bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Sod‐Seeding Legumes on Hill Land Pasture Productivity and Composition1
Authors: Bryan W. B. 
Published: July 2010

AbstractProduction and quality of hill land pasture may be improved by introducing a legume. Sod‐seeding is used extensively to introduce legumes into grassland, but little work has been reported for hill land pasture. Two identical experiments were conducted to determine the productivity and composition of hill land pasture when sod‐seeded with red clover (Trifolium pratenseL.) and birdsfoot trefoil (Lotus corniculatusL.). The effects of sod‐seeding date (spring or fall), soil amendment (lime and P), herbicides, and insecticide on hill land herbage dry matter (DM) accumulation and botanical composition were examined. The experiments were carried out in permanent hill land pastures consisting mostly of Kentucky bluegrass (Poa pratensisL.), meadow fescue (Festuca elatiorL.), redtop (Agrostis albaL.), white clover (Trifolium repensL.), and herbaceous broadleaf plants. The soil (fine‐loamy, mixed, mesic Typic Fragiudalfs) had an initial pH of 4.8 (Experiment 1) and 5.3 (Experiment II) with medium P and high K. Experiment I started in 1978 and experiment II in 1979. Both continued for 4 yr. Pasture composition and herbage accumulation were estimated in mid‐June, late July, and late September each year. In Experiment I herbage accumulation increased in the order: no amendment < legumes and P = lime and P < legumes, lime, and P < lime, P, and N. Pasture with no amendment was 50% as productive as sod‐seeded pasture (legumes, lime, and P). Nitrogen at 168 kg ha−1yr−1increased yearly herbage accumulation 20 to 120% compared to sod‐seeding. Results in Experiment II were similar except in the first year when sod‐seeded pasture produced 30% less than control pasture because paraquat (l,l‐dimethyl‐4,4'‐bipyridinium ion) application resulted in a herbage loss in June. Pasture sod‐seeded with red clover (RC) produced 20 to 25% more than pasture sod‐seeded with birdsfoot trefoil (BFT) only in year 1 (Experiment I) and year 2 (Experiment II). Spring was the best time to sod‐seed RC and fall for BFT. In Experiment II, lime had no effect on percentage total legume in the pasture, but in experiment I lime increased percentage total legume. Herbicide, method of herbicide application, and insecticide had small and transitory effects on pasture production and percentage total legume.
Wetting Effects on the Yield and Quality of Legume and Legume‐Grass Hays1
Authors: Collins Michael 
Published: July 2010

AbstractInformation is needed on rain effects on yield and quality of legume and legume‐grass hays. A field study was conducted on a Piano silt loam soil (fine‐silty, mixed, mesic, Typic Argiudoll) to evaluate rain effects on the yield and chemical composition of hays from pure swards of alfalfa (Medicago sativaL.), red clover (Trifolium pratenseL.), and birdsfoot trefoil (Lotus corniculatusL.) and mixtures with smooth bromegrass (Bromus inermisLeyss.). Plots for the factorial experiment (each 1.1 by 7.6 m) were arranged in a split plot design with legume species and pure or mixed sward type combinations as main plots and wetting treatments as the sub plots with four replicates. Wetting treatments consisted of field drying to 750 g dry matter (DM)/kg of total mass (TM) or more without rain or exposure to rain or artificial wetting during drying. Samples were collected just after cutting and after hay curing for quality analysis. Rain reduced the proportion of leaf by 109 and 151 g/kg for alfalfa and birdsfoot trefoil, respectively, but did not affect red clover leaf content. Rain increased DM loss by as much as 154 g/kg (pure alfalfa) but did not affect DM loss for the birdsfoot trefoil‐grass mixture. Legume‐grass hays generally had more neutral detergent fiber (NDF) and lower N and in vitro dry matter disappearance (IVDMD) concentrations than pure legume hay. Rain or wetting reduced IVDMD by from 13 g/kg (birdsfoot trefoil‐grass) to 64 g/kg (alfalfa). Except for Ca, which was reduced in some cases, rain or wetting did not affect mineral concentrations in dry hay. The presence of grass in the sward provided consistent advantage in hay drying only for red clover. Rainfall increased DM losses during hay curing except for the grass‐dominated birdsfoot trefoil mixture. Rain or wetting reduced hay quality by reducing IVDMD and increasing NDF concentration. Nitrogen, P, K, and Mg concentrations were not greatly affected by rain or wetting.
Growth and Yield of Sunflower and Soybean under Soil Water Deficits1
Authors: Cox W. J. , Jolliff G. D. 
Published: July 2010

