bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fertilization Effects on Yield and N Concentration of Midland Bermudagrass1
Authors: Mathias E. L. , Bennett O. L. , Lundberg P. E. 
Published: July 2010

AbstractA high yielding summer forage grass capable of with standing high temperatures and low moisture is needed in the northeastern U. S. ‘Midland’ bermudagrass( Cynodon dactylon (L.) Pers.) would meet these requirements, but production and management methods for the northeast need to be investigated.Studies were conducted over 3 years at two locations in West Virginia to determine the effects of N and K rates on yields and N recovery of ‘Midland’ bermudagrass. Treatments consisted of factorial combinations of zero, 112, 224, and 448 kg of N and K/ha. Herbage was harvested two or three times at both locations each year, depending on the growing season. Herbage yield and N concentration of the herbage increased and percent recovery of the applied N decreased as N application rates increased. Oven‐dried forage yields reached 19,000 kg/ha when N was applied at 448 kg/ha. Yield, N concentration of forage, and percent N recovery varied in response to K application with K having little overall effect. Weed encroachment was enhanced by N application at one location, but not at the other location. Temperatures as low as −29 C were recorded with no apparent winter killing.Soil pH decreased slightly with N application at one location, but not at the other. Available soil K correlated positively with K application rates and negatively with N application rates. Available soil Mg at both locations and available Ca at one location were decreased as N rates increased. Available soil Mg was decreased when K was applied at the zero N level, but otherwise, it was unaffected by K application.These studies indicate that while N is necessary for maximizing herbage yield of ‘Midland’ bermudagrass, other factors such as location and soil type are important in determining persistence and longevity. Also, additional nutrients, such as Mg, need to be considered as N levels are increased.
Estimating Forage Yield with a Disk Meter1
Authors: Santillan R. A. , Ocumpaugh W. R. , Mott G. O. 
Published: July 2010

AbstractThe disk meter technique of estimating forage dry matter yields has been used by many researchers in recent years. However, few comparisons have been made on which size, weight, and technique of use gives the most precise results, or if species of grass has any effect on the results. A simple‐disk and a weighted‐disk were evaluated as techniques for estimating forage dry matter yield on several grasses. Predictions of dry matter yield were based on settling heights measured with the meters. Yield estimates were made on annual ryegrass (Lolium multiflorum Lam.) pastures, and swards of bahiagrass (Paspalum notatum Flügge), digitgrass (Digitaria decumbent Stent.), and limpograss [Hemarthria altissima (Poir.) Stapf et C. E. Hubb]. Separate linear regression relationships between dry matter yield and settling height were calculated (Y = bX). Correlation coefficients (r) of 0.79 to 0.99 with most r values exceeding 0.92 were found between height and dry matter yield. Standard deviations from regression ranged from 73.2 to 282.4 kg/ha for different sampling techniques, disk sizes, and grass types. Increasing the disk size (0.25 to 0.75 m2) increased the correlation and regression coefficients, and reduced standard error from regression. The largest disk provided contact with a greater area of biomass and resulted in yield estimates of greater precision, but the additional precision obtained by using the 0.75‐m2 disk over the 0.50‐m2 disk does not offset the reduced ease of use of the larger disk. In addition, the 0.25‐ and 0.50‐m2 disks gave more uniform b values across grasses than the other disks. Thus, one combined b value was found to adequately describe the relationship between settling height and dry matter yield for all four grasses with these two disks. These results substantiate that the disk meter is a useful, practical, and versatile instrument for estimating forage dry matter yield in small plots and grazed pastures. The simple‐disk meter proved to be equal to the weighted meter for predicting dry matter yield, however, the simple‐disk has the advantage over the weighted meter because it is much easier to use in the field.
Differential Susceptibility of Corn Cultivars to Zinc Deficiency1
Authors: Safaya N. M. , Gupta A. P. 
Published: July 2010

