bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lime and P Applications and Their Residual Effects on Corn Yields1
Authors: Lim K. L. , Shen T. C. 
Published: July 2010

AbstractLime need for corn (Zea mays L.) production has been widely recognized in Malaysian soils. Little work has been done, however, to study the chemical behaviour of these soils after applications of lime. This field study was conducted to monitor some of the chemical changes in a Serdang colluvium (Tropofluvent) soil when lime and phosphate fertilizer were applied to corn. The residual effects of these treatments on the nutrition and yield of corn were also studied. Six consecutive corn crops were grown over a 2‐year period. Ground limestone (CaCO3) at 0, 3,000, and 6,000 kg/ha and P (triple superphosphate) at 50, 100, and 150 kg/ha were applied. Ground limestone was applied for the first crop and half of the P levels were applied for the first crop while the other for the second crop. Their residual effects were observed for six crops. Results indicated that 3,000 kg/ ha of limestone was sufficient to maintain yields for the first three crops while 6,000 kg/ha provided sufficient lime for all six crops. Grain yield responded significantly to 100 kg/ha P and continued to provide enough P through the sixth crop. Liming increased soil pH from 4.3 to 5.5 and decreased exchangeable AI and % AI saturation from 1.9 to 0.3 meq and 67 to 7%, respectively. A strong negative relationship existed between grain yield and exchangeable AI which accounted for 74% of the yield variations. Leaf Mg concentration was also increased from 0.14% to 0.40% with lime application. Plant analysis showed that poor plant growth on unlimited plots was not due to poor P uptake. Grain yield, available P, and leaf P concentration relationships showed critical available P at 25 ppm and P concentration at 0.27%.
Volatilization of Microencapsulated and Conventionally Applied Chlorpropham in the Field1
Authors: Turner B. C. , Glotfelty D. E. , Taylor A. W. , Watson D. R. 
Published: July 2010

AbstractThe effectiveness of preemergence applications of herbicides to soil surfaces may be seriously reduced by losses due to volatilization to the air. Direct measurements of volatilization rates of two chlozopropham (isopropyl‐m‐chlorocarbanilate) formulations, a microencapsulated and a conventional emulsifiable concentrate, were made to establish the differences in volatilization rates in the field. During the first day after application to a bare silt loam soil, without cultivation, on 25 May, the volatilization from the encapsulated residues was about one.third that from the emulsified material. Volatilization decreased rapidly over the first 3 days, when 60% of the encapsulated and 30% of the emulsified chlorpropham remained in the target area. Volatilization was still measurable after 50 days, when 20% of the encapsulated and 2% of the emulsified remained. Over this whole period the emulsified residues volatilized about five times faster than the encapsulated. The results indicate the potential value of microencapsulaton techniques for controlling vapor losses and increasing the persistence of volatile herbicides in the field.
Spring Wheat Yield Model for Limited Moisture Conditions1
Authors: Rasmussen V. P. , Hanks R. J. 
Published: July 2010

AbstractModels are useful to predict the effect of one or more of the complex climatic soil, water, or crop variables on yield. Such predictions can be used to make economic evaluation of, for example, the cost and benefit of irrigation or date of planting on yield. The objective of this study was to develop a model for spring wheat (Triticum aestivum L.) which could be used for such purposes and which required only readily available data. The model, a modified form of that developed by Hanks (1974) for corn (Zea mays L.), is based on a water balance of irrigation, precipitation, soil water, evapotranspiration, and drainage. Relative dry matter yield is assumed to be directly related to relative seasonal transpiration. Relative grain yield is assumed to be related to the multiple of relative transpiration for each of four growth stages raised to the 0.25 power.The validity of the model was tested in 1975 using field experimental data collected especially for this purpose. Two soft white spring wheat and three hard red spring wheat cultivars were grown under several levels of irrigation. Predicted yields agreed closely with measured yields. An additional test of the validity of the model for other irrigated cultivar trials in 1975, 1974, 1973, and 1972 at the same location, and a dryland trial in 1975 at another location, was made. Good agreement with measured results was found for the 1973, 1974, and 1975 irrigated and the 1975 dryland trial. However, the predicted results for the 1972 irrigated trials were about 20% lower than the measured yields.
Nitrogen Fertilization of Irrigated Russian‐Thistle Forage. I. Yield and Water Use Efficiency1
Authors: Fowler J. L. , Hageman J. H. 
Published: July 2010

