Agricultural Science Commons^™

Evaluation Of Tillage, Crop Rotation, And Cover Crop Impacts On Corn Nitrogen Requirements In Southeastern South Dakota, Sara Louise Berg

Electronic Theses and Dissertations

Nitrogen (N) is a vital factor of corn (Zea mays) production. Previous work in South Dakota has shown that there is uncertainty as to whether nitrogen requirements are the same for corn raised under no-till (NT) versus conventional till (CT) production systems. The objective of this study was to evaluate whether N requirements continue to be greater under long-term NT versus CT production systems in southeastern South Dakota, while also considering effects from cover crops and crop rotation. This was a two year study conducted at the SDSU Southeast Research Farm near Beresford, SD; it was superimposed on a long-term …

Grain Sorghum Leaf Reflectance And Nitrogen Status, Akwasi A. Abunyewa, Richard B. Ferguson, Charles S. Wortmann, Stephen C. Mason

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen deficiency is a common but readily managed constraint to grain yield. A quick and nondestructive detection of crop N status using remote sensing could be a means to increased N use efficiency. Research was conducted in a greenhouse in 2006 at the University of Nebraska-Lincoln to establish the relationship of spectral reflectance with N status in leaves of grain sorghum, to develop indices for interpretation of the results and to predict chlorophyll content. Nitrogen stress decreased chlorophyll meter reading and leaf N content, but increased leaf and canopy reflectance. The SPAD values were significantly increased by both water and …

Nutrients In The Nexus, Eric A. Davidson, Rachel L. Nifong, Richard B. Ferguson, Cheryl Palm, Deanna L. Osmond, Jill S. Baron

Department of Agronomy and Horticulture: Faculty Publications

Synthetic nitrogen (N) fertilizer has enabled modern agriculture to greatly improve human nutrition during the twentieth century, but it has also created unintended human health and environmental pollution challenges for the twentyfirst century. Averaged globally, about half of the fertilizer-N applied to farms is removed with the crops, while the other half remains in the soil or is lost from farmers’ fields, resulting in water and air pollution. As human population continues to grow and food security improves in the developing world, the dual development goals of producing more nutritious food with low pollution will require both technological and socioeconomic …

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 …

Grassland Renovation And Consequences For Nutrient Management, Johannes Isselstein, Manfred Kayser

IGC Proceedings (1977-2023)

Sward degradation is a serious threat to the functioning of grassland and the provision of ecosystem services. Renovation measures are frequently applied in order to restore degraded swards. However, the success is highly variable and substantial tradeoffs are often found following renovation such as among agronomic and environmental services. Starting from a general classification of renovation measures the paper investigates the processes induced by renovation that lead to a change of the vegetation and that affect carbon and nitrogen fluxes. These processes are strongly interrelated and dependent on site, climate and management condition as well as on the time scale. …

Using Stable Isotopes To Quantify Nitrogen Fates In Container Plants, Sam Raimann, Greg Michalski, Michael V. Mickelbart

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently, in the agriculture field, it is not yet known the accurate amount of Nitrogen in fertilizer that plants take up. This statistic, known as the Nitrogen Use Efficiency is currently known to be within the 30-50% range (Lea-Cox and Ross, 2001). This is very important figure to know and it is a figure that can be improved, and therefore much time, energy, and resources can be saved. This research project will use concepts involving stable isotopes to examine red maple plant material and the soilless media that the plants were grown in. Three different isotope-labelled fertilizer treatments will be …

Respon Tanaman Kelapa Sawit Terhadap Bakteri Pelarut Fosfat Dan Bakteri Penambat Nitrogen Di Pembibitan Awal (Pre Nursery), Intan Ratna Dewi Anjarsari, Mochamad Arief Soleh, Erni Suminar

