bluuebunny/crossref_metadata_2025_split huggingface dataset:
Techniques for Thermocouple Placement and the Automation of Temperature Measurements in the Microenvironment of Kentucky Bluegrass1
Authors: Welterlen M. S. , Watschke T. L. 
Published: July 2010

AbstractA Kentucky bluegrass (Poa pratensis L.) sward is comprised of many closely spaced, minute plants forming a dense, low canopy. Measurements of soil and basal tiller temperatures require careful placement of many small sensors. The objectives of this research were to develop expedient methods for obtaining precise point measurements of tiller, thatch, and soil temperatures with thermocouples in the field. Measurements were made in ‘Touchdown’ Kentucky bluegrass mowed to 5 cm.Throughout the study, Chromel‐Alumel thermocouples were used. A 40‐channel, microprocessor‐based data acquisition system and a computer compatible nine‐track magnetic tape were used for uninterrupted data collection. Irradiance, measured approximately 1 km from the experimental site, and air temperature, sensed by an aspirated thermocouple located 1.5 m above the turf, were recorded simultaneous with sod temperature measurements.Thermocouples [20 AWG (0.81 mm)] placed horizontally and vertically, thermocouples [40 AWG (0.076 mm)] placed vertically, and thermocouples [40 AWG] fastened to 0.6 cm diameter wooden dowels were placed 2 cm below the thatch‐soil interface and compared for precision and placement expedience. Vertically placed fine‐gauged thermocouples (the most expedient means of installation) were as precise as the other methods. Although gauge did not influence precision in this test, in some situations (particularly vertical placement) the potential for error may exist due to heat flow along the wire.Two methods of thermocouple (40 AWG) placement into basal tillers were compared for expedience of placement and relative precision. In one method, thermocouples were threaded through the tiller base leaving the thermocouple bead inside the tiller with lead wire connection on opposite sides. The other method involved direct insertion into a hypodermic puncture in the tiller base. The inserted thermocouple method was found to be the most expedient, and no significant temperature differences were found between the methods. Tiller base temperatures measured in the field on a cloudy afternoon on 11 June 1979 ranged from 16.8 to 21.1 C, with a maximum difference of 0.6 C between the two methods (insignificant at the 0.05 level). The coefficients of variation for each method were not greater than 10.6. Temperatures measured during a clear afternoon on 12 June 1979 ranged from 23.1 to 31.5 C. At 1500 hours, the difference between the methods of placement was greatest (3.3 C) but was not significant at 0.05. The maximum coefficient of variation was 15.3 and 13.7 for the inserted and threaded thermocouples, respectively. Throughout the day, the threaded method had generally lower coefficients of variation.
Growth Analysis of Maize Hybrids Differing in Photosynthetic Capability1
Authors: Gaskel M. L. , Pearce R. B. 
Published: July 2010

AbstractThere is, theoretically, a close association between leaf photosynthesis and dry matter production. However, many factors affect plant productivity and photosynthesis under field conditions which are not measured with leaf photosynthesis in the laboratory. Studies were undertaken to determine if there are patterns of leaf area development or dry matter accumulation in maize (Zea mays L.) plants that may interfere with a leaf‐photosynthesis, plant‐productivity relationship.Six experimental maize hybrids were selected for detailed growth analysis during vegetative development. Three of these hybrids had previously exhibited higher CO2 exchange rates (CER) and three had exhibited lower CER. Plants were sown in the field in early May and early June to obtain densities of 5.3 plants/m2 during the 1978 and 1979 growing seasons. The soil was a Clarion (Typic Hapludoll, fine‐loamy, mixed mesic) soil. Leaf CER of excised blades, leaf blade area on main culms and tillers, and dry weight of main culms and tillers were measured weekly through 6 weeks of growth.The hybrids maintained the CER status for which they were selected during all growth periods. High‐CER hybrids tillered more profusely than did low‐CER hybrids. Overall leaf area was greater in high‐CER hybrids, primarily due to greater tillering. Dry weight of main culms and tillers among hybrids generally followed leaf area distribution. Dry weight accumulation patterns between main culm and tillers during late vegetative development suggested that high‐CER hybrids exported “excess” main culm assimilates to nonproductive tillers or belowground sinks. This phenomenon, if real, would affect any yield advantage attributable to high CER capability.
Subsurface Irrigation and Fertilization of Field Corn1
Authors: Mitchell W. H. 
Published: July 2010

