Agriculture Commons^™

The Effect Of Adjuvants At High Spray Pressures For Aerial Applications, Bradley K. Fritz, W. Clint Hoffmann, Ryan S. Henry

West Central Research and Extension Center, North Platte

Controlling droplet size is a critical part of making any successful agrochemical spray application. This is particularly true for higher-speed aerial applications where secondary atomization from air shear becomes the most dominant factor driving spray droplet size. Previous research has shown that higher spray pressures can result in larger droplet-sized sprays by increasing the exit velocity of the spray liquid from the nozzles, which in turn decreases the differential velocity between the spray liquid and surrounding airstream, reducing secondary breakup. This work explores the effects of higher-than-normal spray pressures on two typical aerial application nozzles in the presence of a …

The Paper Trail: An Arid Connection & A Book Of A Thousand Plants, Stephen L. Young, Peter Alpert

West Central Research and Extension Center, North Platte

Following my Ph.D., I moved on to Nebraska, where as a beginning faculty member I was able to start a research program in ecology and continue to study what intrigued me most: plant competition and stress. It was during this time that I came across the paper by Peter Alpert (see his article below) and his colleagues on “Invasiveness, invasibility, and the role of environmental stress in preventing the spread of non-native plants” (Perspectives in Plant Ecology, Evolution and Systematics 3:52–66). It was an “aha” moment in reading about biological invasion research and the current consensus at that time regarding …

Invasion During Extreme Weather: Success And Failure In A Temperate Perennial Grassland, James C. Han, Stephen L. Young

West Central Research and Extension Center, North Platte

Invasive and native plant species compete for resources in similar pools, with disturbances often favoring the invader. Yet, increased climate variability may be shifting the competitive edge back toward the natives. We conducted field studies in perennial grasslands to determine the effects of clipping and drought on resource availability (light and moisture) and subsequent establishment of Carduus nutans. We measured light penetration and soil moisture content in C. nutans monoculture, clipped and non clipped grassland with C. nutans, and bare ground control plots. We also tracked phenology of the invader and grasses. Our studies revealed that light was a limiting …

Cattle Grazing Effects On Phragmites Australis In Nebraska, Jerry D. Volesky, Stephen L. Young, Karla H. Jenkins Pas

West Central Research and Extension Center, North Platte

Phragmites australis (common reed) is one of the most widely distributed flowering plants in North America. The introduced lineage occurs in wetland and riparian areas covering a range of climatic types. In Nebraska, an abundance of livestock could help to reduce P. australis with proper timing and grazing intensities. In 2011, a 3-yr study was initiated to evaluate targeted cattle grazing and herbicide effects and the nutritive value of this species. Treatments included a single application of imazapyr (Habitatt, BASF Corporation, Research Triangle Park, NC) herbicide applied in the first year, grazing, and a control. Grazing was applied for up …

Field Abundance And Performance Of Hoverflies (Diptera: Syrphidae) On Soybean Aphid, James O. Eckberg, Julie A. Peterson, Colin P. Borsh, Joe M. Kaser, Gregg A. Johnson, John C. Luhman, Donald L. Wyse, George E. Heimpel

West Central Research and Extension Center, North Platte

The management of the soybean aphid Aphis glycines Matsumara is a major challenge to soybean production in the north-central United States. The identification and characterization of the insect predator community has informed integrated pest management strategies by providing insight on predators that can suppress soybean aphid populations. Hoverflies (Diptera: Syrphidae) are known predators of A. glycines, but more information is needed on their diversity, abundance, and performance to evaluate their importance as biological control agents of A. glycines. In this study, syrphid abundance was evaluated across two growing seasons in four soybean fields in east-central Minnesota. Six methods …

Corn Residue Stocking Rate Affects Cattle Performance But Not Subsequent Grain Yield, L. A. Stalker, H. Blanco-Canqui, Jennifer A. Gigax, A. L. Mcgee, T. M. Shaver, S. J. Van Donk

West Central Research and Extension Center, North Platte

This study investigated effects of stocking rate on cattle performance, quality and quantity of corn residue, and impact of residue removal on grain yield for 5 yr at the University of Nebraska – Lincoln West Central Water Resources Field Laboratory near Brule, NE. Four removal treatments—1) no removal (control), 2) grazing at 2.5 animal unit month (AUM)/ ha, 3) grazing at 5.0 AUM/ha, and 4) baling—were applied to a center pivot–irrigated corn field (53 ha). The field was divided into eight 6.6-ha paddocks to which replicated treatments were assigned. Samples of residue were collected in October and March (before and …

