bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting Nitrogen Fertilizer Requirements After Land Leveling1
Authors: Thomas J. R. , Heilman M. D. , Lyles L. 
Published: July 2010

AbstractReduced yields and nutrient‐deficient crops on cut areas after land leveling are recognized problems. The objectives of this study were to determine if the variability in crop production between cut and fill areas of leveled fields could be minimized without overfertilization by adjusting the soils to a uniform level of available N based on the soils' capacity to supply N (N index) and to relate the N fertilizer requirement to the N index.Five leveling methods which resulted in the removal of different amounts of top soil were used. Soils from leveled and nonleveled areas were incubated and the soils' capacity to supply N were described by the regression model N = a + bt1/2, where N is ppm of NO3‐N in the soil after t days incubation, and b is the N index. With a 14‐day incubation, the nonleveled soils supplied N at the rate of 174 kg/ha. Therefore, based on the leveled soils' ability to supply N in this time period, sufficient NH4NO3 fertilizer was applied to establish N levels of 174, 219, and 263 kg/ha. The leveled fields were cropped to forage sorghum (Sorghum bicolor (L.) Moench).Dry matter forage yields, N uptake, and the growth rate during the first 19 days of growth were significantly related to the N index. Uniform crop production over the whole area was achieved when the available N level of the top 30 cm of soil was adjusted to 174 kg/ha, except on the conventional leveled soils where all of the top soil was removed. A regression model was developed that expressed the N fertilizer requirement as a function of the N index.
Response of Lowland Rice to Time and Method of Application of Phosphate1
Authors: Patrick W. H. , Peterson F. J. , Wilson F. E. 
Published: July 2010

AbstractField experiments were carried out for several years with lowland rice (Oryza sativa L.) to investigate methods and time of application of phosphate. Drill application of P at seeding was compared to topdressing 2 to 3 weeks after seeding. Topdressing at various times after seeding were also compared. Drilling phosphate fertilizer at seeding was superior to early‐season topdressing. Topdressing 2 weeks after seeding gave higher yields than topdressing later in the growing season.
Zinc Accumulation by Corn Seedlings as Influenced by Phosphorus, Temperature, and Light Intensity1
Authors: Edwards J. H. , Kamprath E. J. 
Published: July 2010

AbstractZinc deficiencies of corn (Zea mays L.) are often associated with cool, cloudy weather and appear to be intensified with high P fertilization. Experiments were conducted under controlled conditions to determine the effect of light intensity, temperature, and P on the uptake and translocation of Zn.Corn seedlings were grown at 30,000 lux light intensity for 6 days in nutrient solutions containing either 0 or 0.1 mM P and at 18/14C or 30/26C day‐night temperatures. The seedlings were then exposed to Zn solutions of 0, 0.4, and 0.8 μM Zn for 48 hours with the same temperatures being maintained as during the initial growth period. Phosphorus pretreatment had no effect on Zn accumulation or translocation. At the low temperature there was very little uptake of Zn from an external solution.In a second experiment, corn seedlings were grown for 6 days in a complete nutrient solution at light intensities of 19,300, 25,800 and 30,000 lux and temperatures of 18/14C or 30/26C. The seedlings were then exposed for 48 hours to treatments of 0, 0.4, and 0.8 μM Zn containing either 0 or 0.1 mM P. The initial temperature and light intensities were maintained during the uptake period. Phosphorus treatments did not affect Zn translocation to the shoots. Temperature influenced the translocation of Zn. More Zn accumulated in the roots at the lower temperature than at the higher temperature. Also, total Zn accumulation was reduced markedly as light intensity was decreased from 30,000 to 19,300 lux. At low light intensity Zn contained in the seed was the main source of Zn for young corn seedlings.The shoot‐to‐root ratio increased with a high supply of P. With decreasing light intensity, root growth decreased and shoot.to‐root ratio increased. The effect of low light intensity in reducing root growth more than shoot growth appears to be an important reason for the occurrence of early season Zn deficiencies.
Chemical Regulation of Grass Growth. I. Field and Greenhouse Studies with Tall Fescue1
Authors: Elkins D. M. , Suttner D. L. 
Published: July 2010

