bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production and Quality of Limpograss for Use in the Subtropics1
Authors: Kretschmer Albert E. , Snyder George H. 
Published: July 2010

Abstract‘Greenalta’, ‘Redalta’, and particularly ‘Bigalta’ limpograsses [Hemarthria altissima (Pior.) Stapf and Hubbard] have been commercially planted in south Florida during the past decade. Since little information is available on agronomic attributes of limpograss during the cool‐season when tropical grass growth is markedly reduced, cool‐season productivity and in vitro organic matter digestibility (IVOMD) were compared with other commercial tropical grasses adapted to south Florida.Effects of nitrogen rates, cutting interval, and fall fertilization dates also were determined for Bigalta to provide information on productivity and IVOMD. The soil used was an Oldsmar fs, a spodosol.The three limpograss cultivars, ‘Transvala’ digitgrass (Digitaria decumbens Stent.), and ‘Coastcross‐1’ bermudagrass (Cynodon sp.) were equally productive during the cool season and more productive than ‘Pangola’ digitgrass (Digitaria decumbens Stent.), Bigalta IVOMD generally was greater than that of Greenalta and particularly Redalta, equal to that of Transvala and Pangola, and higher than that of Coastcross‐1. Dry matter yields of Bigalta, Coastcross‐1‐ and Transvala were similar at 3 or 4‐week cutting intervals (CI), but Bigalta produced less at a 2‐week CI. During a 24‐week period as CI increased from 4 to 12 weeks (total of 336 kg N/ha applied), Bigalta total yields increased, forage IVOMD and N contents decreased, and yield of digestible organic matter increased. Delaying fall fertilization from 17 September or 1 October until 29 October resulted in greatly reduced forage production when harvested on 17 December. The IVOMD and N contents increased as fertilization was delayed. Many of the N contents from the fertilization date and CI studies were below the acceptable level for maximum voluntary intake of forage by ruminants.Productivity of the limpograsses and Bigalta response to N during the cool season indicate that they offer alternatives to other commercially available tropical grasses. The high digestibility of Bigalta can provide reserve coolseason pasture with quality equal to or better than that from other grasses, however, low N contents may limit intake without proper grass management and N fertilization.
Substitution Value of Birdsfoot Trefoil for Alfalfa‐Grass in Pasture Systems1
Authors: Marten G. C. , Jordan R. M. 
Published: July 2010

AbstractConventional alfalfa (Medicago sativa L.)‐gass grazing systems do not permit sufficiently high animal intake of energy for high roducing ruminant animals. Provision of pasture swards containing a higher proportion of legume should increase energy intake. Our primary objective was to determine whether lamb daily gains could be increased by increasing the legume percentage in grazing systems via substitution of pure birdsfoot trefoil (Lotus corniculatus L) for alfalfagass as one‐third of the total rotational pasture. We compared four grazing systems for lambs in each of 3 years. The control system had an alfalfa‐smooth bromegrass (Bromus inermis Leyss.)‐orchardgrass (Dactylis glomerata L.) mixture in each of three rotationally grazed paddocks. A second system had orchardgrass in paddock 1, reed canarygrass (Phalaris arundinacea L.) in paddock 2, and smooth bromegrass in paddock 3; each grass was mixed with alfalfa. In the third and fourth systems paddocks 1 and 2 were identical to those in the control; paddock 3 in these systems had pure birdsfoot trefoil either grazed in sequence in late May or stockpiled for initial grazing in late June.Substitution of birdsfoot trefoil for alfalfa‐grass as one‐third of total seasonal pasture resulted in 22 to 24% increases in lamb average daily gains over a 3‐year period. The birdsfoot trefoil‐containing systems provided forage that had significantly higher legume composition, in vitro digestibility, crude protein concentration, and ap parent intake potential (lower concentration of cell walls) than did forage provided by the control (all alfalfa‐grass) system. The sometimes lower carrying capacity of the birdsfoot trefoil containing systems partly offset the greater gains of lambs on these systems. However, they provided a mean 17 to 18% increase in lamb product perha, com ared with all alfalfa‐grass systems. The birdsfoot trefoil containing systems also had lower overhead costs, because fewer animal units were required per unit of gain.The stage of maturation of birdsfoot trefoil at first grazing each year (immature vs. stockpiled) did not significantly influence animal performance or birdsfoot trefoil persistence. Use of a mixture of alfalfa‐smooth bromegrass‐orchardgrass in all paddocks (control), compared to orchardgrass, reed canarygrass, or smooth bromegrass as single species mixed with alfalfa in individual pad. docks, did not influence animal performance.A “pasture‐type,” creeping rooted alfalfa cultivar (‘Rambler’) did not persist as well as two “hay‐type” cultivars (‘Saranac’ and ‘Agate’). Invasion of weeds in the 3rd year proved to be a disadvantage of using pure stands of birdsfoot trefoil in grazing systems.
Yield and Rooting Activity of Forage Grasses on a Surface‐mined Soil of Texas1
Authors: Hons F. M. , Hossner L. R. , Whiteley E. L. 
Published: July 2010

