bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Dicyandiamide‐Amended Fertilizers on Kentucky Bluegrass1
Authors: Mosdell D. K. , Daniel W. H. , Freeborg R. P. 
Published: July 2010

AbstractDicyandiamide (DCD), a nitrification inhibitor, is a 67% N compound of low volatility that can be incorporated into fertilizer granules. Urea, ammonium sulfate (AS), and a complete fertilizer (COMP), all amended with DCD so that 10% of the N was derived from DCD, were evaluated in field studies at West Lafayette, IN, on ‘Wabash’ Kentucky bluegrass (Poa pratensis L.) grown on Toronto silt loam (fine‐silty, mixed, mesic Udollic Ochraqualfs). Urea, AS, sulfur‐coated urea (SCU), and isobutylidene diurea (IBDU) were included for comparison. Equal treatments were applied two or four times per season to provide 196 kg N ha−1yr−1. Clipping yields in response to DCD‐amended fertilizers were similar to those of urea and AS at both N regimes. Initial response to DCD‐amended fertilizers was rapid and response to residual N shorter than that of IBDU and SCU; however, recovery of applied N in the tissue was similar between DCD fertilizers and IBDU, and SCU. Averaged over 3‐yr, recovery of N ranged from 41.1% for IBDU to 36.4% for AS at 2 ✕ 98 kg N ha−1, and 39.0% for COMP + DCD to 32.6% for AS at 4 ✕ 49 kg N ha−1, respectively. Turf quality of plots receiving IBDU was superior to all N sources. Measurements 24 days after a 15 November application in 1984 indicated DCD inhibited NO‐3 formation at the 2 ✕ 98 kg N ha−1 rate (14.6 kg DCD ha−1). Fall‐applied DCD did not influence soil NO+4 and NO‐3 concentrations at 0 to 0.20 m the next spring. The short period of effectiveness of DCD would seldom warrant its use as a nitrification inhibitor in turf.
A Model to Estimate Harvest Losses Due to Taproot Breakage in Sugarbeet1
Authors: Cole D. F. 
Published: July 2010

AbstractSugarbeet (Beta vulgaris L.) yields can be reduced due to root breakage. These losses are difficult to estimate when the taproot is broken below the soil surface during harvest. The objective of this investigation was to develop a model to estimate harvest losses in sugarbeets due to taproot breakage. Sugarbeet roots of 14 and 13 cultivars were harvested manually from six environments in 1982 and 1983, respectively. Significant differences were detected among cultivars and environments for root weight, length, circumference, and diameter. Significant correlations between root weight, length, circumference, and diameter were observed. Several regression models were developed to estimate harvest losses based on the morphological data. The best single variable model was percent loss = −3.8 + 32.3 (diameter of the taproot break/root length) with a coefficient of determination R2 = 0.92. Regression coefficients were not affected by cultivars, however, they were affected by environments. This is the first model developed to estimate harvest losses in any crop using morphological data.
Bahiagrass Response to Lime and Nitrogen under Pines1
Authors: Teare I. D. , Wright D. L. , Stanley R. L. , Kidd B. T. 
Published: July 2010

AbstractThe fertilization of slash pine trees (Pinus eliotti Engelm), a practice initiated in the sixties, stimulates bahiagrass (Paspalum notatum Flügge) production, providing under‐canopy forage for the beef cattle industry of the Southeast on sandy, acid soils. Little research has been conducted to determine the production potential of limed and N fertilized bahiagrass growing under pine. The objectives of this research were to measure bahiagrass forage production under slash pine, comparing lime (2.24 Mg ha−1) vs. no lime, four N rates (28, 56, 112, 224, kg ha−1), and to observe changes in extractable soil P, K, and pH on a Norfolk sandy loam (fine‐loamy, siliceous, thermic Typic Paleudult). During the 4yr period, application of 2.24 Mg ha−1 lime empirically decreased bahiagrass forage yield under pines when averaged across N levels. Liming at 2.24 Mg ha−1 yr−1 for 4 yr did change the soil pH from 5.0 to 6.1. Nitrogen rates did not affect bahiagrass forage production the first year, but without lime, we found a quadratic response to N rates each year thereafter. The highest yields of bahiagrass forage with lime were obtained with 56 kg ha−1 N. Economic analysis shows the greatest net return ($441 over 4 yr) for no lime at 112 kg ha−1 N and with lime ($211) at 56 kg ha−1 N.
Alkaloid and Nitrate Concentrations in Pearl Millet as Influenced by Drought Stress and Fertilization with Nitrogen and Sulfur1
Authors: Krejsa Beverly B. , Rouquette F. M. , Holt E. C. , Camp B. J. , Nelson L. R. 
Published: July 2010

