bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of N, P, and K Fertilization on Yield and Mineral Composition of Native Bluejoint Grass on the Lower Kenai Peninsula, Alaska1
Authors: Laughlin Winston M. , Smith Glenn R. , Peters Mary Ann 
Published: July 2010

AbstractDomestic grasses are difficult to establish and maintain in the Caribou Hills of the lower Kenai Peninsula in Alaska. Thus this 8‐year study sought to determine native bluejoint [Calamagrostis canadensis(Michx.) Beauv.] response to varying N, P, and K fertilization rates applied annually and stand persistence when two cuttings were made each growing season. A 4 × 22factorial experiment with four N rates (67,134,201, and 268 kg N/ha) and two P and K rates (84 and 168 kg P/hq 93 and 186 kg K/ha) was established on Kachemak silt loam (thixotropic over loamy, mixed Typic Cryandept) at 366 m elevation. Concentrations of NO3−N, total N, P, K, S, Ca, Mg, and Si in the plants were determined and uptake of these constituents calculated, During this 8 years with two annual harvests and with fertilization the bluejoint stand became more dense. Each increasing N rate through 134 kg/ha generally increased the annual yield. Concentrations of N03−N and total N in both cuttings and annual N uptake were increased by each increasing N increment while the Si concentration of each cutting was depressed. Significant yield interaction between N and K occurred with greater response to N or K at the higher rates of the other. Application of P increased forage yield, P, Ca, and Mg concentrations, and P, K, S, Ca, and Mg uptake. Doubling the P rate further increased these values. Potassium application increased yield, K concentration, and P, K, and S uptake. Doubling the K rate increased the yield at higher N rates and decreased Ca, Mg, and Si concentrations and uptake. Ranchers in the lower Kenai Peninsula area of Alaska can now be assured native bluejoint can be the most important forage grass to provide supplemental winter livestock feed. Persistent high yields can be maintained with less cost than with any other presently known forage.
Yield and Yield Components of ‘Braxton’ Soybeans as Influenced by Irrigation and Intrarow Spacing1
Authors: Ramseur E. L. , Quisenberry V. L. , Wallace S. U. , Palmer J. H. 
Published: July 2010

AbstractYield and yield components of ‘Braxton’ soybeans [Glycine max(L.) Merr.], Maturity Group VII, were measured for differing irrigation regimes and intrarow spacings. Soybeans were planted in 0.91 m rows in mid‐May, 1980 and 1981 on a Cecil sandy loam soil (clayey, kaolinitic, thermic Typic Hapludults). Prior to the V3 growth stage, plots were thinned to achieve intrarow spacings of 61,76,102, 152,305, and 457 mm in 1980 with spacings of 43 and 51 mm added in the 2nd year. Soil water regimes were full‐season irrigation (FSI), irrigation beginning at bloom (BI), and no irrigation (NI). Beginning at R4, plants from a 0.5‐m section of row were removed at 10‐ to 14‐day intervals for determination of seed growth rate and effective filling period. Yield components (pod number, seed number, seeds per pod, and single seed weight) were determined at R7 or maturity. Final seed yields were determined by harvesting bordered rows following end trimming. Seed yields for the 2 years, averaged over all spacings, were 3023,2876, and 1322 kg/ha for the FSI, BI, and NI higation treatments, respectively. While yields were increased significantly with irrigation, no significant difference in yield was measured between FSI and BI treatments. Yields among plant spacings were not significantly different for any irrigation treatment either year with the exception that the yield of the 457‐mm spacing of the BI treatment was significantly reduced in 1981. Seed number was highly correlated with seed yield, whereas single seed weight was not significantly correlated with yield. Increases in seed number under the irrigation treatments were due to increases in both pod number and seed per pod. Seed growth rate was increased and effective filling period was decreased by irrigation. We concluded that intrarow spacings up to 457 mm had little influence on yield. Even though rainfall was low during vegetative growth prior to bloom in both years, full‐season irrigation gave no yield advantage over bloom irrigation.
Postemergence Sprayer with Adjustable Width Row Shields1
Authors: Michel J. A. , Fornstrom K. J. , Borrelli J. , Jackson G. D. 
Published: July 2010