AbstractTrickle irrigation is a rapidly developing technology with high potential for water and energy conservation. Surface placement of emitter lines is typical of current installations. The lines interfere with cultural operations leading to costly annual replacement and limiting its use to high value crops. The objective of this experiment was to determine if deeply placed emitter lines could be used to effectively deliver water and anhydrous ammonia (AA) to the sub‐tillage root zone of field corn (Zea mays L.) in the presence of several broadcast N, P, K treatments.Field corn was grown on Matapeake silt loam (fine silty, mixed mesic Typic Hapludult) and subsurface irrigated during the period 1973 to 1979. Emitter lines were placed 90 cm apart at a depth of 36 cm. Irrigation treatments included no irrigation, subsurface irrigation (SSI), and SSI plus AA. Broadcast N, P, K was applied annually at 0, ½, 1, 2, and 3 time rates with the 1 time rate equal to 112,25, and 94 kg/ha of N, P, K, respectively. Annual treatments with N, P, K were made from 1965 to 1973 but following 1973 P and K treatments were discontinued although N applications were repeated annually through 1979.Anhydrous ammonia applied through the SSI system increased N use efficiency when compared to broadcast ammonium nitrate. When AA was injected through the SSI system no benefit was derived from broadcast‐N applications. Phosphorus and K availability, as measured by ear leaf analysis, was increased when AA was injected through SSI. The application of AA through SSI depressed soil pH but the effect was localized within a 10 to 12‐cm radius of the emitter lines. Corn roots concentrated in soil adjacent to emitter lines causing an increase in organic matter that appeared to stabilize emitter line flow rates. It was concluded that a properly installed SSI system can have a functional life of at least 7 years.
Quality Estimates and Chemical Characterization of Fermented and Unfermented Summer Annual Forages1
Authors: Burns J. C. , Kimbrough E. L. 
Published: July 2010

AbstractLivestock enterprises require forage crops that provide feed during or after midsummer. Ten cultivars representative of forage and grain sorghums [Sorghum bicolor (L.) Moench], sorghum ✕ sudangrass (Sorghum vulgare sudanense) hybrids, and millet [Pennisetum americanum (L.) Leeke] that provide forage during this time of the year were evaluated for quality and fermentation characteristics. Chemical and bioassay measurements were compared prior to and after fermentation.Fermentation patterns were altered by sample handling. Expulsion of air from plastic fermentation bags by simply hand pressing or removal or air in the field by vacuum produced satisfactory silage for experimental purposes. Additional handling in the laboratory to heat seal was undesirable as it significantly increased pH and lactic acid concentrations and reduced titratable acidity.Fermentation generally reduced differences in IVDMD among cultivars within major types in the unfermented forage. Both N and crude fiber (CF) concentrations in oven‐dried samples generally were higher in fermented than in unfermented forage, but no difference was noted between 45 and 90 days of fermentation. Water‐soluble carbohydrate (WSC) levels were significantly altered by the drying method and fermentation. The WSC levels for unfermented forage and that fermented 45 and 90 days were 16.7, 6.6, and 7.6%, respectively. The WSC levels averaged 19.8% in unfermented freeze‐dried forage and 13.7% in unfermented oven‐dried forage. The WSC levels for fermented freeze‐dried forage were similar to those for oven‐dried forage (7.5 vs. 6.7%). The WSC percentages in the freeze‐dried, unfermented forage was not significantly correlated with either acetic or lactic acid production in 45‐day freeze‐dried fermented forage (r = 0.67 and 0.54, respectively), but were significantly correlated with titratable acidity (r = 0.93**). There was no indication of improved quality in fermented forage for which the WSC concentration was high in the unfermented tissue. Total digestible nutrients (TDN), computed from CF, averaged 58.2, 57.0, and 56.9% for the oven‐dried unfermented and 45 and 90‐day fermented silages, respectively, compared with IVDMD percentages of 52.6, 45.1, and 46.0.
Sod‐Seeding Forage Legumes in a Tall Fescue Sward1
Authors: Olsen F. J. , Jones J. H. , Patterson J. J. 
Published: July 2010