AbstractPearl millet [Pennisetum americanum (L.) Leeke] forage, which had been previously reported to become unpalatable under drought stress conditions, also contained high levels of nitrate and total alkaloids. This study was conducted to determine the effect of irrigation, drought stress, and drought stress elimination, as well as fertilization with 0 and 56 kg S ha−1, and 112, 224, and 336 kg N ha−1, on alkaloid and nitrate levels in pearl millet. ‘Millex 24’ hybrid millet was grown in the field during a hot, dry summer on a Darco soil (loamy, siliceous, thermic Grossarenic Paleudult) in East Texas. Chemical analyses for nitrate and total alkaloid levels were conducted on leaf blades and stems plus sheaths of vegetative plants. Alkaloid levels increased in pearl millet after extended drought and with increasing N fertilization rate. Total alkaloid concentration was higher in leaf blades (46 mg kg−1) than in stems plus sheaths (16 mg kg−1). Nitrate levels increased with improving plant water status and with increasing N fertilization. At the lowest N fertilization rate, nitrate concentrations were similar in irrigated and nonirrigated millet. At the highest N fertilization rate, nitrate was nearly two times higher in irrigated than in nonirrigated millet due to accumulation in stem portions. Nitrate concentration was higher in stems plus sheaths (14 g kg−1) than in leaf blades (5.1 g kg−1), but nitrate levels were highly correlated (r=0.90**; n=48) among plant parts. Sulfur application had no effect on either alkaloid or nitrate levels. A significant interaction between S and N rate occurred in stem plus sheath nitrate concentration (P<0.01). Whole plant alkaloid and nitrate levels were significantly correlated under N fertilization and irrigation but were not correlated under moderate drought stress or under drought stress elimination.
Nitrogen Fertility and Irrigation Influence on Grain Sorghum Nitrogen Efficiency1
Authors: Zweifel T. R. , Maranville J. W. , Ross W. M. , Clark R. B. 
Published: July 2010

AbstractLittle of the research concerning efficient use of N by crops has examined genotypic variation for the amount of dry matter produced per unit of N absorbed by a plant. A replicated field experiment was conducted for 2 yr to determine the influence of N fertility and irrigation on the N use efficiency of selected grain sorghum [Sorghum bicolor) L.) Moench] hybrids. Thirty‐six F1 hybrids, produced from six female and six male inbreds, were grown under dryland or irrigated conditions with 0 or 112 kg ha−1 N. Samples of the aboveground dry matter were harvested after physiological maturity, separated into leaf, stalk, and grain fractions, and analyzed for reduced N. Hybrid N efficiency was evaluated by ratios of dry weight to plant N content. Significant differences were found among the hybrids and their common parent averages for efficiency ratios, dry weight, and N content. Irrigation had little effect on N utilization efficiency and produced no significant change in the relationship among hybrids for N efficiency. Hybrid N efficiency values were over 30% higher in plots without N fertilizer. Interactions among hybrids and N levels were significant for N efficiency traits and grain weight. Alternate definitions of N efficiency emphasized different characteristics, but the potential for selection of sorghum hybrids with improved efficiency of N use was evident.
Herbicide Selectivity among Grain and Weedy Amaranthus Species1
Authors: Endres C. S. , Longer D. E. 
Published: July 2010