Jurnal Kultivasi

The objective of this experiment was to study response of oil palm seedlings in prenursery to Phosfat solubilizing bacteria and nitogen fixaxing bacteria. This experiment was conducted at experimental field, Jatinangor, KabupatenSumedang from April until October 2012. Experimental field located at altitude 753 m above sea level with rainfall C type according to the classification of Schmidt and Fergusson. Experimental design was the simple pattern of Randomized Design Group (RDG), consisting of twelve treatment and repeated three times. The treatment were Without inoculation; Azotobacter 20 mL/plant; BPF 20 mL/plant; 10 mL/plant BPF + 10 ml/plant Azotobacter; 10 mL/plant BPF + …

Respon Tanaman Kelapa Sawit Terhadap Bakteri Pelarut Fosfat Dan Bakteri Penambat Nitrogen Di Pembibitan Awal (Pre Nursery), Intan Ratna Dewi Anjarsari, Mochamad Arief Soleh, Erni Suminar

Jurnal Kultivasi

The objective of this experiment was to study response of oil palm seedlings in prenursery to Phosfat solubilizing bacteria and nitogen fixaxing bacteria. This experiment was conducted at experimental field, Jatinangor, KabupatenSumedang from April until October 2012. Experimental field located at altitude 753 m above sea level with rainfall C type according to the classification of Schmidt and Fergusson. Experimental design was the simple pattern of Randomized Design Group (RDG), consisting of twelve treatment and repeated three times. The treatment were Without inoculation; Azotobacter 20 mL/plant; BPF 20 mL/plant; 10 mL/plant BPF + 10 ml/plant Azotobacter; 10 mL/plant BPF + …

Remote Estimation Of Nitrogen And Chlorophyll Contents In Maize At Leaf And Canopy Levels, Michael Schlemmer, Anatoly A. Gitelson, James S. Schepers, Richard B. Ferguson, Y. Peng, J. Shanahan, Donald Rundquist

Department of Agronomy and Horticulture: Faculty Publications

Leaf and canopy nitrogen (N) status relates strongly to leaf and canopy chlorophyll (Chl) content. Remote sensing is a tool that has the potential to assess N content at leaf, plant, field, regional and global scales. In this study, remote sensing techniques were applied to estimate N and Chl contents of irrigated maize (Zea mays L.) fertilized at five N rates. Leaf N and Chl contents were determined using the red-edge chlorophyll index with R2 of 0.74 and 0.94, respectively. Results showed that at the canopy level, Chl and N contents can be accurately retrieved using green and red-edge Chl …

High Yield Soybean Management: Planting Practices, Nutrient Supply, And Growth Modification, Evan Sonderegger

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

Growers are constantly seeking ways to improve yield in soybean [Glycine max (L.) Merr.]. There has been much interest in the use of selected alternative practices to maximize soybean yield. These practices include planting soybean at higher than recommended seeding rates, planting soybean in narrow rows, breaking apical dominance to induce branching, application of strobilurin fungicides prophylactically to minimize disease and extend the seed filling period, the use of N fertilizer both in furrow and foliar applied, and the use of seed treatments to promote early stand establishment and health. Field studies were conducted at the University of Nebraska …

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 …

Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons

Graduate Theses and Dissertations

Corn (Zea mays L.) requires higher rates of nitrogen fertilizer than any other major U.S. crop partly because N fertilizers are subject to loss through various mechanisms. Because of this, corn may suffer from inadequate nitrogen fertilization or producers may over-apply nitrogen to compensate for early-season nitrogen losses. A timely, accurate, and precise method for measuring in-season corn N status is needed to allow producers to keep nitrogen use efficiency high within a growing season.

Using appropriate software, hue, saturation, and brightness values of digital images can be combined in a dark green color index (DGCI) which is closely associated …

Short-Term Denitrification In The Metalimnion Of A Eutrophic Reservoir, Aki Kogo, Erin M. Grantz, Thad Scott

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Denitrification in metalimnetic water was examined under different conditions to determine how addition of nitrate (NO3 -) and particulate carbon (PC), aeration, and concentrations of nitrate affect denitrification. In the first experiment, water samples from a metalimnion were treated with different combinations of NO3 - and PC. Changes in excess N2 -N concentration for 10 days were measured using membrane inlet mass spectrometry (MIMS). The second experiment used the same treatments as the first experiment after aeration of water. Besides excess N2 -N concentrations, O2 concentrations were measured for 16 days. The third experiment examined how different initial concentrations of …

