bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen and Rhizobium Effects on Establishment of Legumes via Strip Tillage1
Authors: West Charles P. , Martin N. P. , Marten G. C. 
Published: July 2010

abstractThe success of interseeding pastures with forage legumes via strip‐tillage is limited by the rate and degree of seedling establishment. Before biological nitrogen (N) fixation is initiated, the legume plant must depend on combined N from the soil or seed for establishment. Soils under permanent grass sod are known to contain very low levels of combined available N.Field studies were initiated to determine the effects of seed rhizobium inoculum level and N fertilizer level on the establishment of three forage legumes introduced into grass pastures via strip‐tillage. 'Ramsey' alfalfa (Medicago sativa L.), 'Arlington' red clover (Trifolium pratense L.), and 'Carroll' birdsfoot trefoil (Lotus corniculatus L.) were interseeded into pastures at two locations (L 1 and L 2) with differing soils (Typic Haplaquoll and Typic Hapludoll, respectively). Location 1 had predominantly Kentucky bluegrass (Poa pratensis L.) , and L 2 had a mixture of Kentucky bluegrass and smooth bromegrass (Bromus inermis Leyss.). The grass was temporarily suppressed by a broadcast application of glyphosate [N‐(phosphonomethyl)glycine] at 0.84 kg/ha. Inoculum treatments consisted of 4,000 and 40,000 rhizobia seed. The four fertilizer levels applied at seeding were 0, 30, 60, and 90 kg N/ha.Legume establishment was not affected by seed rhizobium inoculum level. Seedling vigor, first cutting leg ume, and total herbage yields increased significantly with added N fertilizer at both locations. Legume percentage in the sward followed a quadratic pattern with N level in the second cutting of the first year at L 2 and in the first cutting of the second year at L 1; legume percentage increased at the intermediate N levels and decreased at the highest N level in these cases. Increasing the N level resulted in either negative linear or quadratic changes in crude protein concentration in the 1st year, depending on location. Neutral detergent fiber concentrations in the total forage increased linearly with inoreased N at both locations in the first year. Herbage in vitro dry rnatter digestibility concentration was quadratically influenced by N level in the regrowth of the first year only at L 1.We conclude that the application of 30 to 60 kg N/ha before interseeding legumes into a grass sod having low soil N availability may enhance early legume seedling growth and increase the initial legume contribution to the sward herbage yield, as well as total herbage yield.
An Automated Sample Weighing System1
Authors: McLaughlin N. B. , Townley‐Smith T. F. 
Published: July 2010

AbstractA rapid weighing system was developed in order to eliminate reading and transcription errors during the recording of weights of large numbers of plot samples. The weighing system described consists of a digital electronic scale with parallel BCD outputs, an interface (described in detail), and an IBM 029 card punch. Computer cards were prepunched with the same identification code as the labels on the samples and are arranged in the same order. When initiated, the interface automatically reads the BCD output on the scale, converts it to a serial decimal form and sequentially supplies signals to the card punch simulating pressing the corresponding numeric characters on the card punch keyboard. When all digits have been punched, the card punch program automatically releases the card, feeds the next card and advances it to the correct column for the next weight to be punched.
Preparation of Customized Pressure Chamber Seals for Irregularly‐Shaped, Succulent Organs1
Authors: Simonelli Mary L. Neat , Spomer L. Art 
Published: July 2010

AbstractThe pressure chamber is commonly used to evaluate plant water status. The compression sleeves supplied with commercial units provide inadequate seals on irregularly‐shaped, succulent stems or petioles of organ samples. This makes accurate measurements of the water status of organs difficult, if not impossible. This note briefly describes a technique for making customized seals by molding them out of silicone rubber directly onto representative stems or petioles. Such seals have been demonstrated to provide superior sealing action with little or no tissue change.
Occurrence of Al and Mn in Grass Tetany Cases and Their Effects on the Solubility of Ca and Mg In Vitro1
Authors: Allen Vivien G. , Robinson D. L. 
Published: July 2010

