bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Susceptibilities of Weeping Lovegrass Strains to an Iron‐related Chlorosis on Calcareous Soils1
Authors: Foy C. D. , Voigt P. W. , Schwartz J. W. 
Published: July 2010

AbstractObservations of weeping lovegrass (Eragrostis curvula (Schrad.) Nees) strains growing on a calcareous soil at Woodward, Okla., indicated differing degrees of susceptibility to a chlorosis tentatively attributed to Fe deficiency. To test this hypothesis thoroughly, we grew 41 strains in greenhouse pots containing a mixture of calcareous Millville and Quinlan soils, both of which were known to produce Fe‐deficiency chlorosis in several crops. The final pH of the mixture was 7.8. Weeping lovegrass strains differed widely in susceptibility to chlorosis and in top growth on the calcareous soil mixture. Chlorosis‐susceptible strains had higher Mn concentration and lower Fe:Mn ratios than did the chlorosis‐resistant strains. Some chlorosis‐ susceptible strains seemed to have unfavorable Fe:Cu and Fe:Zn ratios. Differential chlorosis was not directly related to concentrations of Fe, P, Zn or Cu in plant tops. Chlorosis susceptibility seems to be related to inhibited Fe metabolism, rather than to reduced Fe uptake by plants. Several experimental strains of weeping lovegrass were far more resistant to Fe deficiency chlorosis than current cultivars used. Results suggest that superior cultivars of this species can be bred for adaptation to calcareous soils in which Fe‐deficiency chlorosis is a problem.
Influenced of N Nutrition on Total N, Nitrate, and Carbohydrate Levels in Soybeans1
Authors: Brevedan R. E. , Egli D. B. , Leggett J. E. 
Published: July 2010

AbstractA better understanding of the effects of varying the N supply to the soybean (Glycine max (L.) Merrill) be obtained by studying, after treatment, the resultant changes in N and carbohydrate levels in the various plant parts. Greenhouse and field experiments were conducted to determine the effect of varying the N supply to the plant during flowering and pod‐filling on the dry weight, total N, NO3‐, and the total available carbohydrates. The greenhouse experiment was conducted in a gravel culture hydroponics system with 5 meq NO3‐/liter m the nutrient solution. Some plants were shifted to 12.5 and 18.0 meq NO3‐/liter at initial bloom and maintained at these levels until maturity, while others were exposed to the high NO3‐ levels only until the end of bloom. Treatments in the field consisted of 168 kg N/ha as NH4NO3 applied at initial bloom, at the end of bloom, or at both times (total of 336 kg N/ha). Increasing the N supply to the plant during the period from initial bloom increased the dry weight of the vegetative plant parts at the end of bloom and at mid‐podfill. The effect was much greater in the greenhouse than in the field. Increasing the N supply to the plant also increased the concentration of N and NO3‐ in the vegetative tissue at the end of bloom; differences in N and NO3‐ were also apparent at midpodfill although the magnitude was not so great. The concentration of total available carbohydrates in the vegetative tissue decreased when the N supply to the plant increased. Treatment effects were similar in the greenhouse (non‐nodulated) and in the field (nodulated) experiment. A previous paper reported that yield was increased by increasing the N supply to the plant during flowering and pod set, primarily as a result of an increase in seed number. The increase in yield was associated with increased tissue levels of N and NO3‐ and decreased levels of total available carbohydrates. The data demonstrate the importance of high tissue levels of N during the period of flowering and podset.
Grass Tetany Potential of Tall Fescue as Affected by Soil O21
Authors: Elkins Charles B. , Haaland Ronald L. , Hoveland Carl S. , Griffey Wallace A. 
Published: July 2010