Physical And Biological Effects Of Modified Polysorbate 20, Kevin Penfield, Bryan Young, Julie K. Young, Greg R. Kruger, Ryan Henry, Greg Lindner

West Central Research and Extension Center, North Platte

Three experimental polyoxyethylene sorbitan monolaurate derivatives were synthesized with molecular fingerprinting techniques applied to experimental materials, confirming the target compounds had been produced. Chemical property measurements were compiled that aligned with theoretical predictions and physical property measurements confirmed their intentional differences yielded the anticipated changes in surfactant behavior. Imidacloprid uptake data confirmed penetration of leaf cuticles was enhanced in the presence of polyoxyethylene sorbitan monolaurates with several experimental materials providing uptake equivalent to reference material. Select materials were included in field and greenhouse trials where observations included good biological response with a range of individual herbicides as well as improved …

Root Growth Of Two Perennial Grass Types And Musk Thistle (Carduus Nutans) In Temperate Grasslands Of North America, Chengchou Han, Stephen L. Young

West Central Research and Extension Center, North Platte

Root architecture of prairie grasslands, which depends on plant phenology and edaphic conditions, strongly influences susceptibility to invasion by nonindigenous plant species. Field studies were conducted to compare in situ root growth patterns of warm-season (WS) and cool-season (CS) perennial grasses and musk thistle during a 2-yr period that included a drought in the second year. In 2 yr, CS grasses had the highest amount of roots (1,296 m roots m^–2 [395 ft roots ft^–2]) across shallow (0 to 28 cm [0 to 11 in.]), medium (28 to 56 cm), and deep (56 to 98 cm) depths …

Bioeconomic Factors Of Beef Heifer Maturity To Consider When Establishing Criteria To Optimally Select And/Or Retain Herd Replacements, M. C. Stockton, R. K. Wilson, D. M. Feuz, L. A. Stalker, R. N. Funston

West Central Research and Extension Center, North Platte

Understanding the biology of heifer maturity and its relationship to calving difficulty and subsequent breeding success is a vital step in building a bioeconomic model to identify optimal production and profitability. A limited dependent variable probit model is used to quantify the responses among heifer maturities, measured by a maturity index (MI), on dystocia and second pregnancy. The MI account for heifer age, birth BW, prebreeding BW, nutrition level, and dam size and age and is found to be inversely related to dystocia occurrence. On average there is a 2.2% increase in the probability of dystocia with every 1 point …

Late Gestation Supplementation Of Beef Cows Differing In Body Condition Score: Effects On Cow And Calf Performance, D. W. Bohnert, L. A. Stalker, R. R. Mills, A. Nyman, S. J. Falck, R. F. Cooke

West Central Research and Extension Center, North Platte

A 2-yr study utilizing 120 mature, crossbred (Angus × Herford) cows/year, evaluated the influence of cow BCS and dried distillers grains with solubles (DDGS) supplementation during late gestation on cow performance and productivity of subsequent offspring. Treatments were arranged as a 2 × 2 factorial in a randomized complete block design with 2 BCS and with or without DDGS supplementation. Cows were nutritionally managed to enter the last trimester of gestation with a BCS of approximately 4 (LBCS) or 6 (HBCS) and were thereafter managed in a single herd (initial BCS were 4.4 and 5.7 for LBCS and HBCS treatments, …

Heifer Calving Date Positively Influences Calf Weaning Weights Through Six Parturitions, R. A. Cushman, L. K. Kill, Richard N. Funston, E. M. Mousel, G.A. Perry

West Central Research and Extension Center, North Platte

Longevity and lifetime productivity are important factors influencing profitability for the cowcalf producer. Heifers that conceive earlier in the breeding season will calve earlier in the calving season and have a longer interval to rebreeding. Calves born earlier in the calving season will also be older and heavier at weaning. Longevity data were collected on 2,195 heifers from producers in South Dakota Integrated Resource Management groups. Longevity and weaning weight data were collected on 16,549 individual heifers at the U.S. Meat Animal Research Center (USMARC). Data were limited to heifers that conceived during their first breeding season. Heifers were grouped …

Tillage And Crop Residue Removal Effects On Evaporation, Irrigation Requirements, And Yield, Simon Van Donk, Norman L. Klocke

West Central Research and Extension Center, North Platte

Irrigators in the western Great Plains and other irrigated regions face water restrictions caused by decreased well capacity, water allocations imposed by water policy, and/or rising energy costs. These growers require water management practices that optimize grain production. When not enough water is available to produce full yields, the goal for water management is to maximize transpiration and minimize nonessential water losses such evaporation of soil water.

