Life Sciences Commons^™

The Effect Of Preflood Nitrogen And Flood Establishment Timing On Rice Development, Nitrogen Uptake And Grain Yield, Tyler Richmond

Graduate Theses and Dissertations

Urea-N fertilizer is typically applied at the 5-leaf stage to rice (Oryza sativa L.) grown in a dry-seeded, delayed-flood production system. How long the preflood-N can be delayed without adverse effects on yield potential is poorly understood. The research objective was to determine the effects of preflood-N application and flood establishment timing on aboveground-N content, 50% heading, yield components, and grain yield. Trials were established on silt loam soils at the Pine Tree Research Station (PTRS) and Rice Research and Extension Center (RREC) during 2015 and 2016. Urea-N was applied at 0, 45, 90, 135, and 180 kg N ha-1 …

Nitrogen Availability And Use Efficiency In Corn Treated With Contrasting Nitrogen Sources, Avneet Kakkar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The plant-soil nitrogen cycle plays a significant role in allocation of available N to plants, and improved understanding of N cycling helps sustainably increase fertilizer use efficiency. There are various processes (nitrogen mineralization and nitrification) involved in the availability and mobility of nitrogen in the soil. The primary objective of this study was to determine the NUE under contrasting nitrogen treatments over a period of five years. Additionally, we examined the effect of different N treatments on N mineralization and nitrification in conventional and organic farming systems.

This project was funded by Agriculture and Food Research Initiative Competitive Grants Program …

Effects Of Nitrogen And Phosphorus Fertilizer And Topsoil Amendment On Native Plant Cover In Roadside Revegetation Projects, Heidi L. Hillhouse, Walter H. Schacht, Jonathan M. Soper, Carol E. Wienhold

Department of Agronomy and Horticulture: Faculty Publications

Establishing vegetation on roadsides following construction can be challenging, especially for relatively slow growing native species. Topsoil is generally removed during construction, and the surface soil following construction (“cut-slope soils”) is often compacted and low in nutrients, providing poor growing conditions for vegetation. Nebraska Department of Transportation (NDOT) protocols have historically called for nitrogen (N) and phosphorus (P) fertilization when planting roadside vegetation following construction, but these recommendations were developed for cool-season grass plantings and most current plantings use slower-establishing, native warmseason grasses that may benefit less than expected from current planting protocols. We evaluated the effects of nitrogen and …

N2o Emissions From California Farmlands: A Review, Elizabeth Verhoeven, Engil Isadora Pujol Pereira, Charlotte Decock, Gina Garland, Taryn Kennedy, Emma Suddick, William Horwath, Johan Six

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Of the greenhouse gases emitted from cropland, nitrous oxide (N2O) has the highest global warming potential. The state of California acknowledges that agriculture both contributes to and is affected by climate change, and in 2016 it adopted legislation to help growers reduce emissions of greenhouse gases, explicitly including N2O. Nitrous oxide emissions can vary widely due to environmental and agronomic factors with most emission estimates coming from temperate grain systems. There is, however, a dearth of emission estimates from perennial and vegetable cropping systems commonly found in California's Mediterranean climate. Therefore, emission factors (EFs) specific to California conditions are needed …

Population-Level Coordination Of Pigment Response In Individual Cyanobacterial Cells Under Altered Nitrogen Levels, Jaclyn Murton, Aparna Nagarajan, Amelia Y. Nguyen, Michelle Liberton, Harmony A. Hancock, Himadri B. Pakrasi, Jerilyn A. Timlin

Biological Sciences Faculty Publications

Cyanobacterial phycobilisome (PBS) pigment-protein complexes harvest light and transfer the energy to reaction centers. Previous ensemble studies have shown that cyanobacteria respond to changes in nutrient availability by modifying the structure of PBS complexes, but this process has not been visualized for individual pigments at the single-cell level due to spectral overlap. We characterized the response of four key photosynthetic pigments to nitrogen depletion and repletion at the subcellular level in individual, live Synechocystis sp. PCC 6803 cells using hyperspectral confocal fluorescence microscopy and multivariate image analysis. Our results revealed that PBS degradation and re-synthesis comprise a rapid response to …

Nitrogen And Phosphorus Application Effects On Pearl Millet Forage Yield And Nutritive Value, D. D. Serba, A. Obour