AbstractDue to widespread deficiency of Zn in the northwestern plains of India, germplasm screening for identifying less susceptible cultivars of crop plants has become as essential as recommending proper methods of Zn fertilization. To study the relationship between differential susceptibility to Zn deficiency and nutrient composition of plants, 13 cultivars of corn (Zea mays L.) were grown in the greenhouse at 0 and 2.5 ppm of applied Zn, with uniform N‐P‐K rate, in 4‐kg lots of Zn‐deficient loamy sand of pH 8.5. After 45 days of growth, dry matter yield (DMY), and P, K, Ca, Mg, Fe, Mn, Cu, and Zn in the leaf, culm, and root fractions were measured. Significant cultivar differences in DMY and nutrient composition and the degree of their response to Zn were observed. The reduction in DMY of whole plants due to Zn deficiency ranged from 26.6% (‘Basi’) to 74% (White Opaque 2). However, the differential susceptibility of corn cultivars to Zn deficiency was not related to their Zn absorption characteristics. Zinc‐deficient plants revealed higher concentration of all nutrients (except Zn) in their tissues. The uptake of P was significantly higher in the shoots of Zn‐deficient plants. From regression analysis between the percent reduction in shoot DMY and the relative increase in the concentration of different nutrients in Zn‐deficient plants, only leaf and culm P concentrations were found to bear a high positive correlation (P<0.01) with the susceptibility index of cultivars. Relative increase in Fe concentration of shoots showed a positive correlation and in roots a negative correlation (P<0.05 for both) with the percent reduction in shoot DMY. These results show that the susceptibility to Zn deficiency in corn is intimately related to the P and Fe absorption and transport mechanisms.
Post‐Freeze Deterioration of Six Sugarcane Cultivars1
Authors: Gascho G. J. , Miller J. D. 
Published: July 2010

AbstractSugarcane (a complex trispecies hybrid, Saccharum spp) deteriorates following a killing freeze resulting in decreased sugar recovery with time. When the freeze is severe, sugarcane becomes unmillable. Cultivar differences in deterioration rates following freezes have been reported but most modern sugarcane cultivars have not been tested under field conditions. The main objective of this study was to compare the deterioration rates of six sugarcane cultivars during a 9‐week period following severe freezes at Belle Glade, Fla. 18 to 20 Jan. 1977. Samples of ‘CP 57‐603’, ‘CP 68‐1026’, CP 65‐357', CP 68‐1067', ‘Cl 41‐223’, and ‘CP 63‐588’ were randomly selected from the plots of a randomized complete block experiment each week. Brix, raw juice pH, titratable acidity, stalk weight, and juice polarization were measured. Theoretical yield of sugar per metric ton of cane, percent juice sucrose, percent purity, and sugar loss with time were obtained by standard calculations. Deterioration rates were estimated by regression of sugar parameters with time. All cultivars deteriorated rapidly and linearly over the 9‐week period following three nights of freezes (the lowest temperature was −6 C). The average loss in theoretical sugar yield was 13 kg of suagr/metric ton of cane/week. The rate of deterioration for the 9‐week period, as gauged by the data collected, was lowest for CP 65‐357. During the first 5 weeks following the freezes, theoretical sugar yield and purity were highest for CP 63‐588; however, during the final weeks of the experiment, juice quality was highest for CP 65‐357. The mean loss of sugar for all cultivars was 9.2% per week.
Nitrate Fertilizer Timing, Irrigation, Protein, and Yellow Berry in Durum Wheat1
Authors: Robinson Frank E. , Cudney David W. , Lehman William F. 
Published: July 2010

AbstractIn the irrigated desert area of Imperial Valley, Calif., Cocorit 71 durum (Triticum durum Desf.) was developing sufficient yellow berry to be penalized in price received by growers. The objectives of the study were to define the relationship between nitrate fertilizer timing, protein, and yellow berry in grain and to recommend the N fertilization program leading to the highest yield of low yellow berry grain yield. The study was conducted on a well drained vertic torriorthent of the entisol order. Plots were fertilized with 0, 135, 202, 270, or 404 kg/ha of N as ammonium nitrate in three treatments: all preplant (P), half preplant, and half at tillering (PT); and one‐third each at the preplant, tillering, and boot stages (PTB). Grain protein content differed significantly between treatments. Yellow berry decreased by 16.4 to 18.5% for each percentage increase in crude protein in the grain. PTB gave significantly higher protein in the grain than the other treatments. Protein content had significant linear correlation with shatter, lodging, average grain size, and grain density. PTB at 270 kg N/ha was the lowest N application that gave a consistently high yield, with less than 25% yellow berry. The wetter of two irrigation treatments had significantly less lodging in 1976, and longer straw, higher yield, and lower grain density in 1977. Effects were similar to the above in comparison treatments of ‘Mexicali 75’ durum and ‘Yecora Rojo’ (Triticum aestivum L.), a hard red spring wheat. It was recommended that N fertilization be 90 kg/ha at preplant, again at tillering, and again at the boot stage.
N Deprivation in Maize During Grain‐Filling. I. Accumulation of Dry Matter, Nitrate‐N, and Sulfate‐S1
Authors: Friedrich J. W. , Schrader L. E. , Nordheim E. V. 
Published: July 2010

