bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diurnal Variation in Alfalfa (Medicago sativa L.) Dry Matter Yield and Overnight Losses in Harvested Alfalfa Forage1
Authors: Knapp W. R. , Holt D. A. , Lechtenberg V. L. , Vough L. R. 
Published: July 2010

AbstractResearch reported here was designed (a) to study diurnal variation in dry matter yield and nonstructural carbohydrate percentages in alfalfa (Medicago sativa L.) and (b) to compare overnight dry matter and carbohydrate changes in alfalfa cut and left in the field with the changes in standing alfalfa.First‐ and second‐growth alfalfa were harvested at 7 AM and 7 PM over three 3‐day periods. Each evening, additional alfalfa samples were cut and left overnight in the field so that overnight dry matter and carbohydrate changes in cut and uncut alfalfa could be compared.Dry matter yields were measured, and freeze‐dried, ground samples were analyzed for carbohydrates. Sucrose and reducing sugars were extracted with ethanol. Starch in the remaining residue was hydrolyzed with amyloglucosidase. The carbohydrates in the extracts were quantitatively assayed using ferricyanide, resorcinol, and phenol‐sulfuric acid procedures.Dry matter yields, as well as starch and sucrose concentrations, were significantly higher in the evening than the following morning. Glucose and fructose percentages did not change from evening to morning. Through the day, dry matter increased by 5 to 12%, but half or more of this increase disappeared during the night. Standing alfalfa lost 5.5% of its dry matter overnight, while cut forage lost 7.2% overnight in May and 11.0% in July. Dry matter losses in the cut forage were closely related to night temperature, with greatest losses occurring on warmest nights. Cut forage, however, retained higher starch, sucrose, and fructose concentrations through the night than the standing crop. Seventy percent of the night loss of dry matter in standing alfalfa was nonstructural carbohydrate, but only 20% of the loss in cut material was carbohydrate.
Inbred Maize Performance Following Tassel and Leaf Removal1
Authors: Hunter R. B. , Mortimore C. G. , Kannenberg L. W. 
Published: July 2010

AbstractMechanical detasseling in hybrid seed production fields of corn (Zea mays L.) frequently is accompanied by loss of some leaf material. Little is known about the effect of this practice on seed production in those instances where the seed parent is an inbred line. We investigated the effects of tassel removal and tassel plus leaf removal on 5 short season inbred lines grown at Guelph, Ontario and 5 later maturing lines grown at Harrow, Ontario. Treatments at both locations consisted of a check, and the removal just prior to anthesis of the tassel, tassel plus one leaf, tassel plus two leaves, and tassel plus three leaves. When tassels alone were removed, there was an average increase “of 6.9%g rain yield. When 1, 2, and 3 leaves were removed with the tassel, yield reductions for the 10 inbreds averaged 1.5, 4.9, and 13.5% relative to the yield for tassel removal only. Yield differences were the result of a reduction in both kernel weight and number of kernels per row. However, yield responses to leaf removal varied greatly between inbreds, and therefore, it is impossible to generalize on the effects on grain yield of leaf removal during detasseling. For some inbreds, particularly shorter season ones, the reduction in yield due to removal of 2 and 3 leaves with the tassel is large enough to warrant consideration in seed production. On the other hand, yield of some of the later inbreds was reduced only slightly when 3 leaves were removed with the tassel. This probably reflects the higher percentages of leaf area removed in earlier inbreds as compared to the later inbreds.
Soybean Yields with Direct and Residual Nitrogen Fertilization1
Authors: Welch L. F. , Boone L. V. , Chambliss C. G. , Christiansen A. T. , Mulvaney D. L. , Oldham M. G. , Pendleton J. W. 
Published: July 2010

