bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fate of Tagged Urea N in the Field with Different Methods of N and Organic Matter Placement
Authors: Tomar J. S. , Soper R. J. 
Published: July 2010

AbstractA field experiment of factorial randomized block design was conducted with barley (Hordeum vulgare L.) to evaluate the effect of organic matter and fertilizer N placement on the efficiency and immobilization of applied N. Also, the experiment was to determine whether immobilization was a factor in causing the differences in efficiencies for broadcast and banded N. The plots used consisted of open‐ended iron cylinders 35 cm in diameter pressed into the soil to a depth of 25 cm. Labelled urea containing 19.15 atom %15N was either banded at 10 cm soil depth or surface broadcast at a rate of 100 kg N/ha. Oat straw (Avena sativa L.) was used us the organic matter source and applied at 5,000 kg/ha and was either mixed throughout the soil to a 10 cm depth or spread evenly on the soil surface. Fertilizer N removed by the above‐ground portion of the crop and that remaining in the 100 cm soil depth at harvest time was determined.Nitrogen uptake and barley yield were greater from banded N than from broadcast N. The differences in uptake for the two methods of N placement were enhanced by adding organic matter to the soil. Recovery of fertilizer N in plant tops varied between 22.8 and 42.8% for urea surface broadcast and between 42.0 and 53.1% for urea applied in a band. About 83 to 87% and 82 to 95% of the applied N was accounted for in the soil and plant at the end of the experiment for broadcast and band‐N applications, respectively. Leaching losses of applied N were negligible for both methods of N application. Significantly more labelled N was found in soil from the broadcast than from the banded fertilizer (40.3 vs. 34.0% of added N) at the end of the experiment and the effect was particularly enhanced by mixing straw with the soil.Since leaching losses were negligible and unaccountable differences probably as gaseous losses were essentially the same for broadcast and banded N applications (13 and 15%, respectively), the superiority of banded N over broadcast N applications with respect to barley yields and N uptake was largely due to the reduced immobilization of banded N.
Population Density and Planting Date Effects on Kenaf Performance1
Authors: Campbell T. A. , White G. A. 
Published: July 2010

AbstractPopulation density and planting date can have substantial effects on kenaf (Hibiscus cannabinus L.) performance in temperate climates. The effects of population densities of up to 395,000 plants/ha on kenaf have been evaluated in Maryland. Because positive yield responses have been derived from higher populations at other locations, the effects of five population densities [247,100 (PI), 370,700 (P2), 494,200 (P3), 617,800 (P4), and 741,300 (P5) plants/ha] on ‘Cuba‐2032’ and ‘Tainung‐1’ were studied in 1976 and 1977 on the Eastern Shore of Maryland. Soil was a Bertie silt loam (fine‐loamy, mixed thermic Aquic Hapludult). Yields of Tainung‐1 were maximized at approximately 370,000 plants/ha whereas yields of the less vigorous Cuba‐ 2032 were maximized at approximately 500,000 to 700,000 plants/ha. Plants grown at P1 and P2 generally achieved greater height and stem diameter than those grown at P3 to P5; stand reduction was generally higher at P3 to P5 than at P1 and P2. Neither height nor stem diameter was significantly correlated with percent stand reduction. The primary cause of stand loss was probably greater intraspecific competition at the higher populations.Early (28 April) and late (19 May) planting of kenaf led to comparable dry matter yields in a 1970 study in Maryland. We concluded that a more detailed study of planting date was needed and experiments were conducted in 1976 and 1977 on the Eastern Shore of Maryland. Soil and cultivars were the same as for the density studies. Planting dates were 5 May in 1976 and 11 May in 1977 (D1), 19 May (D2), 2 June (D3), 16 June (M), and 30 June (D5). Planting on D1 and D2 generally led to significantly (0.01 level) greater yields than did planting on D3 to D5. Date of planting had no substantial effect on height; stem diameter and stand reduction responses were erratic.
Use of Paired Sampling to Quantify Soil Productivity1
Authors: Munn L. C. , Schweitzer B. D. , Lund R. E. , Nielsen G. A. 
Published: July 2010

