Biochar: Properties And Potential Benefits For Agricultural Soil In Rwanda, Andromede Uwase

Honors Theses

Physical and chemical soil degradation is becoming a major challenge for agricultural productivity in Rwanda, which is the most important part of the country’s economy. The wide spreading soil degradation in Rwanda is mainly a result of naturally poor soils coupled with unsustainable soil management leading to, for example, accelerated soil erosion, acidification, nutrient loss, compaction, and to decreasing yields. Biochar, as an end product of pyrolysis of biomass in the absence of oxygen, has been proposed as a soil amendment in remediation strategies because of its positive effects on soil productivity relevant parameters such as soil pH, structure, nutrient …

American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison Ludwig

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …

Soil Chemical Properties After 12 Years Of Tillage And Crop Rotation, Maysoon M. Mikha, Gary Hergert, Xin Qiao, Bijesh Maharjan

Panhandle Research and Extension Center

Crop rotation in combinationwith tillage can improve productivity, enhance economical return, and reduce soil erosion. The objective of this study was to evaluate the impact of moldboard plow (MP), strip tillage (ST), no-tillage (NT), and crop rotations on: (1) crop yield; (2) soil chemical properties; and (3) particulate organic matter (POM). The study was initiated in 2007 at the University of Nebraska-Lincoln Panhandle Research and Extension Center near Scottsbluff, NE. Crops in rotation were corn (C; Zea mays L.) and dry bean (DB; Phaseolus vulgaris L.) organized in a 3-yr rotation (C–DB–C) and a 4-yr rotation with the addition of …

Remediation Strategies To Reduce Heavy Metal Uptake In Lettuce Grown In Contaminated Urban Soil, Ryley Thomas

UCARE Research Products

Urban soils are increasingly used to produce food for local consumption, which requires at the same time management strategies that prevent the plant uptake of potentially present contaminants. This study was conducted to test different soil amendments for their ability to retain lead (Pb) and arsenic (As) within the soil matrix. The analyzed soil was taken from a potential community garden lot near a railroad in Lincoln, NE where elevated concentrations in Pb and As had been detected. Ponderosa pine biochar and spent coffee grounds were used as soil additives because of their documented chemical reactivity towards soil cations or …

Management Effects On Soil Quality Of The Geary Soil Series In Thayer County, Nebraska, Aime Nishimwe

UCARE Research Products

The CGIAR reports that around 40% of global crop yield variability is explained by climate. While global food consumption is expected to soar in 2050, the impact of climate change accounts for approximately 5% decrease in crop productivity. FAO estimates a 60% increase in global food demand by 2050, with global population reaching 9.8 billions. Sustainable soil management was also noted to boost agricultural food production by 58%. The evaluation of the impact of different management practices on dynamic soil properties was conducted on Geary silty clay loam, 3 to 7 %, eroded soils, which are mainly used for crop …

Defining, Measuring, And Applying Soil Quality: An Unresolved Debate, Salvador Ramirez Ii

Doctor of Plant Health Program: Dissertations and Student Research

Paradigm shifts occur periodically in the sciences. Proposed paradigm shifts offer opportunities to reexamine extant paradigms and evaluate new ones. Soil science experienced a controversy resembling a proposed paradigm shift in the late 1990s and early 2000s when it grappled with the idea of soil quality (SQ). The most contentious points in the SQ debates were (1) the word “quality” itself and designing a functional definition, (2) identifying appropriate soil quality indicators, (3) the integration of soil quality indicators, and (4) the interpretation of soil quality indicators. The latter three disagreements were rooted in the established, fundamental, soil science paradigm. …

Quantitative Appraisal Of Non-Irrigated Cropland In South Dakota, Shelby Riggs

Honors Theses

This appraisal attempts to remove subjectivity from the appraisal process and replace it with quantitative analysis of known data to generate a fair market value of the subject property. Two methods of appraisal were used, the income approach and the comparable sales approach. For the income approach, I used the average cash rent for the region, the current property taxes for the subject property, and a capitalization rate based on Stokes' (2018) capitalization rate formula to arrive at my income-based valuation. For the comparable sales approach, I utilized Stokes' (2018) research in optimization modeling to estimate a market value for …

