bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen Fertilizer Source, and Method and Time of Application Effects on No‐till Corn Yields and Nitrogen Uptakes1
Authors: Fox R. H. , Kern J. M. , Piekielek W. P. 
Published: July 2010

AbstractThe increasing use of both no‐tillage corn (Zea mays L.) production and urea‐containing fertilizers makes it imperative that we develop management strategies that maximize economic return from applications of these fertilizers to no‐till corn. A 3‐yr experiment was conducted on a Murrill silt loam (fine‐loamy, mixed, mesic Typic Hapludult) to determine the relative efficiencies (yield and N uptake per unit of N applied) of three common N sources [NH4NO3 (AN), urea, and urea‐ammonium nitrate solution (UAN)] used on no‐till corn. They were applied either as a surface band or as an injected band at or near the time of planting, or as a sidedress 26 to 31 days after plant emergence. Surface‐banded AN, injected AN, and injected urea all produced similar no‐till corn yields and N uptakes. The apparent NH3 volatilization loss from surface‐banded urea was strongly influenced by the number of days after application until a total of 10 mm of rain fell. Apparent losses ranged from less than 50 g kg−1 of applied N with 10 mm of rainfall within 2 to 3 days after application, to over 300 g kg−1 with 5 to 7 days of dry weather after application. Both surface‐banded and injected UAN were less efficient than AN or injected urea. Sidedress applications of N resulted in more efficient N fertilizer utilization with all sources, but particularly with urea‐containing sources. Shorter rain‐free periods after sidedress applications may have contributed to this effect. Surface applications of an experimental fertilizer, 3:1 urea/urea phosphate, produced greater ear‐leaf at silking N concentrations than did surface‐banded urea. Amending urea with KCI, or UAN with ammonium thiosulfate, did not result in yields, ear‐leaf N concentrations, or N uptakes significantly different from those obtained with their unamended surface‐applied counterparts in the one year that each was tested.
Environment and Cultivar Effects on Winter Wheat Response to Ethephon Plant Growth Regulator1
Authors: Wiersma D. W. , Oplinger E. S. , Guy S. O. 
Published: July 2010

AbstractRecent introductions of new disease resistant, higher yielding winter wheat (Triticum aestivum L.) cultivars and plant growth regulators (PGRs) to reduce lodging, coupled with a growing awareness of high wheat yields in Europe, has resulted in an increased interest in and the development of Intensive Cereal Management (ICM) systems in the USA. Increases in fertility levels and seeding rates, practices used in ICM systems, may significantly increase lodging in winter wheat. The objective of this study was to evaluate the effects of the PGR ethephon [(2‐chloroethyl) phosphonic acid] on grain yield, lodging, plant height, test weight, and moisture percentage of seven winter wheat cultivars grown in various environments. Averaged across environments and cultivars, ethephon reduced lodging and plant height, and increased grain yield an average of 0.28 Mg ha−1, of 6.4%. Average environment × PGR and cultivar × PGR interactions were nonsignificant for grain yield, plant height, lodging, and test weight, but orthogonal contrasts showed variable responses to ethephon between environments and cultivars. Lodging and grain yield were negatively correlated, while lodging and plant height were positively correlated. With the exception of the cultivar Caldwell, grain yields were not increased by PGR applications when there was no lodging.
Tillage System and Date of Planting Effects on Yield of Corn on Soils with Restricted Drainage1
Authors: Herbek J. H. , Murdock L. W. , Blevins R. L. 
Published: July 2010

AbstractIt has been reported that no‐tillage corn (Zea mays L.) production on poorly‐drained soils results in more uneven stands and slower early growth as compared to conventional tillage methods. A field study was established in 1979 at Princeton, KY, on a Johnsburg silt loam (Aquic Fragiudults) intergrading to a Tilsit silt loam (Typic Fragiudults), to compare corn planting dates under no‐tillage (NT) and conventional tillage (CT) systems. For the NT system, a yield increase trend was observed as planting date progressed from the first planting date (late April) to the second (mid‐May). Grain yields from conventionally tilled treatments decreased with delayed planting dates. No‐tillage corn performed better than CT corn during drier growing seasons, and conventionally tilled corn produced yields equal to or slightly higher (no significant differences) for early planting dates, during years in which wet and cool climatic conditions existed during the early part of the growing season. There appears to be a greater risk associated with early planting dates for NT corn on these soils. From a management viewpoint, corn planting on these cooler soils with slow internal drainage can be delayed due to excessive wetness without substantial yield losses if NT management is used.
Developmental Morphology of Dent Corn and Popcorn with Respect to Growth Staging and Crop Growth Models1
Authors: Stevens E. J. , Stevens S. J. , Flowerday A. D. , Gardner C. O. , Eskridge K. M. 
Published: July 2010

