Life Sciences Commons^™

Did Cover Crop Or Animal Manure Ameliorate Corn Residue Removal Effects On Soil Mechanical Properties After 10 Years?, Hans W. Klopp, Humberto Blanco-Canqui, Michael Sindelar, Virginia L. Jin, Marty R. Schmer, Richard B. Ferguson

Department of Agronomy and Horticulture: Faculty Publications

Crop residue removal may negatively affect soil mechanical properties, which are key components of soil quality. To evaluate potential long-term effects, we assessed the 10-yr impact of corn (Zea mays L.) residue removal (59 % of non-grain biomass annually) on surface soil mechanical properties (0–20 cm). We also evaluated whether adding carbon (C) amendments, such as using a winter rye (Secale cereale L.) cover crop or surface-applying cattle manure (24 Mg ha− 1 biannually) can ameliorate the effects of crop residue removal. This long-term study was under irrigated no-till continuous corn on a silt loam soil in south-central …

Evaluating Drill Interseeded Cover Crop Establishment And Nitrogen Impact In Irrigated Corn, Victor De Sousa Ferreira

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

The adoption of cover crops as a strategy to improve soil health and cropping systems sustainability is on the rise in the United States. PRE herbicides with soil residual activity are widely applied in corn production systems to prevent early season weed development, crop-weed competition, and yield loss. When preemergence herbicides are applied in the field, the active ingredients remain in the soil rhizosphere for a period of time, killing weed seedlings as they emerge. However, PRE herbicides can also impact the establishment of interseeded cover crops. Greenhouse bioassay was conducted to evaluate the preemergence herbicide carry-over potential to interseeded …

Intensifying A Crop–Fallow System: Impacts On Soil Properties, Crop Yields, And Economics, S. J. Ruis, S. Stepanovic, Humberto Blanco-Canqui

Department of Agronomy and Horticulture: Faculty Publications

Intensifying crop–fallow systems could address increased weed control costs, increased land or rental costs, reduced crop diversity, and degraded soil properties in water-limited environments. One strategy to intensify such systems could be the insertion of a short-season crop during fallow. But, how this strategy affects soils, crop production, and farm economics needs further research. Thus, we studied the impacts of replacing fallow in a winter wheat (Triticum aestivum L)–corn (Zea mays L.)–fallow system with a short-season spring crop [field pea (Pisum sativum L.)] on crop yields and economics from 2015 to 2019 and 5-yr cumulative effects on …

A Glass Bead Semi-Hydroponic System For Intact Maize Root Exudate Analysis And Phenotyping, Martha G. Lopez-Guerrero, Peng Wang, Felicia Phares, Daniel P. Schachtman, Sophie Alvarez, Karin V. Van Dijk

Department of Agronomy and Horticulture: Faculty Publications

Background: Although there have been numerous studies describing plant growth systems for root exudate collection, a common limitation is that these systems require disruption of the plant root system to facilitate exudate collection. Here, we present a newly designed semi-hydroponic system that uses glass beads as solid support to simulate soil impedance, which combined with drip irrigation, facilitates growth of healthy maize plants, collection and analysis of root exudates, and phenotyping of the roots with minimal growth disturbance or root damage. Results: This system was used to collect root exudates from seven maize genotypes using water or 1 mM CaCl2, …

Techniques To Improve The Volume, Texture And Nutritional Quality Of Gluten Free Bread, Zachary Christman

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

This article highlights the use of soy flour to improve the protein and fiber of gluten free bread. Also, the use of an extrusion process on soybean and corn flour blends improves the volume and texture of the bread. A full listing of the ingredients and method for production of higher quality gluten free bread is included.

Assessment Of Grain Safety In Developing Nations, Jose R. Mendoza

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Grains are the most widely consumed foods worldwide, with maize (Zea mays) being frequently consumed in developing countries where it feeds approximately 900 million people under the poverty line of 2 USD per day. While grain handling practices are acceptable in most developed nations, many developing nations still face challenges such as inadequate field management, drying, and storage. Faulty grain handling along with unavoidably humid climates result in recurrent fungal growth and spoilage, which compromises both the end-quality and safety of the harvest. This becomes particularly problematic where there is little awareness about health risks associated with poor …

Influence Of Cover Crop Management Practices On Rainfed Corn Production In Semi-Arid Western Nebraska, Alexandre Tonon Rosa