Identifying And Addressing Soil Property Issues Affecting Roadside Vegetation Establishment, Xu Li, Martha Mamo, Walter H. Schacht, Tala Awada, Humberto Blanco-Canqui

Nebraska Department of Transportation: Research Reports

Attaining adequate vegetation cover along highways is important for NDOR to comply with EPA’s stormwater regulations. However, low plant cover is a common problem on shoulders (first 16 feet off the pavement) of many highways in Nebraska. The ultimate goal of this study is to identify cost-effective engineering solutions that assure adequate seed beds (i.e., soil conditions) for establishment of selected seeding mixtures. The objectives of this study are to (1) characterize the soil properties along roadsides where vegetation stands have not developed well, and (2) verify the effects of select soil property parameters on plant germination and establishment.

Sampling …

A Desert In Disguise: The Resilience Of The Nebraska Sandhills, Jeff Hartman

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

The Nebraska Sandhills are the largest sand dune system in the Western Hemisphere, and are unique because they remain relatively undisturbed from row crop agriculture. Research in the past two decades demonstrated that the Sandhills are dynamic on millennial timescales, switching between stabilized, vegetated states to non-vegetated, mobilized states. The Sandhills are currently stabilized, but understanding how ecological processes are altered as sand dunes transition from stabilized to mobilized states, provides insight into the thresholds, stability, and resilience of this grassland ecosystem. My research investigated the impacts of vegetation disturbances on ecological processes and the sand dune surface stability. For …

Cover Crops And Ecosystem Services: Insights From Studies In Temperate Soils, Humberto Blanco-Canqui, Tim M. Shaver, John L. Lindquist, Charles A. Shapiro, Roger Wesley Elmore, Charles A. Francis, Gary W. Hergert

Department of Agronomy and Horticulture: Faculty Publications

Cover crops (CCs) can provide multiple soil, agricultural production, and environmental benefits. However, a better understanding of such potential ecosystem services is needed. We summarized the current state of knowledge of CC effects on soil C stocks, soil erosion, physical properties, soil water, nutrients, microbial properties, weed control, crop yields, expanded uses, and economics and highlighted research needs. Our review indicates that CCs are multifunctional. Cover crops increase soil organic C stocks (0.1–1 Mg ha^–1 yr^–1) with the magnitude depending on biomass amount, years in CCs, and initial soil C level. Runoff loss can decrease by up …

A Regional Investigation Of In-Season Nitrogen Requirement For Maize Using Model And Sensor-Based Recommendation Approaches, Laura J. Stevens

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

N management for corn can be improved by applying a portion of the total N during the growing season, allowing for adjustments responsive to actual field conditions. This study was conducted to evaluate two approaches for determining in-season N rates: Maize-N model and active crop canopy sensor. Various sensor algorithms designed for making in-season N recommendations from crop canopy sensor data were evaluated. The effects of corn hybrid and planting population on recommendations with these two approaches were considered. In a 2-yr study, a total of twelve sites were evaluated over a 3-state region, including sites in Missouri, Nebraska, and …

Decomposition And Nutrient Release Of Different Cover Crops In Organic Farm Systems, Jianru Shi

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

Cover crops act as green manure adding organic matter to agricultural-soils. For legume green manures to be an effective nitrogen (N) source for organic farming systems, their N release must be in synchrony with crop N demand. The objectives of this study were 1) determine the decomposition rates of three common cover crops (white clover, (Trifolium repens,L ) red clover (Trifolium pratense L.) and soybean (Glycine max L) in order to determine when most N was released and its synchrony with subsequent corn crop uptake; 2) we focused on the effect of cover crops on soil …