AbstractAlthough many factors associated with forages have been demonstrated to affect Mg balance in ruminants, none of the factors has been shown to cause grass tetany consistently. This investigation was begun with the objective of identifying mineral imbalances associated with individual grass tetany cases. Soil and forage samples were collected from tetany‐producing pastures and samples of rumen contents were collected from animals that had died with grass tetany. Rumen content samples were also collected from fistulated steers and cows grazing under non‐tetany conditions. Tetany pastures were found to contain areas where forages commonly contained 2,000 to 8,000 ppm Al. All rumen content samples from dead tetany animals contained high levels of Al, averaging 2,373 ppm. Samples from non‐tetany animals averaged 405 ppm Al. The rumen content samples from tetany and non‐tetany animals averaged 306 ppm and 139 ppm Mn, respectively.In view of evidence that ruminant animals absorb Mg primarily in the reticulo‐rumen, an in vitro experiment was designed to determine the effects of Al ana Mn on the solubility of Mg and Ca in various combinations of ryegrass, rumen fluid, and buffer solution. Seven treatment combinations of Al and Mn were used: control, 1,000 and 2,000 pm Mn, 4,000 and 8,000 ppm Al, 1,000 ppm Mn plus 4,000 ppm Al, and 2,000 ppm Mn plus 8,000 ppm Al. After 48 hours of incubation, added Al had reduced Mg and Ca in solution by 56 and 74%, respectively (P ≤ 0.01). Manganese decreased Ca in solution when added alone, but had no effect on Mg or Ca when added with Al (P ≤ 0.05). This research indicates that high Al levels in forages and rumen contents are actively involved in the etiology of grass tetany in ruminants.
Afternoon Water Deficits and Grain Yields in Old and New Soybean Cultivars1
Authors: Boyer J. S. , Johnson R. R. , Saupe S. G. 
Published: July 2010

AbstractPlant water deficits affect many metabolic processes, and soybean (Glycine max L. Merr.) is subject to water deficits during midday even when soil water is adequate under field conditions. Our objective was to determine if yield improvement by plant breeding has been associated with avoidance of these deficits in soybean. A 3‐ year experiment was conducted on highly productive soils in central Illinois with two soybean maturity groups each represented by four cultivars. The cultivars had been released between 1911 and 1968 in the USA.Soil water availability was high in all 3 years. However, leaf water potentials were frequently below −11 bars at midday, which we defined as a water deficit. Cultivars with low yields experienced larger water deficits than those with high yields. The largest water deficits were found in the oldest cultivars and were present in all the fully illuminated leaves of the canopy. The deficits were large enough to be potentially inhibitory to afternoon photosynthesis and other metabolic processes.Considerable yield improvement was apparent in the newer cultivars of both maturity groups when their yields were compared with those of older cultivars in the common environment represented by this experiment. Rooting densities of two cultivars showing extremes of midday water deficits indicated that the cultivar with the least water deficit (‘Wayne’) had a greater root density than the cultivar with the largest deficit (’Richland’).The data suggest that old cultivars experience yield inhibiting water deficits at midday in central Illinois in soil containing adequate water. Breeding soybean for high yield has, at the same time, selected for superior shoot water status in midday, perhaps as a result of increased root densities.
Manure and Inorganic Fertilizer Effects on Sorghum and Sunflower Growth on Iron‐Deficient Soil1
Authors: Mathers A. C. , Thomas J. D. , Stewart B. A. , Herring J. E. 
Published: July 2010

AbstractIron chlorosis occur in grain sorghum [Sorghum bicolor (L.) Moench] and other Fe‐inefficient crops on calcareous soils in spots throughout the Great Plains. Economical control of Fe deficiency in these crops will allow them to be grown in places where they are otherwise not adapted.Grain sorghum (‘Dekalb E‐59’) and sunflower (Helianthus annuus L. ‘Hybrid 896’) crops were grown on Arch fine sandy loam (Ustochreptic Calciorthid of the fineloamy, mixed thermic family) to compare their growth on calcareous soil and to study the effects of soil treatments with beef feedlot manure (11 and 33 metric tons of dry matter/ha), and inorganic N, P, and Fe (168‐56‐22) kg/ha) fertilizer. Sunflower seed yield was not changed significantly by any of the treatments. In 1977, the second year of the study, sorghum grain yield where N + P was applied was about half that of the check plot. However, in 1978 forage yield was reduced only about 10% below the check by N + P. Iron‐deficiency symptoms in sorghum were very severe on both check and N + P treatments; many sorghum plants died and others did not produce heads. When 22 kg/ha Fe was added with the N + P, grain yield was increased 66% over the check in 1977, and forage yield was twice that of check in 1978. Sorghum grain yield where manure was applied was three times the yield on check Plots in 1977, indicating that manure keeps both Fe and P available for use by grain sorghum on calcareous soil. The study also showed that sunflower is not highly sensitive to iron deficiency and could serve as an alternative crop for iron‐deficient soils.
Effectiveness of Nitrapyrin with Surface‐Applied Fertilizer Nitrogen in No‐Tillage Corn1
Authors: Frye W. W. , Blevins R. L. , Murdock L. W. , Wells K. L. , Ellis J. H. 
Published: July 2010