AbstractGrowth control of grass and other vegetation has been achieved on a limited scale by the use of chemical retardants on highway roadbanks and similar rough turfgrass areas. A few chemical growth retardants are available commercially and a number of experimental chemicals have been developed recently. Five greenhouse experiments and four field studies were conducted from 1970 to 1972 at Southern Illinois University to evaluate commercial and experimental chemical retardants on ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.), one of the leading grasses used in Illinois for roadbank stabilization. Nineteen chemicals or formulations were tested with potted tall fescue in the greenhouse and several rates of eight different chemicals were evaluated under field conditions. On selected dates after treatment, grass plots were evaluated as to height, color maintenance, stand losses, and weed infestations.In greenhouse trials the most promising results were obtained with Slo‐Gro, a maleic hydrazide (MH) formulation [diethanolamine salt of 6‐hydroxy‐3‐(2H)‐pyridazinone]; MON‐820 (N‐phosphonomethylimino‐diacetic acid); MON‐845 [N,N‐Bis(phosphonomethyl)glycine]; MBR‐6033 (3‐trifluoromethyl‐ sulfonamido‐p‐acetotoluidide); and Maintain CF‐125 (methyl‐2‐chloro‐9‐hydroxyfluorene‐9‐carboxylate, methyl‐9‐hydroxyfluorene‐9‐carboxylate, methyl‐2, 7 dichloro‐9‐hydroxyfiuorene‐9‐carboxylate). MBR‐6033 showed considerable potential in providing balanced control of growth while enhancing or maintaining a desirable green color. Sustaining color was difficult with other chemicals evaluated when used at rates sufficient to reduce growth over a long time interval.MON‐820, MON‐845, Slo‐Gro (MH), and Maintain CF‐125 reduced grass growth and dry matter yield markedly at selected rates in field studies. However, color deterioration, stand reduction, and weed infestation were serious at higher chemical rates. MON‐814 (ethanolamine‐p‐nitrobenzene‐sulfonylurea), MON‐139 (phosphonomethylglycine, isopropyl‐ammonium salt), and MON‐464 (phosphonomethylglycine, calcium salt) were less consistent in reducing growth while sustaining color. Slo‐Gro, MBR‐6033, and Maintain CF‐125 effectively suppressed tall fescue seedhead development.Information gained from these studies indicates that treatment with selected commercial and experimental growth retardant chemicals can result in effective tall fescue growth control and seedhead suppression. In some instances, chemical treatment of grass resulted in some degree of phytotoxicity and grass color losses. A notable exception was treatment with MBR‐6033 (Sustar), which gave good growth control while maintaining or enhancing grass color.
Diversity and Suitability for Hybrid Production of Different Sources of Cytoplasmic Male Sterility in Maize1
Authors: Gracen V. E. , Grogan C. O. 
Published: July 2010

AbstractThe epiphytotic of Helminthosporlum maydis, race T, in 1970 on the Texas male sterile cytoplasm demonstrated the dangers of using a uniform cytoplasm for hybrid corn production. Resistance to H. maydis, race T, was obtained by switching to non‐male‐sterile cytoplasms. This shift increased cytoplasmic diversity but necessitated the return to detasseling female parents. Sources of male sterile cytoplasms resistant to H. maydis, race T, are known and are being substituted for non‐male sterile cytoplasms in the production of commercial corn hybrids. We have proposed that a return to male sterile cytoplasm is practical if precautions are taken to ensure that cytoplasmic diversity is maintained. It was our objective in this study to determine the extent of diversity as measured by differential fertility restoration reactions within most of the known sources o[ cytoplasmic male sterility and to evaluate the suitability of each male sterile cytoplasm for hybrid production in various inbred backgrounds. We, therefore, examined the fertility restoration of 38 sources of cytoplasmic male sterility in 28 inbred backgrounds. The sources of male sterility could be divided into three groups (C,S, and T groups) with similar fertility restoration patterns within groups by 11 of the inbred lines. Cytoplasmic sources B, CH, D, EP, LF, NT, OY, SG, 181, and 234 did not fit the fertility restoration pattern of any of these groups. Although three groups of cytoplasms were distinguished, the fertility restoration reactions with some inbred lines indicated diversity within the groups. Sixteen inbred lines restored certain members of a group of cytoplasms but failed to restore others. Most of the inbreds tested formed fully male sterile combinations with several cytoplasmic sources. The feasibility of producing hybrid corn utilizing a physical mixture of male sterile cytoplasms (multiplasm) to insure cytoplasmic diversity is discussed.
Effects of Nitrogen Levels and Row Widths on Kenaf1
Authors: Massey John H. 
Published: July 2010