AbstractGrass tetany, a metabolic disorder in cattle on pasture, has been related to low Mg and high K levels in tall rescue (Festuca arundinacea Schreb.) and other forages. These mineral imbalances in forages and most cases of tetany usually occur in late winter and early spring when soil O2 is low because of frequent precipitation and low evaporation rates.In a greenhouse experiment, gas mixtures were used to study the effect of soil O2 levels on Mg and K in forage of four tall rescue entries. Magnesium content of these entries was 0.25% or less at 2% soil O2 but ranged from 0.35 to 0.44% at 21% soil O2. Entries differed in Mg content at 21% but not at 2% soil O2. Potassium content ranged from 2.1 to 2.7% at 2% soil O2 and from 2.9 to 3.7% at 21% soil O2. Root length was greatly reduced by low soil O2 levels and was the only root characteristic we studied related to Mg and K uptake.A replicated field experiment was used to study the effect of soil drainage on forage Mg content of ‘Kentucky 31’ tall rescue. Forage from poorly drained areas had Mg contents of 0.18 to 0.25%, whereas nearby well‐drained areas produced forage with 0.27 to 0.40% Mg.Our results showed that low soil O2 levels and, therefore, poor soil drainage may be important factors in production of tetanogenic tall fescue forage. Draining wet areas, removing animals from poorly drained pastures, and maintaining legumes on these problem areas should be helpful practices for preventing tetany.
A Procedure for Determining Numbers of Experimental and Sampling Units1
Authors: Geng S. , Hills F. J. 
Published: July 2010

AbstractResearchers often sample experimental units to measure certain characteristics, for example, percent protein in grain or percent sucrose in plant roots. Thus, in planning such experiments, one of the first questions encountered is how many samples and replications should be used.A procedure is suggested for using the non‐central F distribution to determine the number of replications and samples needed per experimental unit. The method requires the specification of the treatment effects to be detected, the probability of type I and type II errors, and an estimate of population variance. Sugar beet (Beta vulgaris L.) trials, employing sampling for sucrose content of roots, are used to illustrate the procedure in completely randomized, randomized complete blocks, latin square, and split‐plot designs. It is shown that fewer samples and/or replications are required when orthogonal comparisons can be defined.
Growth and Nutrient Uptake of Soybean Roots Under Field Conditions1
Authors: Barber Stanley A. 
Published: July 2010

AbstractAlthough soybean (Glycine max L. Merr.) root growth in soil has been measured, the nutrient flux characteristics of the roots during the growth of the plant in the field have not. Soybean root amount and distribution were measured using approximately biweekly samplings during the growth of ‘Williams’ soybeans on Chalmers silty clay loam soil (Typic Argiaquoll) near Lafayette, Ind., in 1973, 1974, and 1975. Root length and fresh weight were measured with depth and distance from the row. Shoot samples taken at each sampling were analyzed for P and K. Shoot growth rate averaged 135 kg ha−1 day−1 between plant ages of 50 and 100 days. Shoot concentration of P decreased until 60 days then increased as beans began to form. Shoot concentration of K decreased during the sampling period. Root length increased until 70 to 80 days, remained constant to 100 days, and then decreased. Maximum root length averaged 24 cm per cm2 of soil surface. Average proportion of the roots in the 0 to 15 cm layer increased with plant age after 36 to 49 days and reached a maximum of 59% at 113 to 120 days. Soybean root density was approximately one‐fifth that observed at the same location for corn (Zea mays L.). Influx of P and K into soybean roots was less than with corn during early growth but more than corn later in the season. This result indicates that soybeans may not respond to fertilizer banded near the seed at planting but would require higher P and K fertility in the whole rooting volume of soil than corn after 50 days in order to sustain the required nutrient influx into the roots.
Yields, Nutrient Removal, and Nutrient Concentrations of Double‐Cropped Corn and Small Grain Silage1
Authors: Murdock L. W. , Wells K. L. 
Published: July 2010

