The Illinois Soil Nitrogen Test: Should It Be Used In Iowa?, 2016 Iowa State University
The Illinois Soil Nitrogen Test: Should It Be Used In Iowa?, John E. Sawyer, Mohammod Ali Tabatabai
John E. Sawyer
The test was developed several years ago at the University of Illinois by researchers in the Department of Natural Resources and Environmental Sciences. It is a laboratory procedure designed to measure N liberated from soil heated for 5 hours with dilute alkali solution (sodium hydroxide). The test does not measure nitrate, but does measure exchangeable ammonium and a fraction of soil organic N.
Evaluation Of Fertilizer Additives For Enhanced Nitrogen Efficiency In Corn, 2016 Iowa State University
Evaluation Of Fertilizer Additives For Enhanced Nitrogen Efficiency In Corn, Daniel W. Barker, John E. Sawyer, Michael J. Castellano
John E. Sawyer
The use of N additives and slow release materials with ammoniacal fertilizer varies throughout the U.S. Corn Belt due to differing N loss potentials across climate, soils, and production systems. In Iowa, recent years of high rainfall events and prolonged wet soil conditions has renewed interest to protect fertilizer N loss from denitrification, leaching, and greenhouse gas emission with use of nitrification inhibitors. These loss processes can be significant in Iowa soils that are poorly drained and have high organic matter, high pH, and high populations of denitrifying bacteria. Subsurface tile drainage is also prevalent in farmer fields throughout ...
Drought Impacts On Soil Fertility Management, 2016 Iowa State University
Drought Impacts On Soil Fertility Management, John E. Sawyer
John E. Sawyer
If crop production was severely reduced because of dry conditions this year, there are a few items you can consider when planning for next year's crop. One, with severely damaged crops and low yields you might credit some of the phosphorus (P) and potassium (K) applied for this year's crop to next year, as much less removal will occur in grain harvest of the lower than expected yield.
45th Annual North Central Extension-Industry Soil Fertility Conference, 2016 Iowa State University
45th Annual North Central Extension-Industry Soil Fertility Conference, John E. Sawyer
John E. Sawyer
If you would like to learn more about current soil fertility issues and research being conducted at universities across the North Central region, then consider attending the 45th Annual North Central Extension-Industry Soil Fertility Conference on November 4-5, 2015, from 1 p.m. to noon, at the Holiday Inn Airport in Des Moines, Iowa. The conference will include invited presentations from university and industry leaders, research reports from university soil fertility researchers, and posters outlining research by graduate students at universities across the North Central region (Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Nebraska, North Dakota, Ohio, Ontario, Pennsylvania, South ...
Sulfur Management For Iowa Crop Production, 2016 Iowa State University
Sulfur Management For Iowa Crop Production, John E. Sawyer, Brian J. Lang, Daniel W. Barker
John E. Sawyer
Summary of statewide evaluation in Iowa of alfalfa and corn yield response to applied sulfur fertilizers. On-farm, small-plot and field-length strip trial yield response data presented from 2005-2013.
Nutrient Considerations With Corn Stover Harvest, 2016 Iowa State University
Nutrient Considerations With Corn Stover Harvest, John E. Sawyer, Antonio P. Mallarino
John E. Sawyer
Weigh the relationships between corn stover harvest (as compared to grain only harvest) with the research presented in this publication.
Make informed decisions about using stover harvest for bioenergy and using corn residue for soil sustainability. Find corn N, P, and K fertilization recommendations needed to maintain desirable soil-test values.
Interpretation Of Soil Test Results, 2016 Iowa State University
Interpretation Of Soil Test Results, Antonio P. Mallarino, John E. Sawyer
John E. Sawyer
A detailed explanation on how to interpret soil test results to assist with soil nutrient recommendations.
The Cosmic-Ray Neutron Probe Method For Estimating Field Scale Soil Water Content: Advances And Applications, 2016 University of Nebraska-Lincoln
The Cosmic-Ray Neutron Probe Method For Estimating Field Scale Soil Water Content: Advances And Applications, William A. Avery
Dissertations & Theses in Natural Resources
The need for accurate, real-time, reliable, and multi-scale soil water content (SWC) monitoring is critical for a multitude of scientific disciplines trying to understand and predict the earth’s terrestrial energy, water, and nutrient cycles. One promising technique to help meet this demand is fixed and roving cosmic-ray neutron probes (CRNP). However, the relationship between observed low-energy neutrons and SWC is affected by local soil and vegetation calibration parameters. This effect may be accounted for by a calibrated equation based on local soil type and the amount of standing biomass. However, determining the calibration parameters for this equation is labor ...