AbstractMaize (Zea mays L.) has a noted propensity for accumulating large amounts of nitrate‐N (NO3‐N). However, the availability of such NO3‐N for assimilation during periods of restricted N supply has not been assessed. In addition, the availability of sulfate‐S (SO4‐S) affects the accumulation and assimilation of NO3‐N. Little is known about the effect of NO3‐N supply on SO4‐S accumulation. Such information is vital to efforts to improve the efficiency of nutrient utilization by crops. The objective of this greenhouse experiment was to determine the effect of N deprivation during grain‐filling on the accumulation of dry matter, NO3‐N, and SO4‐S. Maize plants were grown hydroponically in a modified Hoagland's solution. At silking the nutrient solution was replaced with fresh solution, with or without NO3‐N. Plants were harvested and separated into seven fractions at silking and 1, 2, 3, 5, and 7 weeks after silking. Plants that were supplied NO3‐N during grain‐filling contained almost twice (1.8×) as much N at physiological maturity (7 weeks after silking) as did N‐deprived plants. Ear dry weight was not affected by N deprivation. The concentration of NO3‐N in all fractions declined during grain‐filling; however, N deprivation enhanced this decline in the roots, lower stem, and upper stem. Lack of N did not affect NO3‐N concentration in the lower leaves, upper leaves, or ear. The concentration of SO4‐S in the roots nearly doubled between silking and physiological maturity when plants were deprived of NO3‐N, but did not change when N was supplied. The concentration of SO4‐S in all other parts was not markedly affected by N deprivation. Apparently, maize plants can compensate for a restricted N supply during grain‐filling by utilizing NO3‐N stored in the roots and stem.
Evaluation of Big Bluestem, Indiangrass, Sideoats Grama, and Switchgrass Pastures with Yearling Steers1
Authors: Krueger C. R. , Curtis D. C. 
Published: July 2010

AbstractIdeal pasture systems must supply high yields of quality forage throughout the grazing season. When cool‐season grasses predominate, forage is often in short supply during the summer months. This study was designed to compare improved cultivars of perennial, warm‐season grasses that were grown for pasturage in July and August. Pure stands of ‘Pawnee’ big bluestem (Andropogon gerardi Vitman), ‘Holt’ indiangrass (Sorghastrum nutans (L.) Nash), ‘Pierre’ sideoats grama (Bouteloua curtipendula (Michx.) Torr.), and ‘Nebraska 28’ and ‘Summer’ switchgrass (Panicum virgatum L.) were grazed with yearling steers from 1973 to 1975 at the Pasture Research Center, Norbeck, South Dakota. Grazing was initiated about 9 July and continued for 42 days on big bluestem, 38 days on sideoats grama, 33 days on Nebraska 28 switchgrass, and 31 days on indiangrass and Summer switchgrass. Steer gains averaged 1.08 to 0.70 kg/day, and were highest on indiangrass, similar on Nebraska 28 and Summer switchgrass and sideoats grama, and lowest on big bluestem. Number of steerdays of grazing per hectare ranged from 199 on big bluestem to 111 on indiangrass. Beef gains per hectare ranged from 147 to 112 kg, and were highest and similar on Nebraska 28 and Summer switchgrass and big bluestem, and lowest on indiangrass and sideoats grama. The results of this experiment indicate that big bluestem and switchgrass pastures can be used successfully for beef production in July and August.
Methodology for Identifying Wide Adaptability in Crops1
Authors: Nor Khalid M. , Cady Foster B. 
Published: July 2010

