Agronomy and Crop Sciences Commons^™

Responses Of Maize To Different Irrigation Regimes In Semi-Arid Western Nebraska, Swathi Palle

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

As the “Cornhusker State”, Maize (Zea mays) is an important crop in Nebraska. However, farmers in the state are challenged by unstable supply of surface water and limited groundwater resources. A better understanding of maize's response to water stress that occurs at different growth stages can help implement the best irrigation practices that conserve water while maintaining yields. In this study, we conducted field experiments at the Panhandle Research, Extension, and Education Center to compare the responses of maize to eight irrigation treatments which included both limited and deficit irrigation regimes during 2022 and 2023 growing seasons. Specifically, …

Assessing The Morphological And Physiological Traits Of Smooth Brome Pastures Under Long Term Grazing And Nutrient Enrichment In Eastern Nebraska, Hassan Shehab

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

Climate change together with the increase in demands for food, feed, fuel, and fiber are becoming a threat to sustainability and resilience of agriculture and pasture lands. Bromus inermis (smooth bromegrass) dominates pastures for cattle grazing in Eastern Nebraska, US, where it is planted in monocultures, and is considered high quality forage because of its palatability and high nutritional value for cattle, especially under intensive management practices. Sustainable management of these pastures is key to long-term resilience. This study aims to assess the performance of smooth bromegrass pastures to the combined effects of long-term management practices (since 2005) of fertilization …

Overexpression Of Acetyl Coa Carboxylase 1 And 3 (Accase1 And Accase3), And Cyp81a21 Were Related To Cyhalofop Resistance In A Barnyardgrass Accession From Arkansas, Fidel Gonzalez-Torralva, Jason K. Norsworthy

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] is the most difficult-to-control weed species of rice production systems worldwide. It has evolved resistance to different herbicide sites of action, including the acetyl-CoA carboxylase (ACCase)-inhibiting herbicides. Target-site mutations conferring resistance to ACCase-inhibiting herbicides are well documented; however, the role of the different ACCase genes in conferring resistance to cyhalofop-p-butyl (cyhalofop), an ACCase-inhibiting herbicide, remains poorly understood. This research assessed the contribution of gene amplification and expression of ACCase genes in a cyhalofop-resistant barnyardgrass accession. Additionally, the expression of glutathione-S-transferases (GSTs) and cytochrome P450 monooxygenases (P450s) genes as possible …

Mapping Variability Of Soybean Leaf Potassium Concentrations To Develop A Sampling Protocol, Carrie C. Ortel, Trenton Roberts, Kyle A. Hoegenauer, Aurelie M. Poncet, Nathan A. Slaton, W. Jeremy Ross

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The spatial variability of soybean [Glycine max (L.) Merr.] leaf-K (potassium) concentrations must be considered when collecting samples to monitor crop K status. Five commercial soybean fields were sampled at a 0.4-ha grid resolution at two reproductive growth stages to quantify the trifoliolate tissue-K concentration. The objectives of this study were to identify the potential field variability of soybean leaf-K concentrations in typical Mid-south US soybean production fields, evaluate interpolation methods, and develop a sampling protocol for in-season soybean tissue monitoring. No consistent spatial dependencies were found in the leaf-K concentrations across the fields and sample times, indicating that …

Cover Crops Integration With Nitrogen Management For Dryland Cotton In Sandy Ultisols, Swabir Alhassan Musah

All Theses

One of the many benefits of cover crops (CCs) is nutrient provision, which can be optimized by synchronizing the nutrient release from residue decomposition with the demand for subsequent cash crops. This study is part of a multistate research (13 states) to measure cotton lint yield in response to cover cropping as a nutrient management strategy. This research-based information will help farmers optimize nitrogen (N) fertilization when integrating CCs into their production systems. A two-year field trial was conducted in 2021 and 2022 with four cover crop treatments (cereal rye, crimson clover, mixtures of cereal rye and crimson clover, and …