AbstractVariations in management inputs and climatic conditions between fields and from year to year are major complicating factors in attempts to quantify soil productivity. A study of soil productivity for spring wheat (Triticum aestivum) in northcentral Montana is used to illustrate the advantage of the paired sampling technique as compared to a non‐paired design for evaluating yields on contrasting soils. The two soils in the study were both Aridic Argiborolls which occur as a complex in the same fields. Relative efficiency of the paired design compared to nonpaired sampling ranged from 0.9 to 6.5 for the 11 crop and soil variables measured (mean relative efficiency was 2.0).
Small‐Scale Dryer Design1
Authors: Navratil R. J. , Burris J. S. 
Published: July 2010

AbstractHigh ear corn (Zea mays L.) drying temperatures are known to affect subsequent seed quality. In addition, genotypes have been known to differ in their tolerance to higher drying temperatures. Therefore, in order to experimentally test some of the most widely grown public inbred lines for tolerance to dryer induced injury at 35, 40, 45, and 50 C, four small‐scale, single‐pass movable dryers were constructed. Each unit consists of a cap and stackable trays on top of a base, which houses the thermostat, fan, and a resistance heat source. Units were operated during the 1979 and 1980 harvest seasons. Measured mean temperatures both years were within 0.3 C of the desired temperatures.The dryers are quite flexible. They are capable of drying shell corn or bulk soybeans [Glycine max (L.) Merrill] as well as earn corn. By connecting the exhaust ports of two adjacent stacks, these units can be used to recycle exhaust air in a two‐pass arrangement through the second stack. Convenient unstacking of the trays facilitates rapid addition or removal of samples and transfer of samples from one drying environment to another. These units can not only be used to screen germplasm for tolerance to high drying temperatues, but can also serve to supply seed that have been dried under defined conditions for physiological studies.
Impact of Simulated Land Treatment with Oily Sludges on Ryegrass Emergence and Yield1
Authors: Brown K. W. , Brawand H. , Thomas J. C. , Evans G. B. 
Published: July 2010

AbstractThe proper design and management of facilities for the land treatment of hazardous industrial wastes require information on the effects of the oily wastes on the soil and on the growth of vegetation. Measurements were made on the impact of two oil‐water separator sludges (a refinery sludge which originated from a petroleum refinery, and a petrochemical sludge which originated from a petrochemical plant) on the emergence and dry matter yield of ryegrass (Lolium multiflorum Lem.) grown on four diverse soils in the greenhouse. Each sludge was applied at 0, 5, 10, and 20% v/v to each of four soils to determine the influence of application rates. After growth periods of approximately 6 weeks, the grass was harvested and the soil‐sludge mixture was air‐dried, remixed, and reseeded. A total of eight sequential harvests were made. Measurements of soil wettability were made twice to evaluate physical problems.Concentrations of refinery sludge at 5% v/v and above depressed ryegrass emergence and yield through two mechanisms. Phytotoxic constituents initially acted to retard plant growth. Several months were required for the sludge to degrade sufficiently to allow normal plant growth. Subsequent yield reductions resulted from impaired water relations associated with residual hydrophobic hydrocarbons.The petrochemical sludge had higher concentrations of both organic carbon and aromatics and suppressed emergence and yield proportional to the amount of sludge applied. The suppression lasted longer than that caused by the refinery sludge. Seedling emergence from soils treated with 20% refinery sludge did not differ from those in the unamended control by the second planting, while the corresponding treatments using petrochemical sludge were less than those in the control for the first five replantings. Grass yield from the 20% refinery sludge treatment required 13 months to reach control levels. The corresponding petrochemical treatment yield increased to only 47 % of the control, 17 months after application.Thus, while oily sludge may initially be phytotoxic and may reduce the yield of vegetation that managed to emerge, the toxicity diminishes with time, so that soils used for land treatment of oily sludges can eventually be revegetated.
Reseeding Crimson Clover as a N Source for No‐Tillage Grain Sorghum Production1
Authors: Touchton J. T. , Gardner W. A. , Hargrove W. L. , Duncan R. R. 
Published: July 2010

