Physical Sciences and Mathematics Commons^™

Water-Energy-Food Linkages In Community Smallholder Irrigation Schemes: Center Pivot Irrigation In Rwanda, Ankit Chandra, Derek M. Heeren, Lameck O. Odhiambo, N. Brozovic

Daugherty Water for Food Global Institute: Faculty Publications

Water, energy, and food are linked in intricate ways in irrigated agriculture and understanding the interplay of these components is crucial for sustainable and profitable crop production, particularly in smallholder setting such as in sub-Saharan Africa. This study evaluates water-energy-food linkages, engineering and economic performance, irrigation decision making, and challenges faced around water management in a community-based mechanized irrigation scheme in Rwanda. The research is the first to analyze such as scheme, which uses technology typically used by large farmers in a smallholder setting. The study investigates the variation in water requirements and the relationship and impacts of this variability …

Downstream Hydrochemistry And Irrigation Water Quality Of The Syr Darya, Aral Sea Basin, South Kazakhstan, Bagdat Satybaldiyev, Baimurat Ismailov, Nurbek Nurpeisov, Kairat Kenges, Daniel D. Snow, Arindam Malakar, Omirzhan Taukebayev, Bolat Uralbekov

Daugherty Water for Food Global Institute: Faculty Publications

New hydrochemical measurements from the Syr Darya provide insights into factors affecting the composition and quality of a major freshwater source replenishing the Aral Sea. This river is heavily used for power and irrigation and crosses territories of four Central Asia republics. It is intensely managed, draining several major tributaries, many reservoirs, and numerous irrigation distribution systems and canals. Analysis of seasonal changes in dissolved ion concentrations using geochemical diagrams, elemental ratios, statistical correlation, and equilibrium modeling allowed the characterization of mineral formation processes that control the dissolved chemical composition. Measured water hydrochemistry and composition type differs substantially from previous …

Analysis Of Soil Change Across Nebraska, Trinity Baker

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

The world’s population is growing and an increasing populace requires more resources. These requirements place increasing pressure on the environment and the soil. Soils serve many important functions throughout the world. These functions range from offering a media for food production, providing a sink for organic carbon, nutrient cycling, and improving water quality. It is important to focus on the human impact on soils and their change over time.

For my research I examined how soils across Nebraska have changed over a time period of roughly 65 years. I sampled and analyzed 39 pedons from four Major Land Resource Areas …

Irrigation’S Impact On A Precipitation Event During Grainex In Nebraska, Usa, Daniel Whitesel

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

Numerous precipitation events were observed during the Great Plains Irrigation Experiment (GRAINEX). However, the precipitation event that was observed the morning of 23 July 2018 is the focus of this thesis. Six experiments were conducted which involved increasing or decreasing soil moisture by 5% increments over the irrigated cropland. An additional experiment, which changed the irrigated land use to grassland, showed precipitation increases. It was found that regardless of strength of irrigation, average precipitation decreased. Average precipitation decreased by up to 72% when irrigation increased compared to the control simulation and decreased by up to 85% when irrigation decreased compared …

Impacts Of Irrigated Agriculture On The Near Surface And Planetary Boundary Layer Atmosphere: Results From The Great Plains Irrigation Experiment (Grainex), Emilee Lachenmeier

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

Modification of natural prairie grasslands into irrigated and rainfed agriculture in the Great Plains produced significant impacts on regional weather and climate including temperatures, precipitation, energy fluxes, and the planetary boundary layer (PBL) atmosphere. The Great Plains Irrigation Experiment (GRAINEX) during the 2018 growing season collected data over irrigated and non-irrigated crop fields to further understand these impacts. The data were collected during two intensive observation periods (IOPs) in early June (IOP 1: 30 May – 13 June of 2018) and late July (IOP 2: 16 July – 30 July of 2018). The data analyzed include latent (LE) and sensible …

Identifying Advantages And Disadvantages Of Variable Rate Irrigation – An Updated Review, S. A. O’Shaughnessy, Steve R. Evett, Paul D. Colaizzi, Manuel A. Andrade, Thomas H. Marek, Derek M. Heeren, Freddie R. Lamm, Jacob L. Larue

Department of Biological Systems Engineering: Papers and Publications

Variable rate irrigation (VRI) sprinklers on mechanical move irrigation systems (center pivot or lateral move) have been commercially available since 2004. Although the number of VRI, zone or individual sprinkler, systems adopted to date is lower than expected there is a continued interest to harness this technology, especially when climate variability, regulatory nutrient management, water conservation policies, and declining water for agriculture compound the challenges involved for irrigated crop production. This article reviews the potential advantages and potential disadvantages of VRI technology for moving sprinklers, provides updated examples on such aspects, suggests a protocol for designing and implementing VRI technology …

Irrigation Impacts On Minimum And Maximum Surface Moist Enthalpy In The Central Great Plains Of The Usa, Tianyi Zhang, Rezaul Mahmood, Xiaomao Lin, Roger A. Pielke Sr.