AbstractA postemergence sprayer with adjustable width row shields was designed and constructed to apply nonselective herbicides between the crop rows while shielding the emerged crop. An over‐the‐row spray boom is mounted beneath the row shields for banding selective herbicides over‐the‐row. The implement was used successfully in no‐tillage corn (Zea maysL.), dry beans (Phaseolus vulgarisL.), and sugar beets (Beta vulgarisL.).
Cation Composition of Tall Fescue Forage as Affected by K and Mg Fertilization1
Authors: West J. W. , Reynolds J. H. 
Published: July 2010

AbstractGrass tetany has been observed in cattle grazing cool‐season grasses during the late winter and early spring in the southeastern USA. It has been suggested that Al is involved when this problem occurs on wet sites. Tall fescue (Festuca arundinacea Schreb.) experiments were located at Knoxville (2 years) and Chapel Hill, Tenn. (1 year) to determine fertilizer effects on K, Mg, Ca, and Al concentrations of forage grown on soils subject to flooding. The soils were Lindside loam (fine‐silty, mixed, mesic Fluvaquentic Eutrochrepts) and Roellen silty clay loam (fine, mixed, thermic Vertic Haplaquolls). Treatments consisted of a control and fall applied Sul‐Po‐Mag (2 MgSO4 • K2SO4), Epsom salts (MgSO4 • 7 H2O) + potassium sulfate (K2SO4), Epsom salts alone, or potassium sulfate alone to supply 112 kg Mg and/or 181 kg K ha−1. The forage was sampled from February through early May while these soils were usually saturated with water and at some times while there was water standing on the surface. Magnesium fertilization had little effect on forage Mg while K fertilization usually increased forage K. As growth increased, forage K increased in early spring. Equivalent ratios of K/(Ca + Mg) closely followed trends of forage K and increased potential for tetany but remained below 2.2. Magnesium concentrations remained low (< 2 g kg−1) in the forage through early May. Aluminum and Ca concentrations were usually unaffected by fertilization treatments. There was no apparent benefit from fertilizing these soils with Mg sources. Concentrations of Al dropped considerably when the plant growth was not close to the wet soil surface and when standing water was not present. Apparently, soil Al adhered to the leaves in contact with wet soil or standing water since Al uptake through the roots would be very limited with the soil pH about 6.0.
Distribution of 15N‐Depleted N in Protein Fractions of Rice as Affected by Placement and Timing of N Fertilizer1
Authors: Patrick W. H. , Reddy K. R. , Mulbah Charles 
Published: July 2010

AbstractBoth the quality and quantity of increased protein resulting from fertilization of grain crops are important considerations in evaluating the effects of N fertilization. A field experiment in which 15N‐depleted N fertilizer was applied to lowland rice (Oryza sativa L.) growing on Crowley silt loam (fine, montmorillonitic, thermic Typic Albaqualf) using different methods and times of application showed that total protein content could be increased, especially by late‐season application, but that little effect on protein distribution was obtained. Late‐season application resulted in a larger amount of fertiliizer N being present in the glutelin fraction but with no apparent effect on the more important water‐soluble albumin fraction.
Nitrogen Fixation in Soybeans: An Evaluation of Measurement Techniques1
Authors: Vasilas B. L. , Ham G. E. 
Published: July 2010

AbstractAccurate estimates of N2fixation by soybeans [Glycine max(L.) Merr.] are needed to evaluate specific interactions between Rhizobium, legume host, and environment. This study compares Kjeldahl‐N, isotope dilution, and ‘A’‐value techniques in the estimation of N2fixation by field‐grown soybeans receiving different levels of soil N. Experiments were conducted in 1979 and 1980 at Becker (Alfic Udipsamment) and Rosemount (Typic Hapludoll), MN. After planting but before emergence, 15N‐labeled (NH4)2SO4, was surface applied in solution at rates of 5, 20, and 100 kg N/ha in 1979; and 10 and 100 kg N/ha in 1980. A non‐nodulating soybean line was used as the control plant. Plant samples for N and 15N analyses were collected at full bloom, full pod, and full seed at Becker; and at full bloom, beginning seed, and physiological maturity at Rosemount. Combined N had little or no effect on N accumulation, vegetative production, nor grain yields of nodulating plants. Percentagewise, N fertilizer utilization in general was similar by nodulating and non‐nodulating plants and tended to increase as fertilizer rates increased.Although rarely statistically different, ‘A’‐values consistently produced the highest and the isotope dilution technique the lowest estimates of N2fixed. Even under conditions of very low soil N availability, there was excellent agreement between the difference method and the isotope dilution technique. These two methods produced essentially the same values under conditions of low soil N and high fertilizer N (Becker, 100 kg N/ha). At the lowest level of applied N, N2fixation, measured by isotope dilution, contributed approximately 77 and 48% of total plant N at Becker and Rosemount, respectively. Maximum N2‐fixation values of 198 and 167 kg N/ha were achieved at Becker and Rosemount, respectively.
Degradation of Potassium Hydroxide‐Treated ‘Coastal’ Bermudagrass Stems at Two Stages of Maturity1
Authors: Spencer Roland R. , Akin Danny E. , Rigsby Luanne L. 
Published: July 2010