AbstractWhen several cultivars are grown over a range of environments, regression measures of stability or wide adaptability can be estimated. The most commonly used measures include Eberhart and Russell's and Finlay and Wilkinson's. These measures use the average yield of the cultivars at each site as an index of the site's productivity. Because of conceptual and statistical problems associated with using the site mean yields, emphasis is now on a principal component method, based on measurements of environmental variables at each site, for formulating an environmental index. We wished to retain the regression approach of the earlier developers. The objective of this paper, therefore, to develop multivariate regression methodology for providing an alternative environmental index not dependent on the cultivar responses. The index is based on physical measurements of the environments affecting crop yield. The resulting data analysis, based on a beta response model, is straightforward and easy to apply in the same general situations as previous stability and adaptability studies. The methodology is applied to a set of corn (Zeo mays L.) data from several New York environments. Adaptability rankings using the new methodology compare favorably with those based on site means (Spearman rank correlation of 0.69 with 16 degrees of freedom). With improved measurement techniques and understanding of site variable and yield relationships, the environmental index methodology can be an alternative regression measure of stability or wide adaptability.
Effect of N Fertilizer on Yield, Protein Content, and Symbiotic N Fixation in Fababeans
Authors: Richards J. E. , Soper R. J. 
Published: July 2010

AbstractFababeans (Vicia faba L. var. minor) are potentially an important source of crude protein in Western Canada. Thus the effect(s) of combined inorganic N on fababean growth performance are of considerable interest. This experiment was conducted to determine the effect(s) of fertilizer‐N on fababean shoot and root yields, protein contents, N uptake, N fertilizer uptake, and symbiotic N fixation. Nitrogen fertilizer as NH4NO3, was applied to fababeans grown in an Udic Haploborall soil in rates up to 900 mg N/pot (300 mg N/kg soil), as split applications of 75 mg N/pot (25 mg N/kg soil), and as single large mid‐season applications of 300 mg N/pot (100 mg N/kg soil. 15N‐labelled fertilizers were used to measure N fertilizer uptake, and were also used with a reference crop to measure symbiotic N fixation. The split application treatment received labelled‐15N in the manner described by Fried et al. (1975), enabling efficiency of N fertilizer uptake for each application time to be determined.Fababeans, when nodulated with effective strains of Rhizobia, obtain their N from soil and symbiotic fixation. Results obtained from this experiment indicate that these two sources of N were able to fully satisfy fababeans' N demand throughout their entire growth cycle. Aerial yield was not affected by N fertilizer up to 600 mg N/pot (200 mg N/kg soil) applied at seeding, by 300 mg N/pot applied in four 75‐mg portions, nor by single midseason applications of 300 mg N/pot. Only the highest rate of N employed, 900 mg N/pot at seeding, significantly increased fababean yield, the increase being 13.2%. However, protein content and total N uptake into fababean shoots were unaffected by all N applications used.Fababeans, nodulated with an effective Rhizobia strain were efficient symbiotic fixers. Fababeans receiving no N fertilizer fixed 708 mg N/plant, or 87.10%, of their total N content. Fababeans were capable of fixing substantial amounts of N after pod‐fill, amounting to at least 28% of the total seasonal symbiotically fixed N. A significant (r3 = 0.99) linear inverse relationship occurred between fertilizer‐N uptake and symbiotic N fixation. Increasing quantities of fertilizer uptake into fababean tissues decreased plant N derived from fiiation.Fababeans were as adept as barley in extracting available soil and fertilizer‐N, and evidence indicates fababeans preferentially feed from soil and fertilizer N sources.
Potassium Fertilization Influences on Coastal Bermudagrass Rhizomes, Roots, and Stand1
Authors: Keisling T. C. , Rouquette F. M. , Matocha J. E. 
Published: July 2010

AbstractLosses of yield and stand of ‘Coastal’ bermudagrass (Cynodon dactylon L. Pers.) due to inadequate K fertility have been observed numerous times. Stand deterioration has been attributed to “winter‐kill”, disease, and lack of “physiological hardening” of the plants. Since all the aerial parts of the bermudagrass plant die when temperatures are as low as ‐2 to ‐3 C, underground stems (rhizomes) are important for maintaining and generating growth in the spring. Studies were conducted to investigate the effects of K fertility practices on rhizome production and rhizome regrowth reserve as related to certain stand and tissue characteristics. Old P and K factorial rate studies on Darco (Grossarenic Paleudult; loamy, siliceous, thermic) and Cuthbert (Typic Hapludult; clayey, mixed, thermic) soils were used. Annual fertility rates used on prior experiments were 0, 112. and 224 kg/ha K, 0 to 136 kg/ha P, and 364 to 504 kg/ha N. The influence of residual P and K fertility on stand ratings, rhizome production, and Ca, Mg, and K content of the forage was measured. Stand ratings in the spring were found to be related to rhizome production. The first increment of 112 kg/ha of K increased rhizomes 800 kg/ha on the Darco soil. Rhizome production required higher rates of K on the Cuthbert soil which gave a response of 1,500 kg/ha of rhizomes to the highest K rate used. Lowering the K rate resulted in lower K in the tissue and an observable loss of vigor in the root system. Depending on the soil K reserve, production levels ,and previous fertility practices, Coastal bermudagrass hay meadows on which K fertility levels are inadequate may exhibit the characteristics described above.
Yield and N Content of Closely Clipped Bahiagrass as Affected by N Treatments1
Authors: Beaty E. R. , Tan K. H. , McCreery R. A. , Powell John D. 
Published: July 2010

