bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo Performance of Bloom and Bloomless Sorghum Forage1
Authors: Cummins D. G. , Sudweeks E. M. 
Published: July 2010

AbstractIn vitro digestibilities of green leaf segments of bloomless sorghum [Sorghum bicolor, (L.) Moench] are higher than those from bloom (white, powdery‐appearing wax on leaf and stem surfaces) sorghum, but it is not known if these differences will affect performance of animals fed bloom and bloomless sorghum forages. The objective of this study was to determine through in vivo trials if the bloomless characteristic of sorghum forage affected digestibility and animal performance. Two near isogenic lines of ‘Redbine 60’ sorghum differing primarily in the bloom and bloomless characterstic were grown under uniform conditions for 3 years at Experiment, Ga. At the dough stage of grain maturity, forage was harvested and ensiled in 1973 and 1974 and stored briefly at —13 C in 1975. Rumen volatile fatty acid production in steers fed silage was higher from the bloomless sorghum than the bloom sorghum, which indicates greater digestion of the bloomless sorghum. Steers fed bloom and bloomless sorghum silage did not differ in average daily gains at the end of a 6‐week period, but the latter gains were significantly higher at the end of the second week. Green forage digestibility by sheep was higher on the bloomless compared to the bloom type for dry matter, crude protein, crude fat, and crude fiber. These studies suggest that quality of sorghum forage may be improved by developing hybrids with the bloomless characteristic.
Application of Statistical Design Theory to Crop Estimation with Special Reference to Legumes and Mixtures of Cultivars1
Authors: Federer W. T. , Hedayat A. , Lowe C. C. , Raghavarao D. 
Published: July 2010

AbstractForage crop researchers often need to determine the proportion of legume, weed, and grass contents of hay. This is often done by sampling and hand‐separation or by visual estimates of the relative proportions. The sampling and hand‐separation method is costly and time‐consuming, and both procedures are subject to errors of separation and vagaries of sampling. As alternatives, procedures employing mixtures of cultivars and spring balance weighing design and balanced, incomplete block design theory are presented. Errors and biases associated with sampling and hand‐separation and visual‐estimate procedures are eliminated. Also, a procedure is presented to measure the general competitive effects of cultivars and to determine how much more (or less) effective a cultivar is in a blend than when grown alone.
Soybean Nodulation as Affected by Wheel Traffic1
Authors: Voorhees W. B. , Carlson V. A. , Senst C. G. 
Published: July 2010

AbstractA significant quantity of nitrogen is made potentially available for plant uptake through symbiotic fixation in the nodules of legume roots. Several aspects of soil environment that can affect the formation and development of these nodules can be altered by soil being compacted by farm vehicular wheel traffic. Field experiments were conducted on a Nicollet silty clay loam (Aquic Hapludoll) to define the extent to which wheel traffic can affect nodulation on roots of soybeans [Glycine max (L.) Merr. ‘Corsoy’]. Wheel traffic of tractors and implements during normal field operations for soybean culture in the northern Corn Belt was controlled to produce soybean rows with no wheel traffic on either side, and wheel traffic on only one or both sides. Measurements of nodule number and mass from undisturbed soil monoliths showed that rows with wheel traffic on both sides had from 20 to 30% fewer nodules and about 36% less total nodule mass than rows with wheel traffic on only one side. Wheel traffic increased the specific nodule mass in both the tracked interrow area and the adjacent nontracked row area. Nontracked interrows had a greater percentage of nodule mass in the upper 30 cm than did wheel tracked interrows. Thus, by controlling the wheel traffic of normal farming operations, the quantity and distribution of nodules can be altered in ways which have implications for increasing nitrogen fixation.
Colorimetric Determinations of Exchangeable Ammonium, Urea, Nitrate, and Nitrite in a Single Soil Extract1,2
Authors: Onken Arthur , Sunderman Herbert D. 
Published: July 2010

