Agriculture Commons^™

Estrus Synchronization And Periconceptual Supplementation Affect The Profitability Of A Replacement Heifer Enterprise, D. M. Larson, R. D. Richardson, K. H. Ramsay, R. N. Funston

West Central Research and Extension Center, North Platte

Experiments evaluated estrus synchronization and periconceptual supplementation on pregnancy rate and calf production. Approximately one-half of heifers in 2 pastures (yr 1) or 4 pastures (yr 2) were injected with prostaglandin F_2α (PGF; n = 1,182) or not (NPGF; n = 1,208) 5 d after fertile bulls were introduced for 25 d. In yr 2, a total of 1,230 heifers were randomly assigned to 1 of 4 pastures; 2 received a supplement providing 100 g/d of Ca propionate (1.4 kg/d, 20% CP) 2 d before through 19 d after bull exposure and 2 did not in a 25-d breeding …

Effect Of Crop Residue On Soil Water Content And Yield Of Deficit-Irrigated Corn And Soybean, Simon Van Donk, Steven R. Melvin, James L. Petersen, 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 and …

Pollen Interception By Linyphiid Spiders In A Corn Agroecosystem: Implications For Dietary Diversification And Risk-Assessment, Julie A. Peterson, Susan Romero, James D. Harwood

West Central Research and Extension Center, North Platte

Dietary diversification, including consumption of plant tissues such as pollen, can enhance the fecundity of generalist predators, resulting in improved control of pest prey. Supplemental pollen feeding has been observed in many natural enemies, including sheet-web spiders (Araneae: Linyphiidae), which represent a major component of food webs in agroecosystems. Their horizontal, ground-based webs have the potential to intercept pollen grains during anthesis of crop plants, providing the opportunity for consumption of pollen to occur. In laboratory feeding trials, Frontinella communis and Tennesseellum formicum (Araneae: Linyphiidae) readily fed on pollen grains dusted on their webs, with 82 and 92% of spiders …

Robots For Weed Control In Eden?, Stephen L. Young

West Central Research and Extension Center, North Platte

In the Biblical account, weeds were the result of the curse for Adam’s sin. In the 21st century, we are still toiling by the sweat of our brow to control weeds. What Adam and the rest of mankind have endured for thousands of years, may soon be controlled by a robot, similar to the ones that vacuum your floor, protect your car and entertain your kids.

Spatio-Temporal Relationship Between Water Depletion And Root Distribution Patterns Of Centaurea Solstitialis And Two Native Perennials, Stephen L. Young, Guy B. Kyser, Jacob N. Barney, Victor P. Claassen, Joseph M. Ditomaso

West Central Research and Extension Center, North Platte

In a 2-year field study, we quantified lateral root growth patterns and soil water depletion dynamics in the invasive annual Centaurea solstitialis and two native perennials, Elymus glaucus and Grindelia camporum. Centaurea solstitialis produced lateral roots most actively from early April to mid-June, during the late rosette to spiny seedhead stage while both root growth and water depletion were completed before flowering. In the wet year, roots were evenly distributed throughout the soil profile to 180 cm deep. Lack of deep soil moisture recharge in the second year restricted root distribution to shallow soil depths (< 60 cm). In contrast to C. solstitialis, …

Tree Fruits As Annual Crops?, Stephen L. Young

West Central Research and Extension Center, North Platte

Orchard systems have gone through dynamic changes over the past 50 years. High-density plantings and dwarfing rootstocks have allowed growers to make changes in production practices more quickly as markets have expanded and become more volatile. Will these changes in woody perennial crops in the past five decades be equaled or surpassed in the next?

From this research, it is clear that with breeding and genetics, intensive orchard systems can come into full production at a faster rate than those of the pre-twentieth century era. Future research will provide clues as to how even faster production capacity can be achieved …

Performance Of Solid-State Sensors For Continuous, Real-Time Measurement Of Soil Co2 Concentrations, Stephen L. Young, Francis J. Pierce, Jason D. Streubel, Harold D. Collins

West Central Research and Extension Center, North Platte

Recent advances in sensor technology provide a robust capability for continuous measurement of soil gases. The performance of solid-state CO₂ sensors (Model GMM220 series, Vaisala, Inc., Helsinki, Finland) was evaluated in laboratory, greenhouse, and irrigated winter wheat (Triticum aestivum L.). In ambient CO₂ concentration, the GMM222 sensor averaged 427 ± 8.3 μL L⁻¹. Under variable CO₂ concentrations, the sensor was slightly lower than concentrations measured with an infrared gas analyzer (IRGA). In greenhouse pots planted with triticale (Triticale hexaploide Lart.) and an agricultural field of irrigated winter wheat, soil CO₂ concentration exceeded …