AbstractLignite mining is an expanding industry within Texas. Little or no research has been reported concerning forage production and revegetation following disturbance in this region. Forage plots were established in 1975 to determine the effect of disturbance upon forage production in an area which had been surface‐mined for lig nite in 1972.The mined soil was originally classified in the fine , montmorillonitic, thermic family of Udertic Paleustalfs. Forages used included NK‐37 bermudagrass (Cynodon dactylon L. Pers.), Pensacola bahiagrass (Paspalum notatum Flugge), coastal bermudagrass (Cynodon dactylon L. Pers.), and Kleingrass (Panicum coloratum L.)Forage production on the mined soil was comparable to or greater than yields reported on unmined Soils at similar rates of N application. Nitrogen applications were much more significant in determining forage yields than were P additions.Surface soils were finer in texture following mining due to the mixing of the profile in the mining process. The mined soil possessed a greater percentage of water at field capacity than did an unmined surface soil, primarily because of the finer texture after mining. The potentially increased moisture holding capacity may account for production comparable to that reported for unmined soils with less total moisture received.The total rooting mass for coastal bermudagrass on the mined soil was approximately three times greater than the root mass observed on a soil genetically related to the unmined soils of the region. Increased rooting activity may result from the destruction of the dense claypan associated with the soil before mining plus the potentially increased moisture holding capacity of the soil following mining.
A Microplot Seeder1
Authors: McLaughlin N. B. , Townley‐Smith T. F. , Dyck F. B. 
Published: July 2010

AbstractPlots with short rows provide an attractive alternative to hill plantings where seed or space is scarce. The lower planting density in short rows allows for more normal phenotypic expression and easier separation of individual plants. This paper describes an attachment for the Swift Current self‐propelled plot seeder for sowing 0.5 m rows perpendicular to the direction of travel. The attachment consists of a spade‐type opener supported by a linkage which allows it to move in a vertical plane, a seed distribution system, and a control system. Hydraulic cylinders automatically move the opener up and down and open and close the opener blades. In the down position, a 0.5 m long furrow is opened and seeds are dropped into the furrow; in the up position, the opener advances to the next row. The automatic control system both controls and synchronizes the opener movements and the dropping of seeds to ground speed. Border rows can be sown at either end of the micro plots and parallel to the direction of travel with the outside two double disc openers on the seeder.
A Model for Predicting Soybean Yields from Climatic Data1
Authors: Hill R. W. , Johnson D. R. , Ryan K. H. 
Published: July 2010

AbstractThe single most important factor that influences soybean (Glycine max (L.) Merr.) yields from one location to another, or from one year to the next, is moisture availability. A better understanding of how water influences yields is essential for maximizing yields through water management practices. The objective of this study was to develop a model that determines soybean yield as a function of moisture availability during four periods of growth.Data inputs include the amount of soil water in storage at the beginning of the season, available soil water storage capacity for the root zone, and daily values of rainfall, irrigation, maximum and minimum temperatures, and specific parameters for each cultivar that relate phenology to daylength and temperature.The program predicts yield as a function of the relative transpiration during each of four growth periods: emergence to beginning flowering; beginning flowering to beginning podfill; beginning podfill to end of flowering; end of flowering to maturity.When the program is used for scheduling irrigation, the required amount and timing of irrigation water for any planting date is determined by simulating the effects of applying supplemental water in incremental amounts and times. The “best” resultant irrigation scheduling is indicated for any pre‐selected yield level.The program does not eliminate the need for field trials, but it can be used for identifying management practices that will maximize yields through water management or the avoidance of dry periods. Thus, field research can be concentrated on problem areas with resultant savings of time and money.
Field Assessment of Air Pollution‐induced Soybean Yield Losses1
Authors: Howell R. K. , Koch E. J. , Rose L. P. 
Published: July 2010