AbstractReports on yield, water use efficiency, and nutritive value of Russian‐thistle (Salsola spp.) have suggested its potential as a forage crop for areas with limited water resources. This study was initiated to determine the effect of N fertilization, irrigation management, time of first harvest, and cutting height on the yield and water use efficiency of Russian thistle. Russian‐thistle was grown in irrigated field plots in 1975 and 1976. The influence of N fertilization (0, 28, 56, 112, and 224 kg N/ha), stage of maturity at first harvest (prebloom and 3/4 bloom), and cutting height (7.5 and 15.0 cm) on dry matter yield and water use efficiency was evaluated in 1975. Yield and water use efficiency generally improved as N application rates increased. Thistle harvested at 3/4 bloom produced 3,600 kg/ha more dry matter and 27% more shoot dry weight/ha‐cm of water applied than thistle cut at prebloom. Cutting at 15 cm increased yield by 8 and 15% at prebloom and 3/4 bloom, respectively, over that at 7.5 cm. In 1976, application of N (0, 28, 56, and 112 kg N/ha) generally improved both yield and water use efficiency. Quantity of water applied (24, 35, 40, and 60 cm) did not significantly affect yield but the highest application reduced water use efficiency. No N fertilizer ✕ irrigation interactions occurred. Forage yields ranged from 6,090 to 11,009 kg/ha and water use efficiency from 102 to 414 kg shoot dry weight/ha‐cm of water applied.
Seasonal Patterns of Forage Quality of Weeping Lovegrass Cultivars1
Authors: Holt E. C. , Dalrymple R. L. 
Published: July 2010

AbstractWeeping lovegrass (Eragrostis curvula (Schrad.) Nees) is used for grazing in both the growing season and the dormant season, yet little information is available on seasonal patterns of forage digestibility, particularly in the dormant season. A study was conducted to determine the influence of N on dry matter digestibility of forage in the growing season and stockpiled forage in the dormant season. Four cultivars with known differences in forage palatibility were fertilized at three N levels and harvested at intervals during the growing and dormant seasons. In vitro digestible dry matter (IVDDM) was determined during a 3‐year period. ‘Morpa’ and ‘Renner,’ both selected for palability, tended to be higher in IVDDM than ‘Ermelo’ and ‘Common’ weeping lovegrass. The initial spring growth ranged from 60 to 67% IVDDM. Digestibility declined 10 to 20 units from April to August or September, increased in August or September in some years, and then declined to lows of 28 to 48% in January and February. Renner and Morpa showed more August–September recovery in IVDDM than Ermelo and Common. Neither the amount nor time of N fertilization had any influence on forage digestibility. Seasonal differences in digestibility were greater than cultivar differences. Forage digestibility in both midsummer and midwinter may reach low enough levels to limit animal performance if not supplemented.
Molybdenum and Sulfur Interaction Effects on Growth, Yield, and Selected Chemical Constituents of Burley Tobacco1
Authors: Sims J. L. , Leggett J. E. , Pal U. R. 
Published: July 2010

AbstractMolybdenum accumulation by plants is decreased by high levels of SO42‐ in the rooting media. This relationship is of interest since Mo is deficient in some soils, and certain fertilizers contain large amounts of SO42‐. The present study was conducted to determine the effect of MoO42‐and SO42‐ interaction on growth, yield, and selected chemical constituents of burley tobacco (Nicotiana tabacum L.), Tobacco (CV ‘Ky‐14’) was grown in a field experiment during 2 years. Treatments consisted of four rates of Na2Mo04 (0, 0.56, 1.12, and 2.24 kg/ha) applied annually in all combinations with four rates of SO42‐ (0, 112, 224, and 448 kg/ha) to Maury silt loam soil (Typic Paleudalfs). Plant samples were taken at varying dates during one growing season for chemical measurements while cured leaf yields were measured both years.Adding Na2Mo04 increased average Mo concentration of leaves over the control (about threefold), nitrate reductase activity of leaves (35%), N content of the total plant (5 to 10%), and cured leaf yields (7%). Adding SO42‐ fertilizers decreased Mo concentration (33 to 55%, but increased total N content (5 to 10%) and cured leaf yields (7%). Sulfate had no effect on S concentration at any sampling date, but a trend existed for SO42‐ to lower nitrate reductase activity.Significant Mo rate × SO42‐ rate interactions existed for Mo concentrations, total N content, and yields of cured leaf. These interactions suggest that adding SO42‐ fertilizer will have detrimental effects on plant growth, nitrate reduction, and leaf yields at low soil Mo levels but positive effects at high soil Mo levels.
Growth and Mineral Composition of Mungbean as Influenced by P and Fe Fertilization1
Authors: Bassiri A , Kashirad A , Kheradnam M 
Published: July 2010

