bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response Curves of Various Turfgrasses to Application of Several Controlled‐Release Nitrogen Sources1
Authors: Volk G. M. , Horn G. C. 
Published: July 2010

AbstractResponses of turfgrasses to controlled‐release N sources, especially the newer materials have not been adequately evaluated under field conditions. This study obtained N time‐release curves as measured by clippings taken periodically after the initial response to readily available N such products contain had subsided. Materials were suface‐applied once, or at widely spaced intervals, to six different turfgrasses. Three to 4‐day growth clippings were taken periodically to assess current N uptake rate against that from a standard treatment consisting of a continuous, uniform, weekly application of NH4NO3. Sulfur‐coated urea (SCU of 9% dissolution rate) gave the most desirable type of response for summer fertilization, followed by isobutylidene diurea (IBDU), activated sewage sludge (Milorganite), and ureaform (UF). The latter two were quite similar in latent response characteristics. IBDU was superior to the other materials for winter usage, because it did not show the cold weather depression of latent N release exhibited by Milorganite, SCU, and UF. It is postulated that an initial slow N‐release rate of IBDU, and the favorable cold weather response curve is the result of the differential effect of temperature on nitritication and, therefore, on acidity and dissolution rate of IBDU in the microenvironment of the pellet. Responses to IBDU of various pellet‐size ranges corroborates that surface dissolution is the N‐release mechanism, and that varying the pellet size is a valuable method for controlling the N‐release rate.
Turfgrass Wear Tolerance Mechanisms: I. Wear Tolerance of Seven Turfgrass Species and Quantitative Methods for Determining Turfgrass Wear Injury1
Authors: Shearman R. C. , Beard J. B. 
Published: July 2010

AbstractThe relative wear tolerance of seven cool‐season turfgrass species was determined for both sled (foot‐like) and wheel (vehicular) wear injury. Four methods of evaluating wear tolerance differentials were used: 1) visual rating of wear injury, 2) percent total cell wall content (TCW), 3) percent verdure, and 4) percent chlorophyll/unit area remaining after wear treatment. Manhattan perennial ryegrass (Lolium perenne L.) was most tolerant to wheel wear; Kentucky 31 tall fescue (Festuca arundinacea Schreb.) and Merion Kentucky bluegrass (Poa pratensis L.) ranked second; Pennlawn red fescue (F. rubra L.) and Italian ryegrass (L. multiflorum Lam.) were intermediate; while Cascade chewings fescue (F. rubra var. commutata Gaud.) and rough bluegrass (P. trivialis L.) ranked lowest. The relative ranking for sled wear was slightly different from that for the wheel. Visual ratings indicated that Manhattan, Kentucky 31, and Merion were equally tolerant to sled wear. However, Merion was the most wear tolerant to sled injury, according to ratings based on the percent verdure remaining after treatment. Manhattan and Kentucky 31 ranked second and third, respectively; while, Cascade chewings fescue and rough bluegrass were almost destroyed by the crushing, tearing action of the sled.Wear tolerance differentiation among species for the four methods tested was in high agreement. However, percent verdure remaining was the preferred method for quantitatively evaluating wear tolerance differentials. It eliminated arbitrary decisions that were inherent in the visual rating system, and involved fewer procedural steps than either the percent TCW or percent chlorophyll content determinations.
Nitrogen‐Sulfur Relations in Soft White Winter Wheat. I. Yield Response to Fertilizer and Residual Sulfur1
Authors: Ramig R. E. , Rasmussen P. E. , Allmaras R. R. , Smith C. M. 
Published: July 2010

