ exchange through its influence on physiological and soil physical processes. However, the majority of previous research analyzing the influence of soil moisture on soil and soil-respired δ¹³C-CO₂ has been conducted with limited consideration of topographical variation, which controls the distribution of soil moisture across a landscape. This study characterized the stable isotopic composition (δ¹³C) and concentrations of soil CO …

Assessment Of Surface Soil Moisture Using High-Resolution Multi-Spectral Imagery And Artificial Neural Networks, Leila Hassan-Esfahani, Alfonso Torres-Rua, Austin Jensen, Mac Mckee

AggieAir Publications

Many crop production management decisions can be informed using data from high-resolution aerial images that provide information about crop health as influenced by soil fertility and moisture. Surface soil moisture is a key component of soil water balance, which addresses water and energy exchanges at the surface/atmosphere interface; however, high-resolution remotely sensed data is rarely used to acquire soil moisture values. In this study, an artificial neural network (ANN) model was developed to quantify the effectiveness of using spectral images to estimate surface soil moisture. The model produces acceptable estimations of surface soil moisture (root mean square error (RMSE) = …

Extending The Soil Moisture Data Record Of The U.S. Climate Reference Network (Uscrn) And Soil Climate Analysis Network (Scan), Ethan J. Coopersmith, Jesse E. Bell, Michael H. Cosh

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Soil moisture estimates are valuable for hydrologic modeling, drought prediction and management, climate change analysis, and agricultural decision support. However, in situ measurements of soil moisture have only become available within the past few decades with additional sensors being installed each year. Comparing newer in situ resources with older resources, previously required a period of crosscalibration, often requiring several years of data collection. One new technique to improve this issue is to develop a methodology to extend the in situ record backwards in time using a soil moisture model and ancillary available data sets. This study will extend the soil …