AbstractThe highly lignified and rigid stem tissue of grasses form a formidable barrier to digestion and physical destruction in the rumen of the animal. Alkali treatment has been shown to increase the digestibility of many feeds. The objective of this research was to compare the effect of potassium hydroxide treatment on the physical structure and on the degradation of specific tissues by rumen microorganisms in ‘Coastal’ bermudagrass [Cynodon dactylon(L.) Pers.] stems. Scanning electron microscopy was used to study the relative extent of in vitro cell wall digestion of stems at 6, 24, and 48 h for two stages of maturity. The less mature top stem (TS) was taken from the upper first or second internode while the more mature bottom stem (BS) was taken from the lowest internode above the root. Potassium hydroxide treatment disrupted tissues and caused a swelling of the vascular, sclerenchyma, and epidermal cells. Alkali treatment appeared to break down the bonding in the intercellular layer allowing this material to be degraded by the rumen microorganisms. Similar material in untreated tissues was resistant to microbial attack. Untreated TS were degraded to a greater extent than untreated BS. This difference occurred in parenchyma tissues, of which more cells gave a positive reaction for lignin with the chlorine‐sulfite test in the more mature BS than in TS. Potassium hydroxide treatment increased the disruption of both TS and BS, resulting in a fragile residue, but the TS was more degraded than BS. However, even after alkali treatment and microbial degradation, epidermis, sclerenchyma ring, and disrupted vascular cells were recognizable structures in the residue. The TS was 19% more digestible than the mature BS both before and after alkali treatment. The treated TS and BS's digestibility was increased by 33% over the untreated material.
Effects of N and Seeding Rate on Grass‐Legume Mixtures on Coal Mine Spoils: Biomass Production, Soil Factors, and N2 Fixation1
Authors: Yamanaka K. , Holl F. B. 
Published: July 2010

AbstractThe importance of N2‐fixing legume species in colonization and the development of stable ecosystems on reclaimed mineral spoils has long been recognized. In greenhouse experiments on coal mine spoils some of the factors affecting early plant performance have been evaluated. Applied N was rapidly taken up by plants or leached from the spoil material, such that N would be a limiting factor under similar field conditions. Total biomass production increased with increasing grass seeding rates and at high N fertility while N2 fixation was depressed at higher grass seeding rates and with high N fertility. In the same treatments, a significant (P < 0.01) grass − fertilizer interaction was reflected by an observed decrease in legume biomass. Changes in aboveground total biomass and N2 fixation were related to changes in the legume component and were largely independent of soil N. Optimum biomass production and N2‐fixing activity were obtained by a treatment combination of 17.5 kg/ha grasses, 30 kg/ha legumes, and 50 kg/ha N.
Tillage Modifications of Dry Edible Bean Root Colonization by VAM Fungi1
Authors: Mulligan M. F. , Smucker A. J. M. , Safir G. F. 
Published: July 2010

