bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of Switchgrass and Bluestem Cultivars Mixed with Cool‐Season Species1
Authors: Jung G. A. , Griffin J. L. , Kocher R. E. , Shaffer J. A. , Gross C. F. 
Published: July 2010

AbstractForage availability in summer is critical for sustaining high stocking densities of herbivores on pasture in the eastern U.S. The objective of this study was to determine forage productivity and quality of switchgrass (Panicum virgarumL.) and bluestems [Andropogon gerardiiVitman, Schizachyrium scoparium(Michx.) Nash, and Bothriochloa caucasica(Trin.) C.E. Hubb.] in summer. The experimental site was located in southwestern Pennsylvania on Guernsey silt loam (fine, mixed, mesic Aquic Hapludalf) soil. Two replicates, each containing eight warm‐season grasses with different proportions of volunteer cool‐season grasses and overseeded legumes were grazed from 1975 to 1977 and then harvested for hay in 1978 and 1979. Pastures were grazed each year in mid‐May, late July or early August, and early October. Nitrogen at 0, 45, and 90 kg ha−1and P at 0, 20,40 kg ha−1were applied to subplots. ‘Blackwell’ switchgrass and ‘Kaw’ big bluestem from the Great Plains readily established stands but did not persist as well as cultivars from the eastern USA. Total annual production from switchgrass‐dominated pastures was about 8.0 Mg ha−1and that from ‘NY 1145’ big bluestem was 6.0 Mg ha−1, Over a 4‐yr period, NY 1145 produced about 70% more forage in late July than did Kaw big bluestem. Mean yield distribution of the switchgrass and bluestem pastures was approximately 15% in May, 55% in July‐August, and 30% in October. July yield increased about 11 kg kg−1of N applied. Mean in vitro dry matter disappearance (IVDMD) values for switchgrass and bluestem ranged from 470 to 570 g kg−1,, but it was determined that IVDMD under‐estimated in vivo digestibility by 100 to 200 g kg −1, Crude protein concentration ranged from 70 to 120 g kg−1, Mean crude protein concentration of grass fertilized with 45 and 90 kg N ha−1over a 3‐yr period was 10 and 26% higher, respectively, than that for unfertilized grass. Overseeded legumes, especially red clover (Trifolium pratenseL.), established good stands in warm‐season grasses with < 75% stands. Mixed stands of warm‐ and cool‐season grasses and legumes can be maintained under grazing or hay production, with a substantial shift in seasonal yield distribution that can be very beneficial to beef (Bos taurus) producers.
Electronic Detection of Bolus Swallowing to Measure Forage Intake of Grazing Livestock1
Authors: Forwood J. R. , Hulse M. M. , Ortbals J. L. 
Published: July 2010

AbstractUnderstanding forage intake of grazing livestock is critical to understanding their level of performance. Unfortunately, current methods of measuring intake of free‐roaming ruminants are laborious and indirect. To overcome these problems, two devices were tested with confined animals to measure passage of boli within the esophagus of cattle (Bos taurus) as an estimate of intake. The first, labeled a conductivity transducing cannula (CTC), consisted of electrodes mounted slightly above the sleeve on a conventional metal sleevetype esophageal cannula so they would contact material passing within the esophagus. A stable current source allowed data to be transmitted to a strip chart recorder via coaxial cable. The second device, a pressure transducing cannula (PTC), involved a flexible water‐filled tube mounted on the conventional cannula sleeve. Material passing within the esophagus exerted pressure on the tube. A pressure transducer converted water pressure to an electrical signal which was received by a strip chart recorder. The PTC device was discarded for lack of accuracy and portability. The CTC device was modified and inserted in year‐old esophageally fistulated steers fed known amounts of forage in confinement. The cannula accurately signaled forage swallowing events. The CTC device appears to distinguish boli swallowing from eructation and water swallowing. The CTC device also shows a positive relationship between number of swallows and dry matter intake of differing levels of orchardgrass hay (r2= 0.81) and chopped big bluestem grass (r2= 0.99).
Modeling of PAR Interception and Productivity of a Prickly Pear Cactus, Opuntia ficus‐indicaL., at Various Spacings1
Authors: de Cortázar Victor García , Nobel Park S. 
Published: July 2010

