bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen Fertilization of Corn and Sorghum Grown in Oxisols and Ultisols in Puerto Rico1
Authors: Fox R. H. , Talleyrand H. , Bouldin D. R. 
Published: July 2010

AbstractThe requirement of fertilizer N for high yields, its generally high price, and the ever‐present possibility of large leaching losses of inorganic N makes it essential that fertilizer N be managed as efficiently as possible in the humid tropics. Three rates and 2 times of application of fertilizer N were applied to 15 corn (Zea mays L.) and 3 sorghum (Sorghum bicolor Moench) crops on 2 Ultisols and 3 Oxisols during 5 successive growing seasons in Puerto Rico to determine the most effective means of applying fertilizer N to these crops. Additional objectives were to determine the apparent recovery of fertilizer N by the crops; the interrelationships between crop yield, N fertilization and soil inorganic N content; and the effectiveness of slow‐release sulfur‐coated urea as a source of fertilizer N for corn and sorghum. All soils had been under cultivation for at least 50 years and received relatively high rates of fertilizer for the last 20 years.The results indicated that: 1) postplant sidedress applications of fertilizer N resulted on the average in higher yields and plant recovery of fertilizer N than preplant applications; 2) when there were no limiting factors of climate or disease, and there was a response to N, the recovery of postplant applied N was comparable to that observed in temperate areas; 3) maximum corn grain yields were approximately 6.3 metric tons/ha; near‐maximum corn grain yields were obtained with 67 kg/ha of postplant‐applied N; 5) preplant‐applied sulfur‐coated urea was no more effective than preplant urea in increasing yields or N recovery; 6) soil inorganic N content was generally not a good index of soil N supplying power in these soils; 7) drought and disease frequently reduced yields; 8) there was very little residual effect of the fertilizer N applied in this experiment; and 9) the clayey Oxisols and Ultisols in Puerto Rico had a relatively high N‐supplying power.
Plant Height, Grain Yield, and Yield Component Relationships in Spring Wheat1
Authors: McNeal F. H. , Smith E. P. , Berg M. A. 
Published: July 2010

AbstractThe relationships of grain yield to plant height and yield components in spring wheat (Triticum aestivum L.) were studied in two yield nurseries in 1971 and 1972 at Bozeman, Montana, in order to determine if selection should be directed at yield, or at yield components. Genetic and environmental effects were separated by correlation analysis and analysis of variance.Correlation coefficients computed with various combinations of replications, years, and cultivars or selections (genotypes) showed that cultivars account for most of the variation among both plant height and yield component comparisons. Simple correlation coefficients showed that grain yield was more closely related to heads/4.9 m than with kernels/head or kernel weight. A multiple correlation analysis between grain yield and yield components was found to be significant for only one of the two nurseries. Simple correlations among the three yield components were either negative or of a nonsignificantly positive value.We were unable to determine whether selection should be based on grain yield or on one or more of the yield components. However, the r values among yield components provided very small R2 values, suggesting that compensating effects among yield components were small in this study.
Water Relations of Cotton. I. Root Growth and Water Use as Related to Top Growth and Soil Water Content1
Authors: Taylor Howard M. , Klepper Betty 
Published: July 2010

AbstractMany experiments have evaluated the effects of decreasing soil water contents on top growth and yield of plants, but few experiments simultaneously have evaluated root growth.An experiment was conducted to determine the response of cotton (Gossypium hirsutum L. ‘Auburn 623b’) roots and tops to decreasing soil water content. Plants were grown m rhizotron compartments with rainfall excluded by metal covers over the soil. Soil profile or irrigation schedule treatments provided different levels of soil and plant water potentials. Soil water content was determined with a neutron probe; rooting density, from measurements of roots on the glass viewing surface of each compartment. Plant water potential was determined with a pressure chamber apparatus, and top growth was evaluated by plant height.At the same time that total root length stopped increasing plant top growth slowed or ceased, and plant water potential near sunrise decreased. Root length ceased to increase when the soil water content of any layer decreased to about 0.06 to 0.07 cm3/cm3, which corresponds to a soil water potential slightly wetter than −1 bar or a hydraulic conductivity of about 2 ✕ 10−4 cm/day. Thus, for conditions of this experiment, cotton root growth was correlated with decreases both in plant water potential and in soil water content.
Comparison of Different Phosphorus Extractants in Soils of the Western State of Nigeria1
Authors: Oko Bernard F. D. , Agboola Akinola A. 
Published: July 2010