AbstractInterest in N transformations in soils has increased greatly in recent years, particularly with increased use of urea‐containing fertilizers. However, only one procedure for determination of exchangeable ammonium, nitrate, nitrite, and urea in a single soil extract has been proposed and it requires the use of both distillation and colorimetric equipment. It would be useful to have a set of colorimetric procedures for the determination of these N forms in a single extract. Previous research indicated sodium sulfate, as an extractant, would be least likely to produce unwanted interferences in these procedures. Thus, research was initiated to determine (i) if Na2SO4, could be used as an extractant for exchangeable NH4+, NO3‐, NO2‐ and urea and (ii) necessary modifications to make desirable colorimetric procedures usable in a Na2SO4 extraction system.A procedure for the colorimetric determinations of exchangeable NH4+, urea, NO3‐, and NO2‐ in soil using a single soil extract is described. The soil sample is extracted with Na2SO4 containing phenylmercuric acetate for 30 min and then leached with four 25 ml portions of extractant and made to volume. The extract is analyzed for NH4+ by a modified Nessler reagent, urea by either diacetyl monoxime and thiosemicarbazide or p‐dimethyl aminobenzaldehyde depending on concentration, NO3‐ by chromotropic acid and NO2‐ by 4‐aminobenzenesulfonic acid and 1‐aminonaphthalene hydrochloride. The procedure gave quantitative recovery of NH4+‐N, urea‐N, NO3‐ N, and NO2‐‐N added simultaneously to five different soils.
Fitting Plants Nutritionally to Soils. II. Cotton1
Authors: Brown J. C. , Jones W. E. 
Published: July 2010

AbstractFifteen cotton varieties (Gossypium hirsutum L.), representing germplasm recommended for different areas of the United States, were subjected to Fe, Zn, and Cu stresses and Al and Mn toxicities to determine their nutrient requirements. They were grown on the seven different soils described in part I of this study for soybeans. All cotton varieties grown on Quinlan soil (Fe stress) developed deficiency symptoms that were similar to symptoms produced in cotton grown on Shano and Taunton soils (Zn stress). On Quinlan and Taunton soils, the plants responded to both Fe and Zn. Iron added to Taunton soil decreased the uptake of Fe and increased the uptake of Zn by the plants. Lime added to Richland soil induced a Zn deficiency that increased Fe uptake by the plants. When Zn was added to this soil, yields increased and Fe uptake decreased in the plants. All 15 cotton varieties grew poorly on acid Bladen soil (Al toxic), and yields were doubled by liming and yield of C‐7105, 73‐319 doubled again by adding Cu. Best yields, with no toxicity symptoms, were obtained on Richland soil (Mn toxic). Cotton and soybean had different nutrient requirements. For example, cotton was Cu and Zn inefficient and Mn tolerant, whereas soybeans were Cu and Zn efficient and Mn intolerant in most varieties tested.
Use of a Weighted‐disk Measure as an Aid in Sampling the Herbage Yield on Tall Fescue Pastures Grazed by Cattle1
Authors: Vartha E. W. , Matches A. G. 
Published: July 2010