AbstractOpuntia ficus‐indicuL. is a prickly pear cactus composed morphologically of flattened stems (cladodes). It is cultivated worldwide for fruit or forage, generally in plantations at low plant densities. A model developed for simulating light interception by each cladode at any plant density was used to simulate the effect of plant morphology on production of dry matter. Different plant structures and cladode orientations leading to high stem area indices (SAI; total surface area of stems per unit ground area) were tested to maximize Productivity, while maintaining the crop within limits of size and spacing compatible with practical management techniques. Results indicate that productivities 40% greater than those observed in the field and similar to certain other row crops can be obtained by increasing SAI up to 4.0 for plants that are five cladodes tall. for much greater SAIs, crops become very dense with no significant increase in productivity. For whole plants at low SAIs and for top cladodes at all SAIs, higher productivity occurred for cladodes facing east‐west. However, at high plant densities row direction and orientation of individual cladodes had little effect on productivity, although plants with their cladodes facing north‐south tended to have a higher productivity. The simulations presented can aid in the design of field trials for productivity studies of O. ficus‐indicaand other cultivated platyopuntias.
Ergot Toxicity from Endophyte‐Infected Grasses: A Review1
Authors: Bacon Charles W. , Lyons Philip C. , Porter James K. , Robbins Joe D. 
Published: July 2010

AbstractClarifying the role of grasses parasitized by a tribe of clavicipitaceous endophytes (Balansiae) in the etiology of the many cattle (Bos taurus) ergot toxicity syndromes is essential for identifying the correct toxic grass and establishing the proper pasture management practice necessary to eliminate toxicity. The distinction is required as the management practice used to prevent ergot toxicity by Clavicepsdoes not apply because of the systemic habit of the Balansiae. Research is reviewed, which established that endophytic parasites of many genera of warm‐season perennial weed grasses and tall fescue (Festuca arundinaceaSchreb.) are producers of toxic ergot alkaloids. This group of fungi is distinct from the closely related genus Clavicepsin being an intercellular parasite of leaf tissue. These fungi are parastic on nine tribes of grasses that have a wide geographic distribution in the western hemisphere. Nine ergot alkaloids belonging to the clavine group have been isolated from four species of Balansiacultured in laboratory media, and several of these have been isolated from parasitized grasses. Ergot alkaloid production by the remaining nine species of Balansiahas not been examined. The endophyte of tall fescue produced both the clavine and ergotamine peptide groups of alkaloids in culture and in the grass. The production of ergot alkaloids by weed grass endophytes is host‐related; therefore, each parasitized weed grass must be assessed for alkaloid production. All isolates of B. epichloe(Weese) Diehl from smutgrass (Sporobolus poiretiiRoem. and Schult.) and 54% of the isolates of B. henningsiana(Moell.) Diehl from broomsedge (Andropogon virginicusL.) produced the following alkaloids in culture: chanoclavine, ergonovine, ergonovinine, and agroclavine. Isolates of these two fungi from other grass genera did not produce alkaloids. While no extensive survey has been done to date, all infected tall fescue examined contains ergot alkaloids. The main peptide alkaloid produced by the tall fescue endophyte is ergovaline. The effects of this peptide alkaloid on cattle have not been determined. However, the total alkaloids produced in culture by B. epichloereduced the serum prolactin levels in cattle and along with prior published accounts on the physiological effects of the clavine and peptide ergot alkaloids, established that these alkaloids can cause toxicity symptoms in cattle consuming infected plant material. Thus, pasture management practices must include procedures that will prevent the growth of grasses that serve as host for endophytic fungi.
Quality and Yield Response of Four Warm‐Season Lawngrasses to Shade Conditions1
Authors: Barrios E. P. , Sundstrom F. J. , Babcock D. , Leger L. 
Published: July 2010

