bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulfur Fertilization Effects on the Constancy of the Protein N:S Ratio in Low and High Sulfur Accumulating Crops1
Authors: Gaines T. P. , Phatak S. C. 
Published: July 2010

AbstractAn accurate quantitative separation of protein from non‐protein in plant tissue is necessary for answering the question whether the protein N:S ratio, (N/S)p, is constant or is affected by plant part, age, or nutrient supply. Previous studies in our laboratory have shown that plant tissue extracted with hot 0.5% acetic acid to remove non‐protein N (NPN) prior to Kjeldahl analysis give results very close to those for true protein N (PN). The objective of this study was to determine the effect increased S rates during growth had on the constancy of the (N/S)p ratios of low and high S‐accumulating crops.Corn (Zea mays L.), soybean (Glycine max L. Merr.), and cowpea (Vigna Unguiculata L. Walp.) were selected as low S‐accumulating plants and tomato (Lycopersicon esculentum L. Mill.), cotton (Gossypium hirsutum L.), and okra (Abelmoschus esculentum L. Moench.) as high S‐accumulating crops. Plants were grown hydroponically with S levels of 0, 16, and 32 ppm and constant N levels (126 ppm N) and harvested when the 0 ppm S‐treated plants showed moderate S deficiency. Samples were analyzed for protein S (PS), non‐protein S (NPS), total S (TS), PN, NPN, and total N (TN).Increased S levels increased the dry weights of corn, soybean, cowpea, and tomato tops and soybean roots. Protein S had a greater demand for limited S than NPS. Non‐protein S began to accumulate only after PS demands were satisfied. Low S‐accumulating crops had higher and more constant (N/S)p ratios than high S‐accumulating crops. High S‐accumulating crops showed a slight but consistent decrease in (N/S)p ratios due to proportionately higher PS levels when S supply was increased. When S supply was sufficient, the (N/S)p ratios were 15 to 16 for corn, 20 for soybeans, 15 for cowpeas, 12 for tomatoes, and 8 to 9 for cotton and okra. The accuracy of the (N/S)p ratio is contingent on the method of fractionating protein from the non‐protein fraction.
Seasonal Variation of Rhizobium meliloti in Alfalfa Hay and Cultivated Fields in North Carolina1
Authors: Mahler R. L. , Wollum A. G. 
Published: July 2010

AbstractLittle is known about native populations of rhizobia in soils of the southeastern United States. This study was undertaken to observe the influence of season on fluctuations of native soil Rhizobium meliloti populations in cultivated and alfalfa (Medicago sativa L.) hay field environments throughout North Carolina.Soil samples were collected from the Ap horizons of fields in three physiographic regions of North Carolina every 30 days for a 14‐month period. Rhizobium meliloti were enumerated using a most‐probable‐number (MPN) technique and alfalfa as the host for plant infectivity tests. Serial dilution and pour plate techniques were used to determine bacteria.The cultivated fields did not have a recent history of alfalfa. Conversely, alfalfa hay fields had been in alfalfa continuously for at least 2 years. Larger soil populations of R. meliloti existed in alfalfa hay fields than in cultivated fields. Seasonal variation was evident in North Carolina alfalfa hay fields with populations averaging 1.3 ✕ 105/g soil in April and 1.2 ✕ 104/g in October. Seasonal distribution differences were not noted in cultivated fields. Rhizobium meliloti constituted from 0.01 to 1.67% of the total aerobic bacterial population in alfalfa fields and < 0.001 to 0.01% of the population in cultivated fields.
Portland Cement for Liming a Strongly Acid Soil1
Authors: Ernst F. F. , Stivers R. K. 
Published: July 2010