AbstractNitrapyrin [2‐chloro‐6‐(trichloromethyl)pyridine] has been shown to slow the nitrification process by selectively inhibiting nitrifying soil bacteria, thus keeping N less susceptible to losses by leaching and denitrification. Since nitrapyrin is volatile, the manufacturer recommends incorporation into the soil immediately after applying. However, in no‐tillage production of corn (Zea mays L.), fertilizers usually are not incorporated. The objective of this study was to determine the effectiveness of nitrapyrin sprayed onto granular ammonium nitrate and urea fertilizers which were then applied to the soil surface for no‐tillage corn. Eight field experiments were conducted at four locations in Kentucky over a 5‐year period on soils that are usually wet during the spring. Nitrogen fertilizers were applied at rates ranging from 0 to 180 kg/ha of N. The rate of nitrapyrin application was 0.56 kg/ha. Nitrapyrin resulted in increased corn yields in most cases where N fertilizers were applied at yield‐limiting rates. This study indicated that nitrapyrin functions effectively for no‐tillage corn when applied directly to N fertilizer granules and broadcast on the soil surface. It was thought that volatilization of nitrapyrin was not great enough to render it ineffective when concentrated in the soil with the NH4+. Grain yield response in notillage corn may be expected when environmental conditions would cause severe leaching or denitrification losses and plant growth limitation without nitrapyrin.
Temperature Effect on the Inclination of Lateral Roots of Soybeans1
Authors: Kaspar T. C. , Woolley D. G. , Taylor H. M. 
Published: July 2010

AbstractGenetic and environmental factors influence the size and shape of soybean (Glycine max (L.) Merr. root systems. Ten soybean lines were grown in sand culture at four different sand temperatures (10.0, 15.6, 21.1, and 26.7 C) to determine if temperature affects the angle of inclination of soybean lateral roots. The plants were grown in a growth chamber set for a constant air temperature (± 2.4 C) equal to the treatment temperature. The treatments were imposed until the unifoliate leaves had spread apart and unfolded. The sand was then washed from the roots, and a tracing on acetate was made of the root sysem, which was suspended in water at the time. The inclination of the lateral roots of each plant was determined from the acetate tracings by averaging the measured angles between the horizontal and the 10 up permost lateral roots. The effects of temperature, lines, and the interaction of temperature and lines were significant. The maximum angles of inclination occurred at either 26.7 or 21.1 C, and the minimum values at 10.0 C for most of the lines. ‘Hawkeye’ was not affected by temperature and had the largest angle of inclination averaged over the four temperature treatments. ‘Clark 63’ had the largest increase in the angle of inclination with an increase in temperature.
Basic Cation Saturation Ratios as a Basis for Fertilizing and Liming Agronomic Crops: I. Growth Chamber Studies1
Authors: Eckert D. J. , McLean E. O. 
Published: July 2010

AbstractBasic cation saturation ratios are often used as a basis for making fertilizer and lime recommendations; however, little expermental evidence is available to support or refute the concept. This study was conducted to evaluate crop growth as influenced by varying soil cation ratios. A Loudonville silt loam (Ultic Hapludalf, fine loamy, mixed, mesic) was amended with K. and Mg to the following levels: 2.5 and 5% base saturation of K; 4, 8, and 16% Mg; and with Ca as Ca(OH)2 to pH 5, 6, and 7. The soil was then cropped with German millet (Setaria italica L. Beauv.) and alfalfa (Medicago saliva L.). Maximum yield of German millet was obtained at several soil K/Mg/Ca ratios. Yield increased as soil and plant Mg/Ca ratios increased, except where high soil Mg and low soil Ca levels induced Ca deficiency in the plants. Alfalfa also grew well at several ratios, particularly at the higher soil pH levels. The data indicated that balance of cations in the soil was unimportant, except at the extremely wide ratios where deficiencies of one element were caused by excesses of others. Hence, no best ratio existed for either or both crops.
Effects of N Fertilization and Cutting Schedules on Stockpiled Tall Fescue. II. Forage Quality1
Authors: Collins Michael , Balasko J. A. 
Published: July 2010