AbstractIntroduction of forage legumes into tall fescue (Festuca arundinacea Schreb.) swards by sod‐seeding may greatly enhance herbage production. This study was undertaken to determine the establishment and productivity of selected legumes sod‐seeded in tall fescue and to assess the effectiveness of selected chemicals for the temporary suppression of grass foliage. This work was conducted in southern Illinois on a Stoy soil (fine‐silty, mixed, mesic Aquic Hapludalf). Five forage legume species, alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), crownvetch (Coronilla varia L.), ladino clover (Trifolium repens L.), and red clover (Trifolium pratense L.), were sod‐seeded in tall fescue with the Allis‐Chalmers No‐Till planter and the Zip sod‐seeding drill. Selected alfalfa and red clover cultivars were evaluated and the effectiveness of four chemicals at three different rates for temporary suppression of the tall fescue top growth was also assessed.All forage legumes except crownvetch were established successfully by sod‐seeding. The introduced legumes enhanced the total overall dry matter yields of the tall fescue sward by up to three times under hay production management. Alfalfa was the most productive and long‐lived sod‐seeded legume. Red clover and ladino clover appeared to be well suited legumes for sod‐seeding for short‐term stands. There were no notable differences in herbage production among alfalfa cultivars evaluated, but there were differences among red clover cultivars the 3rd year. The red clover cvs. ‘Kenstar’ and ‘Florie’ persisted for three growing seasons. Glyphosate [N‐(phosphonomethyl) glycine] and paraquat (1,1'‐dimethyl‐4, 4'‐bipryidinium ion) both suppressed tall fescue topgrowth for an adequate period of time for successful legume establishment by sod‐seeding. Acceptable forage legume stands were obtained with the Allis Chalmers No‐Till planter and Zip seeder under proper soil moisture and plant cover conditions.
Foliar Application of Selenium to Field Corn1
Authors: Cary E. E. , Rutzke M. 
Published: July 2010

AbstractMuch of the northeastern quarter of the USA produces feed corn (Zea mays L.) that contains too little selenium (Se) to meet animal nutritional requirements. This experiment was conducted to determine if Se concentration in corn (‘Cornell 281’) could be increased by foliar application of Se. Selenium was applied by hand sprayer to corn growing on Mardin silt loam (Typic Fragiochrept) in a field when the 4th to 6th leaves were the last fully expanded or when tassels were just emerging. Treatments were 0, 7.5, and 15 g Se/ha added as Na2SeO3 in 359 liter/ha of water containing 48 ml of surfactant. Selenium rate, stage of growth, and Se × stage of growth were highly significant (P<1%). At maturity, the concentration of Se in the whole plant minus the ear vs. grain and ear leaf blade vs. grain was linearly correlated, with r = 0.99** and r = 0.88*, respectively. The concentration of Se in grain with no added Se was 0.01 ppm Se. Doubling the Se concentration sprayed on the corn increased the Se concentration from 0.05 to 0.12 ppm Se in grain for the early treatment and from 0.14 to 0.24 ppm Se in grain from the late treatment. The increase in Se concentration in plants sprayed at early tassel stage over those sprayed at a younger age apparently was associated with the total amount of Se intercepted by the plant. Foliar application may be an efficient and safe way to increase Se in feeds and forages.
Phosphorus Uptake by Fescue from Soils Amended with Sewage Sludge Compost1
Authors: Sikora L. J. , Tester C. F. , Taylor J. M. , Parr J. F. 
Published: July 2010