AbstractEstimates of soybean [Glycine max (L.) Merr.] yield losses induced by ambient concentrations of air pollutants are ambiguous, but such estimates are Erequently requested and reported. The objectives and justification of this field experiment were to answer the questions: 1) What soybean yield losses are attributable to air pollution and 2) Do open‐top chambers properly estimate the impact of air pollution on soybean yields? An experiment including cylindrical open‐top field chambers was established in 1973 at Queenstown, Md., on a Mattapex (Typic hapludults) silt loam and repeated in 1974 and 1975 to estimate seed yields of soybean cultivars ‘York,’ ‘Dare,’ ‘Cutler,’ and ‘Clark.’ Yields were com ared for plants growing in chambers (3 m diam an8 2.4 m height) equipped to provide carbon‐filtered air or unfiltered air, and in no‐chamber plots. Treatments were arrayed as four replications of a randomized complete block design with quadrants and cultivars forming a 4 ✕ 4 Latin square as a split‐plot for each environment. Concentrations of photochemical oxidants at the experimental site varied by year and within years, but were comparable to concentrations measured near Washington, D.C. During the 3 years, there was no significant cultivar ✕ environment interaction. Mean seed yields from plants grown in nonfiltered air chambers (24.0 quintals/ha) were significantly lower than those grown in either carbon‐filtered air chambers (30.0 quintals/ha) or in nochamber plots (30.2 quintals/ha). We could not demonstrate that carbon‐filtered air would significantly improve soybean yields over yields of commercially field grown soybeans in this 3‐year test. The 20% yield difference between yields of plants grown in carbon‐filtered air and in nonfiltered air may be an artifact of the chambers and not a true estimate for air pollution induced soybean yield losses. Soybean seed sizes were significantly increased by drought and by carbon‐filtered air.
Leaf Area Index Estimates for Wheat from LANDSAT and Their Implications for Evapotranspiration and Crop Modeling1
Authors: Wiegand C. L. , Richardson A. J. , Kanemasu E. T. 
Published: July 2010

AbstractGround measurements of leaf area index (LAI) are tedious and costly. If they could be estimated spectrally from earth observation satellite data, evapotranspiration and photosynthesis models that use LAI as inputs could be implemented for large areas. Thus, we related LAI measurements of winter wheat (Triticum aestivum, L.) made in Kansas during the 1974–1975 and 1975–1976 growing seasons to three spectral vegetation indexes in the literature: transformed vegetation index (TVI), green vegetation index (GVI), and perpendicular vegetation index (PVI). The three vegetation indexes were each significantly linearly correlated (r = 0.70** to 0.95**) with measured LAI from the time LA1 was ≃ 0.3 until plant senescence, and their seasonal time courses were similar to those of directly measured LAI. Thus the indexes capture information on crop development and growing conditions manifested by LAI. We conclude that LAI can be calibrated in terms of the vegetation indexes to provide crop model inputs for as many fields as are of interest, or can serve as an independent check on model calculations when not used as a direct input to physical and physiological process models affected by the amount of vegetation present.
Growth and Water Relations of Wheat Plants with Roots Split Between Soil and Nutrient Solution1
Authors: Erickson P. I. , Kirkham M. B. 
Published: July 2010