AbstractWarm‐season turfgrasses differ widely in their tolerance to low light. Shade conditions, as the result of shrub or tree presence, are greatly influenced depending on whether the tree or shrub is deciduous or evergreen in nature. The purpose of this study was to determine the influence of deciduous shade on the quality and yield of four major warm season lawngrasses. Zoysiagrass [Zoysia japonica(Stued.) ✕ Z. tenuifolia(Willd.) ‘Emerald’], St. Augustinegrass [Stenotaphrum secundatum(Walt.) Kuntze] ‘Floratam’ and ‘Floratine’, and centipedegrass [Eremochloa ophiuroides(Munro.) (Hack.) ‘Oklawn’] were sodded in outdoor plots on an Olivier silt loam (fine‐silty, mixed, thermic aquic, Fragiudalf) soil. All were exposed to unshaded and 47 and 63% shade regimes of green saran screening for 7 months each year to simulate Gulf South deciduous shade tree conditions. Determination of lawngrass quality and yield responses were made for 3 yr. Increased shade decreased air temperature at sod level. Mean air temperature at sod level was not correlated with quality of any lawngrass. Mean air temperature at sod level was significantly correlated only with clipping yields of Floratam St. Augustinegrass and Oklawn centipedegrass. Lawngrass quality generally decreased with increasing shade. Photon flux density was significantly correlated with quality of all lawngrasses except Oklawn. Quality ratings in 63% shade indicate that Floratam St. Augustinegrass quality was most intolerant, while Oklawn centipedegrass quality was most tolerant of reduced light conditions. Quality and yield were not significantly correlated in any lawngrass. Lawngrass yield generally decreased with increasing shade. Emerald Zoysiagrass mean clipping yields were least reduced, and Floratam St. Augustinegrass mean yields were most reduced in 63% shade treatments.
Copper Deficiency in Cereal and Oilseed Crops in Northern Canadian Prairie Soils1
Authors: Karamanos R. E. , Kruger G. A. , Stewart J. W. B. 
Published: July 2010

AbstractTransitional grassland/forest light soils in Saskatchewan are often deficient in Cu. The high cost of micronutrient fertilizers necessitates extreme care in identifying micronutrient deficiencies and selecting effective products and methods of application. Comparison of tissue and grain or seed analysis for spring wheat (Triticum aestivumL.), canola (Brassica napusL.), and flax (Linum usitatissimumL.) vs. DTPA‐extractable soil Cu levels revealed that diagnosis of Cu deficiencies can more accurately be achieved via the latter. The critical DTPA‐extractable Cu levels were 0.40 mg Cu kg−1of soil for spring wheat and 0.35 mg Cu kg−1of soil for canola and flax. A series of field experiments comparing different forms of soil and foliar Cu fertilizers were conducted on several transitional grassland/forest soils. Copper oxide applied in the spring was generally ineffective in the year of application but alleviated Cu deficiencies in the following year. Copper‐sulfate (blue stone) and chelated products (polylignosulphonic acid) were effective in the year of application. However, the latter had no residual value at the rates of application used. This, combined with their extremely high current prices, makes them an undesirable Cu fertilizer source for the soils in the study area. Foliar Cu applications of either Cu‐sulfate or Cu‐chelate may be effective, but their performance has been erratic; hence, they should only be considered as an emergency measure for correcting of Cu deficiency.
Planting Date and Foliar Fertilization of Corn Grown for Silage and Grain under Limited Moisture1
Authors: Giskin M. , Efron Y. 
Published: July 2010

AbstractCrop production costs have increased in recent years, which has caused a search for more economical cultural practices. In view of this, field experiments were carried out in 2 successive years to study the effect of seeding date and foliar fertilization on grain and silage yields of corn (Zea maysL.). The plantings ranged from 15 February to 1 April. The soil was a silty clay loam (Typic Chromoxerert). The crop was given supplemental irrigation only and received one or two foliar applications of N,P,K, and S, applied at the four‐ or five‐leaf stage. In the first year silage and grain yields decreased with each delay in planting date. The foliar application of N,P,K, and S resulted in a significant uptake on N and P, but not of K, with the increase in plant‐N being a function of seeding date. Foliar fertilization resulted in a significant 16.6% increase in grain yield, but no addition to silage yield. In the second year either one or two foliar applications of essential nutrients significantly increased silage and grain yields. Two foliar applications were significantly more effective than one application in increasing silage yield, but not grain yield. In both years yields of the February and March plantings were affected by low soil and air temperatures during the seedling stage; the yields of the April seeding were affected by a shortage of moisture from silking through grain fill. Planting early was critical for obtaining maximum benefits from foliar fertilization when applied at the four‐ or five‐leaf stage. Foliar application of N,P,K, and S resulted in yield increases of both silage and grain if moisture was not limiting from silking to physiological maturity.
Effect of High Sulfate Irrigation Waters on Soil Salinity and Yields1
Authors: Papadopoulos I. 
Published: July 2010