Bacterial Diversity In Biological Soil Crusts From Extrazonal Mountain Dry Steppes In Northern Mongolia, Anne Kemmling, Birgit Pfeiffer, Rolf Daniel, Michael Hoppert

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Biological Soil Crusts (BSCs), consisting of prokaryotes, microalgae, lichens, mosses and eventually small vascular plants, cover wide areas in arid and semi-arid environments. In the present study, the microbial diversity of these crusts was explored at extrazonal mountain steppe sites in the western Khentej (Northern Mongolia). At the study site the Siberian taiga borders on the Mongolian-Daurian forest steppe, resulting in a unique intermixture of the dark taiga, the light taiga, and forest steppe (DULAMSUREN 2004). Due to the presence of boreal, temperate and dauric elements the forest steppe is eminently rich in species (MÜHLENBERG et al. 2004).

BSCs in …

Evaluation Of Algorithm Thresholds For Crop Canopy Sensor-Based In-Season Nitrogen Application In Corn, Brian T. Krienke

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen fertilizer is frequently the most limiting nutrient in corn production. Typically most nitrogen is applied before planting. Since nitrogen can leave the soil system fairly easily, the result can be an inefficient use of nitrogen fertilizer. Previous research has shown increased efficiency with no reduction in yield by applying nitrogen later in the season when the crop is actively growing, with rates regulated spatially through the use of active crop canopy sensors. This study evaluated the potential for N cutoff thresholds using a sufficiency index as the threshold value for areas with poor stand or an unrecoverable N deficiency. …

Distribution Of Dioecious Eastern Red Cedar (Juniperus Virginiana) Along An Environmental Gradient In Ogallala, Ne., Taylor Sloey

Department of Environmental Studies: Undergraduate Student Theses

Abstract

The purpose of this research was to study the sex distribution and energy allocation of dioecious Eastern Red Cedars (Juniperus virginiana) along an environmental resource gradient. The trees surveyed were growing in a canyon located at the University of Nebraska’s Cedar Point Biological Research Station in Ogallala, Nebraska. Due to the geography of this canyon, environmental factors necessary for plant growth should vary depending on the tree’s location within the canyon. These factors include water availability, sun exposure, ground slope, and soil nitrogen content, all of which are necessary for carbon acquisition.

Juniperus virginiana is a dioecious conifer. Dioecious …

Relating Fires Affect On Forest Succession And Forest's Effect On Fire Severity In One Burned And Unburned Environment, Tyler Jay Seiboldt

Department of Environmental Studies: Undergraduate Student Theses

Wildfires are a natural part of many forest ecosystems and play a vital role in maintaining their health. Wildfires can have a critical influence on a landscapes plant community through their relative frequency, seasonality, and severity. One of the most heavily influenced regions by wildfire disturbance is the Klamath Mountain region of California. I looked at the affect a wildfires severity had on the Whiskey creek valley within the Whiskeytown National Recreation Area. 8 tree species and 4 flower species were examined on both the burned and unburned regions within this valley nearly a year after the wildfire (May 17-23 …

An Integrated Crop- And Soil-Based Strategy For Variable-Rate Nitrogen Management In Corn, Darrin F. Roberts

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen (N) management in cereal crops has been the subject of considerable research and debate for several decades. Historic N management practices have contributed to low nitrogen use efficiency (NUE). Low NUE can be caused by such things as poor synchronization between soil N supply and crop demand, uniform application rates of fertilizer N to spatially variable landscapes, and failure to account for temporally variable influences on soil N supply and crop N need. Active canopy reflectance sensors and management zones (MZ) have been studied separately as possible plant- and soil-based N management tools to increase NUE. Recently, some have …

Using Gis To Locate Areas For Growing Quality Coffee In Honduras, Ellen Mickle

Department of Environmental Studies: Undergraduate Student Theses

Abstract Small-scale coffee producers worldwide remain vulnerable to price fluctuations after the 1999-2003 coffee crisis. One way to increase small-scale farmer economic resilience is to produce a more expensive product, such as quality coffee. There is growing demand in coffee-producing and coffee-importing countries for user-friendly tools that facilitate the marketing of quality coffee. The purpose of this study is to develop a prototypical quality coffee marketing tool in the form of a GIS model that identifies regions for producing quality coffee in a country not usually associated with quality coffee, Honduras. Maps of areas for growing quality coffee were produced …