AbstractSulfur deficiency occurs in some soils in the northwestern United States. Wheat (Triticum aestivum L.) responses to S applications are highly variable and apparently related to N fertilization. Our objective was clarification of this variability by measuring yield responses of wheat (grain and straw) to S applied with a range of N (deficient to excess) for the first wheat crop and monitoring residual S effects on yields of three subsequent wheat crops.A factorial combination of four rates of S (0, 17, 34, and 68 kg S/ha) as gypsum and four rates of N (0, 45, 90, and 180 kg N/ha) as ammonium nitrate was applied to the first wheat crop at seeding. Wheat was grown in rotation with peas (Pisum sativum L.), wherein the peas were not fertilized and subsequent wheat crops received only a blanket application of N at the optimum rate (56 kg N/ha).First wheat crops after fertilization did not respond to S when N was deficient or optimum. Sulfur applied with excess N increased straw but not grain yield. Significant N to S interactions were noted. Residual S increased straw yield in all wheat crops and grain yield in 1 of 4 second, 3 of 3 third, and 2 of 2 fourth‐wheat crops. All S application rates gave similar yield increases in the second wheat crop. Residual S from 17 kg S/ha gave responses below maximum in the third wheat crop and residual S from 34 kg S/ha was marginally adequate in the fourth wheat crop.Wheat response to residual S was influenced by N rates applied to the first wheat crop. High N and S fertilization resulted in early drought and curtailed yields. Gradual release of residual S from recent organic matter apparently provided S at a rate adequate for efficient water use and maximum yield.
Evaluation of Laboratory Methods for Determining Quality of Corn and Sorghum Silages: II. Chemical Methods for Predicting In Vivo Digestibility1
Authors: Marten G. C. , Goodrich R. D. , Schmid A. R. , Meiske J. C. , Jordan R. M. , Linn J. G. 
Published: July 2010

AbstractNumerous chemical procedures have been suggested for predicting feeding quality of perennial forages but none have been adequately tested for their ability to predict quality of silages of corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench, S. sudanense (Piper) Stapf, and their hybrid]. The objective of this phase of a comprehensive study was to determine the value of 20 of these chemical procedures for predicting in vivo digestibility of corn and sorghum silages.We determined in vivo digestible dry matter (DDM) of 51 silages (17 in each of 3 years) in conventional sheep feeding trials.Acid detergent fiber (ADF) was the best chemical predictor of in vivo DDM for both corn and sorghum silages. ADF concentration accounted for 80% of the variation in digestibility of sorghum silages and 61% of the variation in digestibility of corn silages. More than half of the variation in digestibility of these silages was also accounted for by calculated cellulose and by crude fiber (CF) concentration. Permanganate lignin accounted for 74% of the variation in digestibility of sorghum silages but only 23% of the variation in corn silage digestibility. Inclusion of crude protein concentration did not improve the digestibility prediction potential of ADF, CF, or the other chemical methods.The Van Soest summative equation, acid detergent lignin (ADL), ADL/ADF, dry matter solubility in 1 NH2SO4, and solubility in acid pepsin all failed to provide satisfactory estimates of corn or sorghum silage digestibility.None of the chemical methods equaled our modified Tilley and Terry in vitro DDM as a predictor of in vivo DDM of corn or sorghum silages. However, ADF accounted for only 4% less of the variation in digestibility of sorghum silages and 9% less of the variation in digestibility of corn silages than did in vitro DDM. The relatively low cost of ADF analysis makes it a useful procedure for testing silages that are intended as feeds for ruminants.We present simple regression equations for prediction of in vivo DDM of corn and sorghum silages from their concentrations of several chemical entities.
Indexes of Sulfur Deficiency in Alfalfa. II. Plant Analyses1
Authors: Westermann D. T. 
Published: July 2010

AbstractBoth soil and plant analysis are diagnostic tools used in identifying S deficiencies; however, soil tests evaluating soil S availability levels are not always successful and deficiencies must then be identified by plant analysis. In addition, the diagnostic tool must be correlated to crop responses under various growing conditions to be useful. Identification of S deficiency on alfalfa (Medicago sativa L.) in southern Idaho permitted the collection of correlation data for both S soil tests and plant analyses. The S soil test correlation data has been previously reported (Agron. J. 66:578–581, 1974). This paper reports the relationships found between the plant S indexes of total S, SO4‐S and total (N/S) ratio, and the response of alfalfa to S fertilization. All data were evaluated by correlation analyses.The total S and SO4‐S concentrations and the total (N/S) ratio were all found to be satisfactory indexes of S deficiency in whole alfalfa at early bloom. Maximum forage yields were obtained when the tops contained between 0.15 to 0.20% S or 0.05% SO4‐S. Total S and SO4‐S were related and readily interchangeable as indexes. Increases in total S above 0.14% S resulted from the accumulation of SO4‐S. Yield responses to S fertilization were obtained when the total (N/S) ratio was greater than 17 to 18. Total N and total S were not related, but protein N increased linearly as protein S increased. The protein (N/S) ratios were not constant and increased from 17 to 23 as the degree of S deficiency increased.
Stomatal Behavior of Wheat Cultivars in Relation to Their Transpiration, Photosynthesis, and Yield1
Authors: Shimshi D. , Ephrat J. 
Published: July 2010