AbstractPhosphorus is among the principal nutrient elements needed for growth by many crops in arid and semi‐arid agricultural regions. The advantageous effects of P, especially for legumes, have been studied in detail. However, relatively large amounts of soil P interfere with the availability of Fe to plants. The effects of P and Fe on growth and mineral composition of mungbeans, Phaseolus aureus (Roxb.) Hepper, are reported herein. Mungbeans were grown for 8 weeks in a silty clay soil, classified as Xerollic Xerochrept, treated with levels of P (0,50,100, and 200 ppm) and Fe (0,5,10, and 20 ppm). Maximum top and root dry weight and plant height occurred with 50 ppm P. Iron treatments reduced top and root dry weight and plant height. It was concluded that mungbeans required 50 ppm P and no Fe for optimum growth in this soil under the conditions of this experiment. Increased levels of P in the soil caused significantly higher P uptake, greater P and N concentration, and lower Zn concentration in the tops. The concentration of Fe, N, K, and Ca in the tops was significantly increased, while the concentration of Mg and the uptake of P, N, K, Ca, Mg, and Zn decreased with increasing Fe levels in the soil.
Relationship of Week of Flowering and Parameters of Boll Yield in Cotton1
Authors: Turner J. H. , Worley S. , Ramey H. H. , Hoskinson P. E. , Stewart J. M. 
Published: July 2010

AbstractCotton (Gossypium hirsutum L.) experiments generally are reported in yield per unit area of land. This yield is a product of number of bolls per unit area and yield per boll. Estimates of yield per boll include an element of sampling. Our purpose was to relate week of flowering to the variability of boll yield components. Boll samples derived from 5 consecutive weeks (periods) of blooming in six diverse cotton cultivars in 1974 and 1975 were used to estimate the separate seed and fiber parameters that are components of boll yield. Seed yield per boll (SY/B) declined from the first through then fifth period of bloom, due to a significant loss in weight per seed ( g / S ) . Seed number (S/B) was lowest from first period fruit. Fiber yield per boll (FY/B) increased from the first to third period of bloom, but decreased sharply the last two periods. The weight per fiber (μg/f) was the main component to influence fiber yield adversely in late season bolls. The number of fibers per mm2 of seed surface showed a differential response for the two seasons over the bloom periods. Seed surface area (S.S.A./S) was influenced b bloom periods, cultivars and years. All components or FY/B gave significant year × period interactions. These data suggest that sampling should emphasize bolls derived from bolls set during the peak of flowering. Further implications of these results upon sampling technique in cotton research are discussed.
Influence of Different Levels of Irrigation and Nitrogen on Yield and Nutrient Uptake by Wheat1
Authors: Singh N. T. , Vig A. C. , Singh Rachhpal , Chaudhary M. R. 
Published: July 2010

AbstractIrrigation and fertilizers are two vital but costly inputs in irrigated agriculture. Their economic use demands that maximum yield should be obtained per unit application of these inputs. A constraint on irrigation water supply must accompany a corresponding cut on fertilizer application and vice versa. A study was, therefore, conducted to find out the response of wheat (Triticum aestivum L.) to different levels of irrigation and N for 3 years in a deep sandy loam soil underlain by a clay loam, belonging to the family fine loamy, hyperthermic, mixed, calcareous, Typic Ustocherpt. The irrigation treatments were check, 1, 2, and 3 irrigations applied according to irrigation water applied per pan evaporation ratio of 0.90 and N levels were 60, 80, 100, and 120 kg N/ha. In the normal rainfall years of 1974–75 and 1976–77, wheat yield increased with number of irrigations. In the unusually wet year of 1975–76, however, response to irrigation was non‐significant. No response was observed beyond a N application of 80 kg/ha without irrigation, whereas, the response was linear up to 120 kg N/ha in the three irrigation treatment. The uptake of N was a linear relationship with crop yield. Apparent water use by the crop increased in the high rainfall year and with increasing number of irrigations.
Associations Among Seed Weight, Seedling Emergence, and Planting Depth in Cicer Milkvetch1
Authors: Townsend C. E. 
Published: July 2010