AbstractResearchers in Western Nigeria have a problem in choosing a universally accepted extractant for soil test correlations. Many P extractants that are in use today have been adopted without sufficient investigation.In the present study, 8 different P extractants were used in extracting P from 90 surface soil samples taken from 2 different ecological zones of the Western State of Nigeria. Soil P values for the different extractants before the first crop of rice (Oryxa saliva var. ‘OS6’ upland rice) were correlated with P uptake of the first crop, cumulative P uptake (P uptake for two croppings of 8 weeks each), and with cumulative yield (dry matter for two croppings). Soil P values after first crop were correlated with P uptake of the second crop.Results suggested that different ecological zones may require different extractants, viz. Bray No. 2 (0.03 N NH4F + 0.1 N HC1) (r = 0.433*) for the swamp soils; Bray No. 4 (0.5 N NH4F + 0.1 N HC1) (r = 0.491**) for the Ikenne soils, and Bray No. 1 (0.03 N NH4F + 0.025 N HC1) (r = 0.383*) for the Ilora soils, but the general purpose extractant for rice in soils of the Western State was Bray No. 1 (r = 0.372***).With the swamp soils, there was a negative correlation when soil P after first crop was correlated with second P uptake. The North Carolina extractant (0.05 N HC1 + 0.025 N H2SO4) (r = 0.462**) gave the best reliability for Ikenne soil. The Bray Nos. 1 and 2 were equally useful in both correlations for the above, as well as initial soil P with first P uptake although there was a slight preference in the former for the Bray No. 2 (r = 0.513**) over Bray No. 1 (r = 0.396*). For the 90 soil samples, Bray No. 2 (r = 0.279**) gave better correlation between soil P after first planting with second P uptake.Correlation of initial soil P with one cropping of 8 weeks was better for swamp soils, whereas in Ikenne soils more confidence could be placed on correlations with second cropping and cumulative P uptake. For the Ilora soils and with a combined group (consisting of 90 soil samples) there was little or no significant difference in using either.
Effect of Simazine and Diuron on the Nitrogen Content and Dry Weight of Wheat and Sorghum1
Authors: Rottman G. A. , Tweedy J. A. , Kapusta George 
Published: July 2010

AbstractStudies were conducted to determine if 2‐chloro‐4,6‐bls‐(ethylamlno‐s‐triazine (simazine) or 3‐(3,4‐dichlorophenyl)‐l,l‐dimethylurea (diuron) increased the nitrate or Kjeldahl N content in the shoots or roots of wheat (Triticum aestivum L.) or soghum (Sorghum blcolor (L.) Moench)plants. Wheat and sorghum plants were grown in nutrient solutions containing several concentrations of these two herbicides for various time intervals. Nitrate N and Kjeldahl N were determined in shoots and roots and expressed as totals per plant.Simazine‐ and diuron‐treated wheat plants had a higher nitrate N content and lower dry weight than control 6 days after treatment. The Kjeldahl N per six plants was reduced by diuron and was not affected by simazine. Diuron at 0.25 ppm was phytotoxic to wheat. An increase in nitrate was usually accompanied by a decrease in dry weight.
Corn Cob Hemicellulose Composition of Corn Isolines Involving Several Mutant Genes1
Authors: Helm J. L. , Donnelly B. J. , Glover D. V. 
Published: July 2010