AbstractQuantitative data are needed to support the thesis that sunflower (Helianthus annuusL.) is more drought resistant than soybean [Glycine max(L.) Merr.]. In 1980 and 1981 a comparative study of crop growth, seed yield, and soil water extraction patterns was conducted on a Woodburn silt loam soil (fine‐silty, mixed mesic Aquultic Argixeroll) to characterize the crop responses under moderate and severe soil water deficits. Line source sprinkler designs were used on both crops to generate well‐irrigated, deficit‐irrigated, and dryland treatments. Crop growth and soil water measurements were taken at 7‐ to 10‐day intervals on both crops in 1980 and 1981, respectively. In the well‐irrigated treatments, sunflower and soybean produced comparable total dry matter (1400 and 1350 g m−2, respectively) with seed yields of 4.10 and 3.29 Mg ha−1, respectively. Soil water deficits reduced dry matter production in the deficit and dryland treatments by 22 and 50% in sunflower and by 18 and 70% in soybean; and reduced seed yield by 20 and 51% in sunflower and by 27 and 87% in soybean, respectively. Leaf area index (LAI) was the vegetative growth characteristic of sunflower most sensitive to soil water deficits, and seeds per plant was the yield component most affected. Soil water deficits did not affect the harvest index (HI) of sunflower. In soybean LAI and net assimilation rate (NAR) were reduced under severe soil water deficits. Pod number was the yield component most sensitive to soil water deficits in soybean. Dryland sunflower extracted soil water to a 1.8‐m depth and thus avoided severe water stress during its reproductive period. In contrast, dryland soybean depleted considerably less soil water from the 0.9‐ to 1.8‐m depth. As a result, dryland soybean suffered severe water stress during its reproductive period, which dramatically lowered HI and seed yield. This study confirms that sunflower may avoid prolonged drought better than soybean by extracting water from deeper in the soil profile.
Yield and Physiological Responses of Potatoes to Deficit, High Frequency Sprinkler Irrigation1
Authors: Hang A. N. , Miller D. E. 
Published: July 2010

AbstractPotatoes (Solanum tuberosumL.) of high yield and quality can be produced on sandy soil only with adequate irrigation. It is important to know the minimum water requirement and how the crop responds to water stress. The present study was conducted in 1979 and 1980 to determine the effect of irrigation rate on potato performance. Treatments were initiated at full canopy on a sandy soil (mixed, mesic, Xeric Torripsamments) using the line source technique. Daily sprinkler irrigation near the line source was equivalent to 1.15 times estimated evapotranspiration (Et). Water stress symptoms were first observed in plants receiving the least irrigation water (18% Et in 1979 and 21% Et in 1980) 2 weeks after treatments were initiated. These symptoms included reduced plant size, fewer leaves, more dead leaves, and increased specific leaf weight, compared with nonstressed plants. Tuber and top growth rates increased with increasing irrigation, ranging from 2.62 and 17.63 g m 2day 1and −0.90 (apparent negative value) to 10.01 g m −2day −1, respectively, for the lowest to the highest water application. Partitioning of assimilate to tuber growth decreased with increased irrigation. Results indicate that potatoes grown on sandy soil require irrigation at rates approaching estimated Et if reductions in yield and quality are to be avoided. Increasing irrigation water beyond 100% Et did not increase yields.
Yield Loss Due to Simulated Hail Damage on Corn: A Comparison of Actual and Predicted Values1
Authors: Shapiro C. A. , Peterson T. A. , Flowerday A. D. 
Published: July 2010

AbstractThree simulated hail damage experiments were conducted to compare realized grain yields with those predicted by current hail adjustment procedures. Treatments included reductions in plant density and defoliation. Population density reduction was studied for 3 yr. An initial population of 6.4 plants m−2 was reduced to 5.9, 4.9, 4.0, and 3.0 plants m−2 at the 6‐, 9‐, 12‐, and 15‐leaf stages. Leaf stage did not affect grain yield, but yield decreased −2, 2, 6, and 19%, respectively, with each reduction in population. Yield losses due to population density reduction were less than those predicted by hail insurance procedures, especially for losses after the 10‐leaf stage. One‐hundred percent defoliation at the 4‐, 5‐ and 6‐leaf stages did not significantly reduce grain yield. One‐hundred percent defoliation from the sixth through the ninth leaf stages showed a linear decrease (regression coef. = −1.15) in grain yield with later leaf stage. The effects of early season complete defoliation varied with year. These results generally agree with the hail loss charts for very early season, 100% defoliation. Defoliation of 0, 33, 66, and 100% at the 6‐, 12‐, tassel, and blister stages was performed over four environments. Grain yield was reduced with increasing severity of defoliation, and with growth stages near the tassel stage. Five treatments produced a greater yield reduction than predicted by the hail adjustment procedures, while one treatment showed less yield reduction than predicted. Later treatments tended to show greater yield loss than predicted.
Effects of Temperature on Leaf Appearance in Spring and Winter Wheat Cultivars1
Authors: Baker J. T. , Pinter P. J. , Reginato R. J. , Kanemasu E. T. 
Published: July 2010