AbstractWheat cultivars were found to differ widely in their stomatal aperture under conditions of adequate moisture supply. A field study was carried out to determine whether these differences were related to short‐term transpiration (measured by a hygrosensor cuvette over periods of less then 1 min), short‐term photosynthesis (measured by the uptake of 14CO2 over a period of 20 sec), long‐term water consumption (determined from soil moisture data over periods of several weeks), and grain yield. Rank correlations between the various attributes were determined. Ten wheat cultivars were used in 1 year, 11 cultivars in the other year. Leaf permeability (measured by means of a viscous‐flow porometer) was well correlated to stomatal aperture (measured by means of silicone rubber impressions), and was therefore used as an index of stomatal aperture. Leaf permeability was significantly rank‐correlated with short‐term transpiration (r = 0.97 to 0.98), with short‐term photosynthesis (r = 0.86 to 0.84) and with grain yield (r = 0.70 to 0.74), but not with water consumption (r = 0.01 to 0.22), which was nearly the same for all cultivars. Yields of the cultivars ranged between 4,000 and 5,200 kg ha−1 in the first year, and between 4,250 and 6,150 kg ha−1 in the second year. It is suggested that wheat cultivars having wider somatal aperture produce higher yields without consuming more water, and that the porometer method may be employed in wheat breeding programs.
Long‐term Nitrogen Rates and Sources Influence Sugarbeet Yield and Quality1
Authors: Halvorson A. D. , Hartman G. P. 
Published: July 2010

AbstractApplication of excessive N to sugarbeet‐producing soils has caused a deterioration in sugarbeet (Beta vulgaris L.) quality resulting in decreased sucrose production. The objective of the present work was to determine what rates of N fertilizer would produce maximum sucrose without sacrificing quality. Influences of repeated applications of sugarbeet yield and various quality factors, in a longtime organic and inorganic N sources and rates since 1953 on irrigated sugarbeet‐small grain rotation, were investigated in 1972 at Sidney, Montana. Nitrogen treatments included barnyard manure (22.4 and 67.2 metric tons/ha), green manure (alfalfa and biennial sweetclover), ammonium nitrate (O, 56, 112, 168, 224, 336, 448, and 560 kg N/ha) and a combination organic and inorganic N treatment (67.2 metric tons barnyard manure plus 112 kg inorganic N/ha).Highest sucrose production (7.9 metric tons/ha), obtained with 22.4 metric tons/ha of manure, was accompanied by root yields of 47.5 metric tons/ha, with sucrose percentage of 16.6 and petiole NO3‐N concentration (about 6 weeks before harvest) of 663 ppm. For the inorganic N treatments, highest sucrose yield (7.6 metric tons/ha) was obtained with 112 kg/ha of N, with similar results obtained for the green manure treatments. Inorganic N rates greater than 112 kg/ha caused progressive decreases in sucrose yields, sucrose percentage, and dry matter root weights. Dry matter root/top ratios of two or greater coincide with maximum sucrose yields. Increasing the rate of organic or inorganic N applied decreased dry matter root/top ratios.Results of this study indicate that either barnyard or green manure can be used successfully as a source of N for quality sugarbeet production.
Nitrogen Effects on Crested Wheatgrass as Related to Forage Quality Indices of Grass Tetany1
Authors: Mayland H. F. , Grunes D. L. , Waggoner H. , Florence A. , Hewes D. A. , Joo P. K. 
Published: July 2010