Kansas Agricultural Experiment Station Research Reports

There is limited information on the nitrogen (N) and phosphorus (P) fertilizer requirement of pearl millet forage in dryland systems. Determination of optimum N and P rates for pearl millet forage production in dryland environments of the Great Plains will have economic advantage for farmers and ranchers growing pearl millet for forage. A field experiment was conducted in 2016 at the Agricultural Research Center-Hays, KS, to investigate N and P fertilizer application effects on forage yield and nutritive value of pearl millet. Factorial combinations of five levels of N (0, 30, 60, 90, and 120 lb/a) and three levels of …

Biochar And Nitrogen Effects On Winter Wheat Growth, T. E. Zee, N. O. Nelson, G. Newdigger

Kansas Agricultural Experiment Station Research Reports

Biochar, a co-product of thermochemical bioenergy production, may be a valuable soil amendment, but little is known about its potential long-term effects on plant growth and soil fertility. In order to gain more information, this experiment was performed to see if the addition of biochar, in comparison to lime and fertilizer treatments, has the potential to return key nutrients back to the soil or increase crop yield. A field study to investigate the effects of biochar on plant growth was initiated in 2011 near St. John, KS. Treatments included biochar applied at 16.6 ton/a (biochar), lime and annual applications of …

Nutrient Addition Shifts Plant Community Composition Towards Earlier Flowering Species In Some Prairie Ecoregions In The U.S. Central Plains, Lori Biederman, Brent Mortensen, Philip Fay, Nicole Hagenah, Johannes Knops, Kimberly La Pierre, Ramesh Laungani, Eric Lind, Rebecca L. Mcculley, Sally Power, Eric Seabloom, Pedro Tognetti

Plant and Soil Sciences Faculty Publications

The distribution of flowering across the growing season is governed by each species’ evolutionary history and climatic variability. However, global change factors, such as eutrophication and invasion, can alter plant community composition and thus change the distribution of flowering across the growing season. We examined three ecoregions (tall-, mixed, and short-grass prairie) across the U.S. Central Plains to determine how nutrient (nitrogen (N), phosphorus, and potassium (+micronutrient)) addition alters the temporal patterns of plant flowering traits. We calculated total community flowering potential (FP) by distributing peak-season plant cover values across the growing season, allocating each species’ cover to only those …

Nitrogen And Water Interactions In Drought Stressed Kentucky Bluegrass Conserving Our Vital Resource, Kerri Russell, Bryan G. Hopkins

Journal of Undergraduate Research

Turfgrass is the irrigated crop of greatest acreage in the United States. As urban and suburban developments are growing at an unprecedented rate, the demand for turfgrass is in high demand. Its ecosystem services are valuable and include groundwater protection, erosion control, soil health, and air purification. It also provides high utility to residential and public lands. Despite its environmental benefits, turfgrass has been brought under scrutiny due to natural resource consumption and pollution, particularly in arid and semi-arid regions of the western US. Turfgrass requires a significant amount of irrigation water, a resource that is scarce in the arid …

Nitrogen Pulses And Competition Between Native And Invasive Plant Species, Nicolas Matallana, Mandy L. Slate, Ragan M. Callaway

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Variation in the timing and size of resource fluctuations can influence how plants grow, allocate biomass, and reproduce. Resources are sometimes made available in relatively continuous, reliable pulses while other times they are temporally separated and unpredictable. Native and invasive plant species are thought to respond differently to resource fluctuations, or pulses, which can influence competitive outcomes. The “Fluctuating Resource Hypothesis” predicts that resource fluctuations benefit invasive species more than native species, potentially because many invaders are highly effective at rapidly capturing resources. In a field setting, we examined the effects of varying nitrogen pulses on competition between exotic invasive …

Nitrogen, Phosphorus, And Potassium Fertilization For Newly Established Tall Fescue, D. W. Sweeney, J. L. Moyer, J. K. Farney

Kansas Agricultural Experiment Station Research Reports

Tall fescue production was studied during a third year at two locations. In 2015, Site 1 was affected by an interaction between nitrogen (N) and phosphorus (P) fertilization rates; while in 2016, Site 2 mainly received production differences by N fertilization rates. Potassium (K) fertilization caused little effect at both sites.

Third-year production of tall fescue was affected by an interaction between nitrogen (N) and phosphorus (P) fertilization rates at Site 1 in 2015, but mainly by N fertilization rates at Site 2 in 2016, with little effect from potassium (K) fertilization at either site.