Variations In Stomatal Traits Of 14 Bornean Tree Species Growing On Soils With Different Moisture Contents In Lambir Hills National Park, Whitney Logan Cannon

Department of Environmental Studies: Undergraduate Student Theses

The goal of this study was to look at variations in stomatal traits of tree species on soils with different moisture contents and fertility at Lambir Hills National Park. Stomates are important structures on the surface of leaves that mediate conduction of moisture and gassesin and out of the leaf. If stomatalt raits are important for regulation, then there should be variation in stomatal traits in regards to their soil specialization. The 14 Borneant ree speciess ampledi ncluded6 sandyl oam specialists6, clay specialistsa nd 2 generalistsfo und growing with equald istributionso n both sandyl oam and clay. Confocal microscopy was …

Adoption Of Riparian Forest Buffers On Private Lands In Nebraska, Usa, Peter Skelton, Scott J. Josiah, James W. King, James R. Brandle, Glenn A. Helmers, Charles A. Francis

Department of Agricultural Leadership, Education, and Communication: Faculty Publications

Pesticide and nutrient runoff from agricultural fields is a socio-environmental problem in the Midwestern United States. Riparian forest buffers (RFBs) are a proven conservation practice that effectively manage this problem, though adoption rates are low. A mail survey was conducted to determine differences between adopter and nonadopter characteristics and attitudes with regard to the use of RFBs. Data were collected from 48 RFB adopters and 261 RFB nonadopters in two Nebraska watersheds. Inferential and multivaririate statistics were used to identify differences between adapter status and producer status groups. About half (50.8%) the respondents were nonproducers. Nonproducers are agricultural landowners not …

Chemical, Physical And Mineralogical Properties Of Mitchell And Tripp Soils In The Nebraska Panhandle, G. A. Uzochukwu, D. T. Lewis

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Mitchell and Tripp soils are some of the most important agricultural soils in the Nebraska Panhandle. Yet, they have received little attention in terms of their basic chemical, physical, and mineral properties. Management decisions can be made on a more informed basis if this kind of information is available. This study was to acquire the information, with special emphasis on mineralogical properties of the soils and their parent materials. This emphasis was given because it is known that other soils in the region contain volcanic ash in measurable amounts. The presence of volcanic ash in soils has been associated with …

Effects Of No-Tillage Fallow As Compared To Conventional Tillage In A Wheat-Fallow System, C. R. Fenster, G. A. Peterson

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

The benefits of reducing tillage by use of herbicides for weed control emphasizes why research was started to study a fallow system where all tillage was replaced by herbicides. Wheat planting was then the only soil disturbing operation. Objectives of the research were to compare the effects of no-tillage (chemical), stubble-mulch and plow (bare fallow) systems of fallow on: 1. Grain yield. 2. Grain protein. 3. Residue retention. 4. Soil nitrate-nitrogen accumulation. 5. Soil water accumulations during fallow. Data presented are in the form of a progress report. These experiments will continue.

Nutrient And Energy Composition Of Beef Cattle Feedlot Waste Fractions, C. B. Gilbertson, J. A. Nienaber, J. R. Ellis, T. M. Mccalla, T. J. Klopfenstein, S. D. Farlin

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

This bulletin describes nutrient and energy composition of beef cattle waste fractions as a function of the ration roughage level and type of feedlot. Results can be used to plan engineering system approaches and research to develop handling and processing equipment necessary for recovery of the most valuable portion of waste.

Growing Season Air-Soil Temperature Relationships At Lincoln, Nebraska, Ralph E. Neild

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

This study concerns the use of weekly average air temperature for predicting weekly average soil temperature under different conditions of surface cover during different times of year. Probabilities of weekly average air temperature for Lincoln as well as other Nebraska locations are available. These probabilities and the soil temperature prediction equations may be used in determining expected soil temperatures.