Quantification Of Bt-Endotoxin Exposure Pathways In Carabid Food Webs Across Multiple Transgenic Events, Julie A. Peterson, John J. Obrycki, James D. Harwood

West Central Research and Extension Center, North Platte

Despite the reported specificity of Bacillus thuringiensis proteins against target pests, a number of studies have indicated that the uptake of Bt-endotoxins from bioengineered crops could have negative effects on natural enemies. It is therefore essential to quantify exposure pathways in non-target arthropod food webs across multiple transgenic events. Adult ground beetles (Coleoptera: Carabidae) were collected from transgenic corn fields expressing lepidopteran-specific Cry1Ab, coleopteran-specific Cry3Bb1, and both Cry1Ab and Cry3Bb1 (stacked event), as well as a non-transgenic isoline. Carabid gut-contents were screened for Cry1Ab Bt-endotoxin using enzyme-linked immunosorbent assay. Significant numbers of carabids tested positive for Cry1Ab from the lepidopteran-specific …

The Effect Of Delaying Initial Feedlot Implant On Body Weight, Average Daily Gain, And Carcass Characteristics Of Calf-Fed Steers, W. Griffin, D. C. Adams, R. N. Funston

West Central Research and Extension Center, North Platte

Two experiments were conducted to determine the effect of delaying initial feedlot implant on BW, ADG, and carcass characteristics. At receiving, steers were assigned to 1 of 2 treatments: 1) implant at feedlot entry (NORM) or 2) implant 30 d after feedlot entry (DELAY). In Exp. 1, steers (n = 200) were not implanted until feedlot entry; however, in Exp. 2 steers (n = 209) were implanted at approximately 50 d of age. In Exp. 1, there was a tendency (P = 0.11) for BW at d 30 to be heavier (10 kg) for NORM compared with DELAY; however, all …

Post Weaning Management Of Heifer Calves Impacts Average Daily Gain And Feed Efficiency As Pregnant Heifers, D. M. Larson, Tonya L. Meyer, L. A. Stalker, Richard N. Funston

West Central Research and Extension Center, North Platte

Three experiments evaluated replacement heifer development systems and subsequent effects on gain and efficiency of pregnant heifers. In Exp. 1 and 2, were developed grazing corn residue (CR; 422 ± 5 kg) or fed in a dry lot (DL; 446 ± 5 kg) prior to breeding. In Exp. 1, a subset of pregnant heifers (n = 40) were individually fed a diet composed of 90% grass hay (11.7 % CP; DM basis) and 10% of a wet distillers grains plus solubles/straw mixture (21.8 % CP; DM basis) during late gestation. In Exp. 2, 55 pregnant …

The Effects Of Corn Coproduct Supplementation On Primiparous Cow Reproduction And Calf Performance, D. M. Larson, R. N. Funston

West Central Research and Extension Center, North Platte

An experiment was replicated over 2 yr to determine the effect of additional RUP and dietary fat from dried distillers grains plus solubles (DDGS; n = 2) or wet corn gluten feed (WCGF; n = 2) before breeding on primiparous cow reproduction and calf production. Over 2 yr, 134 postpartum, primiparous cows (429 ± 5 kg initial BW) were fed 1 of 2 isocaloric, approximately isonitrogenous diets in 1 pen/yr (n = 4) providing varying levels of RUP and dietary fat. Treatments were initiated 21 (yr 1) and 60 d (yr 2) postpartum and continued for 56 (yr 1) or …

Penstemon ‘Sweet Joanne’, Dale T. Lindgren, Daniel Schaaf, Kim Todd

West Central Research and Extension Center, North Platte

Penstemon Mitch. (Plantaginaceae Juss. formerly Scrophulariaceae Juss.) is a diverse genus of ≈271 species that occur throughout the United States (except Hawaii), Canada, Mexico, and Guatemala (Lindgren and Wilde, 2003). Many cultivars have been named (Lindgren, 2006). Although selections from interspecific crosses are less common than intraspecific crosses, many European hybrids have been derived from intercrossing species and hybrids from Mexico with the large flowered P. cobaea Nutt. from the central United States. Most of these large and colorfully flowered European hybrids do not overwinter in the United States except in the milder climates.