Long-Term Effects Of Rice Rotation, Tillage, And Fertility On Near-Surface Soil Carbon And Nitrogen Cycling, Jill Marie Motschenbacher

Graduate Theses and Dissertations

Rice (Oryza sativa L.)-based cropping systems are different from other row crops due to the flood-irrigation scheme used from about one month after planting to a few weeks prior to harvest. The frequent cycling between anaerobic (i.e., flooding during the growing season) and aerobic (i.e., generally, the remainder of the year) conditions can influence the rate of soil organic matter (SOM) decomposition, which can greatly influence carbon (C) and nitrogen (N) storage and sequestration in the soil over time. Therefore, a study was conducted on a silt-loam soil (fine, smectitic, thermic, Typic Albaqualf) at the Rice Research and Extension Center …

Water Use And Yields Of No-Till Managed Dryland Grasspea And Yellow Pea Under Different Planting Configurations, F.J. Calderón, M.F. Vigil, D.C. Nielsen, J.G. Benjamin, D.J. Poss

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

Grasspea (GP) (Lathyrus sativus) is a drought-tolerant legume that can be grown for forage and grain. It has potential value to be used as a nitrogen-fixing crop in dryland rotations with non-legume grain crops. However, the agronomy of GP for the Central Great Plains region have not been investigated. The objective of this research was to compare the grain and biomass yield, as well as N accumulation of GP relative to field pea (FP) in two planting configurations. We carried out a 3-year field experiment to compare dryland GP with Admiral yellow field pea (Pisum sativum) …

Trait Convergence And Plasticity Among Native And Invasive Species In Resource-Poor Environments, Rebecca E. Drenovsky, Albina Khasanova, Jeremy J. James

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

Premise of study: Functional trait comparisons provide a framework with which to assess invasion and invasion resistance. However, recent studies have found evidence for both trait convergence and divergence among coexisting dominant native and invasive species. Few studies have assessed how multiple stresses constrain trait values and plasticity, and no study has included direct measurements of nutrient conservation traits, which are critical to plants growing in low-resource environments.

Methods: We evaluated how nutrient and water stresses affect growth and allocation, water potential and gas exchange, and nitrogen (N) allocation and use traits among a suite of six codominant species from …

The Influence Of Nutrients And Physical Habitat In Regulating Algal Biomass In Agricultural Streams, Mark D. Munn, Jeffrey Frey, Anthony Tesoriero

United States Geological Survey: Water Reports and Publications

This study examined the relative influence of nutrients (nitrogen and phosphorus) and habitat on algal biomass in five agricultural regions of the United States. Sites were selected to capture a range of nutrient conditions, with 136 sites distributed over five study areas. Samples were collected in either 2003 or 2004, and analyzed for nutrients (nitrogen and phosphorous) and algal biomass (chlorophyll a). Chlorophyll a was measured in three types of samples, fine-grained benthic material (CHLFG), coarse-grained stable substrate as in rock or wood (CHLCG), and water column (CHLS). Stream and riparian habitat were characterized at each site. TP ranged from …

Effect Of Nitrogen Application Timing On Corn Production Using Subsurface Drip Irrigation, David D. Tarkalson, Simon J. Van Donk, James L. Petersen

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

The use of subsurface drip irrigation (SDI) in row-crop agriculture is increasing because of potential increases in water and nutrient use efficiency. Research-based information is needed to manage N applications through SDI systems in field corn (Zea-mays L.) production. This study was conducted to assess the effect of different in-season SDI system N application timings on corn production and residual soil N0₃-N at the University of Nebraska-Lincoln West Central Research and Extension Center in North Platte, Neb, on a Cozad silt loam (fine-silty, mixed, mesic Fluventic Haplustoll). We evaluated the effect of three N application timing methods …