AbstractKenaf (Hibiscus cannabinus L.), a potential annual crop source of paper pulp, was grown to determine the effects of nitrogen levels and row widths on yield and other characteristics. Nitrogen level, up to 112 kg/ha, did not affect dry matter yield of plant height but at 90 kg/ha, N increased stem diameter. In 1 of 2 years, kenaf in 36 cm rows outyielded 71 cm rows. Basal stem diameter was greater in 71 than in 36 cm rows, but row width did not affect plant height.
Fate of 15N‐Labeled Anhydrous Ammonia under Simulated Fall and Spring Conditions1
Authors: Chalk P. M. , Keeney D. R. 
Published: July 2010

AbstractMany farmers have found that Fall application of anhydrous NH3 has economic advantages over Spring application. Differences of opinion exist, however, and previous investigations at this station have shown that higher losses of N fertilizer occur when applied in Fall. Precise evaluation of the mechanisms involved are difficult in field studies, and therefore a greenhouse experiment was conducted in which the major variable was application of 15N‐labeled anhydrous NH3 before or after a freeze‐thaw cycle, simulating Fall and Spring applications, respectively. Three soils were used. One, a Pella sil, was high in organic matter (4.44% organic C). The other two soils were the same soil type (Plano sil), but differed in that one was acid (pH 4.9) and the other was close to neutral (pH 6.3). Three or 4 crops of ryegrass (Lolium multiflorum) were grown, and the amount of 15N in the plants and in the soil was determined.Only small losses of fertilizer N (<5%) occurred in the acid Plano soil that was left fallow or cropped to ryegrass. Similar N recoveries were obtained in the pH 6.3 Plano soil and the Pella soil cropped to ryegrass, but losses increased substantially in fallow pots. The magnitude of the losses were directly related to the organic matter content and initial pH of the soils. We found that freezing and thawing of soil significantly increases the rate of denitrification. Fall application of NH3 may lead to significant fertilizer losses by denitrification, since other studies have shown that substantial nitrification will occur in Fall and early Spring.
Simultaneous Uptake of Water and Solutes by Plant Roots1
Authors: Dalton F. N. , Raats P. A. C. , Gardner W. R. 
Published: July 2010

AbstractA theory describing the hydraulic and osmotic transport of water and the diffuse, convective and active transport of solutes across root membranes is formulated. The theory predicts the dependence of the ratio of the osmotic pressures of the nutrient and xylem solutions and of the solute flux upon the rate of water uptake. The theory also predicts a nonlinear relationship between the flux of water and the pressure difference across root membranes. The results are shown to be in good qualitative agreement with a variety of observations on simultaneous uptake of water and solutes.
Diurnal Fluctuation of Leaf‐water Potential of Corn as Influenced by Soil Matric Potential and Microclimate1
Authors: Reicosky D. C. , Campbell R. B. , Doty C. W. 
Published: July 2010

AbstractWater stress during critical growth periods is frequently the limiting factor in crop production. However few data are available on the variation of plant water status under field conditions. The object of this work was to quantify the effect of soil matric potential on plant water status. Sweet corn (Zea mays L.) was grown on a Varina sandy loam soil to determine the effect of the microclimate and irrigation on leaf water potential. Soil water stress was imposed naturally and by use of automated portable shelters that covered the plots during rainfall.Leaf‐water potential was closely related to the diurnal change of incoming energy. A maximum leaf‐water potential of −1.5 bars occurred just prior to sunrise. The minimum value, which occurred during the peak radiation load or stress, was dependent on soil matric potential and stage of plant development. Before tasseling, soil matric potentials of −0.08 and −0.60 bar at the 15‐cm depth in irrigated and nonirrigated plots resulted in minimal leaf‐water potentials of −12 and −18 bars, respectively. After tasseling, soil matric potentials were −0.07 bar at the 15‐cm depth in the irrigated and −3.0 bars in the nonirrigated plots, and the same minimal leaf‐water potential of −18 bars developed for both. Under the same radiation load, minimal leaf‐water potential of irrigated plants was −12 bars before tasseling and − 18 bars after tasseling. The results demonstrate the need to evaluate the influence of environmental stresses and soil water deficits on leaf‐water potential and associated physiological processes.
Correlation Between NaHCO3‐extractable P and Response to P Fertilization in Pot Tests1
Authors: Matar A. E. , Samman M. 
Published: July 2010