AbstractThe value of sewage sludge compost as a source of P for plants has not been evaluated. The study reported is part of a series designed to assess benefits of amending soils with sewage sludge compost and deals specifically with P uptake by fescue grown in two soils amended with combinations of compost and N and P fertilizers. An Evesboro loamy sand (Typic Quartzipsamments) and a Fauquier silt loam (Ultic Hapludalfs) were amended with four rates of sewage sludge compost (0 to 6% equal to 0 to 134.4 metric tons/ha, dry weight), plus an additional lime control and two rates of N, (0 and 195 kg/ha) P, (0 and 390 kg/ha), or N plus P in a factorial greenhouse study. ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.) was grown and harvested at 40,76,120, and 167 days and the clippings were dried and weighed.All of the clippings and one replicate of roots and crowns grown in the Evesboro soil were analyzed for total P. Similar to the data on fescue yields, the cumulative fescue P grown in compost‐amended Evesboro soil was approximately double that from compost‐amended Fauquier. Cumulative P was not linearly related to compost amendment in either soil. Fertilizer N, P, or N and P additions resulted in greater P uptake by fescue grown in both compost amended soils. However, fescue grown in compost amended soils without fertilizer contained adequate P levels to satisfy the nutritional requirements of feed for ruminants. Highly significant regression equations were derived describing total P uptake and fescue P concentration as affected by compost amendment, fertilizer addition, and time. The percentage of total P added as compost that was taken up by fescue grown in Evesboro soil equaled 4.5, 3.0, and 2.5 for the 44.8, 89.6, and 134.4 metric tons/ha amendment rates, respectively.
Wheat and Barley Responses to Rates of Seeding and Fertilizer in Southwestern Saskatchewan
Authors: Read D. W. L. , Warder F. G. 
Published: July 2010

AbstractResearch from 1960 to 1968 at Swift Current, Saskatchewan, on orthic brown chernozemic clay loam under semiarid conditions indicated that the seeding rate of hard red spring wheat (Triticum aestivum L.) could be reduced to half of the seeding rate most commonly used by farmers. This study in 1976 and 1977 extended the testing to orthic brown chernozemic loam and heavy clay soils and included fertilizer treatments.Tests were conducted on stubble and fallow land at three locations in 1976 and 1977. Seeding rates were 20, 40, and 60 kg/ha with fertilizer applied at rates of 0‐0 (check), 10‐9 and 50‐22 kg/ha of N and P, respectively.With the exception of barley (Hordeum vulgare L.) on fallow, no significant fertilizer ✕ seeding rate interactions for yield were recorded, indicating that fertilizer rates and seeding rates were factors that operated relatively independently. However, differences in yield between locations were observed. In 1977, a location ✕ seeding rate interaction was obtained on fallow while location ✕ fertilizer interactions on fallow in 1976 and on stubble in 1977 occurred.Fertilizer increased the yield over the check yield for all crops on stubble and fallow. Reducing the seeding rate to 20 kg/ha for wheat and barley on stubble and to 40 kg/ha for barley and durum (Triticum durum Des. F.) on fallow caused no significant reduction in yield. For durum on stubble and wheat on fallow seeding rates of 60 kg/ha were required for maximum yields. The responses of barley and durum to fertilizer and seeding rates were similar to the responses of wheat for yield, N and P content, kermel and volume weight of the grain.Increased rates of fertilizer produced some increases in the N content of the grain, particularly at the highest rates, but both rates reduced the P content. Higher fertilizer rates tended to reduce the kernel and volume weights for all crops. The higher seeding rates reduced the N and P content of the grain, and the kernel weight, but increased the volume weight.
Dinoseb and Triacontanol as Growth Regulators in Irrigated and Nonirrigated Field Corn1
Authors: Regehr D. L. 
Published: July 2010