AbstractThe cultivation and evaluation of the grain amaranths Amaranthus hypochondriacus and Amaranthus cruentus as potential field crops has been initiated by several investigators worldwide. Because of their similarity to the grain amaranths, the pigweeds (Amaranthus spp.) represent a potential weed‐control problem. To date, no research on chemical weed control in grain amaranth has been reported. Greenhouse herbicide screening studies were conducted on a Captina silt loam soil (fine‐silty, siliceous, mesic Typic Fragiudults) to evaluate herbicide selectivity for control of smooth pigweed (Amaranthus hybridus L.) and Palmer amaranth (Amaranthus palmeri S. Wats.) without injury to the grain amaranths. Of the herbicides tested, bentazon [3‐(1‐methylethyl)‐1H‐2,1,3‐benzothiadiazin‐4(3H)‐one 2,2‐dioxide], naptalam [2‐[(1‐naphthalenyl‐amino)carbonyl]benzoic acid} + dinoseb [2‐(sec butyl)‐4,6‐dinitrophenol], and metolachlor [2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐N‐(2‐methoxy‐1‐methylethyl) acetamide] exhibited a degree of selectivity towards A. cruentus or A. hypochondriacus. These findings offer encouragement for further studies on the effects of rates and time of application on herbicide selectivity for grain amaranths.
Improved Data Collection Program for a Notebook‐Size Microcomputer1
Authors: Jackson H. O. , Stone J. A. 
Published: July 2010

AbstractThe use of notebook‐size microcomputers for field and laboratory entry of data in agronomy and soils research is limited by the availability of data collection and formating programs. Data collection programs were written in BASIC for the Epson HX‐20 and PX‐8 notebook‐size microcomputers. The programs accept treatment identifiers and response variables for most experimental designs used in agronomy and soils research, and output column‐ and line‐formatted data suitable for analysis without further editing. Once the program is set up for an experimental design, numerical data may be entered in any number of sessions. Data are permanently saved in the microcomputer's internal memory between sessions, but may also be saved on an internal microcassette, transferred to another computer, or transferred to a printer via the units' RS232C ports. These data collection programs improve the efficiency and accuracy of transferring data from field and laboratory observations to analysis programs that accept formatted ASCII input.
Root Trimming Influence on Elongation, Development, and Potassium Influx of Corn Roots
Authors: Mullins G. L. , Edwards J. H. 
Published: July 2010

AbstractThe partitioning of assimilate between vegetative and reproductive plant parts of soybean [Glycine mar (L.) Merrill] during flowering and fruit set could be related to fruit and seed number, and yield. Experiments were conducted in the field (cv. Cumberland) for 2 yr to investigate the effect of alterations in plant growth on the distribution of dry matter during flowering and fruit set. Alterations in plant growth were created by reducing the insolation (63%) during flowering and fruit set by using commercial shade cloth and by low density plantings (spaced plants, approximate equidistant spacing with 0.9 m between plants). The control and shade treatments were grown in 0.76‐m rows (0.71‐m in 1984), and conventional cultural practices were used. Partitioning ratios (reproductive mass/total biomass) were calculated from four samples collected between R1 and R6. Leaves (uppermost fully expanded leaf and the leaf four nodes below it) were sampled during flowering and fruit set for carbohydrate and N analysis. Shade reduced crop growth rate (Rl‐R5), vegetative mass at R5, seed number per square meter, and yield. The spaced plants were much larger and had nearly 80% of their reproductive mass on the branches at R6 compared with 5% for the control plants. Leaf starch and soluble sugar concentrations tended to be reduced by the shade treatment and increased in the spaced plants. There were no treatment effects on leaf N concentration. The treatments had a minimal effect on the partitioning ratios, indicating that distribution of dry matter between vegetative and reproductive plant parts was relatively constant across large differences in plant size and growth rate. This suggests that the fruit and seed numbers may be more closely related to crop growth rate than to the partitioning of assimilate.
A Simple Pump for Extracting Water from Neutron Access Tubes and Mini‐Rhizotrons
Authors: Shouse Peter J. 
Published: July 2010

AbstractWater in neutron‐probe access tubes and mini‐rhizotrons impedes the acquisition of accurate data under wet field conditions. When such situations arise, water must be extracted before data can be taken. The objective was to design, construct, and use a pump that would be easy to operate, portable, and inexpensive. The pump was found to be a useful tool for extracting undesired water from access tubes and mini‐rhizotrons. Only one to three strokes of the pump were necessary to remove all but about 0.05 to 0.1 L of water from a 2.5‐m‐long neutron access tube that was completely filled with water. The pump, which is easily constructed with materials available at any hardware store, proved to be an easy‐to‐use and cost‐effective tool for field use.
Development and Testing of a Versatile Fluid Fertilizer Applicator
Authors: Haby V. A. , Davis J. V. , Smith K. L. 
Published: July 2010