Selections from intersectional crosses between the …

Effect Of Amount And Timing Of Subsurface Drip Irrigation On Corn Production, Simon Van Donk, James Petersen, Don Davison

West Central Research and Extension Center, North Platte

Subsurface drip irrigation (SDI) has the potential of being a more efficient irrigation system compared to systems such as center pivot and furrow irrigation. The objective of this study was to determine the effect of the amount and timing of irrigation, using SDI, on corn (Zea mays) production. A field study was conducted at North Platte, Nebraska in 2007 and 2008, 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 …

My View: Automated Weed Control In Organic Cropping Systems, Stephen L. Young

West Central Research and Extension Center, North Platte

In 2005, for the first time, all 50 states in the United States had some certified organic farmland (USDA 2007). Producers in the United States dedicated over 1.62 million hectares of farmland to organic production systems in 2005. The increase in the number of hectares of crops being grown organically has brought with it a growing need for more labor and nonconventional inputs for weed control. Currently, weed control is ranked as the number one production cost by organic and many conventional growers. Over the past 10 yr, development of machine-guided technologies for site-specific (precision) weed control has advanced rapidly, …

Functionally Similar Species Confer Greater Resistance To Invasion: Implications For Grassland Restoration, Stephen L. Young, Jacob N. Barney, Guy B. Kyser, Tracy S. Jones, Joseph M. Ditomaso

West Central Research and Extension Center, North Platte

Plant community functional composition can be manipulated in restored ecosystems to reduce the establishment potential of invading species. This study was designed to compare invasion resistance among communities with species functionally similar or dissimilar to yellow starthistle (Centaurea solstitialis), a late-season annual. A field experiment was conducted in the Central Valley of California with six experimental plant communities that included (1) six early-season native annual forbs (AF); (2) five late-season native perennials and one summer annual forb (NP); (3) a combination of three early-season native annual forbs and three late-season native perennials (FP); (4) six early-season non-native annual …

Penstemon ‘Dark Towers’, Dale T. Lindgren, Daniel Schaaf

West Central Research and Extension Center, North Platte

Penstemon Mitch. (Plantaginaceae Juss. formerly Scrophulariaceae Juss.) is a genus of plants with ≈ 271 species that can be found from low deserts to high alpine areas (Lindgren and Wilde, 2003; Wolfe et al., 2006). It is one of the largest genera of North American wildflowers. Some Penstemon are easy to grow; others are very challenging to maintain (Lindgren and Wilde, 2003). Numerous selections of Penstemon have been named and released (Lindgren, 2006) and many crosses between species have been attempted (Lindgren and Schaaf, 2007). New Penstemon selections are needed that combine valuable traits of multiple species and cultivars. Several …

The Effect Of Adjuvants, Pesticide Formulation, And Spray Nozzle Tips On Spray Droplet Size, Robert N. Klein, Jeffrey A. Golus, Kelli L. Nelms

West Central Research and Extension Center, North Platte

Many factors, including adjuvants, pesticide formulations, and nozzle tips, affect spray droplet size. It is important to understand these factors as spray droplet size affects both drift and efficacy of pesticides, which is a main concern with pesticide application. A laser particle analyzer was used to determine the spray droplet size and distributions of a range of formulations sprayed through several types of nozzle tips. Nozzles included were extended range flat fan sizes 11003 and 11005 (Spraying Systems XR), air induction flat fan sizes 11005 and 11004 (AI) air induction extended range flat fan size 11005 (AIXR), preorifice flat fan …

Release Of Roadside Native Perennial Grasses Following Removal Of Yellow Starthistle, Stephen L. Young, Victor P. Claassen

West Central Research and Extension Center, North Platte

The ecological benefits of a roadside native perennial grass stand are compromised when invasive species become established. We evaluated the potential to regenerate existing native perennial grass stands populated with yellow starthistle (Centaurea solstitialis) on a roadside planting in the lowland hills of the interior Coast Range of northern California. The experiment was designed to determine the effects of mowing, burning, or herbicide spraying, alone and in combination, on the vegetative cover and density of native perennial grasses and C. solstitialis. The study site contained blue wildrye (Elymus glaucus) and purple needlegrass (Nassella pulchra) as well as C. solstitialis. Burn, …

Effect Of Crop Residue On Soil Water Content And Yield Of Sprinkler-Irrigated Corn, Simon Van Donk, Derrel Martin, Suat Irmak, Steven Melvin, James Petersen