AbstractSoils compacted by excessive secondary tillage and traffic restrict the growth and function of plant root systems. The influence of soil compaction on root and the symbiotic vesicular‐arbuscular mycorrhizal (VAM) fungal associations is essentially unknown. The VAM fungal colonization of dry edible bean (Phaseolus vulgaris L.) roots was investigated on Aeric Haplaquept clay, Typic Hapludalf loam, and Typic Haplaquoll sandy loam soils. Three cultivars were subjected to secondary tillage and traffic treatments on several field experiments. The influences of soil porosity, bulk density, depth and type on the colonization of dry edible bean roots by VAM fungi were characterized 45 days after planting. Excessive secondary tillage and traffic increased the bulk densities of all soil types, decreased plant growth and root development. Colonization of dry edible bean root systems was a function of soil type and decreased with increasing secondary tillage and depth within the soil profile. Dry edible bean cultivars having vigorous root systems which penetrated below the Ap horizon of compacted soils maintained high levels of colonization by VAM fungi. Roots of the cv., Seafarer, which are susceptible to both soil compaction and root rot diseases, had the lowest amount of colonization when growing below the Ap horizon.
Self‐Burial of Wild Oat Florets1
Authors: Somody C. N. , Nalewaja J. D. , Miller S. D. 
Published: July 2010

AbstractSurvival of wild oat (Avena fatua L. and A. sterilis L.) florets is greater if the florets overwinter below the soil surface. Therefore, field experiments were conducted to determine wild oat floret selfburial (burial without tillage) as affected by environment and floret characteristics at Fargo, ND in 1978 and 1979. Soil cracking was necessary for self‐burial. Self‐burial was less on Spottswood sandy loam (fine‐loamy over sandy, mixed pachic Udic Haploborolls) than Fargo silty clay (fine, montmorillonitic, frigid Vertic Haplaquolls), which cracked more than the sandy soil. The geniculate awn was necessary for maximum wild oat floret self‐burial. Self‐burial did not require rain and was not impeded when straw was present on the soil surface. Florets of A. sterilis Accession 278, characterized by a slender awn approximately 2.5 cm long with no bend, were less effective at self‐burial and lateral movement along the soil surface than florets of Accessions 318 and 9, both characterized by a longer thick awn with a distinct bend. Avena sterilis Accession 318 had 73% self‐burial even with the primary and secondary florets connected. Awn length and thickness and floret length of 1200 wild oat accessions were variable, but 98.5% of the accessions had florets with a distinctly bent awn.
Heat Tolerance of Kentucky Bluegrass as Influenced by Pre‐ and Post‐Stress Environment1
Authors: Wehner D. J. , Minner D. D. , Dernoeden P. H. , McIntosh M. S. 
Published: July 2010

AbstractAn understanding of the natural variation in heat tolerance of Kentucky bluegrass is needed to develop predictive models for stress tolerance. The variation in heat tolerance of ‘Adelphi’ Kentucky bluegrass (Poa pratensis L.) over the growing season and the effect of recovery environment on the perceived heat tolerance of the plants was determined. Field‐grown plants (Chillum silt loam, fine‐silty, mixed, mesic Typic Hapludults) were exposed to heat stress on 11 dates over two growing seasons by immersion in a water bath for 30 min at either 42,44, or 46 °C and then placed in either a greenhouse, or one of two growth chamber environments (35/22 or 22/15 °C day/night temperature) for a 2‐week recovery period. The dry weight of the stressed plants expressed as a percentage of the controls (recovery weight) was used as a measure of heat tolerance. Heat tolerance increased from May to July and then decreased from August to October. A significant relationship existed between heat tolerance, daylength (D) and average low temperature (LT) for the sampling dates (y − 128.65*D − 5.67*D2 − 14.46*LT − 0.49*LT2 + 2.21*D*LT − 743.86, R2 = 0.95, P = 0.003). Recovery weights for plants in the greenhouse were not significantly different from recovery weights for plants in either of the other two recovery environments on 10 of the 11 sampling dates.
Dinitrogen Fixation by Soybeans in Alabama1
Authors: Thurlow D. L. , Hiltbold A. E. 
Published: July 2010