AbstractMeasurement of herbage‐on‐offer in grazing trials is useful for monitoring seasonal changes in herbage availability, for defining the grazing pressure, and may serve as the basis for adjusting rates of stocking. Generally, a large number of samples must be harvested per pasture in order to obtain reliable estimates of herbage yield. However, the amount of labor and time needed to harvest and process samples may limit the number of samples which may feasibly be taken per pasture. In this experiment, our objective was to maintain precision with a low number of harvested samples by first determining the mean bulk‐height of the pasture with a weighted disk measure and then harvesting sites of the mean bulk‐height (± 1/2 cm). Every 5 days, 25 measurements of bulk‐height were made at random locations per paddock with a weighted disk meter having a 0.2 m2 disk weighing 2.5 kg and dropped from a height of 80 cm. Mean bulk‐height was calculated and 10 quadrats (0.25 m2) harvested per paddock from locations having the mean bulk‐height. The data obtained in pastures of tall fescue (Festuca arundinacea Schreb.) were influenced by period of sampling (spring, summer, and fall) and grazing treatments (1‐, 2‐, or 4‐paddock rotation). The coefficients of variation for fresh herbage yield of 10 0.25 m2 quadrats at the mean bulk‐height within grazing treatments, were about 5%. For combined data from the grazing treatments, correlation coefficients (r) between herbage mean bulk‐height and dry herbage yield as determined from the harvested quadrats were 0.714, 0.822, and 0.709 for spring, summer, and fall growth. However, the correlation coefficients varied both in spring and fall according to different grazing treatments. In spring grazing, r's were 0.399, 0.918, and 0.670; and in the fall grazing, r's were 0.300, 0.848, and 0.580 for the 1‐, 2‐, and 4‐paddock systems, respectively. Correlation coefficients varied less in summer with r's of 0.904, 0.914, and 0.772 for the 1‐, 2‐, and 4‐paddock systems. Trampling of forage and accumulation of mature residue in some grazing treatments appeared responsible for the low correlation between mean bulk‐height and harvested herbage yield. Use of the disk‐meter appears to have greatest usefulness in pastures where there is not excessive accumulation of plant residues due to undergrazing or trampling. Under such conditions, sites located by mean bulk‐height allow the experiments to quickly obtain reliable herbage yield estimates from fewer sampling sites.
Cotton Seedling Metabolism as Influenced by Germination Temperature, Cultivar, and Seed Physical Properties1
Authors: Krieg D. R. , Carroll J. D. 
Published: July 2010

AbstractGrowth rates of cotton (Gossypium hirsutum L.) seedlings are greatly reduced at minimal germination temperatures. Increased variability in the seedling growth rates are more apparent at low temperatures, and delayed emergence or seedling death result in more erratic and nonuniform stands. The pupose of this study was to determine if a specific area of metabolism might be controlling seedling growth at less than optimum germination temperatures. Cottonseed of four cultivars were separated into density and weight groups and germinated in the dark under two controlled temperature regimes (20 to 30 C and 15 to 25 C). Seedlings were harvested 3, 6, 9, and 12 days after planting and separated into cotyledons and seedling axes. Chemical analyses of each part were used to describe the utilization of cotyledonary reserves as related to seedling growth rates. At minimal temperatures, radicle growth rates were initially related to lipid use but by 6 days became more closely associated with non‐lipid use. Specific cultivar differences existed with respect to seedling growth and non‐lipid use, with N utilization being most affected. Mineral nutrient transfer varied according to cultivar and temperature with no apparent correlation with seedling growth. The results indicate that at optimum temperatures, seed maturity (density) and quantity of available substrate (weight) determine seedling growth rates irrespective of cultivar. Minimal temperatures resulted in a general decrease in metabolic activity. Genetic differences as to the extent of the reduction were quite apparent, however, and thus controlled seedling metabolism and growth rates. Seedling growth reductions due to temperature were related to problems associated with non‐lipid metabolism, especially the protein fraction. The specific cause of this metabolic abnormality was not identified.
Competitive Effects of Turfgrass on the Growth of Ornamental Shrubs1
Authors: Nielsen A. P. , Wakefield R. C. 
Published: July 2010

AbstractPlanting of a shrub or tree into a mature grass sod may result in poor establishment of the woody species. This experiment was designed to measure the field response of four species of ornamental shrubs to turfgrass competition. The shrubs used were forsythia (Forsythia intermedia zabel), azalea (Rhododendron X), Japanese barberry (Berberis thunbergi DC.) and taxus (Taxus media Rehd.). Turfgrass treatments included plots maintained at high or low rates of N fertilizer and receiving, in some cases, supplemental irrigation to maintain high soil moisture. Treatments with no turfgrass were either bark mulch or bare ground. Turfgrass plots were mowed regularly to a height of 7.6 cm. The effects of these variables were measured by evaluating several aspects of growth and development of each shrub species.Turfgrass established 2 years previously on an Enfield silt loam (Typic Distrochrepts) significantly suppressed the growth and development of all four species of shrubs as compared to plots where turfgrass was not a competitor. Differences in soil moisture or temperature are not believed to have been responsible for the differences observed in these findings. Plant competition for N was suggested by both the color ratings and analyses of leaf tissue of the shrubs during the first year of shrub establishment. Additional fertilizer, applied as a topdressing, was more beneficial to the turfgrass than to the shrubs, and did not significantly increase their growth in most cases. The addition of K and P did not increase growth in any of the treatments and apparently was not a factor in the competition between the grass and the shrubs.
Relative Evaluation of Water Stress Indicators for Soybeans1
Authors: Sivakumar M. V. K. , Shaw R. H. 
Published: July 2010