AbstractNitrogen fertilizer is an expensive but essential input for optimum production of non‐leguminous crops. The use of N fertilizer for summer grain crops can be reduced and possibly eliminated by double cropping with leguminous winter crops. Costs of seeding winter legumes, however, are often as expensive as the commercially produced N that they replace. Allowing the legumes to produce seed prior to planting the summer crop may potentially eliminate costs associated with seeding the legume each fall. The purpose of this field study, conducted on a Cecil sandy loam soil (Typic Hapludult), was to determine N fertilizer requirements for no‐tillage grain sorghum (Sorghum bicolor L. Moench) double cropped with reseeding crimson clover (Trifolium incarnation L.) and effects of N treatments on nutrient uptake and on insect populations. Nitrogen treatments were 0, 15, 30, 45, 90, and 135 kg N/ha and the clover tissue was either removed or left on the soil surface as a no‐tillage mulch.No‐till planting sorghum into clover or removing the clover top growth at maturity had no apparent effect on clover stand establishment the following fall. Clover dry matter production was essentially equal among years and averaged 4,762 kg/ha/yr. When averaged over years, the N, P, and K concentrations in the clovertops were 2.02, 0.24 and 2.40%, respectively. The only essential nutrient in sorghum leaves at the bloom stage affected by applied N was Cu which increased linearly as applied N increased. The only effects that removing clover had on nutrient content in the sorghum leaves were to reduce K in 1979 (from 2.47 to 2.31%), N in 1980 (from 2.85 to 2.69%) and P in 1979 (from 0.36 to 0.34%) and 1980 (from 0.34 to 0.29%). The reductions, however, were not sufficient to create a deficiency of either element. Some differences were found among common insect populations and their subsequent damage among treatments but the populations were not great enough to be considered economically damaging. Nitrogen produced by the clover was sufficient for maximum sorghum grain yield (5,760, 7,098, and 2,924 kg/ha in 1978, 1979, 1980, respectively) without supplemental applications of inorganic N. Removing the clover had no effect on sorghum grain yield in 1978 or 1979, but in 1980 this treatment reduced grain yield 601 kg/ha. Even though removing the clover which contained 62 kg/ha N in 1980 reduced sorghum yield, there was no response to applied N which suggests that the yield reduction was not due to a shortage of N.
Soil Compaction Effects on Soybean Nodulation, N2 (C2H4) Fixation and Seed Yield1
Authors: Lindemann W. C. , Ham G. E. , Randall G. W 
Published: July 2010

AbstractOften soil compaction is considered undesirable for plant growth and may limit soybean yield. The objective of this study was to determine the effect of soil compaction on soybean plant growth, yield, nodulation, and N2 (C2H4) fixation. Field experiments were conducted for 2 years (1976 and 1977) on a Webster clay loam soil (fine‐loamy, mixed, mesic Typic Haplaquolls). Plots were compacted by 0, 1, 2, or 3 tractor passes over the same area approximately 2 weeks before planting. Soybean biomass and plant height were measured in 1977, but soil bulk density and soybean seed yield were measured in both years. Nodulation and acetylene reduction activity were measured four times during the season for taproots and two times for lateral roots in both years. Bulk density was increased significantly both years by tractor compaction. In 1976, when extremely dry conditions existed throughout the growing season mean seed yield values were greater on the tractor compacted plots (2,161, 2,106, and 2,283 kg/ha for the 1, 2, and 3 tractor pass treatments, respectively) than on the non‐compacted plots (1977 kg/ha), but the yields were not statistically significant. Taproot nodulation and acetylene reduction were also significantly greater on the 2 tractor pass treatment than on the non‐compacted plots, but little difference in lateral root nodulation and acetylene reduction was noted.In 1977, when greater than normal precipitation occurred, compaction decreased significantly plant growth and taproot nodulation and tended to decrease lateral root nodulation. Acetylene reduction was not affected by compaction. The mean seed yield value was greatest in the non‐compacted plot (4,117 kg/ha) and the mean values declined with increasing tractor compaction (4,105, 3,955, and 3,854 kg/ha for the 1, 2, and 3 tractor pass treatments, respectively), although the yields were not statistically different. The effect of soil compaction in the spring prior to planting appeared to be dependent on the amount of precipitation in the growing season.
Three Tillage Systems Affect Selected Properties of a Tiled, Naturally Poorly‐Drained Soil1
Authors: Costamagna O. A. , Stivers R. K. , Galloway H. M. , Barber S. A. 
Published: July 2010