AbstractAn understanding of the genetic and environmental factors affecting the leaf area of a cereal crop is needed for accurate yield predictions by crop models. Field trials were conducted with three cultivars of winter wheat (Triticum aestivum L. em. Thell) at Manhattan, KS, under dryland and irrigated conditions and with six cultivars of spring wheat at Phoenix, AZ, in 1982 and 1983, respectively. Because leaf growth is strongly influenced by temperature, the rate of leaf appearance was expressed as leaves/thermal unit (Tu=[(TMAX+TMIN)/2]−Tb);w where Tu is thermal units, TMAX and TMIN are maximum and minimum daily temperatures, respectively, and Tb is the base temperature below which growth essentially ceases. The Tb, determined for three winter wheat cultivars, was not significantly different from 0°C (P≤0.05). Phyllochron interval (PI), the inverse of leaf appearance rate, was determined from the inverse of the slope of the regression of Haun scale growth units against accumulated Tu. The R2 values for these regressions were not less than 0.97 and 0.99 for spring and winter wheat cultivars, respectively. The PI was shorter for nonirrigated than irrigated winter wheat leaves (P≤0.01) and for spring wheat leaves formed prior to double ridges than those formed later (P≤0.01). Differences in PI were found among both spring and winter wheat cultivars (P≤0.05). These results illustrate the importance of determining PI for quantifying growth characteristics that determine the leaf area of a cereal crop.
Influence of Weather on Year‐to‐Year Yield Response of Corn to Ammonia Fertilization1
Authors: Hollinger S. E. , Hoeft R. G. 
Published: July 2010

AbstractMulti‐year N studies have shown large year‐to‐year variation in the yield response of corn (Zea mays L.) to N fertilization. The objectives of this study were to (i) determine which normally predicted and measured weather variables account for this year‐to‐year variability; and (ii) to suggest a climate forecast design that will provide the most flexibility in planning N fertilization programs. Relative yield responses to N treatments were obtained from 6 yr of field research on a fine, silty, mixed mesic Typic Haplaquolls. Relative yields and spring N treatments were transformed using natural logarithms (In). The transformed N treatments accounted for more than 95% of the transformed yield responses in 5 of the 6 yr. The only year the regression failed to fit accurately was a very hot, dry year when there was a negative response to N. The analog of the equation was used to obtain α and β coefficients, where α is the fraction of maximum yield expected if no N is applied, and β is the rate of yield increase with each additional unit of applied fertilizer. The α and β values were then related to the ratio of precipitation/evaporation (P/E) from the 11 June to 15 July period in each of the 6 yr. The quadratic relationship explained 99% of the variation in α and 95% of the variation in β. When P/E is less than optimum, water is limiting and the plant is unable to use the applied nitrogen efficiently. When P/E is greater than optimum, N may be lost through denitrification and/or leaching and is thus, unavailable to the plant.
The Effect of the Fungal Endophyte Acremonium Coenophialum in Tall Fescue on Animal Performance, Toxicity, and Stand Maintenance1
Authors: Read J. C. , Camp B. J. 
Published: July 2010