It is generally believed that increasing crop residue levels leads to reduced evaporation. However, crop residue that is removed from the field after harvest is gaining value for use in livestock rations and …

True Integrated Weed Management, Stephen L. Young

West Central Research and Extension Center, North Platte

Using the simplest of definitions, integrated weed management has been described as “putting components [of weed control] together, not taking them apart.” Yet, weed science has stopped at the “field edge” in assembling the components into a truly integrated approach. What is keeping weed scientists from developing real integrated weed control regardless of space and time? The answer to this question lies with our colleagues in the engineering and computer science fields, who have made significant advances in developing automated machinery for real-time detection and control of weeds in cropping systems. By using the latest technologies that can quickly identify …

Effects Of Crop Residue Removal On Soil Water Content And Yield Of Deficit-Irrigated Soybean, Simon Van Donk, Timothy M. Shaver, James L. Petersen, Don Davison

West Central Research and Extension Center, North Platte

Reduced tillage, with more crop residue remaining on the soil surface, is believed to conserve water, especially in arid and semi-arid climates. However, the magnitude of water conservation is not clear. An experiment was conducted to study the effect of crop residue removal on soil water content, soil quality, and crop yield at North Platte, Nebraska. The same field plots were planted to soybean (Glycine max) in 2009 and 2010. There were two treatments: residue-covered soil and bare soil. Residue (mostly corn residue in 2009 and mostly soybean residue in 2010) was removed every spring from the same …

Effect Of Growth Promotants On The Occurrence Of Endogenous And Synthetic Steroid Hormones On Feedlot Soils And In Runoff From Beef Cattle Feeding Operations, Shannon L. Bartelt-Hunt, Daniel D. Snow, William L. Kranz, Terry L. Mader, Charles A. Shapiro, Simon Van Donk, David P. Shelton, David Tarkalson, Tian Zhang

West Central Research and Extension Center, North Platte

Supplements and growth promotants containing steroid hormones are routinely administered to beef cattle to improve feeding efficiency, reduce behavioral problems, and enhance production. As a result, beef cattle manure will contain both synthetic steroids as well as a range of endogenous steroids including androgens, estrogens, and progestogens. A two-year controlled study was conducted in which beef cattle were administered steroid hormones via subcutaneous implants and feed additives and the occurrence of 16 endogenous and synthetic steroid hormones and metabolites was evaluated in runoff from beef cattle feedlots and in manure and soil collected from feedlot surfaces. Samples were extracted and …

Ecosystem Services: The Significance Of Contributions By Invasive Plant Species, Stephen L. Young

West Central Research and Extension Center, North Platte

A symposium was organized to investigate the area of invasive plant species and ecosystem services and further our understanding of the contributions that invasive plants are making to ecosystem services, which, to date, has received limited attention. The following symposium articles address three important areas of assessing the effects of invasive plant species on ecosystem services. Karie Decker et al., in “Landuse, landscapes, and biological invasions,” introduce the concept of resilience in natural systems and use an analysis of the nonnative plants and land use types in Nebraska to emphasize the importance of predicting and quantifying changes in ecological structure, …

Invasive Plant Species As Potential Bioenergy Producers And Carbon Contributors, Stephen L. Young, Gayathri Gopalakrishnan, Deepak R. Keshwani

West Central Research and Extension Center, North Platte

Among recent advances in developing cellulosic and noncellulosic biofuel sources, corn, switchgrass, and others (e.g., camelina, canola) have risen to the top. In surveying the landscape, a potentially promising new area of bioenergy production exists—invasive plant species. The addition of invasive plant species as a bioenergy source will help to diversify the nation’s energy dependence and help in the reduction of the negative environmental and social impacts from energy crop production. In addition, belowground carbon stores may provide an opportunity to reduce the impacts associated with global climate change.