AbstractThe objective of this research was to determine the effect on soybean (Glycine max (L.) Merrill) yields of N added at different rates by different times and methods of application, as direct and residual, and as inorganic and organic sources. A number of studies were conducted over a period of several years at 10 field locations in Illinois.Nitrogen at rates up to 360 kg/ha added for corn (Zea mays L.) the preceding year had no effect on soybean yields. Neither were soybean yields increased by organic sources of N such as manure or alfalfa (Medicago sativa L.), or by combinations of organic and inorganic sources.Fertilizer N added for soybean as plow‐down, disked‐in, and side‐dressed at early flowering and at pod filling did not increase yields. Nitrogen added for soybeans planted on four dates did not increase yields. High rates of N (1800 and 1440 kg/ha), broadcast and disked‐in in the spring, decreased yield due to germination and seedling injury. Considering all the studies, yields were significantly increased in only 3 out of 133 instances and these occurred at high, uneconomical rates of N fertilizer.It is concluded that N available to the plant is not the growth factor that presently limits soybean yields in Illinois.
Carbon Dioxide and the Photosynthesis of Field Crops. A Tracer Examination of Turbulent Transfer Theory1
Authors: Harper L. A. , Box J. E. , Baker D. N. , Hesketh J. D. 
Published: July 2010

AbstractCarbon dioxide was released at ground level in a cotton (Gossypium hirsutum L.) field, and the flux above the crop was measured. The aerodynamic and energy balance methods of calculating carbon dioxide flux underestimated the measured flux by approximately the same amounts. There was considerable variability in the difference between measured and calculated fluxes, and little correlation with meteorological parameters could be found. Differences between measured and calculated fluxes were slightly less with wind orientation across the rows than with orientation parallel to the rows.
Leaching Losses of Sulfur During Winter Months When Applied as Gypsum, Elemental S or Prilled S1
Authors: Rhue R. D. , Kamprath E. J. 
Published: July 2010

AbstractSandy soils of the southeastern United States are often deficient in sulfur. The use of sulfate‐containing fertilizers does not result in any buildup of sulfur in sandy soils since the sulfate is readily leached during winter months. Interest, therefore, has developed in the use of elemental sulfur as a means of maintaining an adequate supply of sulfur where leaching is a problem. Studies were conducted with gypsum, finely divided elemental sulfur, and prilled sulfur on a Wagram loamy sand and a Georgeville silty clay loam to determine the levels of sulfate sulfur resulting from additions of these sources. Sulfate contents of the 0 to 15‐, 15 to 30‐ and 30 to 45‐cm depths were determined at various times over a period of 200 days after the different sulfur sources were applied in October.Almost all of the sulfate, that added as gypsum and that resulting from the oxidation of elemental sulfur, had been leached from the top 45 cm of the Wagram soil 180 days after application. There was essentially no movement of sulfate, however, in the Georgeville soil.Oxidization of finely divided elemental sulfur appeared to be completed in both soils 200 days after application. There was a buildup of sulfate in the Georgeville surface soil from oxidation of the elemental sulfur. In the Wagram soil, however, leaching was rapid enough to prevent buildup of sulfate in the surface soil. Very little oxidation of prilled sulfur appeared to be occurring to any extent in either soil.
Effect of Soil Moisture During Early Stages of Development on Growth and Yield of Cotton Plants1
Authors: Marani A. , Levi D. 
Published: July 2010

AbstractThe effect of three irrigation treatments on the vegetative development of two cultivars of upland cotton (Gossypium hirsutum L.) was studied in two experiments conducted under different climatic conditions. The treatments differed until the middle of flowering and were designated as L (no irrigation), M (regular), and H (early and excessive irrigation). From mid‐flowering onwards all plots were irrigated regularly.In both experiments, treatment L resulted in a slower growth rate, smaller plants, fewer nodes and fruiting branches, and smaller leaf area index (LAI), and dry matter (DM) weight throughout the season. Small differences were found between the effects of treatments M and H. No excessive vegetative development was observed in this study. The highest rates of DM production were associated with LAI values between 2.0 and 3.0.A close relationship was found between, lint yield, DM production and leaf area duration (LAD). Only small increases in lint yield were associated with LAD and DM exceeding values of 100 days and 600 g/m2, respectively, at the end of the main flowering period. Smaller values of LAD and DM, however, were associated with reduced lint yield. Vegetative development was slower under the high temperatures prevailing in the Bet‐She'an valley than in the Coastal Plain area. Lint yield produced from the first cycle of flowering was lower in Bet‐She'an than in the Coastal Plain, but additional yields were produced in Bet‐She'an from the second cycle of flowering.
Effects of Continuous Corn (Zea mays L.), Manuring, and Nitrogen Fertilization on Yield and Protein Content of the Grain and on the Soil Nitrogen Content1
Authors: Anderson F. N. , Peterson G. A. 
Published: July 2010