AbstractPensacola bahiagrass (Paspalum notatum Flugge) is normally grown in pure stands and produces forage primarily on stolons growing along the soil surface. Harvesting by clipping has been at a height of 6 to 7 cm and N fertilization has traditionally been in split applications with the first in March or April. Advantages of split applications have not been established and clip ping at 6 to 7 cm may seriously underestimate forage production. More detailed information is needed to accurately establish total forage yields and seasonal forage production patterns under close clipping. A field clip ping investigation was conducted where bahiagrass sod receiving 0, 84, 168, and 336 kg/ha of N fertilizers in one of six time of application combinations was harvested monthly at a height of 0 to 3 mm.The first year, dry forage production increased from 3,042 kg/ha with 0 N, to 6,398 kg/ha with 336 kg/ha of N. In the second year, forage production at the same N rates ranged from 3,812 to 12,151 kg/ha. Close clipping (0 to 3 mm stubble) resulted in different seasonality of forage production and N concentrations when compared to previous results where clipping was at heights of 6 to 7 cm. Increasing the N application rate increased root and stolon weights.Forage production efficiency of applied N (kg dry matter produced/kg N applied) decreased from 54.6 for the first 84 kg/N/ha applied to 34.0 for the additional N from 84 to 168 kg/ha and further to 5.2 for N from 168 to 336 kg/ha N. With unfertilized bahiagrass, N should be applied by or before early March, but after the first year, time of N application makes no practical difference in yield. At low N rates, harvesting to a stubble height of 3 cm or less will significantly increase the amount of forage utilized , harvested, or reduce the amount of N applied.It was concluded that close grazing or clipping of Pensacola bahiagrass wilt: a) increase digestibility by keeping the forage green; b) increase the effective yield of a pasture; and c) split applications of N may provide better forage distribution over a season without affecting yield.
Seed Protein and Nitrogen Effects Upon Seedling Vigor in Wheat1
Authors: Bulisani E. A. , Warner R. L. 
Published: July 2010

AbstractSeedling vigor appears to be enhanced by seed protein, but the influence of exogenous N supply and timing upon this effect have not been clearly established. Growth chamber and field experiments were conducted to determine the effects of seed protein and N upon seedling vigor of ‘Nugaines’ and ‘Wanser’ winter wheat (Triticum aestivum L.). Seed were obtained from a N fertility experiment, sieved into seven size classes, and analyzed for protein. Seed protein content varied from approximately 8 to 16%. Within each seed lot the largest seed had approximately a 2.5% higher protein percentage than the smallest seed.In growth chamber experiments seedling vigor was significantly increased by seed weight and percent protein. However, most of the variation was attributed to the amount of N in the seed and not to the percentage protein or seed weight per se. The addition of N significantly increased seedling dry weight and N content, and promoted a significant two‐fold increase in the shoot‐to‐root ratio. Differences in seedling vigor due to seed protein content were eliminated if adequate N was applied within the first 3 days of germination. Rate of emergence and grain yields in the field on a Palouse silt loam soil (fine‐silty, mixed, mesic Pachic Ultic Haploxerolls) were not affected by seed protein content. However, large seed significantly increased the seedling emergence rate index and grain yields. Nitrogen application had no effect upon emergence rate which may have been due to the availability of high levels of soil N.Seed protein enhances seedling vigor (dry weight) if N is withheld for more than the first 3 days of germination, but apparently has no effect if adequate N is available during early stages of germination.