AbstractReduced tillage systems for corn (Zea mays L.) have seldom shown a yield advantage on naturally poorly drained soils. This research was intended to further test this hypothesis and to find other advantages of reduced tillage on tiled, naturally poorly drained soils. The effects of three systems of tillage on selected soil properties, and growth and yield of corn were compared for 7 years on a tiled, naturally poorly drained Chalmers silty clay loam (Typic Argiaquoll) soil. Conventional or plow tillage consisted of fall moldboard plowing to about 20 cm, two diskings in spring, planting, and one cultivation; field cultivation included field cultivation in spring to about 15 cm followed by two diskings, planting, and one cultivation, and “light disking” included one disking in spring and planting behind fluted coulters but no cultivation. After 7 years organic matter percentages under field cultivation (4.68%) and light disking (4.89%) systems were higher (p < 0.05) than that under plow (3.79%) tillage at the 0 to 5 cm depth. Mean weight diameters of water‐stable soil aggregates were higher (p < 0.05) for field cultivation (2.74 mm) and light disking (2.48 mm) systems than for the plow tillage (1.51 mm) system. In early October, after a summer of low rainfall, soil moisture was higher (p < 0.05) with field cultivation (35.9%) than with the plow tillage (32.3%) system. Even though tasselling was generally later (5 days in 1974) with the field cultivation and light disking systems than with the plow tillage system, annual (1968‐1974) corn grain yields were 97.1 and 98.9% respectively, of those obtained with plow tillage (8,700 kg/ha).
Effects of Applied Mechanical Stress on Plant Growth and Nutrient Uptake1
Authors: Castillo S. R. , Dowdy R. H. , Bradford J. M. , Larson W. E. 
Published: July 2010

AbstractThe ever‐increasing size of farm tillage machinery is contributing to increased soil compaction. Does this compaction affect dry matter production and nutrient uptake of growing plants? To better understand the consequences of increased mechanical stress on the root system, the effects of confining external stresses on root growth and nutrient uptake by pregerminated pea seedlings (Pisum sativum L. cv. Alaska) were studied in the laboratory. The application of stresses up to 269 kPa around the rooting medium (Dickinson loam, Typic Hapludoll) of pea seedlings reduced root growth and nutrient uptake. In relatively loose soil (1.16 g cm−3), the application of a 90 kPa stress (post‐planting) which resulted in a bulk density of 1.28 g cm−3, reduced Ca, K, Mg, and Mn uptake compared to another treatment where the soil was compacted to 1.30 g cm−3 before seeding. Such stresses, which are often applied to soils during field cultivations, also resulted in reduced root growth and distribution. In another experiment, the increased soil strength of a naturally dense subsoil, which resulted from lowering the soil water potential from −10 to −33 kPa, was associated with a 50% reduction in root length and a 21% reduction in K uptake by pea seedlings. The slower root development and reduced nutrient accumulation will affect the plant's ability to withstand environmental stresses during later stages of development.
Fall Growth and Cold Acclimation of Winter Wheat and Rye Differentially Fertilized with Phosphorus1
Authors: Fowler D. B. , Gusta L. V. 
Published: July 2010

AbstractPhosphorus deficiencies and imbalances are among the factors that have been reported to result in poor cold acclimation of plants. Many soils in the Great Plains are deficient in P. Therefore this study was initiated to determine the effect of P on fall growth and cold acclimation of winter wheat (Triticum aestivum L.) and rye (Secale cereale L.) under field conditions.Trials were located (52°N, 104°W) on phosphate deficient udic haploboroll soils in the northeastern corner of the agricultural area of Saskatchewan, Canada. Added P increased the P content of the crown, leaf and root tissue of wheat and rye plants. In all cases P content was higher in the crowns and leaves than in the roots. Added P increased the crown and root fresh weight and dry weight for both wheat and rye. Root growth in particular was stimulated by added P. Shoot dry weight and leaf fresh and dry weight of rye were also increased by added P. Similar trends were evident for wheat; however, differences were not significant. In spite of this obvious effect on plant growth, soil P deficiency had little effect on the ability of winter wheat and rye to cold acclimate as reflected by measurements of crown cold tolerance.
Critical Nutrient Ranges for Petiole Phosphorus Levels of Sprinkler‐Irrigated Russet Burbank Potatoes1
Authors: Roberts S. , Dow A. I. 
Published: July 2010