AbstractStudies have shown that Portland cement will neutralize soil acidity and increase crop yields on slightly acid soils. However, the cement has not been compared with lime for this purpose on strongly acid soils. A pot experiment was conducted in a controlled‐climate chamber to determine crop response to two levels (0.5 and 1.0% by weight) of commercial portland cement and lime (reagent grade calcium carbonate added to soil). Ockley clay loam (fine‐loamy, mixed, mesic Typic Hapludalf) subsoil with a pH of 4.8 was used. Corn (Zea mays L.) was grown 29 days followed by soybeans (Glycine max L. Merr.) grown for 31 days. Soil pH was raised about the same with equal rates of either lime or portland cement. Dry weight of corn plant top growth was greatest with the 0.5% cement treatment. Total uptake of N, P, K, Ca, Mg, Zn, Cu, Fe, and B by corn grown on this 0.5% cement treatment was also high. For soybeans, all cement and lime treatments produced more plant dry weight than the check treatment (no cement or lime added). Concentration and uptake of Mn in both corn and soybeans were greatest in the check treatment. Only the soybeans had Mn toxicity symptoms.
Nutrient Uptake and Supply to Tomato Plants in a Water Culture System1
Authors: Ben‐Asher J. , Gordon J. M. , Liner A. , Zarmi Y. 
Published: July 2010

AbstractIn horticulture a wide variety of soilless culture is in use. Among them is water culture. In order to provide a quantitative approach for fertilization policy, the kinetics of K+, NO3−, and O2 uptake by tomato (Solanum lycopersicum ‘Naama’) plants in a water culture has been investigated. A solution for a one‐dimensional time‐dependent model is given. Experiments were conducted in 3‐m long channels of a homogeneous nutrient solution. Predicted results agreed with the measured data. For cases in which the Michaelis‐Menten inhibition factor is much smaller than the initial ion concentration, the time dependence of the depletion curve can be approximated by a linear form, which when expressed in terms of dimensionless variables is the same for all ions. The model suggests an algorithm for a number of decisions that should be taken through the process of fertilization. Finally, when extended to the use of saline water under evaporative conditions, the model determines explicitly the worst quality irrigation water that can be used.
Radio Detector and Peg Technique for Locating Sampling Sites in the Field1
Authors: Read D. W. L. , Cameron D.R. 
Published: July 2010

AbstractIt is usually difficult to relocate specific sites in fields. Many methods have been used, including metal detectors, permanent stakes and measuring from bench mark sites. A new system has been developed which has advantages over all these methods. It consists of a peg (transponder) that can be buried below cultivation depth and an easily operated detector that can detect the peg from approximately 2 m distance and home in on the exact position. The accuracy is within 5 cm when the peg is buried at a 1‐m depth. The equipment is of sturdy construction and the pegs remain useable for many years.
A Comparative Evaluation of Three Tests for Determining Plant‐Available Manganese in Soils1
Authors: Sharpe R. R. , Parks W. L. 
Published: July 2010

AbstractAmounts of manganese extracts from soil by three well‐known methods were compared to each other and to soil levels of Ca, P, Fe, and K and soil pH. Seventy‐one soil samples, representing seven soil series, which are members of either the Ultisol or Alfisol orders, were used in the comparisons of soil extraction procedures. The average amount of soil Mn extracted by each procedure was determined for each soil series. The correlations among extractants were very high and the Mehlich‐1 procedure extracted three to four times more Mn than the DTPA procedure and five to six times more than the NH40Ac procedure. As the pH of a soil decreased, the amount of extractable Mn increased. The relationship between the Mehlich‐1 procedure and pH was less than between the other extractants and pH.Plant samples were collected in conjunction with the soil samples and soil Mn as determined by each method was correlated with plant concentrations. Correlations between plant Mn and soil Mn indicates that the Mehlich‐1 extractant may not be as reliable as the NH40Ac or DTPA extractants because the correlations between Mehlich‐1 extractable Mn and Mn in cotton and corn plants were poor.
Moisture Deficits and Grain Sorghum Performance: Effect of Genotype and Limited Irrigation Strategy1
Authors: Garrity Dennis P. , Watts Darrell G. , Sullivan Charles Y. , Gilley James R. 
Published: July 2010