AbstractDouble‐cropping corn (Zea mays L.) and small grain silage has become an important practice but there is virtually no research information upon which to base fertility or management decisions. Consequently a double‐cropping corn and small grain silage experiment was conducted at two locations in Kentucky. The study was initiated to determine production levels from doublecropped silage, the most compatible small grain species for double‐cropped silage, and the rate and method of fertilizer application needed for high production. Field experiments were established on Huntington (fine‐silty, mixed mesic fluventic Hapludoll) and Pope (coarse‐loamy, mixed, mesic fluventic Dystrochrept) soils. Three fertility levels were tested with 392‐128‐280, 280‐89‐232, or 168‐54‐140 kg/ha of N‐P‐K being applied each year. Single and split applications of K were studied. Barley (Hordeum vulgare L.) and oats (Avena sativa L.) were compared as small grain species. Double‐cropped silage produced 26% more dry matter than single cropped silage. Since most of the total silage yield was due to corn, the harvesting management favored this crop so that its yield potential would not be reduced. As a result all small grain species were harvested on the same date and large differences in stage of maturity existed. The small grain species or its stage of maturity at harvest were found to affect the yield of the succeeding corn crop. Corn grown after barley, harvested in soft dough, averaged 25% more yield than that grown after oats, harvested at heading. Fertility rates above 280‐89‐232 kg/ha of N‐P‐K (250‐180‐250 lb/A of N‐P205‐K2O) did not significantly increase the yield. The average nutrient removal at the foregoing rate of fertility was 241‐54‐260 kg/ha of N‐P‐K. The small grain accounted for 47% of the total K removed. Split applications of K increased the corn silage yield at the low application rate (140 kg/ha/yr). At one of the two locations the corn yields were 33% higher when one‐half of the total annual K was added to each crop as opposed to adding all of the K at the time of small grain planting. This study indicates that double‐cropped corn and small grain for silage can result in substantially higher dry matter production per unit land area than single‐cropped corn. Large amounts of minerals are removed, however, particularly K, by the small grain component of the double‐cropping system.
Leaf Elongation and Turgor Pressure in Field‐grown Soybean1
Authors: Wenkert W. , Lemon E. R. , Sinclair T. R. 
Published: July 2010

AbstractCell and leaf elongation have been reported to be highly sensitive to plant water deficit and may represent the primary mechanism of stress and yield reduction. This study was designed to determine if leaf expansion is restricted by the routine daytime water deficit experienced by field plants in moist soil. Leaf elongation in soybean [Glycine max (L.) Merrill ‘Rampage’] was monitored during several 2 to 4‐day periods in the field in conjunction with pressure bomb measurement of water and osmotic and turgor potential. Short‐term (minutes) leaf‐elongation rate was highly responsive to step changes in water deficit but gradually recovered over periods of about an hour. Length that was lost during the transient rate reduction tended to be made up by high rates following improved water status. Mean elongation rates were not limited by normal daytime water deficit (turgor pressure as low as 2 bars), except late in the season when pod‐filling occurred at nodes adjacent to the growing leaves. Elongation rate was always sensitive to temperature. We conclude that within the range of moderate, daytime water deficits we encountered, soybean leaves may adapt to the extent that turgor pressure does not limit growth.
Yield Response of Corn to Irrigation on Sandy Soils1
Authors: Follett R. F. , Benz L. C. , Doering E. J. , Reichman G. A. 
Published: July 2010

AbstractIrrigation is being developed on large areas of coarse and moderately coarse‐textured soils in North Dakota. Extensive areas of similar soils, including those in adjacent States, are near areas planned for irrigation. Knowledge of crop response to water is needed to effectively use irrigation in these large areas. The objective of this study was to investigate the effects of irrigation and precipitation, and to use the Mitscherlich equation to evaluate the effect of limited water supply on crop yields and apparent water use efficiencies. Yield response of corn (Zea mays L.) to the amount of water received (irrigation and precipitation) was investigated in this 3‐year field study. The corn was grown on a Hecla loamy fine sand, a Udic Haploboral, and irrigated weekly at rates based on predicted evapotranspiration calculated using the Jensen‐Haise equation. Irrigation with more water than the amount predicted by the Jensen‐Haise equation did not significantly increase forage or grain yield for any single year, but did significantly increase average grain production over the 3‐year period. Successive, larger increments in the amount of water applied to the crop resulted in successively smaller increases in forage and grain yields. Mitscherlich equations fitted yield data for all 3‐years and predicted limiting yields of 16.48 metric tons/ha of oven‐dry forage and 10,150 kg/ha of grain at 15% moisture. For oven‐dry forage production, apparent water‐use efficiency (AWUE) was about 0.28 and 0.21 metric ton/ha‐cm of water applied (precipitation plus irrigation) between emergence and final harvest for the nonirrigated and highest irrigation rate treatments, respectively. For the corresponding treatments, the respective AWUE's for corn grain production were 323 and 167 kg/ha‐cm of water received (between 3 weeks before silking and final harvest). Yield response to irrigation treatments that considered precipitation probability at Oakes, North Dakota, were calculated. Results indicated that in 95% of the cropping seasons at least 8.9, 10.9, 12.4, or 13.4 metric ton/ha of oven‐dry forage and 6,070, 7,230, 8,060, or 8,650 kg/ha of corn grain at 15% moisture could be expected from irrigating with 20, 30, 40, or 50 cm of water, respectively. In 50% of the cropping seasons, however, only 6.3 metric ton/ha of forage and 3,770 kg/ha of grain or less could be expected with no irrigation.
Frost Heaving in Alfalfa Establishment on Soils with different Drainage Characteristics1
Authors: Russell W. E. , Olsen F. J. , Jones J. H. 
Published: July 2010