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

With the increased cover crop (CC) popularity, producers of semi-arid regions of western Nebraska are questioning whether they could successfully incorporate CC into their rainfed winter wheat (Triticum aestivum L.)-corn (Zea mays L.)-fallow rotations. The major concern is that CCs may deplete soil water affecting the subsequent crop. Therefore, three studies were established under rainfed conditions of western Nebraska to access the effects of CCs on soil water, soil compaction, nutrient cycling, weed demographics, residue coverage, and subsequent corn yield. The first study evaluated the influence of CC planting and termination times prior to corn establishment. …

Transforming Unmanned Aerial Vehicle (Uav) And Multispectral Sensor Into A Practical Decision Support System For Precision Nitrogen Management In Corn, Laura J. Thompson, Laila A. Puntel

Department of Agronomy and Horticulture: Faculty Publications

Determining the optimal nitrogen (N) rate in corn remains a critical issue, mainly due to unaccounted spatial (e.g., soil properties) and temporal (e.g., weather) variability. Unmanned aerial vehicles (UAVs) equipped with multispectral sensors may provide opportunities to improve N management by the timely informing of spatially variable, in-season N applications. Here, we developed a practical decision support system (DSS) to translate spatial field characteristics and normalized difference red edge (NDRE) values into an in-season N application recommendation. On-farm strip-trials were established at three sites over two years to compare farmer’s traditional N management to a split-application N management guided by …

Integration Of Cover Crops Into Midwest Corn-Soybean Cropping Systems And Potential For Weed Suppression, Joshua S. Wehrbein

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

Cover crops have potential to provide benefits to agricultural systems, such as improved soil productivity, nutrient scavenging, weed suppression, and livestock forage. There are several challenges associated with cover crop integration into traditional Midwest corn-soybean cropping systems. One of these challenges is timely establishment in the fall, which is limited by the relatively late harvest of corn and soybean. Cover crop effectiveness is related to the amount of biomass produced, thus maximizing the growth period in the fall is desired. To address this challenge, we evaluated the potential to utilize early-season soybean maturity groups (MGs) to allow for earlier soybean …

Development Of A Nitrogen Recommendation Tool For Corn Considering Static And Dynamic Variables, Laila A. Puntel, Agustin Pagani, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Many soil and weather variables can affect the economical optimum nitrogen (N) rate (EONR) for maize. We classified 54 potential factors as dynamic (change rapidly over time, e.g. soil water) and static (change slowly over time, e.g. soil organic matter) and explored their relative importance on EONR and yield prediction by analyzing a dataset with 51 N trials from Central-West region of Argentina. Across trials, the average EONR was 113 ± 83 kg N ha⁻¹ and the average optimum yield was 12.3 ± 2.2 Mg ha⁻¹, which is roughly 50% higher than the current N rates used …

Evaluation Of Stabilized Fertilizer And Crop Canopy Sensors As Next-Generation Nitrogen Management Technologies In Irrigated Corn, Leonardo Mendes Bastos

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

Nitrogen (N) is often the most limiting nutrient to corn. Once applied to the field, N can be lost through different pathways, which contributes to low N use efficiency (NUE) by plants. Increases in NUE and decreases in N losses can be potentially achieved by using management options that allow a better synchrony between N supply and demand, such as stabilized fertilizers, and spatially-variable sensor-derived in-season N application. Three studies were conducted in order to assess the effects of different stabilized fertilizers and crop canopy sensors on irrigated corn yield. The first study evaluated the effect of urease inhibitor on …

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset …

A Systems Modeling Approach To Forecast Corn Economic Optimum Nitrogen Rate, Laila A. Puntel, John E. Sawyer, Daniel W. Barker, Peter J. Thorburn, Michael J. Castellano, Kenneth J. Moore, Andy Vanloocke, Emily A. Heaton, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Historically crop models have been used to evaluate crop yield responses to nitrogen (N) rates after harvest when it is too late for the farmers to make in-season adjustments. We hypothesize that the use of a crop model as an in-season forecast tool will improve current N decision-making. To explore this, we used the Agricultural Production Systems sIMulator (APSIM) calibrated with long-term experimental data for central Iowa, USA (16-years in continuous corn and 15-years in soybean-corn rotation) combined with actual weather data up to a specific crop stage and historical weather data thereafter. The objectives were to: (1) evaluate the …

Impaired Phloem Loading In Zmsweet13a,B,C Sucrose Transporter Triple Knock-Out Mutants In Zea Mays, Margaret Bezrutczyk, Thomas Hartwig, Marc Horschman, Si Nian Char, Jinliang Yang, Bing Yang, Wolf B. Frommer, Davide Sosso