AbstractThe response of three selected sorghum [Sorghum bicolor (L.) Moench] hybrids to a wide range of timings and intensities of drought stress were studied in field experiments on a sandy soil (Typic Ustipsament) in west central Nebraska. A modified line source sprinkler irrigation gradient was used to create the treatments.Yield reductions (41 to 45%) resulting from the gradual intensification of stress over the entire season were large but very similar among genotypes. Greater genotypic differences occurred in treatments in which irrigation was limited during only one or two growth periodsThe genotypic rankings for yield were quite consistent over the range of treatments, with the hybrid of highest yield potential (RS 626) usually continuing to demonstrate superior yields under drought stress. The hybrid (NB 505) of lowest yield potential did not show a comparatively greater drought resistance (i.e., a lower percentage yield reduction) under severe stress.Grain yield tended to be linearly related to seasonal net water application and to variations in the percent of the soil water deficit that was replaced each week, regardless of variety or the growth stage(s) at which irrigation was limited.The timing of irrigation was quite critical with large differences in the response of each hybrid to the same quantity of seasonal water applied under varying strategies. The data for both years and all genotypes indicated that an optimal strategy for allocating water under limited irrigation would be to apply a constant fraction of the crop's maximum water usage each week, allowing stress to gradually and progressively intensify throughout the season. Yield reductions will occur but these will tend to be lower per unit of irrigation water saved than when irrigation is limited only in individual growth periods.
Forage Yield, Seed Weight, and Inflorescence Characteristics of Isogenic Pearl Millet Hybrids with Four Different Cytoplasms1
Authors: Hanna Wayne W. 
Published: July 2010

AbstractValuable traits that are present in the cytoplasm can be used to improve plants. Using such traits has been demonstrated with cytoplasmic‐genic male sterility. The purpose of this research was to determine if there were cytoplasmic effects due to the A1, A2, B1, or B2 cytoplasm in near‐isogenic pearl millet, Pennisetum americanum (L.) Leeke, hybrids on dry matter yield, inflorescence characteristics, days to flower, and seed set and weight. Replicated field tests were grown in 1975, 1977, 1978, and 1981 on a Fuquay soil (loamy, siliceous, thermic arenic Plinthic Paleudults). Differences in dry matter yields were non‐significant (P = 0.05). Plants with the B2 cytoplasm had significantly shorter inflorescences. No differences were observed in inflorescence width. The difference in days to flower was significant with 1 days being the maximum difference between cytoplasms which probably is of little economic significance. There were significant differences between cytoplasms for selfed seed set but not for openpollinated seed set indicating that differences in seed set were due to fertility restoration. ‘Tift 239D2B2’ was a better fertility restorer for the A, cytoplasm than ‘Tift 23D2B2’ was for the A2 cytoplasm. Seed weight differences were related to seed set with plants setting fewer seeds producing heavier seeds. No significant maternal or A and B line effects were detected in this study.
Fractionation of Forage Grass Carbohydrates Using Liquid (Water) Chromatography1
Authors: Fales S. L. , Holt D. A. , Lechtenberg V. L. , Johnson K. , Ladisch M. R. , Anderson A. 
Published: July 2010

AbstractBecause of simplicity and minimum cost, one of the most promising approaches to carbohydrate analysis uses high performance liquid chromatography (HPLC) to separate neutral sugars on cation exchange resins, with only water as the mobile phase. The purpose of this research was to evaluate this technique for the analysis of carbohydrates in forage grasses.Stem bases from field‐grown tall fescue (Festuca arundinacea Schreb.) were sequentially extracted with 95% ethanol and de‐ionized water to remove free sugars and fructosans, respectively. The fructosan extract was hydrolized with 1.0 N H2SO4. Tall fescue leaf tissue was treated with neutral detergent and the resulting neutral detergent fiber (NDF) was treated with 1.0 N H2SO4 to remove and hydrolize hemicellulose. The neutralized extracts were chromatographed on a column containing Aminex Ql5‐S, Ca++, with water as mobile phase.Neutral sugars identified in 95% ethanol extracts were glucose, sucrose, and fructose. Fructosan hydrolizates contained glucose and fructose, and hemicellulose hydrolizates of leaf tissue contained xylose, arabinose, and a small amount of glucose. Baseline separation of all sugars was achieved within 39 min and injections could be made every 20 min. Although retention times were longer than those obtained using other methods, ease of operation, minimum cost, and column stability over time make this technique suitable for use with automatic sampling devices and data acquisition systems.
Forage Plot Clipping Wagon to Improve Harvesting Efficiency1
Authors: Caddel J. L. , Batchelder D. G. , McLaughlin G. L. 
Published: July 2010

AbstractRemoving forage clippings from borders and alleys of cultivar evaluation and management trials represents a major expense for forage research. A wagon, to be attached to a self‐propelled flail‐type forage harvester, was constructed to reduce the cost of harvesting plots. Clippings from alleys and borders are blown into the wagon and dumped into a pickup truck or larger wagon for removal from the area. This piece of equipment has contributed to a substantial savings in labor involved in harvesting forage plots.
Intraspecific Variation in the External and Internal Copper Requirements of Subterranean Clover1
Authors: Reuter D. J. , Loneragan J. F. , Robson A. D. , Tranthim‐Fryer D. J. 
Published: July 2010