West Central Research and Extension Center, North Platte

Competition for water is becoming more intense in many parts of the USA, including west-central Nebraska. It is believed that reduced tillage with increased crop residue conserves water, but the magnitude of water savings 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 a set of plots planted to field corn (Zea mays). There were two treatments: residue-covered soil and bare soil. Bare-soil plots were created by using a dethatcher and subsequent hand-raking, removing most of the …

Crop Residue In North Dakota: Measured And Simulated By The Wind Erosion Prediction System, Simon Van Donk, S. D. Merrill, D. L. Tanaka, J. M. Krupinsky

West Central Research and Extension Center, North Platte

Residue cover is very important for controlling soil erosion by water and wind. Thus, the Wind Erosion Prediction System (WEPS) includes a model for the decomposition of crop residue. It simulates the fall rate of standing residue and the decomposition of standing and flat residue as a function of temperature and moisture. It also calculates residue cover from flat residue mass. Most of the data used to develop and parameterize this model have been collected in the southern U.S. We compared WEPS‐simulated residue cover with that measured in south‐central North Dakota for 50 two‐year cropping sequences from nine crops species …

Using Temporally Limited Wind Data In The Wind Erosion Prediction System, Simon Van Donk, Chaoying Liao, Edward L. Skidmore

West Central Research and Extension Center, North Platte

The Wind Erosion Prediction System (WEPS) is a computer model for the simulation of windblown sediment loss from a field. The model is used to evaluate the effect of alternative cropping systems and management scenarios on wind erosion. WEPS requires hourly wind data, which for many locations are unavailable. Therefore, the objective of our research was to investigate whether wind speed and direction can be simulated adequately from temporally limited data and to determine suitable times of the day to take measurements if only a few measurements per day can be made. For three locations (La Junta, Colorado; Sidney, Nebraska; …

Native Perennial Grasses In Highway Medians: Pre- And Postplant Techniques For Establishment In A Mediterranean Climate, Stephen L. Young, Victor P. Claassen

West Central Research and Extension Center, North Platte

Within highway rights-of-way, native perennial grasses provide desirable services to support natural and human constructed ecosystems. However, native perennial grass establishment in annual grass dominated roadsides of semiarid and Mediterranean climates of the western United States requires specific cultural and chemical management treatments to control weeds. In 2004, field studies were conducted in Sacramento Valley, California to determine the effect of herbicide, disc cultivation, and species selection on native perennial grass establishment and annual weed persistence. Perennial grass species mixes common to drier and wetter upland areas in northern California were drill seeded at two sites (I-5 North and I-5 …

One-Time Tillage Of No-Till: Effects On Nutrients, Mycorrhizae, And Phosphorus Uptake, J. P. Garcia, Charles S. Wortmann, Martha Mamo, Rhae A. Drijber, David D. Tarkalson

West Central Research and Extension Center, North Platte

Stratification of nutrient availability, especially of P, that develops with continuous no-till (NT) can affect runoff nutrient concentration and possibly nutrient uptake. The effects of composted manure application and one-time tillage of NT on the distribution of soil chemical properties, root colonization by arbuscular mycorrhizae (AM), and plant P uptake were determined. Research was conducted on Typic Argiudoll and Moffic Hapludaff soils under rainfed corn (Zea mays L.) or sorghum [Sorghum bicolor (L.) Moench.] rotated with soybean [Glycine max (L.) Men.] in eastern Nebraska. Tillage treatments included NT, disk, chisel, moldboard plow (MP), and mini-moldboard plow (MMP). …

Native Roadside Perennial Grasses Persist A Decade After Planting In The Sacramento Valley, Ryan E. O'Dell, Stephen L. Young, Victor P. Claassen

West Central Research and Extension Center, North Platte

Restoring native grassland along roadsides can provide a relatively low-maintenance, drought-tolerant and stable perennial vegetative cover with reduced weed growth, as opposed to the high-maintenance invasive annual cover (requiring intensive mowing and herbicide treatments) that dominates most Sacramento Valley roadsides. A survey of long-established roadside native-grass plantings in Yolo County showed that once established and protected from disturbance, such plantings can persist with minimal maintenance for more than a decade, retaining a high proportion of native species. The survey also showed that each species of native perennial grass displays a microhabitat preference for particular roadside topographic positions, and that native …