2020-2021 Field Seasons Of Maize Gxe Project Within The Genomes To Fields Initiative, Dayane Cristina Lima, Alejandro Castro Aviles, Ryan Timothy Alpers, Alden Perkins, Dylan L. Schoemaker, Martin Costa, Kathryn J. Michel, Shawn Kaeppler, David Ertl, Maria Cinta Romay, Joseph L. Gage, James Holland, Timothy Beissinger, Martin Bohn, Edward Buckler, Jode Edwards, Sherry Flint-Garcia, Michael A. Gore, Candice N. Hirsch, Joseph E. Knoll, John Mckay, Richard Minyo, Seth C. Murray, James Schnable, Rajandeep S. Sekhon, Maninder P. Singh, Erin E. Sparks, Peter Thomison, Addie Thompson, Mitchell Tuinstra, Jason Wallace, Jacob D. Washburn, Teclemariam Weldekidan, Wenwei Xu, Natalia De Leon

Department of Agronomy and Horticulture: Faculty Publications

Objectives: This release note describes the Maize GxE project datasets within the Genomes to Fields (G2F) Initiative. The Maize GxE project aims to understand genotype by environment (GxE) interactions and use the information collected to improve resource allocation efficiency and increase genotype predictability and stability, particularly in scenarios of variable environmental patterns. Hybrids and inbreds are evaluated across multiple environments and phenotypic, genotypic, environmental, and metadata information are made publicly available. Data description: The datasets include phenotypic data of the hybrids and inbreds evaluated in 30 locations across the US and one location in Germany in 2020 and 2021, soil …

Economic Analysis Of Sod-Seeded Summer Annuals For Forage And Grazing, Ivanelle Meyer

Graduate Theses and Dissertations

Forage and pasture trials were conducted over the summers of 2021 and 2022 to assess how forage production and nutritive value of sorghum sudangrass, cowpea, and sorghum sudangrass-cowpea mixtures, sod-seeded to bermudagrass pasture would impact stocker cattle performance. The forage trials compared forage production and quality when poultry litter was surface or sub-surface applied biennially in comparison to a no poultry litter control. Poultry litter is a nutrient dense fertilizer utilized on pastures in the mid-southern United States to increase forage nutritive value and yield. Broadcasting poultry litter results in more nutrient losses due to runoff and nitrogen volatilization compared …

Corn And Grain Sorghum Performance Tests 2023, J. F. Carlin, R. B. Mulloy, R. D. Bond, J. C. Mccoy

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers.

The 2023 corn performance tests contained 46 hybrids and were conducted at the Northeast Rice Research and Extension Center (NERREC) at Harrisburg, the Northeast Rice Research and Extension Center (NEREC) at Keiser, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Rohwer Research Station (RRS) near Rohwer, and the Rice Research and Extension Center (RREC) …

Utilizing The Genetic Potentials Of Traditional Rice Varieties And Conserving Rice Biodiversity With System Of Rice Intensification Management, Yheni Dwiningsih

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The genetic potentials of rice cultivars will need to be expressed to their fullest if global rice production is to be expanded enough by 2050 to meet the increased demand of the expanding population while the availability of land and water per capita dwindles. New and ‘improved’ rice varieties have contributed greatly to increased production over the past 50 years, but the rate of rice yield increase based on genetic changes has declined in recent decades compared with the early years of the Green Revolution. In fact, many rice consumers continue to prefer to consume ‘traditional’ rice varieties (referred to …

Uncertainty In Streamflow Measurements Significantly Impacts Estimates Of Downstream Nitrate Export, Shannon L. Speir, C. Nathan Jones, Arial J. Shogren, Carla L. Atkinson

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Across watershed science, two key variables emerge–streamflow and solute concentration–which serve as the basis for efforts ranging from basic watershed biogeochemistry research to policy decisions surrounding watershed management. However, we rarely account for how error in discharge (Q) impacts estimates of downstream nutrient loading. Here, we examined the impact of uncertainty in streamflow measurements on estimates of downstream nitrate export using publicly available data from the U.S. Geological Survey (USGS). We characterized how uncertainty in stage-discharge relationships impacts annual flux estimates across 70 USGS gages. Our results indicate the interquartile range of relative error in Q was 33% across these …