AbstractMore information is needed concerning the effects of high sulfate waters on soil salinization and the magnitude of yield losses of crops irrigated with such waters. This greenhouse study investigated the response of tomato (Lycopersicon esculentumL.), eggplant (Solanum melongenaL.), and bell pepper (Capsicum annuumL.) to soil salinity as influenced by the ionic composition of two naturally occurring sulfate waters (EC=3.1 dS/m) in comparison to rainwater. One of the saline waters was saturated with gypsum (34.8 mmol(−)/L) and the other contained 15, 18, and 14 mmol(±)/L of SO24, Na, and Cl, respectively (mixed water). In all treatments a 0.3 leaching fraction was used. The soil was a Pellic Vertisol, which contained no gypsum. Soil salt buildup was high with the saline waters and followed two stages. A sharp increase of soil electrical conductivity (EC) initially occurred with ions of both sparingly (Ca, SO24) and highly (Mg, Na, Cl) soluble salts contributing to soil EC. Sulfate concentration at the initial stage increased due to the presence of other ions in the soil solution and it was more than twice that of a pure gypsum solution. At the second stage, Ca and SO24concentrations in soil solutions remained unchanged and the increase of EC was slower in comparison with the initial stage. At both stages the increase of soil EC was higher with the mixed water. A significant increase of soil solution sodium adsorption ratio (SAR) also occurred with the mixed water. Fresh fruit yields of tomato decreased by 29 and 21%, and eggplant yields were reduced by 23 and 16% when irrigated with the mixed or the sulfate water in comparison to rainwater, respectively. Lower yield was due to smaller fruit size. Yield of bell pepper was not affected, but quality deteriorated.
Weed Seed Decline and Buildup in Soils Under Various Corn Management Systems Across Nebraska1
Authors: Burnside Orvin C. , Wilson Robert G. , Wicks Gail A. , Roeth Fred W. , Moomaw Russell S. 
Published: July 2010

AbstractThe weed seedbank in the soil makes weed control necessary every year in crop production. Research was initiated to determine if a farmer could reduce weed control practices after several years of excellent weed control. Experiments were conducted at five locations across Nebraska to determine the demise of weed seed in continuous corn (Zea maysL.) where weed seed production had been eliminated for 3 yr (1975–1977) and then four weed management levels were superimposed for another 3 yr (1978–1980). Soils were Cumulic Haplaquolls, Typic Argiudolls, Udic Agriustolls, Typic Haplustolls, and Aridic Haplustolls. Within 1 yr (1978) after weed eradication had stopped, the average number of weed seeds that germinated increased over the four weed management levels; and weed competition to corn was evident within 2 yr (1979). Weeds have the potential to rapidly increase and reinfest a field once there is a lack of vigilance in the weed control program. Thus, the weed seedbank assures a continuity to the weed problem that will require more than eliminating weed seed production for several years. If a farmer has achieved 3 yr of perfect weed control on a given field, he still must expect weed problems in subsequent crops because of seed longevity in soil.
Effects of Carbon Dioxide Enrichment and Soil Water on Maize1
Authors: King K. M. , Greer D. H. 
Published: July 2010

AbstractThe current global rise in atmospheric CO2concentration may lead to changes in yield and water use of crops. This study was done to determine the effects of increased CO2in combination with soil water levels on the growth, yield, transpiration, and water use efficiency of maize (Zea mays L.). Corn plants (cv. PX74) were grown in Opiki humic silty clay loam (fine, illitic, mesic Histic Humaquepts) soil in 22‐L pots from emergence to maturity (111 days) in controlled‐environment rooms at CO2concentrations of 350/360,600/ 650, and 850/900 µL L−1(day/night). Within each room, at a given CO2 concentration, the plants were subjected to one of three soil water treatments: complete replacement of weekly transpiration (control) and 75 and 50% replacement of the control transpiration. The 350 µL L−1treated plants produced an average of 401 g dry matter across all water treatments and the 600 and 850 µL L−1treated plants produced an average of 431 and 436 g dry matter per plant, respectively. The differences in total dry matter between the 600 and 850 µL L−1treated plants remained nonsignificant throughout the experiment. There were significant differences between all soil water treatments in dry matter production with the low soil water level averaging 284 g and the medium and high water level averaging 440 and 544 g plant−1, respectively. Transpiration was reduced with increased CO2concentration and was 80.5 and 70.4% at 600 and 850 µL L−1, respectively, of that at 350 µL L−1averaged across water treatments. The water use efficiency (WUE) increased markedly with increased CO2concentration. At 600 and 850 µL L−1the WUE was 34 and 55% greater, respectively, than at 350 µL L−1. Further work is needed on the applicability of this controlled environment experiment to the real world.
Effect of Tillage Systems on Proso Millet Production1
Authors: Anderson R. L. , Shanahan J. F. , Greb B. W. 
Published: July 2010