AbstractAn applicator was needed for evaluation of fluid fertilizers including spray broadcasting and dribble banding clear liquids and suspensions at selected band spacings, rates, and methods of application. The number of treatment combinations and rates required a system that could be quickly purged, washed, and reset for the next treatment. A three‐point hitch, tractor‐mounted applicator was designed and constructed by the authors to dispense fluid fertilizers from pressurized containers. A regulated air supply was provided by a tractor‐powered compressor. Specific fertilizer rates were regulated by tractor speed, air pressure, changing 3‐m‐long booms that differed in orifice plate spacings and sizes, and by changing nozzle sizes on a spray boom. A second application system on the unit consisted of individual quick‐coupling nozzles that injected pressurized fluids into a flow divider. Gravity moved the fluids from the flow divider to back‐swept knives mounted behind the coulters. Additional features of the applicator included systems to sparge suspension fertilizers, solubilize and mix fluids, spray wash, and apply foliar fertilizers and pesticides.
Photographic Technique for Grass Seedling Root Systems
Authors: Newman P. R. , Moser L. E. 
Published: July 2010

AbstractIn descriptive studies of seedling root morphology a seedling root system must be clearly visible to develop clear photographs. A technique for photographing grass seedling root systems has been developed for morphological‐developmental studies. Seedlings were carefully washed from the growing media and placed in a thin tank with two glass sides filled with water and with a grid pattern on one side. The lower stem and root system were immersed in the water where the natural buoyancy of the root system in water allowed the root to spread out, which improved visibility. Photographs were taken of the illuminated seedling root system and grid pattern with a camera positioned on the shaded side of the tank. Detailed diagrams of the tank and placement of the camera, lights, and shades are presented. This technique produced high‐quality photographs of grass seedling root systems that show seedling root morphology clearly.
Subcrown Internode Length of Spring Wheat and Barley as Influenced by Light and Soil Temperature
Authors: Martin J. M. , Smith C. W. , Ferguson A. Hayden 
Published: July 2010

AbstractBiological theory and some field observations during a dry spring suggest that small grains have an adaptive advantage in an environment with dry surface soil if the crown sets near the seed, because crown roots would have a better chance of forming in moist soil. Our objective was to measure how subcrown internode length in spring wheat (Triticum aestivum L.) and spring barley (Hordeum vulgure L.) responds to soil temperature and light regimes. Eight cultivars of both wheat and barley were evaluated at each of two light intensities and four soil temperature regimes. Both wheat and barley had shorter subcrown internodes when subjected to light as opposed to shade. Decreasing soil temperatures produced shorter subcrown internodes in both species. When averaged over the light and soil temperature regimes, there was a wide range of subcrown internode lengths among the cultivars, with values ranging from 28.1 to 8.3 mm for wheat and from 34.7 to 0.2 mm for barley. Wheat cultivars responded similarly to light and soil temperature treatments, but a differential response to light and temperature was observed with barley. One barley entry initiated its crown at or near the seed across all light and soil temperature regimes. These data suggest that under semiarid conditions, plant breeders should consider subcrown internode length as a selection criterion for spring cereals.
Frost Heave of Alfalfa as Affected by Harvest Schedule
Authors: Van Keuren R. W. 
Published: July 2010