Department of Agronomy and Horticulture: Faculty Publications

Crop yield is critical for human nutrition, yet the underlying machinery that ultimately determines yield potential is still not understood. Crop productivity under ideal conditions is determined by the efficiency with which plants intercept light, convert it into chemical energy, translocate photosynthates and convert these to storage products in harvestable organs (Zhu et al., 2010). In many crops, sucrose is the primary form for translocation inside the conduit (i.e. the phloem). A combination of SWEETmediated efflux from phloem parenchyma and subsequent secondary active sucrose import by SUT sucrose/H+ symporters is thought to create the driving force for pressure gradient-driven …

From Milpas To The Market: A Study On The Use Of Metal Silos For Safer And Better Storage Of Guatemalan Maize, José Rodrigo Mendoza

Department of Food Science and Technology: Dissertations, Theses, and Student Research

This project aimed to implement the use of metal silos to improve quality and safety of maize consumed by inhabitants of the highlands of Guatemala. This manuscript includes a literature review of the maize production chain in Guatemala, a survey about agricultural practices used in the region of study, as well as a characterization of the analyzed maize regarding its mycoflora, nutritional composition, and insect infestation. To better understand the current situation regarding agricultural practices and maize consumption, a survey was carried out. Sample consisted of 280 families representing 14 rural communities distributed in the townships of Todos Santos and …

A Brief History Of Corn: Looking Back To Move Forward, Jon Derek Pruitt

Doctor of Plant Health Program: Dissertations and Student Research

Maize was domesticated from teosinte in Mexico some 7,000 to 10,000 years ago and quickly spread through the Americas. It has become one of the most important crops at a local and global level. Two types, Northern Flint corn and Southern Dent corns provided the basis of the genetic background of modern maize hybrids. The development of hybrids, first double-cross and later single-cross hybrids, along with a transition to high input farming provided huge yield increases, which have continued to improve with improving technology.

Increase in maize production also caused a rise in Western corn Rootworm (Diabrotica virgifera virgifera …

A Vision For Extension: Case Studies On Managing Extreme Weather Challenges In Corn, Anthony J. Mcmechan

Doctor of Plant Health Program: Dissertations and Student Research

Global demand for corn is projected to rise in the coming decades to meet the food and fuel requirements of an increasing human population. Technological innovations have significantly improved corn yields over the past few decades; however, corn production is continually limited by unfavorable weather conditions. Extreme weather events put pressure on producers, adjustors, and consultants to make quick management decisions to maintain the highest return on their investment. Proper management decisions require an understanding of plant response and practical ways of applying this knowledge under real world conditions.

The following document was written after completing a six-month internship at …

Corn (Zea Mays L.) Seeding Rate Optimization In Iowa, Usa, Mark A. Licht, Andrew W. Lenssen, Roger W. Elmore

Department of Agronomy and Horticulture: Faculty Publications

Collecting soil, topography, and yield information has become more feasible and reliable with advancements in precision technologies. Combined with the accessibility of precision technologies and services to farmers, there has been increased interest and ability to make site-specific crop management decisions. The objective of this research was to develop procedures to optimize corn seeding rates and maximize yield using soil and topographic parameters. Experimental treatments included five seeding rates (61 750; 74 100; 86 450; 98 800; and 111 150 seeds ha^-1) in a randomized complete block design in three central Iowa fields from 2012 to 2014 (nine …

Nitrogen And Water Effects On Canopy Sensor Measurements For Site-Specific Management Of Crops, Nicholas C. Ward

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

Water and nitrogen (N) are undoubtedly the two largest agricultural inputs globally. Coupled with advances in site-specific management technology their integration into production agriculture will allow for the most efficient use these crop input resources. Active canopy sensors offer the ability to measure biophysical plant traits rapidly and make assessments about plant status. Specifically, optical sensor measurements of light reflectance assess plant N status allowing for in-season and on-the-go N recommendations and applications; while infrared thermometers (IRT) measurement of canopy temperature can be used a tool for irrigation management. To evaluate how these technologies work among different plant stress environments …

Cambio Climático Reduciría Cultivos: El País Vería Una Baja De Entre Un 20% Y 50% En El Rendimiento Del Frijol, Maíz Y Sorgo, Por El Incremento En Las Temperaturas, Según Un Informe De La Universidad Estatal De Kansas, Rosa María Pastrán

INTSORMIL Impacts and Bulletins

El aumento de la temperatura que se producirá en los próximos 50 años, a consecuencia del cambio climático, provocaría una reducción en la producción de granos básicos en El Salvador, según un estudio del Departamento de Agronomía de la Universidad Estatal de Kansas, Estados Unidos.

En el caso de El Salvador, la investigación encontró que la temperatura actual incrementará entre 3 y 5 grados centígrados (°C). Este aumento afectará, de manera progresiva, el rendimiento de cultivos como frijol, maíz y sorgo, de acuerdo con lo que explicó el profesor Vara Prasad, quien presentó el estudio en el país.