AbstractThe understanding of the relationships between changes in crop foliage to variations in the amount and status of soil water is at best incomplete. Since plant growth is directly affected by deficits of water in plants, and only indirectly by soil‐water deficits and atmospheric stresses, the importance of using plant measurements, rather than soil indices, is warranted and has led to this investigation. Field studies were conducted during 1976 on Ida silt loam [fine, silty, mixed (calcareous) mesic family of Typic Udorthents] at the Western Iowa Experimental Farm, Castana, Iowa, to evaluate three plant measurements (vis., stomatal conductance, leaf‐water potential, and leaf area) as water stress indicators for soybeans [Glycine max (L.) Merr.]. Stomatal conductance and leaf water potential were measured at 2‐hour intervals from 0600 to 2000. Stomatal resistance was measured with a diffusion porometer, with stomatal conductance taken as the reciprocal of leaf resistance. Leaf‐water potential was measured using a pressure chamber. Leaf area was measured with an electronic leaf‐area integrator.Daily means of stomatal conductance and leaf‐water potential measured several times during the growing season were closely related to changes in soil‐water potential. “Rate of leaf‐area expansion” which is defined as the change in average leaf area (leaf area/number of leaves) per plant over a period of time, also showed a close correspondence with soil‐water potential.Relative growth rates of soybeans showed a negative correlation with stomatal conductance, leaf‐water potential, and rate of leaf.area expansion. The three plant measurements should prove useful in explaining water‐deficit effects quantitatively under field conditions.
Root‐Sink Descriptions of Water Supply to Dryland Wheat1
Authors: Rickman R. W. , Allmaras R. R. , Ramig R. E. 
Published: July 2010

AbstractSoil water content changes were supplemented with calculations of water flow between soil layers to provide an improved description of water uptake by dryland wheat (Triticum aestivum L.). This root‐sink description of water use, recognizing both measured change in water content and vertical redistribution (upward or downward) of water by flow between soil layers, is needed for a better understanding of plant‐soil and atmospheric factors involved in water stress when the wheat plant must rely on stored soil water for long periods. Water content changes were estimated from neutron meter measurements. Soil water flux was estimated from field measurements of both hydraulic conductivity and hydraulic head gradients; unsaturated conductivity beyond the range of field measurement was calculated with the pore interaction model of Marshall matched to field measured values at 250 mb. Seasonal water‐uptake patterns, determined by the root‐sink description, differed from those shown by only water content measurements. Peak water‐use rates did not coincide with maximum leaf area index, but coincided with the period from heading to completed head extension. Water flux in the profile was important for supplying water during grain filling and was critical in this layered soil, which restricted rooting to depths less than 150 cm.
Production, Digestibility, and Perloline Content of Fescue Stockpiled and Harvested at Different Seasons1
Authors: Fribourg Henry A. , Loveland Richard W. 
Published: July 2010