AbstractThe susceptibility of alfalfa (Medicago sativa L.) to frost heaving is a major problem in stand establishment in southern Illinois. This study was conducted at Carbondale, Illinois, to determine the effects of frost heaving on the establishment and production of alfalfa cultivars in relation to soil drainage characteristics. Four alfalfa cultivars (‘Cody’, ‘Spredor’, ‘Weevlchek’, and ‘WL‐307’) were seeded on three soil series, a deep well‐drained AIford (Typic Hapluadalf, fine‐silty mixed mesic), a moderately well‐drained Hosmer (Typic Fragiudalf, fine‐silty, mixed, mesic) with a fragipan starting at a depth of 60 to 70 cm, and a nearly level poorly‐drained Weir (Typic Ochraqualf, fine, montmorillonitic, mesic). Piezometers were installed in each soil to monitor the presence of perched water tables and their position to the soil surface. Small wooden dowels were used to assess soil movement in relation to alfalfa seedling heave. The higher amount of heaving as measured by the distance wooden dowels were raised above a reference point occurred when the night temperature was a few degrees below freezing and the day temperature was above freezing, with a perched water table near the soil surface. Poorly‐drained, Weir soil had the highest perched water table, most alfalfa seedling heave, greatest alfalfa seedling winterkill, and most dowel heave. In contrast, well‐drained Alford series had no perched water table, no appreciable seedling heave or winterkill, and least dowel heave. No significant differences in amount of frost heaving of seedlings were noted amonga alfalfa cultivars on any drainage site. Highest dry matter yields were obtained on the well‐drained Alford site; significant yield reductions occurred as soil drainage class became more poorly drained. Alfalfa stands were successfully established on the well‐drained Alford series and the moderately well‐drained Hosmer series. Soil drainage characteristics did influence alfalfa establishment and production in the climatic transitional zone of the central U. S. Poorly‐drained soils should not be considered for alfalfa production.
Growth and Development of Meadow Plants as Affected by Environmental Variables1
Authors: Gomm F. B. 
Published: July 2010

AbstractThe low production of seasonally flooded meadows is a problem in many locations throughout the world. An understanding of the effects of environmental factors on the growth and production of the meadow species will aid in developing practices to increase forage production. Controlled studies were undertaken to determine the effect of soil moisture, temperature, irradiance, and soil fertility on the phenological development and growth of slender sedge (Carex praegracilis W. Boott), beardless wildrye (Elymus triticoides Buckl.), Nevada bluegrass (Poa nevadensis Vasey ex Scribn.), and reed canarygrass (Phalaris arundinacea L.). Potted plants were grown in growth rooms under various environmental conditions: temperatures of 15 and 30 C, irradiances of 4.2 and 42.0 W/m2; soil moisture levels with amounts of moisture added approximating the volume of water that the soil would retain at 0, 0.3, and 10 bars; fertilizer‐N at rates equivalent to 0, 110, 220. and 440 kg/ha. Plant responses were evaluated by number of leaves per stem, number of stems per plant, leaf area per plant, plant height, and herbage yield at the end of three growth periods. In the controlled‐study conditions, mortality of bluegrass plants was high when grown with 4.2 W/m2. Phenological development progressed faster and plant growth‐rate increased when the irradiance received was increased to 42.0 W/m2. Canarygrass, however, continued in a vegetative stage regardless of temperature or light treatments. Increasing temperature from 15 to 30 C increased the rate of growth for plants receiving 42.0 W/m2, but the increased temperature also increased the mortality of all species receiving 4.2 W/m2. Fertilizer rates and soil‐moisture levels generally had no significant effect on plant‐growth parameters when plants, except for canarygrass, were grown at 15 C or with 4.2 W/m2. The greatest rate of growth was produced when plants were grown at 30 C with 42.0 W/m2. Under these conditions, yields tended to increase with fertilizer, and yields from canarygrass increased as fertilizer rates and soil‐moisture levels increased.
Compatibility and Phytotoxicity of Herbicide‐Fertilizer Combinations1
Authors: Martens A. R. , Burnside O. C. , Cramer G. L. 
Published: July 2010