AbstractTall fescue (Festuca arundinacea Schreb.) is the coolseason grass used most frequently to extend the grazing season in mid‐latitude states of the midwestern and eastern United States. Insufficient information is available regarding the influence of fertilization and harvest management on the quality of stockpiled tall fescue forage available during winter. Results of two field experiments dealing with the influence of cutting and N fertilization management on stockpiled tall fescue quality and chemical composition are reported.In Exp. I, treatments consisted of four N rates: 0, 60, 120, and 180 kg/ha applied as split applications of one‐half in March and one‐half in August; three dates when stockpiling began (1) mid‐June, (2) early July, and (3) mid‐July; and three autumn and winter harvest dates (1) mid‐December, (2) mid‐January, and (3) mid‐February. The soil used in Exp. I was a well‐drained loam (Typic Hapludults) with high levels of P and K. The treatment with the greatest influence on in vitro dry matter disappearance (IVDMD) was winter harvest date. Forage IVDMD decreased from 47.3% hi mid‐December to 41.1% by mid‐February. Crude protein (CP) concentration increased from 7.4% at 0 N to 10.4% at the 180 kg/ha N rate averaged over all other treatments and 2 years. Forage P and Mg concentrations were below minimum requirements for dry beef cows by late whiter.In Exp. II, conducted on a silt loam soil (Typic Fragiudalfs), treatments included four N rates: 0, 75, 150, and 225 kg/ha applied at the last summer or autumn cutting which occurred in either early September, mid‐September, or early October. In this experiment, all accumulated forage was harvested in late winter. Nitrogen fertilization increased forage IVDMD and CP, water soluble carbohydrate, K, and Mg concentrations in the stockpiled forage. Data from the two experiments Indicate that supplementation of energy, P, and Mg may be necessary in utilizing stockpiled tall fescue during January and February.
Competition Between Adjacent Fruiting Forms in Cotton1
Authors: Kerby T. A. , Buxton D. R. 
Published: July 2010

AbstractCotton plants (Gossypium hirsutum L.) produce more fruiting forms that can be supplied assimilates, and competition and abortion occurs. The relationship is accentuated with narrow‐row, high population culture. This study was conducted to determine the extent that fruiting forms compete and influence abscission of adjacent fruiting forms. The study was also designed to determine if plant leaf type or plant density altered the effects of competition.Normal, Okra, and Super Okra‐leaf cotton plants were grown in rows 51 cm apart in irrigated basins at 11.2 and 18.5, and 10.0 and 20.0 plants/m2 in 1973 and 1974, respectively. The soil type was a coarse‐loamy, thermic, Typic Torrifluvent (a member of the Gila series). Fruiting positions reaching anthesis were tagged daily. Fruiting positions on sympodial branches were identified as L1 for the first position and L2 for the second position.Averaged over genotypes, plant densities, and years, 25% of the positions at L2 retained bolls when L1 aborted as a square compared to only 10 and 11% when L1 aborted as a young boll or retained a boll until maturity, respectively. Averaged over plant densities and years, when bolls were retained at L1, 60% of the positions at L2 aborted as young bolls for Super Okra‐leaf plants compared to only 34% for normal‐leaf plants. However, normal‐leaf plants aborted 52% of the positions at L2 as squares compared to only 32% for Super Okra‐leaf plants. Averaged over genotypes and years, when L1 retained a boll, high plant densities aborted 45% of the positions at L2 as squares compared to 35% for low plant densities.Under narrow‐row, high‐population culture it was apparent that adjacent fruiting forms competed for available assimilates, and that the potential for developing more than one boll per sympodial branch was low. The use of cultivars which produce long sympodial branches appears to be inefficient under this system.
Yield and Quality Changes with Maturity of Silage‐Type Sorghum Fodder1
Authors: Cummins D. G. 
Published: July 2010