AbstractProso millet (Panicum miliaceum L.) is well‐adapted for the Central Great Plains and could be planted in a winter wheat (Triticum aestivum L.)–millet‐fallow rotation, resulting in two crops in 3 yr. To determine the most suitable tillage system for proso millet production within this rotation, seven tillage management systems were evaluated over a 6‐yr period (1972–1977). The research was conducted on a mesic Pachic Arguistill soil on the Central Great Plains Research Station near Akron, CO. Comparisons included fall vs. spring tillage and replacing a tillage operation with herbicides. Controlling fall weed growth by tillage alone or with atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐S‐triazine) increased grain yield of proso millet and protein content of the grain more than spring tillage for weed control. Increased millet production from fall tillage was attributed to increased soil NO−3‐N levels and increased soil water use by millet. Water use efficiency by millet was also increased with fall tillage. Adding N fertilizer decreased millet grain production.
A Comparison of Sprinkler and Flood Irrigation for Rice1
Authors: Westcott M. P. , Vines K. W. 
Published: July 2010

AbstractSprinkler irrigation of rice (Oryza sativa L.) has recently been considered to reduce water use and increase grower flexibility in U.S. production areas where flood irrigation is predominant. Tests were conducted for 2 yr on a Sharkey clay (Vertic Haplaquept) to evaluate selected rice cultivars under sprinkler vs. flood irrigation. Irrigation methods were main plots and three cultivars in 1983 and six cultivars in 1984 were subplots. Sub‐subplots in 1984 were single or split application of 101 kg N ha−1. Sprinkler irrigation consisted of three weekly applications of 0.038 m water each in 1983 and a similar scheduling to maintain soil moisture tension above –30 kPa in 1984. In 1983, sprinkler irrigation increased sheath blight (Rhizoctonia solani) incidence and decreased grain yield (4448 kg ha−1 vs. 7139 kg ha−1 under flood irrigation), dry matter production, harvest index, and florets per panicle compared to flood irrigation. In 1984, despite chemical control of sheath blight, yields averaged 5901 kg ha−1 under sprinkler irrigation vs. 7846 kg ha−1 under flood irrigation. Nitrogen timing did not significantly affect yields, but a weak N timing ✕ irrigation method interaction (p=0.061) denoted that split N applications may benefit yields under sprinkler irrigation. multiple regression indicated fewer florets per panicle was the primary source of yield loss with sprinkler irrigation. Sprinkler irrigation of rice might decrease water use but it lowers yields and increases need for fungicides compared with flood irrigation.
Nitrogen‐15‐Determined Nitrogen Fixation in Field‐Grown Chickpea, Lentil, Fababean, and Field Pea1
Authors: Rennie R. J. , Dubetz S. 
Published: July 2010

AbstractField‐determined estimates of N2 fixation by 15N isotope dilution have not been determined in irrigated annual grain legumes in North America. Nor does knowledge exist as to which nonfixing control plants are most appropriate for these grain legumes when using 15N isotope dilution methods. Within a crop species grown on two Typic Haploboroll soils for 2 yr, lentil (Lens culinaris Medik), fababean (Vicia faba L. minor), and pea (Pisum sativum L.) cultivars adapted to western Canada did not differ in their ability to benefit from symbiotic N2 fixation. When inoculated, N2 fixed averaged 176,84, 216, and 185 kg N ha−1 for chickpea (Cicer arietinum L.), lentil, fababean, and pea, respectively. The percent plant N derived from the atmosphere averaged 82, 67, 85, and 79%, respectively, for the same crops. Response to inoculation was dependent on the crop even though all were infected by Rhizobium leguminosarum Uninoculated chickpea had no nodules or N2‐fixing activity. Inoculation increased N2 fixation in fababean by 19 to 67% and in lentil by 5 to 16% depending on the site. There was a response to inoculation in pea at only one of the two sites. The presence of indigenous soil R. leguminosarum precluded the use of uninoculated treatments as nonfixing controls (except for chickpea) for estimating N2 fixation by 15N isotope dilution. Barley (Hordeum vulgare L. ‘Galt’) or wheat (Triticum aestivum L. emend. Thell ‘Columbus’) appeared to be appropriate control plants for these grain legumes. Because the 15N‐determined fertilizer use efficiency of these controls was similar to that of the N2‐fixing legumes, estimates of N2 fixation by N balance were not significantly different from those obtained by 15N isotope dilution.