Winter-Time Cover Crop Identification: A Remote Sensing-Based Methodological Framework For New And Rapid Data Generation, Zobaer Ahmed, Lawton L. Nalley, Kristofor R. Brye, V. Steven Green, Michael P. Popp, Aaron Michael Shew, Lawson Connor

Environmental Dynamics Faculty Publications and Presentations

Accurately identifying and systematically mapping winter-time cover crops and their phenological characteristics offer significant benefits to agricultural producers and policymakers, as cover crops are one of several potential solutions to climate change mitigation. We present a methodological framework for identifying and mapping the presence of winter-time cover crops at the field level and aggregated to county scales from 2013 to 2019 by using the Google Earth Engine (GEE), a random forest classifier with time series data from Landsat 8, and yearly cover crop training data from the United States Department of Agriculture (USDA)-Natural Resources Conservation Service (NRCS). The methodology was …

Evaluation Of Weed Control Efficacy And Crop Tolerance To Florpyrauxifen-Benzyl Coated Onto Urea, Bodie Lyn Cotter

Graduate Theses and Dissertations

Frequent off-target movement occurrences to soybean [Glycine max (L.) Merr.], rice (Oryza sativa L.) injury, and a lack of barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.] control followed the commercial launch of florpyrauxifen-benzyl in 2018. Florpyrauxifen-benzyl is a synthetic auxin, Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 4 herbicide used for postemergence weed control in rice and labeled for application at 30 g ae ha-1. Previous research documented that soybean was susceptible to injury following spray applications of florpyrauxifen-benzyl at less-than-labeled rates, and certain varieties of rice are less tolerant to spray-applied florpyrauxifen-benzyl at 30 g ae …

Evaluation Of Oxyfluorfen For Use In Roxy Rice, Casey Hunter Arnold

Graduate Theses and Dissertations

Mid-southern U.S. rice (Oryza sativa L.) producers are challenged every year to control problematic barnyardgrass [Echinochloa crus-galli (L.) Beauv.] and weedy rice (Oryza sativa L.) because they have evolved resistance to most labeled herbicides. Oxyfluorfen is a Herbicide Resistance Action Committee (HRAC)/Weed Science Society of America (WSSA) Group 14 herbicide that inhibits protoporphyrinogen oxidase within the plant. Currently, there are no HRAC/WSSA Group 14 herbicides labeled for barnyardgrass or weedy rice control in midsouthern rice production. Therefore, oxyfluorfen is being evaluated for barnyardgrass and weedy rice control. Plant breeders at the University of California – Davis were able to breed …

A Global Faostat Reference Database Of Cropland Nutrient Budgets And Nutrient Use Efficiency (1961–2020): Nitrogen, Phosphorus And Potassium, Cameron I. Ludemann, Nathan Wanner, Pauline Chivenge, Achim Dobermann, Rasmus Einarsson, Patricio Grassini, Armelle Gruere, Kevin Jackson, Luis Lassaletta, Federico Maggi, Griffiths Obli-Laryea, Martin K. Van Ittersum, Srishti Vishwakarma, Xin Zhang, Francesco N. Tubiello

Department of Agronomy and Horticulture: Faculty Publications

Nutrient budgets help to identify the excess or insufficient use of fertilizers and other nutrient sources in agriculture. They allow for the calculation of indicators, such as the nutrient balance (surplus if positive or deficit if negative) and nutrient use efficiency, that help to monitor agricultural productivity and sustainability across the world. We present a global database of country-level budget estimates for nitrogen (N), phosphorus (P) and potassium (K) on cropland. The database, disseminated in FAOSTAT, is meant to provide a global reference, synthesizing and continuously updating the state of the art on this topic. The database covers 205 countries …

Do Organic Farming Practices Improve Soil Physical Properties?, Humberto Blanco-Canqui, Sabrina J. Ruis, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Organic farming (OF) is a reemerging system that could address food security and adverse environmental footprints of conventional farming (CF). However, how OF affects the soil physical environment, an essential pillar for soil ecosystem service delivery, is not well understood. This paper (1) reviews published global literature up to 13 July 2023 regarding the impacts of OF on soil physical properties compared with CF and (2) underlines research needs. Literature indicates OF improves some soil physical properties relative to CF although studies on some properties were few. Specifically, OF increased wet aggregate stability, saturated hydraulic conductivity, and plant available water …