AbstractWeight gains have been inconsistent and numerous health problems have been associated with animals grazing tall fescue (Festuca arundinacea Schreb.). This study was undertaken to determine the effect of the fungal endophyte, Acremonium coenophialum Morgan‐Jones and Gams [syn. Epichloe typhina (Fries) Tulasne], on weight gains and symptoms of tall fescue toxicity of cattle. Grazing studies were started in the spring of 1982 and continued through the 1982–1983 and 1983–1984 grazing periods, on ‘Kenhy’ tall fescue having high and low levels of endophyte infection, at Dallas, TX, on Houston black clay soil (fine, montmorillonic, thermic Udic Pellusterts). Average daily gains were 0.46 kg and 0.97 kg for the high‐ and low‐infested pastures, respectively. Animals on the high‐infested pastures had elevated temperatures and rougher hair coats than those grazing the low‐infested pastures. During the 1983–1984 grazing period, 5 of the 6 tester animals grazing on the high‐infested pastures, had symptoms of ‘fescue foot’, whereas, none of the animals on the low‐infested grass exhibited any symptoms. Forage production was low and there was a loss of stand in the pastures with low levels of the endophyte. This study supports previous research findings on the effect of the endophyte in tall fescue on animal weight gains, summer syndrome, and drought resistance. An association of this endophyte with fescue foot was observed.
Nitrogen Management and Interseeding Effects on Irrigated Corn and Sorghum and on Soil Strength1
Authors: Olson R. A. , Raun W. R. , Chun yang Shou , Skopp J. 
Published: July 2010

AbstractA 15‐yr experiment on Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudolls) investigated N management effects on corn (Zea mays L.) and grain sorghum [Sorghum bicolor (L.) Moench] grown side by side, under identical furrow‐irrigated conditions. Included were comparisons of anhydrous ammonia (AA) and N solution (UAN) as N sources, planting time (UAN‐PL) vs. summer sidedressing (UAN‐SD) application of the N, and rates of 90,180, and 270 kg N ha−1. Additionally, interseeding of rye (Secale cereale L.) into high N plots and alfalfa (Medicago sativa L.) into check plots of corn was accomplished at the time of ridging for furrow irrigation. The objectives were to evaluate the long term effects of varied management of the two N carriers and the interseedings on grain yields and N utilization, and the relative effects of these treatments on soil strength. Grain sorghum was the more productive crop under conditions of low N availability while corn responded to higher N rates, becoming the more economic crop with yields approaching 10 Mg ha−1 when N was plentiful. Yield increases averaged 5% greater for UAN‐SD over UAN‐PL, and AA was slightly more effective than UAN‐SD for both crops. Interseeded alfalfa and rye green manures provided average corn yield increases of 880 and 585 kg ha−1, respectively, explainable in part by improved N economy. No significant differences in penetrometer or vane shear tests were found between soils from AA and UAN‐SD plots, although there was a tendency toward lower soil‐strength values with both N carriers, relative to check plots.
Sealed Chamber Digestion for Plant Nutrient Analyses1
Authors: Anderson D. L. , Henderson L. J. 
Published: July 2010

AbstractA sealed chamber digestion (SCD), using perchloric acid and hydrogen peroxide, was developed as an alternative to conventional procedures for plant tissue digestion. The SCD procedure was evaluated using eight plant tissue standards obtained from the National Bureau of Standards, University of Georgia, and the University of Florida. The results of the SCD did not differ greatly from reported standard values. The advantages of SCD are (i) the low volume of reagents used and the ability to utilize low volume dilutions, (ii) low temperature of digestion, (iii) use of a closed system eliminating the need for a fume hood, (iv) micro‐sample analyses capabilities, (v) minimal equipment investment, and (vi) simplicity.
Soybean Response to Tillage and Nitrogen, Phosphorus, and Potassium Fertilization1
Authors: Bharati M. P. , Whigham D. K. , Voss R. D. 
Published: July 2010

AbstractConservation tillage is being increasingly recommended as a means of reducing both cost of tillage and soil erosion. A study was conducted for two years with the objective of evaluating the performance of a determinate soybean [Glycine max (L.) Merr.) cultivar, Sprite, planted in narrow rows on a Nicollet (Aquic Hapludo1ls)‐Webster (Typic Haplaquolls) complex, with different tillage systems and different levels of N, P, K fertilization for higher yield. Variables studied included: (i) three tillage systems (disk, chisel plow, and moldboard plow tillage) and (ii) three levels of N, P, and K fertilization (P at 0,74 and 111 kg/ha; K at 0,186, and 279 kg/ha; and N at 0, 135, and 270 kg/ha). Plant population was unaffected by the treatments. Phosphorus and K applications increased soil and leaf P and K contents over time and with application levels. Tillage had no significant effect on grain yield. Lodging was significantly increased by P application. Lodging, plant height, and grain yield were significantly increased by K application. Nitrogen application increased lodging and plant height, but not yield. It was concluded that soybean can be successfully grown with reduced tillage in central Iowa without a yield reduction or change in fertility requirement. Soybean responded to K application when the soil test levels were medium to high.
Effect of Particulates (Dust) on Cotton Growth, Photosynthesis, and Respiration1
Authors: Armbrust D. V. 
Published: July 2010