El cultivo …

Container And Installation Time Effects On Soil Moisture, Temperature, And Inorganic Nitrogen Retention For An In Situ Nitrogen Mineralization Method, Brian J. Wienhold, Gary E. Varvel, Wallace W. Wilhelm

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

Mineralization contributes significantly to agronomic nitrogen (N) budgets and is difficult to accurately predict. Models for predicting Nmineralization contributions are needed, and development of these models will require field-based data. In situ mineralization methods are intended to quantify N mineralization under ambient environmental conditions. This study was conducted to compare soil moisture and temperature in intact soil cores contained in cylinders to those in adjacent bulk soil, compare the effect of two resin-bag techniques on water content of soil within cylinders, and assess the effect of installation duration on inorganic N retention by resins. The study was conducted at a …

Comparison Of Laboratory Methods And An In Situ Method For Estimating Nitrogen Mineralization In An Irrigated Silt-Loam Soil, Brian J. Wienhold

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

Nitrogen (N) mineralization makes a considerable contribution to crop-available N and is difficult to estimate. Reliable methods for measuring N mineralization are needed to produce data sets for developing N-mineralization models, as a component in fertilizer recommendation algorithms, and to assess the effect of management practices on N mineralization. Numerous methods are available for estimating N mineralization. Laboratory methods are relatively easy but may not reflect conditions in the field, and field methods are usually labor-intensive. A study was conducted to compare N-mineralization estimates using anaerobic and aerobic laboratory methods and an in situ field method for the 0- to …

Feed Grains Backgrounder, Linwood Hoffman, Allen Baker, Linda Foreman, C. Edwin Young

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

The U.S. feed grain sector, largest of the major U.S. field crops, faces unprecedented demand conditions. The size and speed of the expanding use of corn by the ethanol industry is raising widespread issues throughout the U.S. agricultural sector. Debate is ongoing over the use of grain for fuel instead of for food or feed and the adequacy of future grain supplies. Increased productivity (yield) and additional area from land planted to competing crops, land enrolled in conservation programs, or idled land is expected to provide an increased supply of feed grains. In 2003, U.S. feed grain farms had an …

Compost And Manure Effects On Fertilized Corn Silage Yield And Nitrogen Uptake Under Irrigation, Gary A. Lehrsch, D. C. Kincaid

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

Dairy manure increases the yields of dry bean (Phaseolus vulgaris L.) and spring wheat (Triticum aestivum L.) from eroded, furrow-irrigated soils and may increase corn (Zea mays L.) silage yield from steeper eroded areas under sprinkler irrigation. In a 2-year field study in southern Idaho on Portneuf silt loam (coarse silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid), the effects of a one-time, fall application of 29 or 72 Mg ha^-1 of dry manure or 22 or 47 Mg ha^-1 of dry compost on subsequent silage yield and nitrogen (N) uptake from previously eroded, sprinkler-irrigated hill …

Impact Of Trap Design, Windbreaks, And Weather On Captures Of European Corn Borer (Lepidoptera: Crambidae) In Pheromone-Baited Traps, Thomas W. Sappington, Brendon J. Reardon, Douglas V. Sumerford

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

Pheromone-baited traps are often used in ecological studies of the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). However, differences in trap captures may be confounded by trap design, trap location relative to a windbreak, and changes in local weather. The objectives of this experiment were, first, to examine differences in O. nubilalis adult (moth) captures among the Intercept wing trap, the Intercept bucket/funnel UNI trap, and the Hartstack wire-mesh, 75-cm-diameter cone trap (large metal cone trap) as well as among three cone trap designs. Second, we examined the influence of the location of the large metal cone trap relative …

Corn Stalk Nitrate Concentration Profile: Implications For The End-Of-Season Stalk Nitrate Test, Wally Wilhelm, Gary E. Varvel, James S. Schepers

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

The end-of-season corn (Zea maysL.) stalk nitrate-N test was developed as a post-mortem to determine if excessive or insufficient N was available to the corn crop during the latter part of the season. The stalk section specified for the test was very specific, the 20 cm-long section between 15 and 35 cm above the soil. Under production conditions, it may not always be possible to collect this precise stalk section. The objective of this study was to determine how nitrate concentration varied within the stalk from the soil level to the ear node, and how this variation could …

Ec1506 Corn Rootworm Control In Nebraska, Ephriam Hixson, Martin H. Muma, Roscoe E. Hill

University of Nebraska-Lincoln Extension: Historical Materials

Extension circular 1506 discusses corn rootworm control in Nebraska.