Brachiaria Spp. (Syn. Urochloa Spp.) Cv. Mulato Ii (Convert Hd364) Mass Production Under Continuous Grazing In The Water/Dry Transition Period, A. L. A. Castro, A. C. Prado, M. C. Silva Júnior, M. S. Soares, M. V. Teixeira

IGC Proceedings (1977-2023)

In the transition period between the rainy and dry seasons there is decreased water, temperature and luminosity, reducing forage production and quality. Because of this variability in forage mass production, it is essential to quantify forage mass for use in planning and decision making about pastures management. The objective was to evaluate Brachiaria spp. (Syn. Urochloa spp.) cv. Mulato II (Convert HD364) growth, biomass production managed under continuous grazing with steers fed with protein supplement feed in-trough and on-ground during the seasonal transition period. The experiment was carried out in the Beef Cattle Sector of Jatai Federal University …

Production And Persistence Of Self-Regenerating Annual Clovers In The Pacific Northwest, Ian Silvernail, Serkan Ates

IGC Proceedings (1977-2023)

Self-regenerating annual legumes are commonly included in dryland pastures to increase the production of high-quality forages to meet the nutritional demands of growing and lactating animals. Balansa clover (Trifolium michelianum Savi), not as widely evaluated as subterranean clover (Trifolium subterraneum L.), has shown promise in Western Oregon. However, there is a paucity of information on the productivity and persistence of annual clover cultivars that have various flowering times. This study investigates the biomass production and persistence of early, mid and late flowering subterranean clover and balansa clover cultivars in Corvallis, Oregon. Averaged across the cultivars, the total annual …

Current Red Clover Breeding Research, Heathcliffe Riday

IGC Proceedings (1977-2023)

Red clover remains a globally important forage legume grown mostly in humid temperate climates on approximately 4 million ha. In the past 25 years global red clover seed production has stabilized around 10 million kg yr^-1, although there is evidence that seed production is increasing globally at around 0.34 million kg yr^-1 since the early 2000s. Globally many red clover programs exist targeting specific global regions with a focus on improving persistence, biomass yield, seed yield, and a few other minor traits. Breeding programs are increasing persistence by selecting for specific disease resistances, specific agricultural conditions such …

Managing Vegetation In Grassland Habitats To Enhance Livestock Or Wildlife Objectives, B. B. Sleugh, S. Flynn, W. Hatler, C. Hart, S. Ingram, Joao B. Cason, D. Ovalle

IGC Proceedings (1977-2023)

Sustainably stewarding grassland systems involves applying various practices to manipulate forage interactions with other plants, the environment, and grazing animals to meet resource manager objectives. These interactions can result in invasion or encroachment and increased abundance of weeds which hinder attainment of management objectives. Weeds influence the structure and function of pasture ecosystems whether forages are grown in improved pastures, rangeland, or grassland communities. They degrade pasture quality and reduce livestock performance by interfering with forage establishment, yield, and quality by competing for resources. Weeds reduce the feed value of forage, decrease pasture carrying capacity, and can be toxic or …

Forage Allowance And Daily Gain Relationships On Rye-Ryegrass Pastures At Different Stocking Rates With Continuous And Rotational Stocking, F. M. Rouquette Jr., K. D. Norman, C. R. Long, E. Van Santen

IGC Proceedings (1977-2023)

‘Maton’ cereal rye (Secale cereale L.) and ‘TAM-90’ annual ryegrass (Lolium multiflorum Lam.) are used for winter annual pastures to background stocker cattle in the southeastern US. Rye and ryegrass were sod-seeded into bermudagrass [Cynodon dactylon (L.) Pers.] pastures and fixed-stocked at different rates under continuous and 8-paddock rotation methods during each of 7 years to: 1) compare stocking methods for daily gain per animal (ADG) and gain/ha; and 2) quantify relationships of ADG with forage mass and forage allowance. Each of 3 levels of stocking rate, 4.9, 6.4, and 8.6 hd/ha, significantly affected ADG at 1.24, …