AbstractThere is a great need for forage legumes that can emerge from deep depths of planting in semiarid environments because deep depths provide a greater cushion against the fluctuating moisture conditions found near the soil surface. Therefore, the objectives of this study were to compare selected progenies of cicer milkvetch, Astragalus cicer L., with seed weights of 3.2, 3.6, 4.0, 4.4, 4.8, 5.2, and 5.6 g/1,000 seeds for seedling traits that might be related to emergence and for ability to emerge from 1.3, 2.5, and 3.8‐cm depths of planting in the field.Seedlings from the seven seed classes differed significantly for hypocotyl diameter, hypocotyl length, radicle length, total length, and dry weight when grown in a dark germinator for 7 days at 25/15 C. In a greenhouse study the seed classes differed significantly for cotyledon dry weight, but not for cotyledon area, when sampled at the earlyprimary leaf stage. In both studies the values for the various characters generally were greater for the highseed‐weight classes than for the low.Although there were large differences between dates of planting both within and between years for seedling emergence in the field, the trends were similar with the high‐seed‐weight classes giving the greatest average emergence. The greatest difference among seed classes occurred at the 3.8‐cm depth, where seedling emergence of the 5.6‐g class was about twice that of the 3.2‐g class. Seedling emergence was similar for the 1.3 and 2.5‐cm depths of planting and generally was much higher for these two depths than for the 3.8‐cm depth. Correlation coefficients between seed weight, the various seedling traits, and seedling emergence at the 3.8‐cm depth were generally significant except for those involving hypocotyl length.
Soybean Leaf N as Influenced by Seedbed Preparation Methods and Stages of Growth1
Authors: Young J. K. , Whisler F. D. , Hodges H. F. 
Published: July 2010

AbstractRecent interest and studies on nitrogen relationships in soybeans [Glycine max (L.) Merrill] have led to a better understanding of the processes regarding N accumulation during vegetative growth and remobilization during seed development. Most of the research work was performed with different N fertilizer treatments and isolines of nodulating and nonnodulating soybeans. Differences in cultural practices which modify the root environment and differences in soybean cultivar have not received much attention in N accumulation and remobilization studies. The objectives of this work are 1) To determine the effect of tillage treatments and cultivar on leaf N levels and 2) to develop a regression equation relating several plant and cultural variables to leaf N levels.‘Forrest’ and ‘Tracy’ cultivars of soybeans were planted on Houston silty clay (very fine montmorillonitic, thermic family of Typic chromuderts) with seven different seedbed preparation methods and assayed for leaf N using the Kjeldhal method. Leaf N concentrations of the two cultivars showed similar patterns of change over the sampling period at each of three positions (top, middle, bottom) on the plant. Tracy had higher leaf N concentrations (5.3 to 3.2%) than Forrest (5.0 to 2.9%) throughout the growing season. Topleaf N remained fairly constant until late R2 maturity stage, after which it decreased rapidly. Middle‐leaf N varied as a quadratic function of plant age. An inverse relationship between lower‐leaf N and plant age was observed. For different cultivars, tillage affected leaf N within each leaf position in the early growing season. A regression model having factors of plant age, cultivar, leaf position and interactions of these factors predicted leaf N with a standard error of estimate of 0.33% and a coefficient of variation (R2) of 0.85.
Control of Hemp Dogbane with Foliar and Soil Applied Herbicides
Authors: Schultz M. E. , Burnside O. C. 
Published: July 2010