Cone In Cone Concretions Of The Stanley Group In Southeastern Oklahoma, 2016 Stephen F Austin State University
Cone In Cone Concretions Of The Stanley Group In Southeastern Oklahoma, Kyle B. Ayres
Electronic Theses and Dissertations
Cone in cone concretions found in the Stanley Group of Southeastern Oklahoma have a variety of external and internal attributes which allow diagenetic and theoretical models of formation to be hypothesized. Stanley Group carbonate cone in cone concretions are initially formed in sulfur reducing horizons at shallow burial depths in a poorly circulated possibly deep trough containing siliceous sediments and organic matter. Collected concretions near the town of Smithville, Oklahoma displayed four different external morphologies and four variations of mineral constituents. All concretions contained microscopic cones which initiated diffusion and/or fluid patterns and is an early cementation process that ...
Barrier Spit Evolution And Primary Consolidation Of Backbarrier Facies: West Belle Pass Barrier, La, 2016 University of New Orleans, New Orleans
Barrier Spit Evolution And Primary Consolidation Of Backbarrier Facies: West Belle Pass Barrier, La, John N. Kramer Iii
University of New Orleans Theses and Dissertations
West Belle Pass Barrier is a barrier spit that formed during the last delta lobe progradation associated with the Lafourche delta complex. Located on the western flank of the Caminada-Moreau Headland, West Belle Pass Barrier and Raccoon Pass are located downdrift of the Belle Pass jetties. Morphological changes stemming from storms, jetty infrastructure, and an expanding tidal inlet are evaluated using historical shoreline data and imagery. Littoral transport around the jetties combined with inlet growth created a framework wherein sediment is transported through Raccoon Pass and sequestered as a flood-tidal delta. These events aided in the landward migration of West ...
Validation Of An Internal Camera Based Volume Determination System For Triaxial Testing, 2016 University of Arkansas, Fayetteville
Validation Of An Internal Camera Based Volume Determination System For Triaxial Testing, Leah D. Miramontes
Civil Engineering Undergraduate Honors Theses
Accurate strain and volume measurements are critical to phase relationships and strength determination for saturated and unsaturated soils. In recent years, laboratory-based photographic techniques of monitoring soil specimens have become more common. These techniques have been used to reconstruct 3D models and to determine strain and volumetric changes of triaxial specimens. A new technique that utilized digital photographs of the soil specimen, captured from within a triaxial testing cell, was utilized. Photographs were processed using photogrammetry software to reconstruct 3D models of the soil specimens. By placing camera equipment within the cell, the technique eliminated the need to account for ...
Gone With The Wind: Soil Moisture Effects On Gaseous Nitrogen Removal From Wastewater, 2016 University of Rhode Island
Gone With The Wind: Soil Moisture Effects On Gaseous Nitrogen Removal From Wastewater, Faith L. Anderson
Senior Honors Projects
Onsite wastewater treatment systems (OWTS), or septic systems, release nitrogen (N), which can be detrimental to aquatic ecosystems. The final step in the treatment of wastewater is dispersal onto a drainfield, where it percolates through the soil. Part of the N is removed from wastewater and released into the atmosphere as N2 and N2O by denitrification, which requires anoxic conditions. Previous studies looking at the effect of soil water-filled pore space (WFPS) on denitrification using clean water with a high level of dissolved O2 (DO) have identified a minimum of 60% WFPS for denitrification to take ...
Alluvial Sedimentation Associated With Logging In Low Gradient Watersheds In Desoto National Forest, Mississippi, 2016 University of Southern Mississippi
Alluvial Sedimentation Associated With Logging In Low Gradient Watersheds In Desoto National Forest, Mississippi, Andrew W. Simmons
Forestry and related businesses are an important factor of Mississippi’s economy, contributing between $11 and $14 billion annually (Mississippi Forestry Commission, 2006). The timber industry is not only important in Mississippi but is an important sector of the economy throughout the Gulf Coast region. While providing positive economic benefits to the region, the forestry industry can also negatively affect soil properties, hillslope stability, and increase sedimentation rates in local streams and rivers. The aim of this research is to determine if forestry removal causes an increase of soil erosion and how it affects floodplain sedimentation in the low gradient ...
Cockatoo Sands In The Victoria Highway And Carlton Hill Areas, East Kimberley: Hydrogeology, Aquifer Properties And Groundwater Chemistry, 2016 Department of Agriculture and Food, Western Australia
Cockatoo Sands In The Victoria Highway And Carlton Hill Areas, East Kimberley: Hydrogeology, Aquifer Properties And Groundwater Chemistry, Don Bennett, John Andrew Simons, Richard George, Paul Raper
Resource Management Technical Reports
Cockatoo Sands are recognised as potentially suitable for irrigated agriculture because they are generally well drained and not subject to waterlogging or inundation. These characteristics allow them to be cultivated and prepared for planting various crops during the wet and dry seasons of northern Australia. Expanding agricultural production onto the Cockatoo Sands around Kununurra will increase opportunities for agriculture by increasing the overall scale of agriculture, allowing year-round agricultural enterprise, new crops and new market opportunities.