AbstractWind erosion suspends large quantities of dust in the atmosphere that settle back to the earth's surface and are deposited on plant leaves when wind velocities decrease. The object of this research was to determine the effect of wind‐erodible size dust particles on upland cotton [Gossypium hirsutum (L.) ‘Dunn 120’] growth and physiology. Dust (< 0.106 mm) at concentrations of 0, 10.8, 15.2, 16.5, 22.1, 28.6, 38.5, and 51.1 µg m−2 was settled onto leaves of 22‐day‐old growth‐chamber‐grown cotton plants in a dust chamber. Net photosynthesis, dark respiration, dust concentration, leaf area, and dry weight were measured 1, 3, 7, and 14 days after dust was applied. Applied dust (> 15.2 µg m−2 ) resulted in reduced dry weight at 3, 7, and 14 days after application, but dry weight accumulation was not reduced by increasing dust concentration after day 3. The dry weight reduction was due to reduced photosynthesis, 1 and 3 days after dust application, and increased dark respiration, 1, 3, and 7 days after application when dust application rates exceeded 28.6 µg m−2. This study indicates that particulate deposits can alter cotton growth without physical damage to the plant and without toxic materials present in the dust. However, rapid removal of particulates by wind and rain and low natural deposition rates (1.5 µg m−2 day−1) indicate that dust deposits on leaves should not be a major problem in cotton production.
Harvest Methods for Estimated Ethanol Yields from Relative Fermentable Carbohydrate Accumulation in Maize Hybrids1
Authors: Widstrom N. W. , Carr M. E. , Bagby M. O. , Black L. T. 
Published: July 2010

AbstractRecurring energy shortages suggest the need for evaluation of alternate fuel energy sources. Conversion of plant carbohydrate to ethanol, as a fuel source, is considered a viable option with efficient energy‐producing crops such as maize, Zea mays L. Three maize hybrids (‘Coker 77’, ‘Pioneer 3369A’, and ‘Sokota Sugar Chop’) were grown in a Norfolk loamy sand (fine‐loamy, silicious Typic Paleudult) from 1981 to 1983 to evaluate four procedures for harvesting. The objective was to identify procedure(s) that maximize carbohydrate production potential, measured as estimated fermentable carbohydrate converted to ethanol. Ethanol yield estimates, calculated from grain or stalk sugars, or both, to make possible direct comparisons of harvest treatments, were analyzed as a split‐plot design with 10 replicates. Whole plots were hybrids, and subplots were harvest treatments. The treatments consisted of (i) covered ear shoots (EC); (ii) removed ear shoots (ER); (iii) grain and stalks harvested simultaneously (P‐SimH); and (iv) stalks harvested separately, 1 to 2 weeks after grain harvest (P‐ SepH). Coker 77 produced the least grain but significantly greater estimated ethanol yields than did the other hybrids in 2 of 3 yr because of greater stalk sugar yields. The P‐SepH and P‐SimH treatments of this hybrid produced less than twice as much estimated ethanol per plant, and other hybrids produced about three times as much as the EC and ER treatments of Coker 77. Differences between the P‐SimH and P‐SepH treatments were nonsignificant, and simultaneous harvest of grain and stalk sugar at physiological maturity proved an efficient procedure to produce high estimated ethanol yields.
Measurement of Nitrogen Utilization Efficiency in Rice Genotypes1
Authors: Broadbent F. E. , De Datta S. K. , Laureles E. V. 
Published: July 2010

AbstractRecent research suggests that there is considerable potential for exploiting genotypic differences in N utilization efficiency by crops. Our research attempted to identify traits associated with rice (Oryza sativa L.) genotypes that support maximum grain production with a minimum input of fertilizer. From field experiments on an Andaqueptic Haplaquoll in three consecutive seasons we identified a group of plant parameters associated with efficiency of N utilization to determine if the different genotypes exhibited consistent and significant variations in these parameters. A group of nine parameters was selected, and rankings based upon different combinations of these parameters were developed and compared. Statistically significant differences among genotypes were observed, and reasonably consistent rankings were obtained from season to season. For example, IR183429‐3‐2‐1‐2 ranked first in two seasons and third in the other. IR18349‐135‐2‐3‐2‐1 ranked second, third, and fifth in the three seasons. These are medium maturity rices. IR42, which is known to perform well on low N soils, ranked between ninth and 17th. The consistency of performance of outstanding genotypes demonstrated in these experiments suggests that the methodology is feasible and practical for use in research on genetic improvement of N utilization efficiency.