AbstractHemp dogbane (Apocynum cannabinum L.) has become a serious weed problem in eastern and southcentral Nebraska. Greenhouse and field studies were conducted to evaluate control of hemp dogbane with herbicides. In greenhouse studies, postemergence applications of herbicide combinations which included 2,4‐D [(2,4‐dichlorophenoxy)acetic acid] ester, 2,4‐D amine, or glyphosate [N‐phosphonomethyl)glycine] controlled hemp dogbane more effectively than those containing dicamba (3,6‐dichloro‐o‐anisic acid) or amitrole (3‐amino‐s‐triazole). Control was greater with equivalent rates of 2,4‐D ester than with 2,4‐D amine. Control with 2,4‐D increased with longer slide‐chain lengths of both ester and amine formulations. Postemergence control of hemp dogbane with herbicides was erratic in field studies over years. Glyphosate generally provided better control than 2,4‐D, and amitrole consistently gave poor control. A preliminary study showed that growth of hemp dogbane from crown and lateral roots could be suppressed or controlled with preplant treatments of thiocarbamate herbicides. Increasing order of effectiveness for controlling hemp dogbane was vernolate (S‐propyl dipropylthiocarbamate), EPTC (S‐ethyl dipropylthiocarbamate), and butylate (S‐ethyl diisobutylthiocarbamate). In the field, butylate + R‐25788 (N,N‐diallyl‐2,2‐dichloroacetamide) and EPTC + R‐25788 at 4.5 + 0.2 kg/ha provided good control (60 to 98%) of hemp dogbane during the first 2 months after corn (Zea mays L.) planting, but decreased to 0 to 40% at harvest. Higher rates of butylate + R‐25788 controlled hemp dogbane slightly longer. Thiocarbamate herbicides inhibited deposition of epicuticular wax on the leaves of hemp dogbane in 1977 but not in 1978. It appears that preplant applications of the thiocarbamate herbicides may aid in controlling hemp dogbane via delayed emergence, reduced plant vigor, and possibly greater adsorption of 2,4‐D applied subsequently as a foliar application.
Shoot and Root Growth of Wheat Seedlings Exposed to Several Levels of Matric Potential and NaCl‐Induced Osmotic Potential of Soil Water1
Authors: Sepaskhah A. R. , Boersma L. 
Published: July 2010

AbstractIn saline media the osmotic potentials are often of the same magnitude as the matric potential. Thus their interaction effects on plant growth are important. This study was conducted to determine the interaction effects of osmotic potentials of soil water induced by NaCl (0, −4, −8, and −12 bars) and matric potentials induced by Carbowax 4000 (−0.3, −2.5, −5.0, and −7.5 bars) on the shoot and root growth and root elongation rate of 2‐week‐old wheat seedlings (Triticum aestivum L.) in a walk‐in growth room. Seedlings of spring wheat, ‘Fielder’, were grown in a Xerollic Durargids loam soil separated from the surrounding nutrient solution by a semipermeable, cellulose‐acetate membrane. Leaf water potential was measured with a pressure chamber apparatus. Root length was estimated by line‐intersection counting of stained root segments during microscopic examination. Plant growth was measured by the determination of dry weights of shoots and roots at the beginning and end of an 11‐day experimental period. Growth was more reduced by decreases in matric potential than by decreases in the osmotic potential. A greater interaction between the effects of the osmotic potential of the soil water and the soil matric potential occurred with shoot growth than with root growth. The 50% reduction, Y50, occurred at osmotic potentials of the soil water ranging from −6.8 to −8.8 bars for shoot growth and at potentials ranging from −6.8 to −8.4 bars for root growth at the soil matric potentials ranging from −0.3 to −7.5 bars, respectively. Shoot growth showed lower tolerance to the decreasing osmotic potentials at soil matric potentials less than −2.5 bars. The Y50 values of potential were −8.6 and −5.4 bars for NaCl‐induced (osmotic) and Carbowax induced (matric) potentials, respectively. Shoot growth ceased at the leaf water potentials of −19.7and −15.3 bars at the NaCl and Carbowax‐induced potentials, respectively. Decrease in root density occurred at the soil matric potentials lower than −5.0 bars while it was reduced at all the experimental levels of osmotic potential. Root elongation rates ceased at matric potentials of −11, −12, −12, and −7 bars at osmotic potentials of 0, −4, −8, and −12 bars. respectively. Osmotic adjustment in the plant cells and possible toxic effects of Na and Cl ions or ionic imbalances on shoot growth and root elongation have been discussed.