Penstemon: A Summary Of Interspecific Crosses, Dale T. Lindgren, Daniel Schaaf

West Central Research and Extension Center, North Platte

Documenting the successful interspecific crosses in a genus is a valuable tool in making decisions in developing strategies for plant breeding activities. However, summarizing the breeding and hybridization can be confusing because of incomplete or lost breeding records and the failure to register the parentage of new cultivar names. A summary of interspecific crosses in the genus Penstemon at the University of Nebraska– Lincoln West Central Research and Extension Center over 10 years provides insight into both successful and unsuccessful crosses. The results, based on seed production and percent of successful crosses, would suggest that interspecific crosses are more likely …

Phosphorus Losses In Runoff After Application Of Litter From Broilers Fed High-Available Phosphorus Corn Feed, David D. Tarkalson, Robert L. Mikkelsen

West Central Research and Extension Center, North Platte

Recent efforts to reduce phosphorus (P) content of corn grain fed to poultry have led to the development of low-phytic-acid corn. Research is needed to evaluate the environmental impact of the application to cropland of manure from animals fed low-phytic-acid corn. The purpose of this research was to determine P losses in runoff from a bare Piedmont soil (cecil clay loam; clayey, kaolinitic, thermic, Typic Kanhapludult) in the southeastern United States receiving surface applications of broiler litter from birds fed a low-phytic-acid corn (HAP broiler litter). The HAP litter was applied at rates of 0, 8, 16, 33, 49, 66, …

Case Study: Dried Distillers Grains As Creep Feed For Yearling Beef Cattle Grazing Sandhill Range, R. N. Funston, D. C. Adams, M. C. Stockton

West Central Research and Extension Center, North Platte

Seventy-nine crossbred steers and heifers born in June or August were stratified by weight, calving group, and sex and assigned to treatment or control. Yearlings in the treatment group (TRT; n = 40) grazed native summer Sandhill range and had access to ad libitum dried distillers grains (DDG) pellet in a creep feeder for 54 d of a 63-d grazing period. Control (CON; n = 39) yearlings grazed in an adjacent pasture without DDG. Immediately after the grazing period, yearlings were placed in a feedlot and fed to a similar finish end point. Individual forage and DDG intake …

Survival And Growth Of Wildflowers With Buffalo Grass Or Blue Grama Grass, Dale T. Lindgren, Daniel Schaaf

West Central Research and Extension Center, North Platte

Two studies in west-central Nebraska to determine the survival of wildflowers planted with buffalo grass [Buchloe dactyloides (Nutt.) Engelm.] and blue grama grass [Bouteloua gracilis (H.B.K.) Lag. ex Steud.)] were conducted in 6 and 10 year studies. In total, 19 forbs and 1 grass were transplanted with ‘Texoka’ buffalo grass in the first study, and 16 forbs were planted in a split-plot design into 3 buffalo grass selections, blue grama or a clean cultivated plot in the second study. Survival between transplants in both studies varied significantly. In the first study, survival was significantly higher for little bluestem …

Comparison Of The Weibull Model With Measured Wind Speed Distributions For Stochastic Wind Generation, Simon Van Donk, Larry E. Wagner, Edward L. Skidmore, John Tatarko

West Central Research and Extension Center, North Platte

Wind is the principal driver of the Wind Erosion Prediction System (WEPS), which is a process−based computer model for the simulation of wind−blown sediment loss from a field. WEPS generates wind using a stochastic wind generator. The objectives of this study were to improve the stochastic generation of wind speed and direction and to update the wind statistics used by the generator with statistics derived from more recent, quality−controlled data for the 48 contiguous states of the U.S. Erosive wind power density (WPD) was chosen to evaluate how well wind is generated, since it is proportional to sediment …

Evaluation Of Three Estrous Synchronization Protocols In Beef Heifers1, R. N. Funston, R. J. Lipsey, T. W. Geary, R. P. Ansotegui

West Central Research and Extension Center, North Platte

Objectives of this study were to evaluate synchronization, conception, and pregnancy rates of heifers synchronized with melengestrol acetate (MGA)-prostaglandin F_2α (PGF_2α,), Select Synch, or Select Synch preceded by MGA (MGA-Select Synch). Heifers in the MGA-PGF_2α group (n = 209; BW = 378 kg) received MGA (0.5 mg/ d per heifer) for 14 d and PGF_2α (25 mg) 19 d later. Select Synch heifers (n = 213; BW = 374 kg) received gonadotropin- releasing hormone (GnRH; 100 μg) followed by PGF_2α (25 mg) 7 d later. The MGA-Select Synch heifers …