AbstractContinuous corn (Zea mays L.) was produced from 1912 to 1972 on an irrigated soil of the Typic Haplustoll group in western Nebraska. Corn yields declined rapidly from 1912 to 1922 when no manure or N fertilizer was used. Annual applications of manure on one‐half of the plot area beginning in 1941 increased yields linearly until 1953. Nitrogen fertilization beginning in 1953 increased corn yields 4685 kg/ha above the control during the first year of application on the nonmanured treatment. Maximum yields have been reached with a combination of manure and N fertilization. Total soil N data indicate that manuring from 1941 to 1972 has returned the soil N level to about 90% of the level that was present in the uncultivated soil in 1912.
Sainfoin‐Birdsfoot Trefoil Mixtures for Pasture, Hay‐pasture, and Hay‐stockpile Management Regimes1
Authors: Cooper C. S. 
Published: July 2010

AbstractTwo nonbloating legumes, sainfoin (Onobrychis viclae folia Scop) and birdsfoot trefoil (Lotus corniculatus L.), were evaluated in pure stands and in mixtures for use in pasture, hay‐pasture, and hay‐stockpile management regimes. Both species, seeded in pure stands or in mixtures, yielded more forage in a hay‐stockpiling management regime than in a pasture or hay‐pasture management regime. In the year of establishment, ‘Remont,’ a twocut‐type sainfoin cultivar, contributed significantly more to yield than ‘Eski,’ a one‐cut‐type sainfoin cultivar, and both sainfoins and sainfoin‐birdsfoot trefoil mixtures yielded more than birdsfoot trefoil alone. Over the 4‐year study period, Remont yielded more than Eski under pasture management, the same as Eski under hay‐pasture management, and much less than Eski under the haystockpile management. Under the hay‐pasture management regime, Eski yielded more than Remont at the hay harvest, but less at subsequent pasture harvests. Under the hay‐stockpile management regime, Eski contributed much more to yield than Remont at the hay harvest, but yields were equal at the late‐September stockpile harvest. Eski was more compatible with birdsfoot trefoil under the hay‐stockpile management system, and produced a higher quality forage at the late‐September harvest. Stand persistence and vigor of both sainfoins under the haystockpile management system were better than under other systems.
Effect of Establishment Method, Variety , and Seeding Rate on the Production and Quality of Alfalfa Under Dryland and Irrigation1
Authors: Hansen L. H. , Krueger C. R. 
Published: July 2010

AbstractEstablishment of alfalfa (Medicago sativa L.) with small grain companion crop is not always satisfactory. This study was designed to compare alternative establishment methods and determine the influence of alfalfa varieties and seeding rates on dry matter and crude protein production and herbage quality. The relationship between alfalfa plant density and root+crown weight and their effect on forage yield were evaluated.Pure stands of alfalfa were established by four methods: 1) no herbicide or companion crop (check); 2) a plant herbicide, S‐ethyl dipropylthiocarbamate (EPTC); 3) a companion crop of oats (Arena sativa L.) harvested for forage; and 4) a companion crop of oats harvested for grain. Three alfalfa varieties were evaluated: T3X‐8 hybrid, ‘Saranac,’ and ‘Vernal.’ Four alfalfa seeding rates were compared: 4.5, 9.0, 13.5, and 17.9 kg/ha of purelive‐seed (PLS). Studies were conducted at three locations in South Dakota. Experiments at Gayville and Norbeck were under dryland conditions and at Brookings under irrigation.Alfalfa established with oats harvested for forage yielded the most weed‐free forage dry matter during the seeding year. This was followed in descending order by the yields of alfalfa established with EPTC, the check, and oats harvested for grain. Herbage crude protein yields were similar during the seeding year regardless of establishment method, except for the oat grain treatment which was lower. Second‐year alfalfa dry matter and protein production were not affected by establishment method.Dry matter yields were higher for Saranac and T3X‐8 hybrid alfalfa than for Vernal when moisture was optimum and winter injury did not occur. Under dryland, there were no differences in yield among the three varieties. T3X‐8 was generally lowest in crude protein content; Vernal was highest in protein late in the season.With irrigation, higher dry matter and crude protein yields were obtained during the seeding year at each increase in seeding rate. Under dryland, no differences in yield were noted above the 13.5 kg/ha rate during the seeding year. Second‐year alfalfa yield~ increased at seeding rates up to 9.0 kg/ha of PLS at Gayville and Brookings, and up to 13.5 kg/ha at Norbeck. Generally, herbage crude protein content was not affected by seeding rate. Root+crown weights of alfalfa decreased as seeding rates increased up to 13.5 kg/ha.
Accumulation of Dry Matter and Nitrogen Content of Burley Tobacco Growing in Fertilizer‐induced Acid Soil1
Authors: Sims J. L. , Atkinson W. O. 
Published: July 2010