In the agriculture sector, harvesting equipment is well advanced for facilitating …

Applications Of Weps And Sweep To Non-Agricultural Lands, John Tatarko, David G. Walker, Simon Van Donk

West Central Research and Extension Center, North Platte

Soil erosion by wind is a serious problem throughout the United States and the world. Dust from wind erosion obscures visibility and pollutes the air. It fills road ditches where it impacts water quality, causes automobile accidents, fouls machinery, and imperils animal and human health. Dust and specifically particulate matter less than 10 microns (PM10), is regulated by the US-EPA National Ambient Air Quality Standards. The Wind Erosion Prediction System (WEPS) model was developed by the USDA Agricultural Research Service, primarily for the USDA Natural Resources Conservation Service to simulate wind erosion and develop conservation plans on cultivated agricultural lands. …

Corn Water Use And Yield For Various Limited Irrigation Treatments, Simon Van Donk, Don Davison, Jim Peterson

West Central Research and Extension Center, North Platte

With limited water resources, it becomes more critical to know how much and when to irrigate. The objective of this study was to determine the effect of the amount and timing of irrigation on corn (Zea mays L.) yield using subsurface drip irrigation (SDI). A field study was conducted at North Platte, Nebraska in 2007 - 2009, using two SDI systems. The study was replicated eight times on the older SDI system (SDI1) and four times on the newer SDI system (SDI2). On SDI1, there were nine treatments to impose different irrigation regimes, ranging from dryland to fully …

Case Study: The Effects Of Maternal Nutrition On Steer Progeny Performance, A. F. Summers, K. H. Ramsay, Richard N. Funston

West Central Research and Extension Center, North Platte

Two locations on a commercial ranch in the Nebraska Sandhills were used to determine the effects of maternal nutrition on male progeny. Crossbred, spring-calving, multiparous cows were managed in a year-round grazing system. Cows at one location (yr 1 = 754; yr 2 = 700) received the equivalent of 0.95 kg/d (DM; 31.6% CP; HN) of supplement, and cows at the second location (yr 1 = 673; yr 2 = 766) received 0.37 kg/d (DM; LN) of the same supplement delivered 3 times weekly while grazing winter range from December through February. After weaning, a random group (yr 1 = …

Feedlot Manure Handling And Application Strategies On Surface Runoff Of Artificial Hormones Applied To Rowcrop Fields, Sagor Biswas, William L. Kranz, Shannon L. Bartelt-Hunt, Terry L. Mader, Charles A. Shapiro, David P. Shelton, Daniel D. Snow, David Tarkalson, Simon Van Donk, Tian Zhang, Steve Ensley

West Central Research and Extension Center, North Platte

Hormones are essential to the function and propagation of almost all organisms, yet the environmental fate of hormones is not well understood. Because these substances are so common in nature, the question is not whether they will be found, but rather at what concentrations and in what form (biologically active or inactive) will they be found. The objective of this research was to determine the effect of manure handling and application strategies on artificial hormone losses in runoff through the use of simulated rainfall. In 2008, rainfall simulations were conducted at the Haskell Agricultural Laboratory near Concord, NE (Latitude: 42 …

Heifer Development Systems: Dry-Lot Feeding Compared With Grazing Dormant Winter Forage, Richard N. Funston, D. M. Larson

West Central Research and Extension Center, North Platte

Two hundred ninety-nine Angusbased, nulliparous heifers (253 ± 2 kg initial BW) from 3 production years were utilized to compare traditional postweaning dry lot (DL) development with a more extensive winter grazing system utilizing a combination of corn residue and winter range (EXT). Heifers developed in the DL were offered a common diet after the weaning period for 208 d in yr 1, 194 d in yr 2, and 150 d in yr 3 until breeding. Heifers developed in EXT grazed corn residue for 135 d in yr 1, 106 d in yr 2, and 91 d in yr 3, …

The Role Of Light And Soil Moisture In Plant Community Resistance To Invasion By Yellow Starthistle (Centaurea Solstitialis), Stephen L. Young, Guy B. Kyser, Jacob N. Barney, Victor P. Claassen, Joseph M. Ditomaso

West Central Research and Extension Center, North Platte

To resist establishment by an invasive plant, a community may require one or more species functionally similar to the invader in their resource acquisition pattern. In this study, communities consisting of native winter annual forbs, non-native annual grasses, native perennials, or a combination of the two native communities were established with and without Centaurea solstitialis to determine the effect of soil moisture and light availability on plant community invasion resistance. The annual plant communities were unable to resist invasion by C. solstitialis. In the native winter annual forb community, senescence in late spring increased light penetration (>75%) to …

What Contributions Are Invasive Plant Species Making To Ecosystem Services?, Stephen L. Young