AbstractDuring the past decade herbicides and liquid fertilizers have been combined for joint application with increasing frequency. This practice has been labeled the “weed and feed” concept. It saves time and labor, reduces soil compaction, and reduces application expenses. Thus, the effect of compatability treatments on phytoxicity of mixture of 10 herbicides with 11 fertilizers were studied in the laboratory and greenhouse. The objective was to determine the feasibility of joint application of each herbicide with each liquid fertilizer selected. Herbicides were generally compatible with suspension‐grade fertilizers and maintained their phytotoxicity for 24 hours with agitation as determined by greenhouse bioassays. Of the clear liquid fertilizers, 11‐37‐0 was the most compatible with the 10 herbicides. Atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine], chloramben [3‐amino‐2,5‐dichlorobenzoic acid], and propachlor [2‐chloro‐N‐isopropylacetanilide] were the herbicides most compatible with the liquid fertilizers. Chloramben remained dispersed for 24 hours without agitation in most of the fertilizers. In general, separation of the herbicide‐fertilizer mixtures occurred within 1 hour after initial mixing, without agitation. Agitation was essential for maintaining phytotoxicity of most herbicide‐fertilizer mixtures. COMPEX (alcohol sulfates) at 0.25% volume/weight (v/w) of spray solution and ATTAGEL 150 (attapulgite clay) at 0.75% weight/weight (w/w) of liquid fertilizer solution were the most effective compatibility treatments added to the herbicide‐fertilizer mixtures. COMPEX retarded the formation of precipitates in fluorodifen [p‐nitrophenol‐α,α,α‐trifluoro‐2‐nitro‐p‐tolyl ether] fertilizer mixtures. Use of a 2:1 water:herbicide (w/w) dilution aided in mixing wettable powder herbicides with liquid fertilizers. Addition of SURFACTANT WK (dodecyl ether of polyethylene glycol) increased compatibility of some wettable powder herbicide‐fertilizer mixtures. However, with adequate agitation nearly all herbicide‐fertilizer mixtures were compatible and herbicide phytotoxicity was maintained without the need for the addition of compatibility agents.
Seasonal Forage Nutritive Value Variation of Coastal and Coastcross‐1 Bermudagrass1
Authors: Jolliff Gary D. , Garza A. , Hertel J. M. 
Published: July 2010

AbstractChronological age is a common basis of reference used in bermudagrass research treatments and forage production management recommendations. Plant growth and development changes due to the environment could cause a confounding of research results when assuming that forage of a given chronological age has a similar nutritive value regardless of the season or year. This field study on victoria clay soil (a Typic Pellusterts) was conducted to measure the mouth‐to‐mouth variation in quality of Coastal and Coastcross‐1 varieties of bermudagrass (Cynodon dactylon, (L.) Pers.) harvested at 4, 8, 12, 16, 20, and 24 week growth intervals through the 1975 growing season, Samples were taken from March through December. Acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP), and in vitro dry matter digestibilit (IVDMD) were measured. Statistical comparisons or quality were made only within age intervals. Fifty percent of 312 month‐to‐month comparisons were significantly different. Coastcross‐1 bermudagrass was more variable than Coastal bermudagrass, because of greater declines as well as greater increases in quality due to environmental changes. The 8‐week‐old forage had the greatest variation in quality in both varieties. The most measurable variability was in crude protein content. Month‐to‐month variability of CP declined with advancing maturity in Coastal and increased in Coastcross‐1. Variation as measured by ADF and IVDMD was second and third to CP, respectively, and the grassa responded similarly. Overall variability measured by NDF was the lowest of the four methods used. Actual percentage changes in ADF, NDF, CP, and IVDMD of 8‐week‐old forage within a 30day period was as high as 9.9, 3.0, 4.6, and 12.7 percentage units, respectively, for Coastcross‐1. The impact of environmental conditions on forage quality was significant and was dependent up on the age of the grass, the specific quality component in question, and the grass variety. Therefore, care should be exercised in extrapolating research data from one season of the year to another even at the same geographical location.