High Plains Regional Climate Center: Personnel Publications

Agricultural activities notably alter weather and climate including near-surface heat content. However, past research primarily focused on dry bulb temperature without considering the role of water vapor (dew point temperature) on surface air heat content. When using dry bulb temperature trends to assess these changes, for example, not including concurrent trends in absolute humidity can lead to errors in the actual rate of warming or cooling. Here we examined minimum and maximum surface moist enthalpy, which can be expressed as “equivalent temperature.” Using hourly climate data in the Central Great Plains (Nebraska and Kansas) from 1990 to 2014, the averages …

Groundwater Recharge Response To Reduced Irrigation Pumping In Western Nebraska, Justin Philip Gibson

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

Given current and continued investment in irrigation scheduling technologies, a need exists to better estimate the longevity and magnitude of water savings at watershed level to avoid the paradox of irrigation efficiency. This paradox occurs within a watershed as not all irrigation inefficiencies lead to the system losing water. For example, irrigation pumping rates in excess of crop water demand may lead to enhanced groundwater recharge or surface runoff that migrates to a stream. Thus, increases in efficiency may not lead to similar magnitudes of water savings. I hypothesize that water savings longevities are short given previous work demonstrating rapid …

Econometric Estimation Of Groundwater Depth Change For The High Plains Aquifer, Jonathan R. Sims

Department of Agricultural Economics: Dissertations, Theses, and Student Research

This article presents a new method for estimating changes in depth to groundwater at a yearly, county level and incorporates these estimates as the dependent variable of econometric models for the High Plains aquifer. The High Plains (Ogallala) aquifer underlies eight states in the central United States and is the primary source of irrigation water for this large food producing region. The stock of groundwater is a finite, non-renewable resource with minimal recharge in most areas. Many fields of study, including hydrology and agricultural economics, are interested in depth to groundwater changes because they serve as a proxy for estimating …

A Compact To Revitalise Large-Scale Irrigation Systems Using A Leadership-Partnership-Ownership 'Theory Of Change', Bruce Lankford, Ian Makin, Nathanial Matthews, Peter G. Mccornick, Andrew Noble, Tushaar Shah

Daugherty Water for Food Global Institute: Faculty Publications

In countries with transitional economies such as those found in South Asia, large-scale irrigation systems (LSIS) with a history of public ownership account for about 115 million ha (Mha) or approximately 45% of their total area under irrigation. In terms of the global area of irrigation (320 Mha) for all countries, LSIS are estimated at 130 Mha or 40% of irrigated land. These systems can potentially deliver significant local, regional, and global benefits in terms of food, water and energy security, employment, economic growth, and ecosystem services. For example, primary crop production is conservatively valued at about US$355 billion. However, …

Analytical Modeling Of Irrigation And Land Use Effects On Streamflow In Semi-Arid Conditions: Frenchman Creek, Nebraska, Jonathan P. Traylor

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

With proliferation of various numerical models, water budget studies commonly resort to numerical modeling techniques. However, availability and uncertainty in input data limit advantages of this approach. Often, analytical models capture the major traits of the watersheds and can assimilate important data. We developed a model for baseflow-dominated watersheds and apply it to Frenchman Creek in southwestern Nebraska. Frenchman Creek has experienced large streamflow reductions since the 1950s. The cause of these reductions is a combination of irrigation, conservation terrace construction, and other land use changes. However, the influence of each factor has not been well quantified. The objective of …

G93-1191 Glossary Of Water-Related Terms, William L. Kranz, Delynn Hay, James W. Goeke, David Gosselin

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide is a glossary of water quantity, quality and human health related terms involving water. Terms are defined in contexts that could affect Nebraskans. We depend upon water for our very existence. The impact of water quality and quantity issues has never been greater. Yet the terminology used to describe the water we drink, the water we provide to plants and animals, the water stored underground, in lakes, rivers, and oceans, is not well understood by many Nebraskans. This listing of water-related terms is intended to reduce the potential for misunderstanding presentations made by elected officials, environmental agencies and …

Irrigation Scheduling Of Corn Utilizing Infrared Thermometry, Kirk L. Clawson

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

No abstract provided.

Influence Of Irrigation On The Microclimate And Development Of White Mold Disease In Dry Edible Beans, L. E. Hipps

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

No abstract provided.