AbstractCrop growth staging and developmental modeling (using regression analysis) requires a series of easily understood and documented field descriptives plus a continuous numerical analogue capable of generating data which conform with the underlying assumptions of regression analysis. One numeric phenological key and two mixed phenological keys combining alphabetic and numeric codes are presently used within the U.S. Corn Belt to describe and model the growth and development of dent corn and sweet corn (Zea mays L.). With respect to developing crop growth regression models, the phenology of popcorn has neither been adequately described nor compared with its assumed analogue, dent corn. The purpose of this research was to (i) document the phenology of popcorn, (ii) evaluate the suitability for popcorn of three commonly used phenological keys developed for dent corn, and (iii) if necessary, develop a universal set of phenological field descriptives and a continuous numeric analogue appropriate to developing corn regression growth models. One locally adapted dent corn cultivar (B73 × Mo17) and three differently maturing popcorn cultivars (P410, P609, and Iopop 12) were evaluated for three seasons (1982–1984) across three planting dates at one location in eastern Nebraska at the University of Nebraska Field Laboratory near Mead in Saunders County. None of the phenological keys tested were completely suitable for describing or modeling (using regression analysis), or both, the phenologies of dent corn and popcorn materials, which displayed contrasting morphological characteristics associated with leaf development, leaf number, grain type, and grain development. The universal phenological key and numeric analogue described in this article was therefore developed for modeling the phenology of genetically diverse cultivars grown across a range of environments.
Effects of Various Fungicides and Insecticides on Emergence of Three Wheat Cultivars1
Authors: Khaleeq B. , Klatt A. 
Published: July 2010

AbstractTreatment of seeds with fungicides, insecticides, or a combination of both has been practiced by seedsmen, scientists, and farmers in order to protect seeds and seedlings from different pests. Treating seeds with recommended rates of application is usually safe, but workmen sometimes add more than the recommended rate. Treated seeds are also kept in storage for some time before planting. The purpose of the study was to find out the effects of those chemicals and to determine whether the treated seeds could be stored without loss of viability. Seeds of three wheat (Triticum aestivum L.) cultivars, Bolal, Bezostaya, and Köse 220/39, were treated with the fungicides carboxin [5,6‐dihydro‐2‐methyl‐1,4‐oxathiin‐3‐carboxanilide] and benlate [methyl 1‐(butylcarbamoyl)‐2‐benzimidazolecarbamate] and the insecticides aldrin [1,2,3,4,10,10‐hexachloro‐1,4,4a,5,8,8a‐hexahydro‐exo‐1,4 endo‐5,8‐dimethanonaphthalene], heptachlor [ 1,4,5,6,7,8‐heptachloro‐3 a.4.7.7a‐tetrahydro‐4,7‐methanoindene), and carbofuran [2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl methylcarbamate] to determine the effects of these chemicals, alone and in combination, on germination and emergence. All seed lots were treated at the same time and were planted 10,30, and 50 days after treatment at 30‐mm depths in soil (a silty clay loam, typical of Turkey's Anatolian Plateau) at a greenhouse in Ankara, Turkey. After the first day of emergence, seedlings were counted daily for 7 days. Aldrin, heptachlor, and carboxin did not reduce seedling emergence. Benlate reduced emergence 17, 18, and 23% in Bezostaya, Bolal, and Köse 220/39, respectively, when seeds were stored for 50 days and seedlings counted 11 days after planting. Carbofuran decreased emergence as the storage period increased, especially in Köse 220/39. Carbofuran was the only pesticide that was consistently more phytotoxic when rates were doubled or tripled. Combinations of carboxin with either aldrin or heptachlor did not generally reduce emergence. However, all combinations involving carbofuran reduced emergence more than carbofuran alone. Cultivars varied in susceptibility to fungicides and insecticides. Bolal, a hard red winter wheat from Nebraska, showed the most tolerance. Seedling emergence of Köse 220/39, a Turkish variety, was reduced 13 to 19% more than was Bolal at the 11‐day seedling count in all seed treatment storage periods. Seedling emergence of Bezostaya, a Russian variety, was intermediate between Bolal and Köse 220/39. Adverse effects of pesticides that reduced emergence were more evident as storage time increased. Results indicated that benlate and carbofuran, used alone or in combination, reduced seedling emergence. Less phytotoxicity resulted if seeds were planted as soon as possible after treatment.
Evaluation of Liquid‐Applied Nitrogen Fertilizers on Kentucky Bluegrass Turf1
Authors: Spangenberg B. G. , Fermanian T. W. , Wehner D. J. 
Published: July 2010