AbstractTwo field experiments were conducted for the purpose of establishing critical nutrient range (CNR) values for P in petioles of Russet Burhank potatoes (Solanum tuberosum L.) for use as standards in assessing plant nutrient status. The CNR is defined as the range of nutrient concentrations in plant tissue at a selected growth stage, above which the crop has an ample nutrient supply and below which the crop is nutrient‐deficient. The experiments were conducted under center‐pivot irrigation on soils classified as Quincy and Winchester loamy sands (mixed, mesic, Xeric Torripsamments). Five treatment levels from 0 to 269 kg P/ha were applied broadcast and incorporated before planting in April. Petioles were analyzed for P six times through the season, and potato yield was determined at harvest in late September. Adequate P fertilization produced maximum yields of 64 metric tons/ha on Quincy soil and 73 metric tons/ha on Winchester soil as compared with yields of only 79 to 86% of maximum without P fertilization. It was concluded that for 95 to 100% of maximum yield the estimated CNR was 0.38 to 0.45% P at the 2‐cm tuber stage in June and generally decreased with time to give a CNR of 0.14 to 0.17% P toward the end of the season 10 weeks later.
Effects of Deep Tillage on N Response by Corn on a Sandy Coastal Plain Soil1
Authors: Chancy H. F. , Kamprath E. J. 
Published: July 2010

AbstractTillage pans in sandy coastal plain soils often restrict utilization of subsoil moisture and nutrients and may limit corn (Zea mays L.) yields. Field experiments were conducted for 2 years on a Wagram loamy sand (Arenic Paleudult) with a tillage pan to evaluate deep tillage treatments and preplant N applications containing nitrapyrin (NI) on corn. Experiments were arranged in a split plot design containing three tillage treatments as the main plots with four N‐treatments as the subplots. The three tillage treatments were: a) disking to a 15 cm depth, designated as conventional, b) chisel‐plowing to a depth of 30 cm at 30 cm intervals, and c) subsoiling in the row to a depth of 45 cm and bedding over the subsoil slit. Four N‐treatments consisted of preplant applications of 0, 112, and 168 kg N/ha broadcast as urea and a urea‐NI solution at a rate of 112 kg N/ha plus 1.12 kg NI/ha. Measurements were made of soil NH+4 and NO‐3 concentrations, leaf N, stover weight, stover N concentration, grain yield, grain N content, and recovery of fertilizer N.Use of NI in 1978 resulted in more of the total inorganic soil N in the 0 to 15 cm depth being in the NH+4 form; however, this did not significantly increase total inorganic soil N content at any depth. Nitrapyrin had no significant effect on inhibition of nitrification in the top 45 cm depth in 1979. Inorganic soil N was moved below the tillage pan into the subsoil by leaching rains. Ineffectiveness of NI to significantly suppress nitrification in 1979 was probably due to the differential movement of NH+4 and NI. Subsoiling significantly increased leaf N concentration above that obtained from conventional tillage in 1979, suggesting root extraction of soil N below the tillage pan. Chisel‐plowing and subsoiling increased corn stover dry matter production above that of the conventional tillage in both seasons.Disruption of the tillage pan by subsoiling or chisel‐plowing increased corn yields above that obtained with conventional tillage. Highest yields were obtained with subsoiling. In 1978, higher grain yields with the deep tillage treatments were thought to have resulted from the utilization of moisture below the tillage pan. Increased yields with deep tillage in 1979 were due to utilization of both moisture and N below the tillage pan. Yields in 1978 were significantly higher with 168 kg N/ha as compared with 112 kg N/ha rate. Yields in 1979 were not significantly different at the 112 and 168 kg N/ha rates. Nitrapyrin had a positive effect only on yields with the chisel‐plow treatment.
Calculation of the Length of Day1
Authors: Keisling T. C. 
Published: July 2010

AbstractWith the advent of sophisticated computing capability many tables and curves that were standard methods of obtaining values in the past can be computed directly with the appropriate formulas. The photosensitivity of many agronomic crops makes knowing the length of hours that the light intensity is above a certain critical level useful. A formula for calculating daylength is presented and methods indicated for obtaining the desired beginning and ending light intensity at any location. The only information necessary to utilize the formula is the latitude of the location and the critical light intensity of interest for the particular crop being used.