AbstractFrost heave of alfalfa (Medicago sativa L.) occurs periodically in northern areas of the United States, and frequently results in serious stand losses. Studies were conducted at Wooster, OH, to determine the effect of date of initial harvest, harvest frequency, and date of final harvest on yield and persistence of alfalfa on a Wooster silt loam (fine‐loamy, mixed, mesic Typic Fragiudalf), a frost heave susceptible soil. Late‐autumn harvests (late October) were a major factor associated with frost heave in this research. An average of 38 and 28% frost heave occurred in 1986 and 1987, respectively, compared to 5 and 7% with no late‐autumn harvests for the same years. The extent of frost heave was not related to average root weight, percent of roots branched, or percent total nonstructural carbohydrates. The two winters had high soil moisture, soil temperatures slightly below freezing, and no snow cover for relatively long periods, factors previously recognized as related to frost heave. Soil cover provided by leaving the autumn regrowth appeared to be the major effect in reducing the amount of frost heave that occurred by modifying the soil temperature. The practice of late‐autumn harvesting has become widespread in recent years. Producers with soils subject to heaving must consider the value of leaving the regrowth as protection against frost heave damage and potential loss of the alfalfa stand, against the value of the harvested forage.
Nodulation and Early Growth of Soybean Mutants with Increased Nodulation Capacity Under Acid Soil Infertility Factors
Authors: Alva A. K. , Edwards D. G. , Asher C. J. , Carroll B. J. , Gresshoff P. M. 
Published: July 2010

AbstractNitrate tolerant symbiotic (nts) mutants have exhibited a greatly increased capacity for nodulation under nonacidic conditions. To evaluate the potential for growing the mutants in acid soils, the nodulation and growth of the mutants were investigated in this study under acid soil infertility factors. The effects of pH, Ca, and Al on nodulation and early growth of ‘Bragg’ soybean [Glycine max (L.) Merr.] and two mutants (nts382 and nts1116) with increased nodulation capacity were evaluated in nutrient solution experiments. In both experiments, the mutants nodulated more quickly than Bragg under conditions conducive to nodulation. The first experiment examined effects of pH (4.0, 4.5, 5.0, and 6.0) and Ca concentration (0.05 and 1.0 mM). At pH 4.0, nodulation was completely inhibited in all lines at 0.05 mM Ca, but only in Bragg at 1.0 mM Ca. Nodule number and nodule weight per plant increased significantly with an increase in solution pH from 4.0 to 5.0, and were much greater in the mutants than in Bragg, particularly at pH 4.5,5.0, and 6.0. Shoot and root weights in Bragg and ntslll6 generally increased with an increase in solution pH. However, there was a strong reduction in shoot and root weight of nts382 at pH 5.0 and 6.0 associated with greatly increased nodule numbers. The second experiment examined the effects of the sum of activities of monomeric Al species (∑aAl mono) up to 70 iiM. The mutants nodulated much more prolifically than Bragg in solutions with ∑a Al mono 32 μM, and only failed to nodulate at 70 μM. Bragg failed to nodulate at 32 μM. Stronger inhibitory effects of lower ∑a Al mono were observed on nodule number and nodule weight than on early shoot growth. Thus, a ∑a Al mono from 0.1 to 0.4 μM reduced nodule number and weight by 10%, whereas 5 to 10 μM was required to reduce shoot weight by 10%.
Response of Ladino White Clover to Sulfur at Cool Temperatures
Authors: Hern J. L. , Peck R. L. , Staley T. E. 
Published: July 2010

AbstractEffective production of quality legumes during the cool portions of the growing season is of importance to animal production systems. However, it is unclear to what extent fertility requirements change under sub‐optimal environmental conditions. Ladino white clover (Trifolium repens L.) was grown in pots with a Lily silt loam (fine‐loamy, siliceous, mesic Typic Hapludult) soil under three temperature regimes. Environmentally controlled growth chambers were employed to approximate conditions common to the hilly terrain of Appalachia (mean air temperatures of 10.7°C, 14.7°C, and 18.2°C) Yield, tissue mineral composition, soil nutrient levels, and P‐, S‐, and N‐uptake were evaluated to determine the effects of S (0, 25, and 50 kg S ha−1 as MgSO4) on Ladino white clover at minimal and adequate P levels [75 and 450 kg P ha−1 as Ca(H2PO4)2·H20]. Shoot dry matter production for the initial 144‐d growth period and two subsequent 22‐d regrowths was significantly higher for the 450 kg P ha−1 rate at all temperatures; however, yield increase resulting from an increase in S was minimal (<10%) and inconsistent. Sulfur application increased uptake of S and N. Estimated N2‐fixation by acetylene reduction at three growth stages following the first harvest was significantly greater for the high rate of S under all temperature regimes. These studies suggest that Ladino white clover may recover faster during cool temperatures and assimilate more S and N with high applications of S.