AbstractSoil matric potential controls plant growth. Yet it is difficult to determine the effect of soil matric potential, by itself, on plant water relationships and growth. One way to isolate matric potential is to split roots between soil and nutrient solution because the soil has a matric potential while the nutrient solution has a matric potential of zero. Therefore, in this study, leaf water potential, stomatal resistance, rate of water use, leaf area, plant height, and root length of winter wheat (Triticum aestivum L. em. Thell. cv. Osage), grown with and without wind, and with roots split between soil:soil, soil: nutrient solution (soln), and soln:soln were measured to determine the effect of soil matric potential on wheat water relationships and growth. During the first 16 days of the 38‐day experiment, the soil (Kirkland silt loam, Udertic Paleustoll) was well‐watered. Water was withheld from all soil treatments after the 16th day. Plants were grown with and without wind, and with and without soil drought, because, in the Great Plains, wind and drought, or a combination of the two, are the main causes of crop loss.Leaf water potential and stomatal resistance of plants with roots in soi1:soln were usually between those of plants with roots in soil:soin and soln:soln. Plants with all roots in nutrient solution had the highest leaf water potential and lowest stomatal resistance. Plants with all roots in well‐watered soil lost 2.5 times less water, but grew as well as plants with all roots in solution. Plants with roots split between solution and well‐watered soil lost the same total amount of water as plants with all roots in solution. But the plants with roots in soil:soln lost 7 and 11 times more water from the solution side than from the soil side of the split root containers for the wind and no‐wind treatments, respectively. Nonstressed plants (no wind, no drought) with roots split between soi1:soln were taller and had a larger leaf area than plants with roots all in soil or all in solution. The results showed that growth of wheat was increased if part of its root system was in media with zero matric potential (nutrient solution) and part in soil.
Growth Stages and Distribution of Dry Matter, N, P, and K in Winter Wheat1
Authors: Waldren R. P. , Flowerday A. D. 
Published: July 2010

AbstractStage of growth descriptions were developed for winter wheat (Triticum aestivum L.) which will apply to single plants or a community of plants. The growth stages are easily discernable and precise. Accumulations of dry matter, N, P, and K in leaves, culms, head, and grain were measured at each growth stage.Observations and plant samples were taken of fieldgrown winter wheat (cultivar ‘Centurk’) over the 3‐year period of 1975‐77. Plants were grown at the Univ. of Nebraska Agronomy Farm, Lincoln, on a Sharpsburg silty clay loam (Typic argiudoll). Plants for growth stage description and chemical analysis were randomly sampled from a field population and separated into leaves, culms, head, and grain as these plant parts developed.Growth stages are defined and illustrated. The 10 developmental stages are: O—Emergence, 1—Crown development and tillering, 2—Leaf sheath elongation, 3—Culm elongation (jointing), 4—Flag leaf emergence, 5—Peduncle elongation (heading), 6—Flowering (anthesis), 7—grain filling, 8—Stiff dough, 9—Hard dough (ripening), and 10—Maturity.Dry matter accumulation increased rapidly from stage 3 through stage 8. Translocation of dry matter from leaves to grain began at stage 6 and from culms and head to grain at stage 7. Nitrogen uptake was most rapid from stage 2 to stage 4 with 80% of the total accumulation occurring by stage 7. Over 70% of the total N uptake was translocated to the grain at maturity. Uptake of P and K was most rapid from stage 3 to stage 7. Seventy‐five percent of P uptake was translocated to the grain at maturity but only 15% of K present in the plant was found in the grain at maturity.The stage descriptions provide a standard for researchers, extension workers, producers, students, and agribusiness personnel to accurately define and determine the growth stages of winter wheat. The dry matter accumulation and nutrient uptake data provides part of the information necessary in making correct management decisions.
Proteins and Amino Acids in Grain of Maize Grown with Various Levels of Applied N1
Authors: Rendig V. V. , Broadbent F. E. 
Published: July 2010

AbstractCereals provide a major source of protein in food chains. Yet, particularly as compared with associated yield responses, relatively little information is available about possible effects of N supply on protein quality in cereal grains. Maize (Zea mays L.) was grown in a series of field plots which received various rata of applied N as ammonium sulfate. The site was in an area mapped as Yolo (Typic Xerorthents) fine sandy loam, and rates of N application of 0, 90, 180, and 360 kg N/ha were used on quadruplicate plots. The entire plot area had been fertilized with K, and sufficient water was applied during the season to meet evapotranspiration needs. Total N in the grain was determined by a Kjeldahl method, amino acids with an amino acid analyzer after subjecting samples to conditions which would hydrolyze protein, and protein fractions were extracted using a modified Osborne‐Mendel procedure.Yields of grain were nearly doubled to approximately 10,700 kg grain/ha by application of N, with no significant difference between yield means for the 180 and 360 kg N/ha rates. Concentrations of crude protein (N ✕ 6.25) ranged from about 6% in grain from plots receiving no added N or 90 kg N/ha, to nearly 10% (mean of concentrations in grain from plots receiving 180 and 360 kg N/ha, which did not differ significantly). The concentrations in the grain protein of tryptophan, lysine, glycine, arginine and threonine were decreased, and the concentrations of alanine, phenylalanine, tyrosine, glutamic acid and leucine increased by applications of N. The first increment of N (90 kg/ha), which had the greatest effect on grain yield, did not have significant effects on the concentrations of tryptophan, lysine or alanine in the protein.The differences in concentrations of the amino acids in the grain from the different N treatments were in part, but not wholly, accountable for by differences in the concentrations of the prolamine (zein) protein fraction. Thus, for example, serine, which is present in relatively high concentration in zein, should have been present at higher concentration in the grain from the N‐fertilized mainze. Valine, histidine and methionine, on the other hand, might be expected to be present at lower concentrations with this treatment.The yields of grain crude protein were approximately 2‐fold greater with applications of 180 or 360 kg N/ha than with no applied N. Treatment effects on yields of amino acids ranged from nil in the case of tryptophan to about four‐fold greater amounts of leucine in grain from plots receiving the two highest rates of N.
Effect of Fertilizer‐N and Herbicides on the Growth and N Content of Soybeans and Cowpeas1
Authors: Behran Sh. , Maftoun M. , Sheibany B. , Hojjati S. M. 
Published: July 2010