Effects Of Silvopasture Establishment On Aqueous And Gaseous Soil N Losses At The University Of New Hampshire Organic Dairy Research Farm, Kathryn Ann Slebodnik

Honors Theses and Capstones

The expansion of local agriculture in the New England region is putting increased pressure on farmers to expand their arable land base. While clear-cutting is a traditional method of converting forested land to agriculture, it is known for having adverse ecological impacts. To minimize these impacts, farmers can create a silvopasture which incorporates a portion of the original forest canopy into pastures or crop fields. This study evaluates the impact of land-use changes for agriculture on soil nitrogen (N) retention. In particular, this study investigates the differences in soil N turnover, gaseous loss, and aqueous loss among an established forest, …

Timing Of Side-Dress Applications Of Nitrogen For Corn In Conventional And No-Till Systems, D. W. Sweeney, D. E. Shoup

Kansas Agricultural Experiment Station Research Reports

Corn yields were affected by tillage and nitrogen (N) side-dress options in 2016. Corn yields were 12% greater with conventional tillage than with no-till. Side-dress applications of N at V10 resulted in greater corn yield than side-dress N applications at V6.

Improving Nitrogen Use Efficiency And Yield In Louisiana Sugarcane Production Systems, Daniel Ernesto Forestieri

LSU Master's Theses

Proper nitrogen (N) management is essential to optimize crop production. This study was conducted to evaluate different N fertilizer management strategies to improve N use efficiency and yield in sugarcane production in Louisiana. This research was initiated in 2013 at the Sugar Research Station in St. Gabriel, LA and was arranged in a randomized complete block design with four replications consisting of different N rates (0, 45, 90, and 135 kg N ha-1) and sources (urea-46% N, ammonium nitrate [AN]-34% N, and urea-ammonium-nitrate solution [UAN]-32% N dribbled and knifed-in) as treatments. Sensor readings were taken from different N response trials …

Effects Of Silicon And Nitrogen Fertilization On Growth, Yield, And Leaf Rust Disease Development In Wheat, Maryamossadat Shahrtash

LSU Master's Theses

There are so many people who have helped me throughout my graduate studies and for whom I am grateful. I would like to take this opportunity to first and foremost thank God for his always guidance throughout my life and giving me the wisdom and the patience I needed to finish my thesis. I would like to thank Dr. Brenda Tubana for taking me in and providing me with guidance and knowledge. I also would like to thank my committee members, Prof. Brian D. LeBlanc who guided me, encouraged me and provided me with knowledge about sustainable agriculture and Dr. …

Soil Properties' Response To Wheat And Corn Stubble Residue Management In Louisiana, Autumn Danielle Acree

LSU Master's Theses

Crop residue plays an important role in improving soil fertility. Crop residue affects soil biological and chemical properties by increasing soil organic matter, nutrient status and availability, and microbial activity. The degree of the effects of crop residue on soil fertility depends on the crop residue management practice. Samples were collected in 2014 in wheat (Triticum spp.) stubble and corn (Zea mays) stubble residue. A second soil sample collection under wheat stubble residue was taken in 2015 in the prescribed fire and no-till sections. A total of 342 soil samples (0-2.5cm) were collected across conventional tillage, no-till, and prescribed fire …

Soybean: Evaluation Of Inoculation, T. M. Albuquerque, O. Ortez, G. I. Carmona, I. A. Ciampitti

Kansas Agricultural Experiment Station Research Reports

Most of the nitrogen (N) required by a soybean plant is supplied via biological nitrogen fixation (BNF). When BNF is adequately established in the soil, soybean can obtain up to 50 to 75% of its N from the air. This project aims to quantify the response to inoculation for soybean in its second year in a field without previous history of this crop. Due to this objective, a field study was conducted during the 2015 and 2016 growing seasons at Ottawa, KS (East Central experiment field location). The treatments consisted of five different N-management approaches: non-inoculated (NI), inoculated ×1 (I×1), …

Soybean: Genetic Gain × Fertilizer Nitrogen Interaction, O. Ortez, F. Salvagiotti, Eric Adee, J. Enrico, I. A. Ciampitti

Kansas Agricultural Experiment Station Research Reports

The United States (US) and Argentina (ARG) account for more than 50% of the global soybean production. Soybean yields are determined by the genotype, environment, and management practices (G × E × M) interaction. Overall, 50-60% of soybean nitrogen (N) demand is usually met by the biological nitrogen fixation (BNF) process. An unanswered scientific question concerns the ability of BNF process to satisfy soybean N demand at varying yield levels. The overall objective of this project was to study the contribution of N via utilization of different N strategies, evaluating soybean genotypes released in different eras. Four field experiments were …