AbstractPot tests were used to estimate potential fertility of major Syrian soils. Soil samples were collected from 270 sites throughout Syria.The relative increase in dry weight yield of wheat (Triticum vulgare L.) seedlings due to the addition of P was calculated. The response of soils to addition of P varied widely among soil groups, depending upon the parent material, degree of weathering, age of the soils, and other factors.The degree of response to P fertilization by the pot test method was calibrated with the response in 20 field tests giving a correlation coefficient of r = 0.81.The NaHCO3‐extractable P in soils studied in pot tests was correlated with the relative increase in wheat yield due to the addition of P fertilizers to soils. The correlation coefficient was poor, when all soils were considered as one group, with r = −0.03. Correlation was improved when the soils were grouped according to its genetic origin, into four major groups. Correlation coefficients (r) between the NaHCO3‐extractable P and the yield response to P addition were: −0.69, −0.87, −0.89, and −0.64 for basaltic, Euphrates Valley, Khabour Valley, and limestone soils, respectively.It was concluded that the pot technique used was satisfactory to estimate the potential fertility of soils and that estimation of the available P in soils by the NaHCO3 method is adequate for soils of diverse genetic origin.
Soil Temperature Increases Induced by Subsurface Line Heat Sources1
Authors: Rykbost K. A. , Boersma L. , Jarman G. D. 
Published: July 2010

AbstractGenerating electricity using the steam cycle produces large quantities of waste heat. Conversion efficiencies range from 32 to 38% which means that for three units of energy input about one unit of electrical energy is produced and two units of waste heat must be disposed of.Circulating the condenser cooling water through a network of underground pipes would result in warming the soil. The present study was initiated to evaluate the effect of increased soil temperatures on crop growth, the energy balance of the proposed system, and the economic feasibility of the system. This report presents results of the energy balance studies.The proposed system was simulated by electrical heating cables, 92 cm deep with 183 cm spacing, maintained at temperatures ranging from 35 to 37 C. Soil temperatures were measured at hourly intervals over a 2‐year period at points forming arrays in planes perpendicular to the heat sources. The temperature measurements were recorded on magnetic tape and later processed to obtain desired information, such as daily averages at various depths. Energy input was measured with watt‐hour meters. With a bare soil surface the average daily soil Temperature at the 5 cm depth increased about 1.0 C during the summer and 1.5 C during the winter. At the 25 cm depth temperature increases were about 4.0 C and 5.5 C, respectively. The average daily temperature of the profile to a depth of 220 cm was increased about 10 C in the summer and 13 C in the winter. The rate of energy dissipation varied from about 0.012 cal/cm2/min in the summer to about 0.030 cal/cm2/min in the winter. During summer months heat flow from the soil to the atmosphere accounted for less than half of the total flux. During the winter the heat flux to the atmosphere accounted for most of the energy dissipation. Very large surface areas would be required to dissipate the waste eat generated by a power plant with an electrical output of 1,000 MW. The proposed system of soil warming is not an efficient primary heat sink. The rate of heat dissipation could be increased by placing the pipes closer to the soil surface and closer together.
Nitrate Contents of Sudangrass and Barley Forages Grown on Plots Treated with Animal Manures1
Authors: Pratt P. F. , Davis Sterling , Sharpless R. G. , Pugh W. J. , Bishop S. E. 
Published: July 2010

AbstractIn areas of high concentrations of domestic animals, such as the Chino‐Corona Basin in southern California, there is a tendency to use large amounts of manures on adjacent croplands. In these situations, there is a need to know the upper safe limits of manure use for protection of animals from excess nitrate (NO‐3) in forage and for the protection of groundwaters from NO‐3 and soluble salts. A field trial on the Moreno Farm of the Univ. of California, Riverside was conducted to respond to these needs. This paper presents the results of this experiment relative to the upper safe limits for NO‐3 in barley and sudangrass forages used by the dairy industry.Barley grown in the winter of 1972–73 and sudangrass grown in the summer of 1973 were analyzed for NO‐3. These crops represented the third year of an experiment with two manures (dry dairy corral manure and liquid manure from a feedyard) and two irrigation treatments (ET and 1.33 ET) on a Hanford sandy loam. Nitrate concentrations in barley decreased progressively as the crop grew, were higher with liquid than with dry manure, and were not affected by irrigation level. The NO‐3 concentrations in sudangrass generally increased as the crop grew until just prior to emergence of flower heads from the boot and then decreased, were higher with liquid than with dry manure, and were higher with the lower water level.Based on the NO‐3 content of sudangrass the safe annual rate of liquid manure, which had 4.8% N on a dry weight basis, for the particular management system in which half of the manure was applied at the time of planting of barley in the fall and the other half at time of planting of the sudangrass, was about 8.6 metric tons of dry weight/ha/year. The safe limit of dry manure, which contained 1.8% N on a dry weight basis, for the same croppingmanagement system was about 29 metric tons of dry matter/ha/year.
Growth and Element Accumulation by two Single‐cross Corn Hybrids as Affected by Copper in Solution1
Authors: Dragun James , Baker Dale E. , Risius Marvin L. 
Published: July 2010