AbstractThe contribution of symbiotic N2 fixation to total N and yield of soybeans [Glycine max (L.) Merr.] ranges widely among soils and cultural conditions. Utilization of nonnodulating soybean isolines and 15N‐dilution techniques has provided estimates of fixation in indeterminate cultivars on soils of relatively high N supply. Few estimates are available, however, for determinate soybeans on low N soils of the southeastern United States. This work compared the N assimilation of ‘Lee’ soybean with that of its nonnodulating isoline (N‐N Lee) at 10 locations in Alabama over an 8‐year period. Nitrogen accumulations by higher yielding cultivars were also determined. Dinitrogen fixation was estimated as the difference in the amount of N contained in N‐N Lee and Lee or other fixing cultivar. One approach considered N in harvested beans only while another approach involved total N in aboveground plant material at physiological maturity. Results showed that Lee soybeans grown in Alabama without irrigation but with rainfall sufficient for yields exceeding 1640 kg ha−1 fixed an average 172 kg ha−1 of N, while maximum yielding cultivars fixed 217 kg ha−1 of N in aboveground plant material. The estimate for midwestern soybeans of 40% of plant total N derived from the atmosphere is too low for Alabama soybeans, where 70% or more is obtained by fixation.
Effect of Soil Temperature and Inoculum Rate on the Recovery of Three Introduced Strains of Rhizobium japonicum1
Authors: Kvien C. S. , Ham G. E. 
Published: July 2010

AbstractIn order to determine the effect of soil temperature on inoculum recovery within soybean [Glycine max (L.) Merr.] nodules, an experiment consisting of four soil temperatures (15, 20, 25, and 30 °C), four soybean lines (Hodgson, Steele, ISZ.7, and 257.428), four inoculation rates (0,3 × 107, 1.5 × 108, and 3.0 × 108 cells/pot) and replicated four times was conducted in a controlled environmental chamber. Single strain inoculants of USDA 110, 138, and 140 on peat base carrier (l08 rhizobia/gram of peat) were mixed and added to each pot at the time of planting. Plants were then grown for 6 weeks. Soil temperature affected plant and nodule growth as well as the recovery of strains of Rhizobium. Plant heights, when averaged over four soybean genotypes, were 12, 15, 45, and 55 cm for soil temperatures 15, 20, 25, and 30 °C, respectively. Plant dry weight, nodule number and nodule fresh weight increased with increasing temperature until a maximum value was reached at the 25 °C soil temperature. Recovery of introduced strains of R. japonicum 110, 138, and 140 was dependent on soil temperature and inoculum rate. Introduced strains of R. japonicum 110 and 138 showed their highest recovery rates at the 15 and 30 °C soil temperatures. At the 20 °C soil temperature recovery of strains 110 and 138 were significantly lower for the cvs. Hodgson and Steele than for the genotypes 257.428 and ISZ.7. The indigenous rhizobia were most difficult to displace at 20 °C. Strain 140 was a poor competitor throughout the entire experiment.
Effect of Slope Position on the Microclimate, Growth, and Yield of Barley1
Authors: Whitman C. E. , Hatfield J. L. , Reginato R. J. 
Published: July 2010

AbstractAnalyses of the relationship between microclimatic data, yield and growth response usually have been conducted utilizing data collected on level terrain and in small experimental plots. A field study was conducted on 290 ha of undulating topography of a Sehorn‐Balcolm complex soil (Entic Chromoxeret and Typic Xerochert) near Dunnigan, CA (38°48′N 121°58′W) during 1977‐78 to evaluate the effect of slope position and microclimate differences on the growth and yield of barley (Hordeum vulgareL. cv. Briggs). The crop was planted on 3 to 9 Dec. 1977 at 112 kg ha−1density in a 0.15‐m row spacing. Sixteen sites were selected in the field prior to planting ranging from level to 36% slope with aspects from north‐ to south‐facing slopes. At each site twice‐weekly measurements were made of plant growth, i.e., height, number of green leaves, leaf area, number of tillers, dry weight, and phenological stage, on 10 randomly selected plants. Yield and all yield components were measured on 20 1‐m2samples at each site at the end of the experiment. Microclimatic data were measured at each site. The largest variations in crop development occurred prior to jointing and after anthesis. Both drainage and irradiance had large effects on plant growth, exhibited through differences in plant height, maximum leaf area, tiller survival, green leaves per plant, tillers per plant, relative growth rate, and dry matter production. A linear relationship was found between dry weight at the end of the season and intercepted radiation with a slope of 1.28 g MJ−1. Dry matter production and yield were affected by irradiance and drainage. The date of 50% heading was inversely related to the final yield and suggested that delayed flowering was detrimental to grain production in the dryland conditions of the Central Valley.