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 …

Epic Evaluation Of The Impact Of Poultry Litter Application Timing On Nutrient Losses, H. Allen Torbert, Thomas J. Gerik, Wyatte L. Harman, Jimmy R. Williams, Melanie Magre

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

Recently, changes in the utilization practices of animal manures for fertilization have been encouraged to reduce the potential of nonpoint pollution of lakes and streams from agricultural land. However, the potential impact of changing some of these practices has not been fully studied. The objective of this study was to examine the potential impact of limiting poultry litter application times on nutrient movement important to water quality. The WinEPIC model was used to simulate poultry litter applications during the winter months and chemical fertilizer application, with both cool season and warm season grass pastures on the major soil regions of …

Nationally Coordinated Evaluation Of Soil Nitrogen Mineralization Rate Using A Standardized Aerobic Incubation Protocol, T. S. Griffin, C. W. Honeycutt, S. L. Albrecht, K. R. Sistani, H. A. Torbert, B. J. Wienhold, B. L. Woodbury, R. K. Hubbard, J. M. Powell

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

Aerobic incubation methods have been widely used to assess soil nitrogen (N) mineralization, but standardized protocols are lacking. A single silt loam soil (Catlin silt loam; fine-silty, mixed, superactive, mesic, Oxyaquic Arguidoll) was subjected to aerobic incubation at six USDA-ARS locations using a standardized protocol. Incubations were conducted at multiple temperatures, which were combined based on degree days (DD). Soil water was maintained at 60% waterfilled pore space (WFPS; constant) or allowed to fluctuate between 60 and 30% WFPS (cycle). Soil subsamples were removed periodically and extracted in 2 M potassium chloride (KCl); nitrate (NO₃) and ammonium (NH …

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 …

Comparison Of Ground-Based Remote Sensors For Evaluation Of Corn Biomass Affected By Nitrogen Stress, Soon-Dal Hong, James Schepers, Dennis D. Francis, Michael R. Schlemmer

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

The nondestructive determination of plant biomass is not possible; however, crop-canopy sensors that determine the normalized difference vegetation index have the potential to estimate living biomass, which is indicative of plant vigor and stress. Pot experiments using sand culture were conducted in 2002 and 2003 under greenhouse conditions to evaluate the effect of nitrogen (N) deficiency on corn biomass and reflectance. Stress was imposed by implementing six to eight levels of N in Hoagland’s nutrient solution. Canopy reflectance measurements made at three growth stages with a variety of handheld spectral sensors (active and passive) were closely correlated with dry weight …

Mineralization Of Nitrogen In Soils Amended With Dairy Manure As Affected By Wetting/Drying Cycles, D. B. Watts, H. A. Torbert, S. A. Prior

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

Interest in manure management and its effects on nitrogen (N) mineralization has increased in recent years. The focus of this research was to investigate the N-mineralization rates of different soil types in Coastal Plain soils and compare them to a soil from Illinois. Soils with and without dairy composted manure addition were subjected to different wetting/drying cycles [constant moisture at 60% waterfilled pore space (WFPS) and cycling moisture from 60 to 30% WFPS] under laboratory conditions at three different temperatures (11 °C, 18 °C, and 25 °C). Samples were collected from three different soil types: Catlin (Mollisols), Bama (Ultisols), and …

Non-Composted Municipal Solid Waste Processing Byproduct Effect On Soil Reclamation, H. Allen Torbert, Dick L. Gebhart, Ryan R. Busby, Kenneth N. Potter, Deborah R. Curtain

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

A new garbage processing technology has been developed that sterilizes and separates inorganic and organic components of municipal solid waste. The non-composted byproduct of this process, Fluff ®, has the potential to be utilized as a soil amendment to improve soil conditions in highly degraded soils. A study was initiated to evaluate Fluff as a soil amendment for establishing native grasses on disturbed US Army training lands. The Fluff was incorporated into a sandy loam soil at Fort Benning Military Reservation, GA on two sites: a moderately degraded and a highly degraded soil. The Fluff was incorporated at rates of …