AbstractNitrogen fertilization of forage is often accompanied by an increased incidence of grass tetany. A field experiment was established on two calcareous soils to evaluate the effects of N fertilizer on forage quality indices of grass tetany. Nitrogen, as NH4NO3, was applied at 0 and 150 kg N/ha in each of 2 years to separate plots. The crested wheatgrass [Agropyron desertorum (Fisch.) Schult] forage was harvested at regular intervals in the Spring tetany period during 1968 through 1971. Forage was analyzed for inorganic cations, N, total water‐soluble carbohydrates (TWSC), aconitic acid, higher fatty acids (HFA), dry matter, and ash alkalinity — a measure of total organic acids.Nitrogen fertilizer increased the concentrations (equiv. basis) of forage Mg and Ca more than the increase in K, thus slightly reducing the K/(Ca + Mg) values when compared to the unfertilized forage. However, forage K/(Ca + Mg) values were usually less than the 2.2 value above which the incidence of grass tetany increases rapidly. The potential dietary benefits from the higher Mg concentrations may have been offset by increased concentrations of K, N, HFA, N/TWSC, and aconitic acid, since these parameters are associated with decreased Mg availability to cattle.Low values for hypothetical blood serum Mg (calculated from forage N, Mg, and K concentrations) coincided with the occurrence of grass tetany in the field. The calculated serum Mg values were lower in the N‐fertilized forage than in the control.The aforementioned effects of N fertilization should not deter the judicious use of N for optimizing forage yields on semiarid ranges, since other research workers have found that grass tetany losses can be reduced by supplementing animals with Mg.
Prediction of Nitrogen Status of Sugarbeets by Soil Analysis1
Authors: Giles J. F. , Reuss J. O. , Ludwick A. E. 
Published: July 2010

AbstractThe production of high sugar yielding crops of sugarbeets (Beta vulgaris L.) is highly dependent on available N. Excessive N fertilization is frequently cited as a cause of low sugar containing beets, which has become a problem in todays beet industry. The objective of this study was to evaluate the usefulness of N soil tests to predict N fertilizer requirements for this crop.Fertilizer trials consisting of 4 N rates (0, 70, 140, and 210 kg N/ha) were conducted on 33 farm sites in central and eastern Colorado over a 2‐year period. Soils ranged in texture from sandy loam to clay loam and were generally calcareous at or near the surface having a pH > 7.0. The results show that soil NO3‐N levels measured before planting are useful in estimating the N requirements of the sugarbeet crop. Soil NO3‐N levels were closely correlated with crop yield and sucrose percentage. Regression analysis indicated that yield and recoverable sugar responses to fertilizer N are unlikely when soil NO3‐N levels (0 to 60 cm) are > 130 kg/ha. A linear decrease in sucrose percent resulted from increasing N levels. Soil NO3‐N had a greater effect on sucrose percentage and plant N content than did an equal amount of fertilizer N during both years. An assessment of the NO3‐N content of the soil to at least the 60‐cm depth was found to be an adequate index of soil mineral N availability.
Ratoon Cropping of Sorghum: I. Origin, Time of Appearance, and Fate of Tillers1
Authors: Escalada Rodolfo G. , Plucknett Donald L. 
Published: July 2010

AbstractThis study was conducted to understand the basic growth patterns and tillering behavior of sorghum (Sorghum bicolor (L.) Moench) from plant crop to succeeding ratoon crops in order to attain maximum production with minimum tillage using a particular practice such as ratooning. Under this system, it is possible to have several harvests from a single planting. Time and location of tiller appearance and survival of tillers are important factors in determining the number and vigor of productive tillers which, in turn, influence the growth, development, yields, and longevity of ratoon crops. Successive tiller production and death of tillers affect the perenniality of the crop.Three cultivars of sorghum ‘Mini‐milo Br 54’, NK 222A, and NK 300 were grown under three plant populations [P1 = 5, P2 = 10, and P3 = 20 plants per 3.7 liter (5‐gal.) pot] and were observed for tillering behavior in relation to the place of origin, time of appearance, duration of early tillers, and to grain and stover yields. Tillers that sprouted early (first and second tillers) originated from basal nodes of the plant. Later tillers (third, fourth, and so on) developed from the nodes adjacent to elongated internodes. Not all tillers which developed, however, reached maturity. Usually the first two tillers died.Tillers developed earlier in lower populations (P1 and P2) than in the higher population, P3. Cultivar NK 222A produced only two tillers per plant in each population. Compared with tillers of ratoon crops, it took a longer time for the two early tillers of the plant crop to die. Tillers that developed on the upper parts of the stubble were more susceptible to breakage.More tillers were produced during the plant crop, and the number declined in each succeeding ratoon crop. High plant populations resulted in development of few reproductive tiller, less uniformity in plant height, and a delay in tiller formation. In spite of this condition, increased plant population resulted in increased grain and stover yields. More plants per unit area compensated for the production of fewer tillers. Mini‐milo Br 54 produced the highest number of tillers per plant, followed by NK 222A, and then NK 300 in the first population.Understanding the basic growth patterns and tillering behavior of a particular sorghum variety, therefore, facilitates management of ratoon crops for maximum production.
Yield and Quality of a Sorghum ✕ Sudangrass Hybrid as Affected by Mixtures of a Grain Sorghum1
Authors: Horner J. R. , Croy L. I. , Denman C. E. 
Published: July 2010