AbstractThe management of tall fescue (Festuca arundinacea Schreb.) to utilize spring, summer, or early fall production in summer, fall, or early winter, could help harmonize livestock pasture requirements with available forage supply. Such utilization must be accomplished without appreciable loss of quality. The effects of several stockpiling schemes (spring, summer, late summer, fall, and spring + fall) on tall fescue dry matter yield, in vitro digestible dry matter (IVDDM), and perloline and total N contents were investigated over a 3‐year period. Nitrogen at the rate of 50 kg/ha was applied in March and September each year. Yield or composition of stockpiled material was not different when fescue was removed gradually or as a single hay cut, and the year × treatment interaction was not significant. Stockpiling did not affect production at other times of the year. Stockpiling made 3,700, 1,300, 650 and 1,000 kg/ha more dry matter available than continuous clipping in summer, early fall, late fall, and winter from spring, early summer, late summer, and fall stockpiling, respectively. Total N content of stockpiled herbage sometimes was lower than the National Research Council's requirement for a lactating beef cow and, occasionally, for a dry beef cow. Herbage stockpiled in spring, in early summer, and in late summer, had 45, 49, and 59% IVDDM, respectively. Fall‐stockpiled herbage had IVDDM in excess of 60%. The perloline content of stockpiled fescue was low (<0.16 mg/g), but summer regrowth after stockpiling removal had a relatively large alkaloid content (0.46 mg/g). Although the largest yields of stockpiled forage resulted from spring accumulations, the quality was low. Lowest quality was measured in forage accumulated in summer. Stockpiling in late summer or early fall produced sufficient material to extend the grazing season several weeks into winter.
Comparison of Soil Properties under Continuous Corn Grain and Silage Cropping Systems1
Authors: Barnhart Steven L. , Shrader W. D. , Webb J. R. 
Published: July 2010

AbstractContinuous corn (Zea mays) harvested for grain only, has been subjected to much study. There is little information available, however, as to the effect on such properties as soil pH, organic matter, available P, and exchangeable K when the entire plant is harvested. We compared these soil properties on plots of continuous corn grain and corn silage as part of a rotation‐fertility experiment established in 1957 on a Typic Hapludol soil. Subplot treatments were four levels of applied N—O, 45, 90, and 135 kg/ha. We applied 17 kg/ha of P each year to all plots during the first 4 years of the study and 26 kg/ha for the remaining 15 years. Until 1974, plots received only nominal quantities of K (5 kg/ha) as starter fertilizer. After 1974, four rates of K were applied—52, 112, 168, and O kg/ha. Soil N and C declined over time under both cropping systems. The original level of soil organic matter was 4.5%, and after continuous removal of only the grain from plots, the soil organic matter declined to 4.1%. Organic matter declined to 3.7% on plots from which all top growth was removed. Exchangeable K levels declined rapidly during the first few years of corn production and then stabilized with corn silage plots stabilizing at 71 ppm and corn grain plots at 100 ppm. Application of 26 kg/ha of P each year resulted in a rise in soil P. Soil acidity and lime requirements were directly related to the rate of N fertilization.
Characterization and Use of Food‐Processing Effluent for Forage and Beef Production1
Authors: Jung G. A. , Pearson G. A. , Fowler R. E. , Mitchell D. M. , Kocher R. E. , Quigley E. H. 
Published: July 2010

AbstractSpray‐irrigating grass swards with food‐processing effluent on the Delmarva Peninsula creates the problem of grass accumulation. We hypothesized that spray‐irrigated grass would support a relatively high stocking rate of grazing cattle, and that the effluent would be a source of fertilizer nutrients and digestible energy for livestock. Four mixed orchardgrass (Dactylis glomerata L.) and tall fescue (Festuca arundinacea Schreb.) paddocks, each 0.202 ha, were rotationally grazed at monthly intervals summer and autumn for 2 years with steers or heifers, averaging about 300 kg. The cattle were fed ground corn (Zea mays L.) at 1% body weight/day. Small amounts of commercial fertilizer were needed periodically to stimulate plant growth. Enough aftermath grass was produced to support 7.4 head/ha in summer and autumn without loss of stand. Forage quality (crude protein, energy, and mineral content) was good throughout the grazing season, but better in autumn than in summer. Energy levels in autumn approached that of concentrates. With the exception of Ca content prior to application of gypsum, mineral element composition of grass in effluent‐irrigated pastures was much superior with regard to animal nutrition than that of untreated controls as well as grass grown elsewhere in the Northeast. Steers gained an average of 1.02 kg/day and totaled 1,075 kg/ha; heifers gained 0.65 kg/day and totaled 673 kg/ha in summer and autumn. Weight gains for a 55‐day period in autumn were 71% greater than those for a comparable period in summer. It was concluded that this highly productive ecosystem should be extensively used for animal production.