The Effect Of Nitrogen Fertilizer Application To Maize And Sorghum On The Bionomics Of Chilo Partellus (Lepidoptera: Crambidae) And The Performance Of Its Larval Parasitoid Cotesia Flavipes (Hymenoptera: Braconidae), N. Jiang, F. Schulthess

All Peer-Reviewed Publications

Laboratory and field trials were conducted to evaluate the effect of plant species (maize, sorghum), plant age (young, middle, old) and four different nitrogen fertilization levels (N0-N3) on the bionomics of the invasive crambid Chilo partellus and the performance of its braconid larval parasitoid Cotesia flavipes. Plant N varied significantly between N0 and N1-N3, but the differences among the latter were not significant. Intrinsic rates of increase and net-reproductive rates of C. partellus followed the same trends: they were lowest with N0 and similar among the other treatments. On maize only, mortality of C. partellus and parasitism by C. flavipes …

Maintenance Of A Narrow Host Range By Oxyops Vitiosa; A Biological Control Agent Of Melaleuca Quinquenervia, G. S. Wheeler

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

Host range expansion in insect herbivores is often thought to be mediated by several factors, principal among them are secondary plant metabolites. In weed biological control, the host range of a prospective agent is one of the most important considerations in its implementation. Extensive host testing tests seek to determine the behavioral acceptance and nutritional value of different test plant species to the potential agent. A list of test plants is compiled that comprises species that are close taxonomic relatives of the target weed plus other species of economic or ecologic importance. The host testing of the Melaleuca quinquenervia biological …

Control Of Witchweed Striga Hermonthica By Intercropping With Desmodium Spp., And The Mechanism Defined As Allelopathic, Zeyaur R. Khan, Ahmed Hassanali, William Overholt, Tsanuo M. Khamis, Antony M. Hooper, John A. Pickett, Lester J. Wadhams, Christine M. Woodcock

All Peer-Reviewed Publications

During investigations into the control of insect damage to maize crops in subsistence farming in Kenya, which involved intercropping with repellent plants, the fodder legumes silverleaf (Desmodium uncinatum) and greenleaf (D. intortum) were also found to reduce dramatically the infestation of maize by parasitic witchweeds such as Striga hermonthica. This effect was confirmed by further field testing and shown to be significantly greater than that observed with other legumes, e.g., cowpea, as were the concomitant yield increases. The mechanism was investigated, and although soil shading and addition of nitrogen fertilizer showed some benefits against S. hermonthica infestation, a putative allelopathic …

Simulation Model For Maize Crop Growth Based On Acquisition And Allocation Processes For Carbohydrate And Nitrogen, O. Bonato, F. Schulthess, J. Baumgärtner

All Peer-Reviewed Publications

A population model for maize growth and development driven by temperature, solar radiation, soil water and soil nitrogen is presented. A time-varying distributed delay model is used to describe the dynamics of the attributes number, biomass and nitrogen belonging to leaf, root, stem, grain, rachys and husk populations. Photosynthate production as well as water and nitrogen acquisition was simulated with a demand-driven ratio-dependent functional response model. Carbohydrate, water and nitrogen supply-demand ratios were calculated to control the growth of different populations of plant. The metabolic pool model was used to allocate carbohydrates to plant subunits. The model was validated with …

Tallgrass Prairie Vegetation Response To Spring Burning Dates, Fertilizer, And Atrazine, Robert B. Mitchell, Robert A. Masters, Steven S. Waller, Kenneth Moore, Linda J. Young

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

Tallgrass prairies provide an important source of hay and summer forage in eastern Nebraska. A study was conducted in 1989 and 1990 on 2 late seral tallgrass prairies near Lincoln and Virginia, Nebraska to determine if production of selected components of tallgrass prairie communities could be altered by burning (not burned, or burned in either early, mid-, or late spring) and applying fertilizer (0 and 67-23 kg N-P ha^-1) and atrazine [6- chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine] (0 and 2.2 kg a.i. ha^-1). Vegetation was harvested the year treatments were applied at about 30-day intervals starting in June and ending …