AbstractNicotiana tabarum L. cv. ‘Burley 21’ was grown in the field to determine the influence of rate of N fertilization on accumulation of dry matter and certain nitrogenous constituents during the growing season. Nitrogenous compounds in tobacco are presently of interest from a human health standpoint and the chemical constituents of tobacco leaves are known to be associated with dry matter accumulation.Accumulation of dry matter, protein N, and total N in plants treated with high rates of N fertilizer (up to 450 kg N/ha) was slower than in plants not fertilized or those fertilized with low rates of N during the early part of the growing season. The reduced rates of accumulation were particularly evident until near the flowering stage of growth (70 to 77 days). Thereafter, accumulation plants treated with high rates of N equalled or exceeded that in plants treated with low rates. Weight of dry matter and all measured constituents were greatest in high N treatments at harvest; however, N fertilizer delayed maturity 1 to 2 weeks.Exchangeable Mn in soil and concentration of Mn in leaves near 40 days increased as N fertilizer level increased. Values for Mn were lower than the literature would suggest as likely to produce toxicity in plants. Thus, factors in addition to Mn toxicity must be considered to explain the observed reduction of early growth by N fertilizers.
Effect of Narrow Trenching in Harlingen Clay Soil on Plant Growth, Rooting Depth, and Salinity1
Authors: Heilman M. D. , Gonzalez C. L. 
Published: July 2010

AbstractNarrow, backfilled trenches (61 and 102 cm deep) were tested in a Harlingen clay soil as a management technique to increase rooting depth and volume of soil available to roots. Cotton (Gossypium hirsutum L.) was planted directly over the trenches each year for 3 years. Cotton yields were significantly increased by trenching during 1971 and 1972. Yields of 815, 995, 1163, and 1018 kg/ha were obtained during 1972 for check, 61‐cm trench soil‐backfilled, 61‐cm trench, soil‐vermiculite backfilled, and 102‐cm trench soil‐backfilled, respectively. Root penetration and distribution was increased from 60 cm for conventional tillage to 122 cm for 102‐cm deep trenches. An average of 83% of roots for conventional tillage were in surface 30 cm as compared with 43% of 102‐cm trench.Trenching increased water infiltration rates, decreased soil bulk density in trenches, and increased soil root volume available to plants.A net reduction in soil salinity occurred for all trench treatments. The greatest reduction was associated with the deepest trench (102 cm). The effects of trenches for decreasing salinity had persisted for 3 years, and it appeared that their effects will persist for several more cropping seasons.
Herbicides, Sprigging Rates, and Nitrogen Treatments for Establishment of Tifway Bermudagrass1
Authors: Johnson B. J. 
Published: July 2010