AbstractSolution and suspension N sources have been developed as substitutes for urea in spray solutions used by lawn‐care professionals. A field study was conducted to evaluate the response of Kentucky bluegrass (Poa pratensis L.) growing on a Catlin silt loam (Typic Argiudoll), to applications of the new solution and suspension N sources, alone or combined with urea, by comparison to turf response from application of the traditional fertilizer materials ammonium nitrate (AN), Nitroform (ureaform), sulfur‐coated urea (SCU), ammonium sulfate (AS), granular urea, spray‐applied urea (US), and urea‐ammonium nitrate (UAN) solution. Also, urea and AS treated with dicyandiamide (DCD) were compared to the untreated sources. Fertilization rate was 195 kg N ha−1 yr−1 split into four applications except SCU which was applied twice. Turfgrass color and clipping production were monitored along with thatch accumulation and soil pH. In a second field experiment, foliar burn potentials of the new N sources were evaluated by comparison to burn potentials from US, UAN, and a liquid 12‐1.8‐3.3 fertilizer. Turf response to Formolene (solution N source) paralleled that due to US. Turf treated with US received higher color ratings than did that treated with Nitroform or FLUF (suspension N source) during the early growing season but this trend was reversed by late summer. Turf fertilized with FLUF resembled turf fertilized with Nitroform but was inferior to turf fertilized with SCU. There was no benefit from the inclusion of DCD with either AS or urea. Soil pH after 2 yr ranged from 5.3 to 6.4 and was lowest with AS treatment; thatch depth ranged from 7.0 to 19.3 mm and was greatest with AS treatment. Formolene and FLUF caused less foliar injury than did US, UAN, or the 12‐1.8‐3.3 fertilizer. Results from the two experiments indicated that the major advantage of using Formolene or FLUF was the reduced potential for foliar fertilizer burn.
Effects of Water Deficits on Yield, Yield Components, and Water Use Efficiency of Irrigated Corn1
Authors: Eck Harold V. 
Published: July 2010

AbstractIrrigated corn (Zea mays L.) is an important feed grain crop on the Southern High Plains where the supply of water for irrigation is declining. Limited irrigation‐applying less water than is required to meet potential evapotranspiration‐is extensively practiced on the drought tolerant crops of grain sorghum [Sorghum bicolor (L.) Moench], wheat (Triticum aestivum L.), and cotton (Gossypium hirsutum L.). The purpose of this paper is (i) to report the effects of timing and duration of water deficit periods on growth and yield components of corn, (ii) to evaluate the seasonal evapotranspiration requirements of corn, and (iii) to give further information regarding the adaptation of corn for limited irrigation in a region of normally high evaporative demand climate. In a 4‐yr study, corn was grown under five irrigation treatments: adequate water, 2‐ and 4‐week water deficit periods during vegetative growth, and 2‐ and 4‐week water deficit periods during grain filling. Water deficits imposed 41 days after planting reduced leaf, stalk, and ear yields, while those imposed 55 days after planting reduced only stalk and ear yields. Deficits during vegetative growth reduced kernel numbers but had little effect on weight per kernel. Deficits during grain filling did not affect leaf and stalk yields but reduced ear yields. Kernel numbers were not affected by water deficits during grain filling unless severe deficits were imposed early in the period; thus, grain yield reductions were proportional to reductions in weight per kernel. With adequate water, seasonal water use averaged 964 mm on graded furrows and 834 mm in level borders. Although water use efficiency (WUE) was sometimes increased slightly when plants were subjected to water deficits, the data indicate that limited irrigation of corn would not be feasible on the Southern High Plains.
Comparison of Nitrogen Fertilizer Methods for Irrigated Barley in the Northern Great Plains1
Authors: Kucey R. M. N. , Schaalje G. B. 
Published: July 2010