West Central Research and Extension Center, North Platte

Invasive plant species can establish in diverse environments, and, with the increase in human mobility, they are no longer restricted to isolated pockets in remote parts of the world. Cheatgrass (Bromus tectorum L.) in rangelands, purple loosestrife (Lythrum salicaria L.) in wetlands, and tamarisk (Tamarix spp.) in riparian areas are examples of invasive plant species that are common to the United States and can be found in monocultures and patches covering many thousands of hectares. Across the world, invasive plant species like water hyacinth (Eichhornia crassipes), cogon grass (Imperata cylindrica), and mile-a-minute weed …

Effects Of Maternal Nutrition On Conceptus Growth And Offspring Performance: Implications For Beef Cattle Production, Richard N. Funston, David M. Larson, K. A. Vonnahme

West Central Research and Extension Center, North Platte

Developmental programming is the concept that a maternal stimulus or insult at a critical period in fetal development has long-term effects on the offspring. Historically, considerable effort has been made to understand how nutrition influences health and productivity during the postnatal period. Whereas maternal nutrition during pregnancy plays an essential role in proper fetal and placental development, less is known about how maternal nutrition affects the health and productivity of the offspring. Conceptus growth is sensitive to direct and indirect effects of maternal dietary intake. Even from the earliest stages of embryonic life, when nutrient requirements for conceptus growth are …

Tillage And Crop Residue Affect Irrigation Requirements, Simon Van Donk

West Central Research and Extension Center, North Platte

Practicing less tillage and retaining more crop residue on the soil surface can reduce the rate of evaporation of water from the soil. These practices also increase the amount of soil water by increasing the amount of water that infiltrates into the soil and decreasing the amount that runs off across the soil surface. Less tillage and more residue coverage can significantly reduce the amount of irrigation water needed to grow a crop.

Effect Of Crop Residue On Soil Water Content And Yield Of Deficit-Irrigated Corn And Soybean, Simon Van Donk, Steven R. Melvin, Jim Peterson, Don Davison

West Central Research and Extension Center, North Platte

It is believed that reduced tillage, with more crop residue on the soil surface, conserves water, especially in arid and semi-arid climates. However, the magnitude of water conservation is not clear. In 2007, a study was initiated on the effect of residue on soil water content and crop yield at North Platte, Nebraska. The experiment was conducted on plots planted to field corn (Zea mays L.) in 2007 and 2008, and soybean (Glycine max) in 2009. There were two treatments: residue-covered soil and bare soil. Bare-soil plots were created in April 2007 by using a dethatcher …

Price Discovery In Nebraska Cattle Markets, Matt Stockton, David A. Bessler, Roger K. Wilson

West Central Research and Extension Center, North Platte

Monthly observations on prices from 10 weight/gender classifications of Nebraska beef cattle are studied in an error correction model (ECM) framework. This study attempts a replication of the 2003 paper on Texas prices by Bessler and Davis, where they find medium heifers (600–700 lb) at the center of price discovery. Using the ECM results Nebraska light steers are found to be weakly exogenous, with the innovation accounting results showing marked differences. Industry structure, production choices, and animal type and breeding herd differences between Texas and Nebraska are proposed as plausible reasons for partial (or incomplete) success at replication.

Crop Residue Cover Effects On Evaporation, Soil Water Content, And Yield Of Deficit‐Irrigated Corn In West‐Central Nebraska, Simon Van Donk, Derrel L. Martin, Suat Irmak, Steven R. Melvin, Jim Peterson, Don Davison

West Central Research and Extension Center, North Platte

Competition for water is becoming more intense in many parts of the U.S., including west‐central Nebraska. It is believed that reduced tillage, with more crop residue on the soil surface, conserves water, but the magnitude of water conservation is not clear. A study was initiated on the effect of residue on soil water content and corn yield at North Platte, Nebraska. The experiment was conducted in 2007 and 2008 on plots planted to field corn (Zea mays L.). In 2005 and 2006, soybean was grown on these plots. There were two treatments: residue‐covered soil and bare soil. Bare‐soil plots …

Weed Control In Organic Cropping Systems, Stephen L. Young

West Central Research and Extension Center, North Platte

Organic producers and many conventional producers rank weed control as their number one production cost. For organic producers particularly, weed control has become increasingly important as organic production has increased its market share. According to the USDA Census of Agriculture, in 2005, for the first time, all 50 states had certified organic farmland, with over 1.6 million total ha (4 million acres) dedicated to organic production systems. In 2006, four major universities in the United States offered new degree programs in organic agriculture with the anticipation that, in five to six years, organic crops will comprise 5 to 10 percent …