AbstractFor diagnosis of Cu deficiency in pastures based on subterranean clover (Trifolium subterraneum L.) and for the management of the Cu nutrition of animals grazing them, it is important to know the extent of intraspecific variation of subterranean clover in internal Cu requirement, response to soil Cu supply, and ability to accumulate Cu in herbage.In the present study, three cultivars (‘Clare,’ ‘Trikkala’, and ‘Seaton Park’) representative of three major subgroups of subterranean clover were grown for 70 days (D70) on a Cu deficient soil supplied with varying rates of Cu fertilizer up to 800 µg Cu/3 kg soil (Cu800). The relationships among Cu supply, yield response, amount of Cu in herbage, and Cu concentrations in young leaves were examined.At optimum Cu supply, all three cultivars produced similar amounts of dry matter. At Cu0 on D70, Clare, Trikkala, and Seaton Park produced 9, 26, and 30%, respectively of their maximum shoot dry matter which they reached at Cu800, Cu400, and Cu200, respectively.At all equivalent levels of Cu supply, the shoots of Clare had lower Cu contents than did those of Trikkala and Seaton Park: the effect was relatively most marked at Cu0 where shoots of Clare had only one‐half and one‐third of the Cu in the shoots of Trikkala and Seaton Park. It is suggested that Clare had a poorer ability to obtain Cu from the soil in this experiment than did Trikkala and Seaton Park and this accounted for its poorer growth at low Cu and its greater response to higher levels of applied Cu.By contrast with their differing external Cu requirements, the three cultivars appeared to have very similar internal Cu requirements for maximum dry matter production. Estimates of critical concentrations of Cu in the youngest open leaf at just adequate Cu supply gave values of about 3 µg Cu/g dry matter for all cultivars.
Field Study of the Fate of Fall‐Applied 15N‐Labelled Fertilizers in Three Alberta Soils1
Authors: Malhi S. S. , Nyborg M. 
Published: July 2010

AbstractFall application of N fertilizers is often less effective than spring application in increasing yields of cereal crops in portions of the Prairie Provinces of Canada. This paper reports on five field experiments (and involving three soils) using 15N‐labelled fertilizers to determine the amounts of mineral N lost over the winter by denitrification, leaching, and immobilization. The labelled N fertilizers were applied at 112 kg N ha−1in October in 1974–1975 experiments and in December in 1975–1976 experiments. The plots were sampled to a depth of 120 or 150 cm in late May. In the two 1974–1975 experiments (Malmo sicl soil), KNO3 and urea were mixed into the 0 to 12 cm depth of soil, and (NH4)2SO4 was placed in a band. Recovery of the labelled fertilizer N found in the total soil N was lowest for KNO3 (60 %), next for urea (71 %), the highest for (NH4)2SO4 (84%). The addition of 50 mm of water to the soil, which reduced the soil moisture tension of the 0 to 15 cm depth to less than 33 KPa on fall freezing, decreased the recoveries of KNO3 and urea in the total soil N to 26 and 54%, respectively. There was no leaching below the 60 cm depth. For the three fertilizers, from a 10th to a third of applied N was immobilized. In the three 1975–1976 experiments, the three soil types were, Demay 1, Malmo sicl, and Falun 1. The fertilizers were placed in bands 5 cm deep into the frozen soil. There was little loss of the labelled N from the total soil N for (NH4)2SO4, but very large losses for KNO3. As in the experiments from 1974–1975, the experiments for 1975–1976 showed no 15N below 60 cm depth for KNO3, and below 30 cm depth for (NH4)2SO4. The percent of applied N which became immobilized range from 7 to 49%, with the highest value for (NH4)3SO4 on a Malmo sicl soil. In summary, substantial losses of late fall‐applied l5N‐labelled fertilizers occurred over the winter, with field experiments that were started in 2 different years. These losses from the soil averaged 67% for KNO3 (five experiments, range of 40 to 87%), 38% for urea (two experiments, range of 29 to 46%), and 10% for (NH4)2SO4 (five experiments, range of 1 to 18%). The overwinter loss of fall‐ or winterapplied N was not through leaching, but through denitrification which apparently took place in early spring. The amount of immobilization of the labelled fertilizers varied from experiment to experiment.
Alfalfa Osmotic Potential: A Comparison of the Water‐release Curve and Frozen‐tissue Methods1
Authors: Brown P. W. , Tanner C. B. 
Published: July 2010