AbstractThe growth regulators dinoseb (2‐sec‐butyl‐4,6‐dinitrophenol) and triacontanol [CH3(CH2)28CH2OH] have previously been applied to several crops, including corn (Zea mays L.), in efforts to stimulate yields. Field performance has been erratic with both yield increases and yield decreases reported. It was hypothesized that crop response to dinoseb and triacontanol may be influenced by environmental stress on the growing crop to which they are applied. This is a report of two field experiments (1978 and 1979) in which dinoseb and triacontanol were applied to irrigated and water‐deficient field corn to test this hypothesis.Two corn hybrids (Pioneer 3369A and Funks G4646) were planted in irrigated and nonirrigated split blocks. Dinoseb (17.4 g/ha) and triacontanol (4.0 g/ha) were applied as foliar sprays, 2 weeks before tasseling. Corn grain yields were significantly reduced in 11 of 12 dinoseb‐treated vs. untreated comparisons. Yield reductions averaged 18.0% in irrigated corn and 18.4% in nonirrigated corn. A significant irrigation ✕ dinoseb interaction occurred in only one of six comparisons. Some of the grain yield reduction in dinoseb‐treated plots could be attributed to reduced harvest index and reduced percentage ear fill.Triacontanol did not affect grain yield in six of eight comparisons of triacontanol‐treated vs. untreated plots. One of the four irrigation ✕ triacontanol interactions was significant, showing a yield increase due to triacontanol under irrigation, and a yield decrease in waterdeficient corn. Harvest index and percentage ear fill were not affected by triacontanol.The hypothesized interaction of environmental stress with the growth regulators dinoseb and triacontanol was not substantiated in these experiments. Triacontanol had minimal effect on corn performance, and dinoseb had very detrimental effects on both irrigated and water‐deficient corn. It is suggested that the inconsistent performance of these compounds, as reported in the literature, should not be attributed to environmental conditions of the growing crops.
Comparison of Water Stress of Cotton from Measurements with the Hydraulic Press and the Pressure Chamber1
Authors: Radulovich R. A. , Phene C. J. , Davis K. R. , Brownell J. R. 
Published: July 2010

AbstractThe Hydraulic Press (HP) is gaining some acceptance as a tool for estimating plant water status and some large cotton growers in the Central California area are already using this instrument for irrigation scheduling. Since no published data validating the use of the HP with cotton have been found, the objective of this research was to develop a data set to support or reject the use of the HP for estimating cotton water status, as compared to the widely accepted Pressure Chamber (PC).Measurements of water status of cotton (Gossypium hirsutum L., Acala SJ2 Var.) obtained with the HP and the PC were compared and correlated hi replicated experiments under greenhouse and field conditions. Results indicate that 1) the HP does not measure low water potential accurately below −940 kPa as determined by the PC, and 2) the most representative endpoint to use with the HP is the pressure at which water exudes from the cut edge of a tip of an uppermost fully expanded leaf.The HP can be used advantageously for irrigation scheduling of cotton if the threshold value is −940 kPa or higher, as determined when the highest water potential values for a day are found (i.e., predawn). However, this inability of the HP to estimate low water potentials of cotton leaves, under the conditions herein described, seems to be a serious limitation of the instrument.
Forage Cell Wall Degradation and ρ‐Coumaric, Ferulic, and Sinapic Acids1
Authors: Akin Danny E. 
Published: July 2010

AbstractPhenolic acids are associated with carbohydrates in forage cell walls. Since phenolic compounds are often toxic to microorganisms, the objective was to test ρ‐coumaric, ferulic, and sinapic acids for their effect on rumen bacterial growth (turbidity and roll tubes), rumen protozoal motility, cellulose (filter paper) degradation, and cell wall digestion using light microscopy. The addition of 0.1% ρ‐coumaric acid to the media inhibited the growth of cellobiose‐utilizing bacteria and increased the days required for cellulose degradation by two to three times. This acid also inhibited the growth of xylan‐utilizing rumen bacteria, and caused a reduction of about 50% of the colonies appearing on xylan roll tubes. The percent motility of the entodiniomorph protozoa, but not the holotrichs, decreased more rapidly with time in the medium with ρ‐coumaric acid than in control medium. Sinapic acid was not toxic in any of the tests. Ferulic acid slowed the growth rate of rumen microorganisms on a habitat‐simulating broth medium, but had little or no effect on cellulose‐utilizing microorganisms. Ferulic acid did reduce slightly the growth of xylan‐utilizing microbes in some tests. At the 0.2% level, ρ‐coumaric but not ferulic acid prevented the degradation of mesophyll and epidermis that were normally easily digested in orchardgrass (Dactylis glomerata L.) leaf blades. The results showed that ρ‐coumaric acid was toxic to certain rumen protozoa and the rumen bacteria expected to play a dominant role in the digestion of forage cell walls.