AbstractYield response curves that consider differences in the effectiveness of fertilization practices are necessary to increase the accuracy of yield response predictions. Such curves are lacking for the northern regions of the Great Plains. A comparison of three commonly used N fertilization practices (broadcasting urea, broadcasting ammonium nitrate, and banding anhydrous ammonia) was conducted to determine their relative efficacies for irrigated barley (Hordeum vulgare L. ‘Gait’) production and to develop N response curves. Spring and late‐fall applications were also compared. Field plots were established on Aridic Haploboroll (Brown Chernozemic) and Typic Cryoboroll (Dark Brown Chernozemic) soils in southern Alberta between 1981 and 1984. Fertilizers were added in late fall or early spring at rates of 30,60,90, and 120 kg N ha−1. Broadcast fertilizers were incorporated into the top 20 mm of surface soil. Anhydrous ammonia resulted in significantly greater barley grain yield responses to N than the addition of urea. Yield responses to ammonium nitrate were intermediate between those for anhydrous ammonia and urea. The fertilizers did not differentially affect grain and straw N concentrations. Application of N fertilizers in the fall, after soil temperatures fell below 5°C, did not result in yields lower than those obtained by equivalent spring‐applied treatments. Yield response equations were developed for the combinations of fertilizer and time of addition.
Area‐×‐Time Equivalency Ratio: A Method For Evaluating The Productivity Of Intercrops1
Authors: Hiebsch C. K. , McCollum R. E. 
Published: July 2010

AbstractProduction systems involving interplanted food crops are widespread in tropical latitudes, and interest in quantifying the productive potential of intercrops is high. Published data often suggest a sizable gain in land‐use efficiency by growing such crops in mixtures. Our thesis is that many of the large intercrop advantages reported in the literature are misleading because the conceptual basis on which the monoculture‐vs.‐intercrop comparisons were made is incomplete. In this paper, we review the various methods for estimating intercrop productivity, propose a concept which we believe will remove the principal limitation in conventional methodology, and test the new concept with intercrop data from the literature. The land equivalency ratio (LER) is the most‐used convention for intercrop‐vs.‐monoculture comparisons, but LER is frequently inappropriate because cropping‐system duration, i.e., time, is not included in its calculation. Duration of land occupancy by an intercrop is often longer than production‐cycle duration for one or more of the interplanted species. We propose an area‐×‐time equivalency ratio (ATER) and suggest that it will correct this conceptual inadequacy in LER. When published intercrop data were reevaluated via the ATER concept, large land‐use advantages ascribed to growing food crops in mixtures disappeared. We conclude that most crop mixtures utilize land area and time (area·time) at about the same efficiency as pure stands of the mixture's components.
Soil‐Dependent Spectral Response in a Developing Plant Canopy1
Authors: Huete A. R. 
Published: July 2010

AbstractA major problem in the use of remote sensing techniques to assess plant biomass and condition over incomplete canopies concerns the soil background contribution toward measured spectral response. An understanding of this soil signal is essential to better relate canopy spectra with plant properties. An interactive, plant‐soil radiant flux model was developed to separate spectral variations associated with soil background from those attributable to vegetation. Field measured spectra taken over n developing cotton (Gossypium hirsutum L.) canopy with four soil types (Cumulic Cryoboroll, Typic Torrifluvent, Ustollic Haplargid, and Typic Calciorthid) alternately inserted underneath were decomposed into soil and vegetation spectra by utilizing the model in a principal component analysis. The soil component included all radiation penetrating the canopy and interacting with the underlying soil. The vegetation component represented all radiation reflected directly from the plant cover with no soil interaction. The soil component was found to resemble the spectral response of green vegetation due to the scattering and transmittance properties of the overlying plant canopy. Results show how the soil signal mixes into various vegetation indices inhibiting reliable vegetation discrimination. The potential improvements in vegetation analysis that can result from filtering soil background response from plant‐canopy spectra are also discussed.
Nitrogen Contribution to Succeeding Corn from Alfalfa and Red Clover1
Authors: Bruulsema T. W. , Christie B. R. 
Published: July 2010