AbstractAll economically successful xylose production procedures require a carbohydrate source rich in hemicellulose and with a minimum content of other pentose sugars. Mature corn (Zea mays L.) cobs are a good source of hemicellulose. However, birchwood sulphite liquor has been a more economical raw material for xylose production in recent years. A strong pleiotropic or linkage relationship between genes used in today's specialty corn programs and increased hemicellulose content or improved composition would facilitate a program to purchase corn cobs of known genotype. The inbred line Oh43 and its isogenic counterparts homozygous for the recessive endosperm genes wx, su1; du, su2, o2 and ae were tested tor hemicellulose content and composition. The results indicate no relationship between composition of mature cobs and any of the six recessive endosperm genes either in a pleiotropic or linkage sense. Additional visual marker genes should be evaluated so that corn cobs could be used as an economically suitable raw material in a xylose production program.
Multiple Assignment Tester Animals for Pasture‐Animal Systems1
Authors: Matches A. G. , Martz F. A. , Thompson G. B. 
Published: July 2010

AbstractDifferent forages or management practices are often evaluated as separate entities in conventional grazing trials. A more meaningful approach is to evaluate “pasture systems” for season‐long grazing, whereby separate pastures of different forages or managements comprise a pasture system, and each component is grazed at different periods during the season. The purpose of this paper is to stress the need for the evaluation of different forages or management practices within the framework of a total system and to suggest two practical experimental designs for pasture‐animal system experiments.Two types of pasture systems using multiple assignment testers are proposed: 1) systems with separate pastures and 2) systems with common pastures. With multiple assignment testers and common pastures, several pasture systems may be compared simultaneously, but require fewer pastures per replication. For example, only 6 pastures are needed for a 3 ✕3 system trial with common pasture, as compared to 18 pastures per replication for system trials with separate pastures. Animal and pasture production may be compiled for the total system and for each component of the system. Multiple assignment tester animals are defined as tester animals assigned to graze two or more components comprising a pasture system.In evaluation of the concept of pasture systems, experimental errors for measuring beef cattle gain per hectare and average daily gain per animal were nearly the same for grazing trials analyzed as a conventional trial and as a system trial with common pastures. The season‐long pasture system approach in grazing research provides the cattle producer with more realistic information on which to plan his pasture program.
Field Use of Microwatersheds with Vertical Mulch1
Authors: Fairbourn Merle L. , Gardner H. R. 
Published: July 2010

AbstractMicrowatersheds and vertical mulch were tested at the Central Great Plains Field Station, Arkon, Colorado, to determine if their effects on storage and use of soil water in the field were similar to responses obtained in the laboratory. Treatments consisted of microwatersheds with vertical mulch, microwatersheds without mulch, and a flat surface control. Each treatment was replicated twice on both crop and fallow plots. All microwatershed plots had slopes treated with a hydrophobe to increase water runoff and check dams placed at uniform intervals across row areas to keep the water on the plots. Biweekly soil water measurements were made during each growing season by gravimetric analysis in 1972 and by the neutron method in 1973. Grain sorghum [Sorghum bicolor (L.) Moench] was grown and plant harvests were made at the end of each crop season. Soil water evaporation was lowest on the microwatershed with vertical mulch treatment as a result of concentration and deep infiltration of precipitation. Increased soil water storage was the major factor responsible for an increase in grain sorghum yield on the vertical mulched microwatershed ranging from 37 to 150% above the control treatment. The vertical mulched microwatersheds seem to have the potential for increasing and stabilizing annual yields in semiarid regions.
Effects of Nitrogen Rate, Source, and Various Anions and Cations on NO3 Accumulation and Nutrient Constituents of Table Beets1
Authors: Cantliffe D. J. , Goodwin P. R. 
Published: July 2010