AbstractMaturity at harvest is a major factor in determining the quality of silage‐type sorghum [Sorghum bicolor (L.) Moench], and there is evidence of quality differences among hybrids at equivalent growth stages. The objectives of this study were to determine the effects of maturity in four height classes of sorghum hybrids and their interactions on dry forage yields and its composition, and to determine quality of heads, leaves, and stalks in terms of in vitro dry matter digestibility (IVDMD) and acid detergent fiber (ADF). Four hybrids, representing height classes of 4.5, 5.5, 6.5, and 7.5 m, were grown under conventional production practices and harvested at the late milk, early dough, dough, and hard dough stages of grain maturity. Dry matter accumulation in all hybrids remained similar after reaching 24.6%. The shorter hybrids had maximum head percentage earlier in maturity than the taller hybrids. The tallest hybrid had higher stalk percentage later in maturity than did the shorter hybrids. Head IVDMD of the short hybrids with high head percentage remained constant or increased with advancing maturity, while that of the tall hybrid with lower head percentage decreased later in maturity. Stalk IVDMD of the tallest hybrid increased with maturity while the other hybrids decreased with maturity. Stalk ADF of the tallest hybrid decreased with maturity, while that of the other hybrids remained relatively constant. Stalk IVDMD and ADF were negatively correlated (r = −0.63**). These results show the potential for improvement in quality of silage‐type sorghum hybrids through selection of breeding lines that maintain high stalk quality late into maturity.
Alfalfa Yield and Water Use When Forced into Dormancy by Withholding Water During the Summer1
Authors: Metochis Chr. , Orphanos P. I. 
Published: July 2010

AbstractUnder the hot (air temperature reaching 40 C) and dry conditions of the inland areas of Cyprus, alfalfa (Medicago sativa L.) yields decline markedly in July to August. Water‐use efficiency (kg DM/m3 of water taken up) decreases from 2.25 to 2.85 in March through May to 0.50 to 0.65 kg/m3 in July through August. This study evaluated several alternatives for increasing water‐use efficiency for alfalfa production.Not irrigating the alfalfa for one growth period in July reduced yield during that period by 68%. However, not irrigating for a second or a third growth period resulted in no forage yield during these periods. When irrigation was resumed, plots not irrigated for one or two growth periods yielded as much as plots irrigated at all growth periods, but plots not irrigated for three growth periods produced 20% less yield during the first period following resumption of irrigation. In the following growth periods, however, these yielded as much as plots irrigated at all growth periods. Discontinuing irrigation for the three growth periods of July to August reduced annual dry matter yield to 17,700 kg/ha compared to 21,500 kg/ha when adequate water was applied throughout, but saved 610 mm of irrigation water out of a normal annual irrigation requirement of 1,400 mm. As a result, water‐use efficiency in 1978–1979 increased from 1.32 kg DM/m3 of water taken up when adequate irrigation was applied throughout the growing season to 1.60 when irrigation was withheld for the three growth periods of July to August. The corresponding figures for 1979–1980 were 1.41 and 1.81, respectively.
Relationships Among Components of Seed Yield in Blue Grama1
Authors: Wilson A. M. , Cuany R. L. , Fraser J. G. , Oaks W. R. 
Published: July 2010

AbstractHigh caryopsis weight in forage plants generally increases seedling emergence, vigor, and establishment. Breeding for improved caryopsis weight in blue grama [Bouteloua gracilis (H.B.K.) Lag. ex Steud.] can be successful only if variations in average caryopsis weight of a plant are not simply a result of variations in the components of caryopsis yield. The objectives of this study were to determine the effects of spikes/culm, spikelets/spike, and fertility on caryopsis weight and the effects of spikes/culm, spikelets/spike, fertility, and caryopsis weight on yield/culm. In a 1,080−plant, spaced field nursery, average caryopsis weight varied among plants from 25 to 70 mg/100. Multiple regression and path analysis indicated that spikes/culm, spikelets/spike, and fertility accounted for only 5% of the variation in caryopsis weight. These components of yield, with caryopsis weight, accounted for 86% of the variation in caryopsis yield/culm. In a polycross nursery of 60 plants selected from the previous nursery primarily for high caryopsis weight, blue grama clones differed significantly in all of the components of caryopsis yield/culm. Blocks in the polycross nursery differed significantly in all components of yield/culm except average caryopsis weight of a plant. These results suggest that it would be possible to select blue grama plants for both high caryopsis weight and high seed yields.