DAFWA has assessed the soil characteristics and agriculturally suitable areas of Cockatoo Sands in the Victoria Highway and Carlton Hill areas near Kununurra. Potential ...
Effects Of Changes In Moisture Source And The Upstream Rainout On Stable Isotopes In Precipitation – A Case Study In Nanjing, Eastern China, Y. Tang, H. Pang, W. Zhang, Y. Li, Shuang-Ye Wu, S. Hou
In the Asian monsoon region, variations in the stable isotopic composition of speleothems have often been attributed to the "amount effect". However, an increasing number of studies suggest that the "amount effect" in local precipitation is insignificant or even non-existent. To explore this issue further, we examined the variability of daily stable isotopic composition (δ18O) in precipitation from September 2011 to November 2014 in Nanjing, eastern China. We found that intra-seasonal variations of δ18O during summer were not significantly correlated with local rainfall amount but could be linked to changes in the moisture source location and rainout processes in the ...
Reconstruction Of The Hirnantian (Late Ordovician) Palaeotopography In The Upper Yangtze Region, 2016 University of Chinese Academy of Sciences
Reconstruction Of The Hirnantian (Late Ordovician) Palaeotopography In The Upper Yangtze Region, Linna Zhang, Junxuan Fan, Qing Chen, Shuang-Ye Wu
Reconstruction of the Hirnantian (Late Ordovician) palaeotopography in South China is important for understanding the distribution pattern of the Hirnantian marine depositional environment. In this study, we reconstructed the Hirnantian palaeotopography in the Upper Yangtze region based on the rankings of the palaeo-water depths, which were inferred according to the lithofacies and biofacies characteristics of the sections. Data from 374 Hirnantian sections were collected and standardized through the online Geobiodiversity Database. The Ordinary Kriging interpolation method in the ArcGIS software was applied to create the continuous surface of the palaeo-water depths, i.e. the Hirnantian palaeotopography. Meanwhile, the line transect ...
Evaluating Pedestrial Compaction Variation & Soil Organic C Content, 2016 Murray State University
Evaluating Pedestrial Compaction Variation & Soil Organic C Content, Gunner B. Decker
Over time, playing fields are monitored by overall appearance. However, pedestrian compaction is not evenly distributed throughout the entire surface.
Transition From Contraction To Extension In The Northeastern Basin And Range: New Evidence From The Copper Mountains, Nevada, Jeffrey M. Rahl, Allen J. Mcgrew, Kenneth A. Foland
Allen J. McGrew
New mapping, structural analysis, and 40Ar/39Ar dating reveal an unusually well‐constrained history of Late Eocene extension in the Copper Mountains of the northern Basin and Range province. In this area, the northeast‐trending Copper Creek normal fault juxtaposes a distinctive sequence of metacarbonate and granitoid rocks against a footwall of Upper Precambrian to Lower Cambrian quartzite and phyllite. Correlation of the hanging wall with footwall rocks to the northwest provides an approximate piercing point that requires 8–12 km displacement in an ESE direction. This displaced fault slice is itself bounded above by another normal fault (the Meadow ...
An Assessment Of Soil Erosion On Pemba Island Using The Universal Soil Loss Equation, 2016 SIT Graduate Institute - Study Abroad
An Assessment Of Soil Erosion On Pemba Island Using The Universal Soil Loss Equation, Emily Gillispie
Independent Study Project (ISP) Collection
Healthy soil is necessary for maintaining agricultural productivity, which is the basis of the economy on Pemba Island, Tanzania. Soil erosion is a notable concern for subsidence-farming villages, as it reduces the agricultural potential of farmland through the loss of nutrients, organic matter, and depth of quality growing soil (Georhing, 2009). The island of Pemba is the perfect case study for soil erosion, as their economy is largely based in agriculture, and the combined hilly topography and monsoonal climate make it highly susceptible to soil erosion. Yet, Pemba’s main cash crops are clove and fruit trees, which have potential ...
Extent Of Capillary Rise In Sands And Silts, 2016 Western Michigan University
Extent Of Capillary Rise In Sands And Silts, Rachel Lynn Salim
The values reported in literature for the height of capillary rise in fine sands, silts, and clays are contradictory. Most of the values were based on mathematical models, which used estimated rather than measured input data. This work measured capillary rise values in laboratory experiments in fine-grained sands and silts.
Two uniform sands with grains 0.35--0.7 mm in diameter and 0.3-0.6 mm in diameter, silt with an average grain size below 40 microns, and 0.35--0.7 mm sand coated with a water-repellant spray were carefully packed into two-inch diameter glass columns. These columns were placed ...