AbstractExcessive N fertilization of table beets (Beta vulgaris L.) can be expensive and can be detrimental to quality of the processed product. The type of N fertilizer applied can lead to differential absorption of N, NO3‐N and other plant constituents. The objectives of the present study were to apply various N fertilizer sources, rates, and supplemental anion‐cation fertilizers to table beets to determine their effect on yield and tissue concentrations of NO3‐N, total N, and other nutrient constituents. Nitrogen as NaNO3, KNO3, NH4C1, (NH4)2SO4, and NH4NO3 was broadcast at rates of 0, 112, and 224 kg N/ha to table beets grown on a fine sandy loam soil. Sodium as NaC1 and Na2SO4 and K as KCI and K2SO4 at rates of 224 kg Na or K/ha were applied to plants receiving 0, 112, or 224 kg N/ha from NH4NO3. Nitrate‐N, total N, P, K, Ca, Mg, Na, C1, Zn, Mn, and Fe were determined on freezedried table beet leaf blades, petioles and roots.Yield of roots as metric tons/ha or $/ha (graded) was significantly increased by each increment of N fertilizer. Although there were no significant differences between N sources used, yields were consistently higher from the NO3 sources. The addition of Na, K, Cl, and SO4 fertilizers had no significant influence on yield.The NO3‐N concentration in beet blades, petioles, and roots were significantly increased by increased amounts of N fertilizer. Nitrate concentrations were lowest in plants receiving NH4 and highest in those receiving NO3 fertilizers. The total N concentration in the plants was increased by N fertilizer. Total N was higher in roots receiving NO3 than those receiving NH4 fertilizer and was lowered below controls not receiving N fertilizer by Na or K. In the blades, these trends were reversed.Nitrogen rates and sources, and cation sources had a varied effect on the tissue concentrations of the other elements that were examined depending on the plant part tested.
Planting Date Effects on Yield, Height, and Stem Diameter of Kenaf1
Authors: Massey John H. 
Published: July 2010

Abstract‘Everglades 71’, ‘Guatemala 4’, ‘Guatemala 45,’ and ‘SH/15R’ kenaf (Hibiscus cannabinus L.) were planted at four 2‐week intervals in 1970–1972, to determine differential response to planting date. There was no planting date ✕ cultivar interaction for yield or plant height in any year, nor for stem diameter in 1970. In 1971, yield tended to decrease with successively later planting dates and was 66% lower at the last as compared with the first planting, but in 1970 and 1972 planting date did not affect yield. Stem diameter and plant height also were reduced by later planting in 1971. Everglades 71 in 1971 and SH/15R in 1972 produced higher yields than the other cultivars. Basal stem diameter of SH/15R was greater than that of other cultivars in 2 of 3 years. Generally, cultivars did not differ in plant height in any year. Results indicate that there was no advantage of one cultivar or planting date over the others tested.
Effect of Preplant‐Only Irrigation on Cotton Yields1
Authors: Bilbro J. D. 
Published: July 2010

AbstractIrrigation practices for cotton (Gossypium hirsutum L.) are changing on the Texas High Plains because the irrigation water supply is declining. The objectives of this study were to calculate yield probabilities for cotton planted on both early and late dates and grown with only a preplant irrigation, and then to compare these yield probabilities with those previously calculated for dryland conditions. Yields from early and late plantings that had received only a preplant irrigation for the period 1960 through 1971 were used for calculating probabilities for various yield levels.The expected average yields (50% probability) of the early and late plantings of preplant‐irrigated cotton are 530 and 503 kg/ha, respectively; and about 70% of the time the respective yields will differ by less than 50 kg/ ha. Thus, the yield potential of preplant‐irrigated cotton was not greatly affected by a wide range of planting dates. Also, 50% of the time preplant‐irrigated land can be expected to yield about twice as much as comparable dryland and to vary much less in year‐to‐year yields.
Residual Fertility in Soil Continuously Field Cropped to Corn by Conventional Tillage and No‐Tillage Methods1
Authors: Moschler W. W. , Martens D. C. , Shear G. M. 
Published: July 2010