AbstractIncreased use of land for “disposal” of industrial wastes and animal wastes such as poultry and swine manure from flocks and herds fed high levels of trace elements will require soil monitoring methods to maintain safe levels of these elements with respect to both crop production and the food chain. The objectives of this investigation were to: 1) measure Cu ion potentials, pCu, associated with minimum and maximum Cu ion activities for growth of corn (Zea mays L.) seedlings; 2) evaluate the influence of the chelator DTPA (diethylenetriaminepentaacetic acid) on plant uptake of Cu; and 3) relate pCu to uptake of Cu and other elements by single‐cross corn hybrids selected for genetic controlled accumulations of relatively high and low concentrations of leaf Cu.Two corn hybrids were grown in the greenhouse using solution cultures of varying pCu. Other essential elements were held constant in solution or supplied by frequent application to 100 g of soil supporting the plants above the solution. For the constantly aerated solutions, pCu, as calculated from formation constants of Cu‐DTPA complexes and pH and as measured with a Cu specific ion electrode, was biologically equivalent to those obtained for solutions devoid of DTPA. For both hybrids, root and top growth were reduced due to Cu toxicity when pCu was ≤ 5.78. A deficiency of Cu was associated with a pCu > 13. While Cu concentrations in plant tops increased with decreasing pCu for both hybrids, the hybrids were different as predicted from the performance of the parental inbred lines. At high levels of Cu (pCu of 5 to 7) hybrid differences and changes in plant concentrations of Cu with pCu in solutions indicated that plant composition could not be used to indicate toxic substrate levels of Cu.
Abnormal Color Response of Turf Ryegrass to Top‐Dressed Isobutylidene Diurea1
Authors: Volk G. M. , Dudeck A. E. 
Published: July 2010

AbstractIsobutylidene diurea (IBDU) is an excellent source of controlled‐release N for turfgrasses, but certain reports imply a generally low toxic potential not completely supported by recent Florida work. To evaluate toxicity, IBDU (0.7 to 1.4 mm diam. pellets) was used in single applications at 1 to 7.3 kg N/are rates on winter ryegrass (Lolium perenne L.) and at 1.5 to 5.9 kg N/are on bermudagrass (Cynodon sp.), the latter in all combinations with 0, 0.25, and 0.50 kg urea‐N/are every week, and of 0 and 2.4 kg Ca(OH)2/are at initiation of tests. A 2.2 kg N/are rate of IBDU resulted in chartreuse green ryegrass when soil pH was above 7.0. At 3.3 to 7.3 kg IBDU‐N/are the ryegrass was chartreuse‐yellow at 1 month after application, regardless of soil pH. Tissue analysis showed an excellent inverse correlation with Mn content. There was no off‐color response to sulfur‐coated urea or ureaform applied at N rates equivalent to those above. Color assessment by chlorophyll extraction with methanol supported visual observations. There was no toxic response of bermudagrass to IBDU at soil pH 5.1 to 7.3 or at any combination of IBDU with Ca(OH)2 and/or urea. Application of IBDU “fine” to ryegrass apparently should not exceed 2.0 kg of N/are if visual toxicity symptoms are to be avoided.
Seed Coating, Precision Planting, and Sprinkler Irrigation for Optimum Stand Establishment1
Authors: Robinson Frank E. , Mayberry Keith S. 
Published: July 2010

AbstractThe legal prohibition of the short handled hoe in California has forced a change in the conventional practice of surplus‐seedling and subsequent thinning to achieve optimum stands with lettuce (Lactuca sativa L.) and sugar beet crops (Beta vulgaris L.). Precision placement of coated seed was evaluated as an alternate method of stand establishment with five crops grown on Meloland sandy clay loam with sprinkler irrigation. Germination was compared to emergence of coated seed. Emergence was: carrot (Daucus carota L.) 86%, onion (Allium cepa L.) 85%, and sugar beet 71%. Single lettuce seeds 38 cm apart had 89% stand, paired seeds 2.5 cm apart on 38 cm intervals and thinned had 97%.