AbstractThis study was conducted to determine the best system for controlling weeds during the establishment of ‘Tifway’ bermudagrass (Cynodon sp.) without causing injury to the turfgrass. Sprigging rates did not significantly affect the turf ground cover after a 5 to 6‐month growing season. However, for a shorter growing season, the rate of establishment was increased with the higher rate (2.0 vs 0.5 or 1.0 m2/are) of sprigging. Nitrogen (490 g/are) applied at biweekly (eight applications) or monthly (four applications) intervals significantly increased turf ground cover and turf appearance as compared with turf not receiving N. Treatments of dimethyl tetrachloroterephthalate (DCPA) retarded early growth of Tifway bermudagrass. The plants had overcome this growth retardation by 11 weeks following sprigging. Postemergence treatments of monosodium methanearsonate + 2,4‐dichlorophenoxy acetic acid (MSMA + 2,4‐D) were nonphytotoxic to the turfgrass. Sequential treatments of DCPA followed with MSMA + 2,4‐D resulted in excellent season long weed control and the plots had 86% ground cover of turf at the end of the growing season. The turf ground cover was only 36% in plots not treated with any herbicide and 68% in plots treated with DCPA. Repeated postemergence treatments of MSMA + 2,4‐D resulted in good to excellent weed control and these plots had 91 to 96% turfgrass ground cover.
Evaluation of a Thermocouple Hygrometer for Measuring Leaf Water Potential In Situ1
Authors: Campbell Gaylon S. , Campbell Melvin D. 
Published: July 2010

AbstractSeveral methods for measuring leaf water potential in situ with thermocouple psychrometers or hygrometers have recently become available. Disadvantages of these methods include difficulty in construction or use, or excessive modification of the leaf environment. Comparisons between in situ and other measurements are generally lacking. We constructed an aluminum hygrometer which is relatively easy to build and use and covers only about 1.5 cm2 of leaf area. This hygrometer was tested in the laboratory and the field and readings were compared with those made with a pressure chamber for several plant species.The leaf hygrometer worked well in both field and laboratory situations. Comparisons between readings with the leaf hygrometer and a pressure chamber gave regression lines with slopes of 1, but the average pressure chamber reading was 0.4 to 1 bar lower than that obtained with the leaf hygrometer. The leaf hygrometer appeared to respond to plant water potential changes in less than 30 minutes. The equivalent error due to temperature gradients within the chamber was found to be less than 0.4 bar. Measurement precision with this technique appears to be about 1 bar or better.
Corn Yield as Affected by Fertilization and Tillage System1
Authors: Fink Rodney J. , Wesley Dean 
Published: July 2010

AbstractRecent adoption of no‐tillage planting systems by many farmers has raised questions concerning comparative yields with conventional tillage systems and problems associated with nutrient absorption. No‐tillage systems generally require surface application of P and K, thus studies are needed to determine whether surface‐applied nutrients can supply plant needs. The objectives of this study were to determine 1) the desirability of applying P and K on the soil surface, 2) comparative yields between zero‐tillage and conventional‐tilled corn (Zea mays L.) production systems, and 3) the movement of P and K into the soil profile.Two soil types, an Ipava and a Clinton silt loam, were selected for these studies. A completely randomized experimental design with four replications was utilized on each soil type. Soil samples were taken at four depths of the soil profile at initiation of the studies and again during the final year. Soils were analyzed for P and K in order to determine the movement of surface applications of these nutrients.Movement of P and K into the soil profile following surface application on untilled areas was slow with both nutrients—K moved more rapidly than P. Following 2 years without P or K, yield levels were restored on plots receiving one annual application of both nutrients. Average yields of corn were similar on both tillage systems on both soil types.Yield trials produced similar yields with conventional and with zero‐tillage systems, although some problems occurred with reduced‐tillage systems. Surface application of P and K was a satisfactory method of meeting the plant needs for these nutrients.
Reflectant Induced Modification of Soybean Canopy Radiation Balance. I. Preliminary Tests with a Kaolinite Reflectant1
Authors: Doraiswamy Paul C. , Rosenberg Norman J. 
Published: July 2010

Abstract‘Amsoy’ soybeans (Glycine max (L.) Merr.) grown at Mead, Nebraska were coated with kaolinite during 1969 and 1970 to test whether reflection of incident solar radiation can be effectively increased in the field. Increased reflection reduces the amount of radiant energy available and hence reduces the quantity of water consumed by transpiration. Total reflection (300 to 3,000 nm) from the coated crop, measured with an inverted pyranometer, was increased by about 8%. Net radiation was decreased by about 8%. Spectral reflection, measured with a spectroradiometer, was increased primarily in the visible range (380 to 750 nm). Treatment induced differences in reflection were minor in the near infra red range (750 to 1,150 or 1,550 nm). Treatment caused some redistribution of light onto the lower canopy. Results of this preliminary study indicate that the radiation balance of field grown soybeans can be altered by application of reflectant materials.