AbstractThe use of leguminous crops as plowdown has stimulated interest in their contribution to soil fertility. The contribution of N from single‐year plowdown to a succeeding corn (Zea mays L.) crop was evaluated in two field experiments located at Elora, Ontario, on a Guelph‐London loam series Grey‐Brown Luvisolic (Typic Hapludalf) soil. In Experiment 1, 20 cultivars of alfalfa (Medicago sativa L.) and 10 cultivars of red clover (Trifolium pratense L.) were compared. Experiment 2 included two cultivars each of alfalfa and red clover under three management treatments. Nitrogen yield of plowdown legumes was considered in relation to the yield and wholeplant N concentration of the succeeding corn crop. In both experiments, whole‐plant N concentration of corn was significantly higher following alfalfa than following red clover. This suggested that alfalfa N was more readily mineralized than that of red clover, as predicted by a decomposability index based on the C/N ratio and lignin concentration of the plowdown material. However, corn yield following alfalfa plowdown was not always greater than that following red clover. Factors other than N‐supply may have influenced corn yield response to legume plowdown. Although significant cultivar variation in plowdown N yield was observed, there appeared to be no association with succeeding corn yield and N concentration. In general, legume plowdown supported corn yields equivalent to those achieved with 90 to 125 kg ha−1 of fertilizer N.
Growth and Yield of Ethephon Treated Maize1
Authors: Langan T. D. , Oplinger E. S. 
Published: July 2010

AbstractEthephon (2‐chloroethylphosphonic acid) has well‐known effects on many horticultural crops and is effective as an antilodging agent for small grains. However, very few studies have tested its effects on maize (Zea mays L.). Field experiments were conducted during 1983 and 1984 on a Plano silt loam (fine‐silty, mixed, mesic Typic Argiudoll) to study the effects of ethephon on maize. Ethephon was applied at rates from 0 to 840 g ha−1 at growth stage V10. Other treatments included populations from 64 200 to 133 330 plants ha−1 and row spacings of 0.38 and 0.76 m. Hybrids included Pioneer hybrids 3901 and 3780. Ethephon had highly significant effects on grain yield, plant height, ear height, and brace root development. Yield of hybrid 3901 generally decreased with increasing ethephon rate, while the lowest rate (140 g ha−1) increased yield of hybrid 3780 by as much as 0.7 Mg ha−1. Yield response of hybrid 3901 to ethephon was linear while that of hybrid 3780 was quadratic. Increasing ethephon rate decreased plant and ear height and promoted brace root development of both hybrids. Response of hybrid 3901 was greater than that of hybrid 3780. Low rates of ethephon can increase grain yield of maize.
Fertilizer Effects on Yield, Grain Composition, and Foliar Disease of Doublecrop Soft Red Winter Wheat1
Authors: Boquet Donald J. , Johnson Catherine C. 
Published: July 2010

AbstractImprovements in cultivars and management technology have increased the yield potential of soft red winter wheat (SRWW) (Triticum aestivum L.). Field experiments were conducted for 3 yr to define fertilizer requirements for doublecrop SRWW grown on Sharkey clay soil (Vertic Haplaquent). Nitrogen rates were 0, 34,56,78, and 101 kg ha−1 applied as both a single February topdress application (growth stage 5, Feeke's scale) and as a fall‐February split with 17 kg of the total N applied preplant. The effects of application of P (20 kg ha−1) and K (24 kg ha−1) were evaluated singly and in combination at a February applied N rate of 56 kg ha−1 and fall + February split N application rates of 17 + 39 and 17 + 62 kg N ha−1. Significant yield increases were obtained from applied N up to the maximum rate of 101 kg ha−1. The best estimate of yield (
Y) plotted against N rate (X) was the linear equation Y = 3002 + 9.9 × (R2=0.98). Kernels per spike increased and specific kernel weight decreased slightly with N application. There was no yield benefit from splitting the total applied N. Leaf rust (Puccinia recondita Rab. ex Desm.) and powdery mildew (Erysiphe graminis D.C.) infection showed a positive linear association with increasing N rate (R2=0.77 and 0.42, respectively). Phosphorus fertilization decreased the incidence of both leaf rust and powdery mildew. Nitrogen, at the rates applied in this study, did not affect grain protein content but did increase total protein per hectare by increasing yield. Nitrogen fertilization increased the S content of grain and tended to decrease P and K content. Phosphorus and K had no effect on grain protein or mineral composition.