AbstractThe increasing importance of no‐tillage crop culture merits investigation of its many aspects. Reports to date on no‐tillage corn (Zea mays L.) fertilization or liming have not fully clarified the requirements, especially with respect to effective utilization of the nutrient elements, which must necessarily include residual supplies left in the soil.This paper reports comparative residual nutrient elements in the 0 to 20, and 20 to 40 cm soil layers after 11 consecutive years of corn grown in the field by no‐tillage and conventional tillage methods. Corn grown by both methods had received the same amounts of calcitic limestone and fertilizer. The data on residual fertility were obtained by repeated greenhouse cropping without lime or fertilizer, followed by testing the soil for pH and acid‐extractable nutrient elements. Greenhouse recovery of residual nutrient elements, coupled with residual soil supplies, were used to draw conclusions.Considerably more P and slightly more N were recovered in the greenhouse corn at the 0 to 20 cm soil depth when no‐tillage corn had been grown than where conventionally tilled soil had been grown. Acid extractable P and Ca, after greenhouse cropping, were higher in no‐tillage soil than in conventionally tilled soil.More Mg and less K were recovered in the greenhouse corn from no‐tillage soil than from conventionally tilled soil at the 20 to 40 em depth. Soil pH and acid extractable P were higher and Mg was lower, after greenhouse cropping, in no‐tillage soil when compared to conventionally‐tilled soil.The increases in soil pH and extractable P at the lower soil depth that were found in no‐tillage soil were assumed to be from chemical or biological causes, or probably a combination of the two.The results of the study should be of considerable economic benefit for maintaining a more permanent soil productivity as well as of scientific interest in soil fertility behavior.
Yield and Botanical Composition of an Irrigated Grass‐Legume Pasture as Influenced by Fertilization1
Authors: Rehm G. W. , Nichols J. T. , Sorensen R. C. , Moline W. J. 
Published: July 2010

AbstractIrrigated pastures are becoming more important for animal production in several Great Plains and Western states. The majority of fertilization studies have been conducted at sites where surface irrigation practices were used on medium to fine textured soils. This study was designed to evaluate the effect of N, P, and K fertilization on forage production and grass‐legume composition of an irrigated pasture containing bromegrass (Bromus inermis Leys.), orchardgrass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) on sandy soils irrigated with automated sprinkler systems.Forage yields were recorded for 3 years at two sites and plant separations to determine the grass‐alfalfa composition were made at one of the two sites. The response to increasing levels of N was curvilinear at both sites throughout the 3‐year period. The application of 252 kg N/ha produced maximum yields at the Holt County site, whereas the use of 560 kg N/ha produced the maximum yields at the North Platte site. These N rates produced increases of 4.7 and 7.0 metric tons/ha, respectively. The response to applied P was linear at the Holt County site but had little influence on yields at the North Platte site. Applied K had no influence on forage yields at either site.Fertilization influenced the grass‐legume composition at the Holt County site to some extent, but trends were not consistent for the 2 years. The data show that N rates in excess of 252 kg/ha decreased the percentage of grass in the mixture while increasing the percentage of alfalfa. Since clipping frequency may have had some influence on grass‐legume composition, changes in the percentage of grass and alfalfa in the mixture cannot be entirely attributed to fertilization.
Relation of Hydrocyanic Acid Potential to Morphological Characteristics and Dry Matter Percentage of Sorghum1
Authors: James John H. , Gray Elmer 
Published: July 2010

AbstractAll Sorghum species are believed to have the potential of producing hydrocyanic acid, and thus, the common usage of Sorghum as a forage results in the threat of poisoning to cattle. Since the determination of hydrocyanic acid potential (HCN‐p) is laborious, we sought to ascertain whether it is possible to predict HCN‐p from other more easily measured plant characteristics.The relationships of HCN‐p to various morphological plant characteristics and dry matter percentage of six sorghum types were studied in 1970 and 1971. Significant differences among the cultivars were found both years for all the plant characteristics—height, diameter of culm, length of stem, number of leaves, width and length of third leaf, dry matter percentage, and HCN‐p. Most of the correlation coefficients between HCN‐p and the morphological characteristics of the cultivars were not significant. Correlation coefficients between HCN‐p and dry matter percentage were all negative, and most were highly significant. It was not possible to predict HCN‐p from measurements of the morphological characters. Although dry matter percentages were influenced by genotype and stage of development, relative differences in dry matter percentages were indicative of relative differences in HCN‐p.