AbstractOsmoadjustment is an important response to water deficits of some plants. The purpose of our study was to examine the suitability of two methods of osmotic potential (Ψπ) measurement for researching osmotic adjustment of alfalfa (Medicago sativa L. ‘Saranac‘). Water release curves for the top fully‐developed alfalfa leaves from different stems were generated from a series of paired leaf mass and leaf water potential (Ψ) measurements using a pressure chamber. Using leaves from the same alfalfa stem, the Ψπ determined from the water release curves were compared with psychrometer measurements on sap expressed from frozen and thawed tissue of the next three to four lower leaves on each stem. Osmotic potential of sap expressed from the thawed tissue was 2.1 to 8.9 bars lower than Ψπ obtained from water‐release curves. The Ψπ of the top leaf used for water‐release curves typically was 1 to 2 bars higher than that of the next three to four lower leaves used in the frozen‐tissue method; however, this between‐leaf Ψπ difference could account for less than 50 % of the difference between methods. The remaining difference is believed to result from production of solutes in thawed tissue by enzymatic hydrolysis of nonstructural carbohydrates because rapid changes in Ψπ were observed in the tissue following thawing. This appears to invalidate routine Ψπ measurements on alfalfa using the frozen tissue method. Unless the Ψπ changes observed in frozen and thawed tissue can be circumvented, we recommend all Ψπ be determined from alfalfa leaf water release curves.
Influence of Herbicides on Yield and Botanical Composition of Alfalfa Hay1
Authors: Dutt T. E. , Harvey R. G. , Fawcett R. S. 
Published: July 2010

AbstractPerennial weeds frequently infest alfalfa (Medicago sativa L.) swards. While herbicides have been identified that control these weeds, alfalfa tolerance to these herbicides and effects on dry matter yields and botanical and chemical composition are largely unknown. Thus, field studies were conducted on a Dodgeville silt loam (Typic Argiudoll fine‐silty over clayey, mixed, mesic) soil near Mt. Horeb, Wis. in 1974 and on a Plano silt loam (Typic Argiudoll fine‐silty, mixed, mesic) soil near Verona, Wis. in 1976 to compare the effects of seven herbicides applied alone, or in combination with pronamide [N (1,1‐dimethylpropynyl)‐3,5‐dichlorobenzamide] to alfalfa swards which had been colonized with quackgrass [Agropyron repens (L.) Beauv.] and several perennial broadleaf weed species. Forage yield and botanical composition were determined. Secbumeton (2‐sec‐butylamino‐4‐ethylamino‐6‐methoxy‐s‐triazine), cyanazine {2‐[[4‐chloro‐6‐(ethylamino) ‐s‐triazin‐2‐yl] amino]‐2‐methylpropionitrile], metribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐as‐triazin‐5(4H)‐one], and S‐6044 [N‐benzyl‐N‐isopropyltrimethylacetamide / 2‐cyclopropanecar‐boxamide‐5‐(2‐chloro‐1,1‐dimethylethyl)‐1,3,4‐thiadiazole], applied to actively growing swards in the fall reduced alfalfa yields in at least one cutting or at one location during the following season. Pronamide increased the total alfalfa yield. In 1974, common dandelion (Taraxacum officinale Weber.) and hoary alyssum [Berteroa incana (L.) DC.] populations increased when quackgrass was suppressed with pronamide. None of the herbicides reduced common dandelion and hoary alyssum populations. Yellow rocket (Barbarea vulgaris R. Br.) populations were reduced by secbumeton at 1.8 kg/ha, terbacil (3‐tert‐butyl‐5‐chloro‐6‐methyluracil) at 0.9 kg/ha, metribuzin at 2.3 kg/ha, and bentazon [3‐isopropyl‐1H‐2,1,3‐benzothiadiazin‐4‐(3H)‐one 2,2‐dioxide] at 1.7 kg/ha. None of the treatments increased total forage yields.