AbstractMany state seed laws have very close tolerences with regard to genetic purity of sorghum [Sorghum bicolor (L.) Moench] ✕ sudangrass [Sorghum sudanense (Piper) Stapf] hybrids. Genetic purity of sorghum ✕ sudangrass hybrid seed is difficult to maintain because of contamination by outcrossing with foreign pollen or selfing of supposedly cytoplasmic male sterile plants which have some fertility. The effect of reduced genetic purity on yield and quality, as evidenced by in vitro dry matter digestibility and protein content, was estimated by mixing various percentages of seed of a sorghum ✕ sudangrass hybrid and a grain sorghum. Treatments consisted of a hybrid (A Redlan ✕ Greenleaf); the grain sorghum (B Redlan); and 90:10, 80:20, 70:30, 60:40, and 50:50 mixtures of a hybrid and grain sorghum. The study was conducted 3 years in a randomized, complete block design.Dry matter forage yields were not significantly affected by the various mixtures of a grain sorghum and hybrid. The grain sorghum yielded significantly lower than all other treatments. Dry matter digestibility of all treatments was above 59%, indicating high quality forage, and was not significantly different among treatments within years. There was no difference in protein content between the hybrid and all mixtures within years. Protein content of the grain sorghum was higher than the other treatments and approached significance. The grain sorghum made slower regrowth and was more immature than all other treatments at each harvest date. The results of this experiment indicate that a small reduction of genetic purity in hybrids would not decrease total forage yields or lower quality of forage, as evidenced by in vitro dry matter digestibility or protein percentages.
Amino Acid and Elemental Composition of Sunflower and Pumpkin Seeds1
Authors: Robinson R. G. 
Published: July 2010

AbstractThe research was undertaken because knowledge of the amino acid and elemental composition of sunflower (Helianthus annuus L.) and pumpkin (Cucurbita pepo L) seeds is meager and incomplete. Yet, in contrast to their present use as snacks, both species are widely‐adapted crops of potential use for staple human food. Seeds of the two species were evaluated as foods, to meet major protein and mineral requirements of adult humans. Sunflower cultivars used for birdfeed, human food, and oil were analyzed to discover differences and similarities. Nitrogen percentage to protein percentage conversion factors for various products are commonly based on the N percentages of their major isolated proteins. A single factor (6.25 or 5.30) is used for sunflowers and pumpkin. Using amino acid analyses from this research, a different N to protein conversion factor was calculated for each species.Sunflower seeds for analyses were harvested from cultivar trial plots grown at four locations for 1 to 4 years. Soils were Typic Hapludoll, Aeric Calciaquolls, and Typic Eutroboralf. ‘Lady Godiva’ pumpkin seeds were harvested for 2 years at Rosemount, Minn. Concentrations of oil were determined by the Soxhlet method, of N by the Kjeldahl method, of other elements by an emission spectrograph, and of amino acids by an automatic amino acid analyzer.Analyses for 18 amino acids and for 15 elements indicate that < 400 g of either sunflower or pumpkin seeds will supply the total daily protein and mineral requirements, other than Ca and Na, for adult humans. Good nutritive value and simple storage and processing requirements make sunflower seeds a potentially important human food. Sunflower seeds of nonoilseed cultivars were significantly higher than ‘Peredovik’ oilseed cultivar in total protein and in concentrations of 16 amino acids and nine elements. Sunflower pericarps had lower concentrations of oil, protein, ash, and 8 of 15 elements than those of the seeds. Factors to convert N percentage to protein percentage were calculated by dividing 100 by the percentage N in the total amino acids of the seed. The factors for all seed‐lots within each species were nearly identical (6.10 for sunflower and 5.65 for pumpkin). These are better estimates of N conversion values than the single factor presently used for both species.