Sulfur Fertilizers For Alfalfa Production In Nebraska, R. L. Fox, A. D. Flowerday, F. W. Hosterman, H. F. Rhoades, R. A. Olson

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

In order to elaborate all aspects of the sulfur problem in alfalfa production, a series of field, greenhouse and laboratory experiments was initiated to determine: 1. The influence of sulfur fertilization on the yield of alfalfa in Nebraska. 2. The influence of sulfur fertilization on the protein, vitamin A, and sulfur contents of alfalfa. 3. The sulfur supplying capacities of various soils under field and greenhouse conditions. 4. The sulfur content of precipitation at widely scattered points in Nebraska. 5. Soil properties associated with sulfur deficiency. 6. Optimum methods for estimating the sulfur status of soils by soil testing. The …

A Soil And Vegetation Inventory And Analysis Of Three Nebraska Sandhills Range Sites, Donald F. Burzlaff

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

This study was undertaken to inventory the soils and vegetation of certain areas of the Sandhills and to seek edaphic characteristics that may be the limiting factor in the distribution of various plant species. Information of this nature will permit formulation of more accurate management practices because of a refinement in delineation of range sites.

Microorganisms And Soil Structure, T. M. Mccalla, F. A. Haskins

Department of Agronomy and Horticulture: Faculty Publications

SUMMARY

Good stable soil structure is valuable for promoting the growth of plants and micro-organisms by permitting enhanced aeration and water penetration and by decreasing erosion under some conditions.

Micro-organisms influence water percolation through the soil. They may plug up soil pores with byproducts of growth and reduce water percolation. On the other hand, if a soil containing a large amount of microbial products is stirred and allowed to dry, then the percolation may be high.

Micro-organisms are involved in stabilizing soil structure by their products of decomposition and their cellular binding material, such as mycelia. Microorganisms differ greatly in …

Influence Of Various Factors On Aggregation Of Peorian Loess By Microorganisms, T. M. Mccalla, Francis A. Haskins, E. F. Frolik

Department of Agronomy and Horticulture: Faculty Publications

Soil structure is important in the attainment of adequate aeration for the aerobic microorganisms whose activities maintain such higher plant nutrients as sulfur, phosphorus, and nitrogen in a highly oxidized and thus readily available state. Good soil structure is also necessary for soil and water conservation, Under Nebraska conditions microorganisms and their decomposition products constitute a major source of soil-aggregating agents. The decomposition of crop residues and plant roots is important in the nutrition of these aggregating microorganisms. Other microorganisms, however, also utilize crop residues and plant roots, and they may decompose the aggregating agents as well, so that the …

Economic Analysis Of Forage Production And Utilization In Dakota And Dixon Counties, Nebraska, Howard W. Ottoson

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

Soil erosion remains a serious problem on many Nebraska farms despite programs of financial assistance, technical aid, and education by several national and state agencies. One reason that soil conserving adjustments in land use have not been made by farmers is that considerable uncertainty surrounds the economics of soil erosion control on the farm level. This study is an attempt to increase knowledge and reduce some of the uncertainty with regard to the economics of erosion control in a specific area.

Commercial Fertilizers For Winter Wheat In Relation To The Properties Of Nebraska Soils, R. A. Olson, H. F. Rhoades

Historical Research Bulletins of the Nebraska Agricultural Experiment Station

It is the purpose of this bulletin to report the investigations that have been made correlating soil properties and fertilization practices with yields of winter wheat. Since the success or failure of fertilization practices is so dependent on specific soil conditions, an attempt has been made here to further characterize the major soils of the different sections of the state which are devoted to wheat production and to analyze fertilizer practices and results in relation to the soil properties determined. The data are summarized for the four sections of the state designated as southeastern, east-south-central, west-south-central and western Nebraska. These …