AbstractLittle is known about herbicide‐N fertilizer interaction with respect to the growth and N content of soybeans (Glycine max (L.) Merr.) and cowpeas (Vigna unguiculata). This study was undertaken to evaluate the effect of added N and trifluralin (α, α, α‐trifluoro‐2, 6‐dinitro‐N, N‐dipropyl‐ρ‐toluidine), nitralin [4‐(methylsulfonyl)‐2, 6‐dinitro‐N, Ndipropylaniline] and diphenamid (N, Ndimethyl‐2, 2‐diphenylacetamide) on the growth and N uptake by these two crops.Soybeans and cowpeas were grown in greenhouse for 74 days in soil treated with various levels of N (0, 25, and 50 ppm) and herbicide (0, 1, 2, and 3 ppm). Leaf chlorophyll, dry matter yields, N concentration and N uptake were determined. All N‐treated soybean and cowpea plants had greater chlorophyll content, produced more growth and contained higher N than untreated check. An increase in growth and N uptake suggests that symbiotic N fixation probably failed to supply all of N required for optimum growth.Application of 1 ppm trifluralin slightly increased growth and N content of cowpea and enhanced chlorophyll content, N concentration and root dry weights of soybean. However, higher concentrations exhibited strong phytotoxic effects. Soybeans treated with 3 ppm of herbicide developed stunted and chlorotic leaves and had fewer nodules than untreated seedlings.Soil amended with nitralin and diphenamid reduced leaf chlorophyll, growth and N uptake of soybeans and cowpeas. Moreover, nitralin exhibited a stronger inhibitory effects in roots than tops and was slightly less phytotoxic than trifluralin. Diphenamid‐treated plants developed chlorotic leaf margins, followed by necrosis at the leaf edge.N addition to trifluralin treatment only affected N content of soybeans significantly, whereas there was increased chlorophyll content, N concentration and top dry weights of cowpea. On the other hand, N applied to nitralin and/or diphenamid‐treated soybeans and cowpeas resulted in an increase in dry weight and N content of tops, probably due to better nutrient and water supply to plants.
Depth of Lime Incorporation for Correction of Subsoil Acidity1
Authors: Doss B. D. , Dumas W. T. , Lund Z. F. 
Published: July 2010

AbstractSince most Southeastern U. S. soils ate acid, crop yields can generally be improved by liming surface soil. However, it is not known if plants will respond to deep incorporation of lime. Field experiments were conducted on two soils (Rhodic Paleudult and Typic Paleudult) at three locations in central and south Alabama to evaluate the effect of depth of Incorporation of surface‐applied lime on root system development, plant growth, and yield on acid soils. Soil pH ranged from 4.1 to 4.8 before liming. Sufficient lime was surface‐applied and incorporated to the 15, 30, and 45‐cm soil depths to increase pH in the treated zone to at least 6.0. All plots were initially chiseled to the 45‐cm depth to reduce physical differences resulting from subsequent lime incorporation. Depth of rooting, soil water extraction, plant height, and cotton (Gossypium hirsutum L.) and corn (Zea mays L.) yields were increased by lime. Based on the results from these two soils, incorporating lime to the 30‐cm depth is sufficient to obtain a satisfactory root system for high crop yields of cotton and corn.