bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sodic Calcareous Soil Reclamation as Affected by Different Amendments and Crops1
Authors: Robbins C. W. 
Published: July 2010

AbstractSodium leaching efficiencies (moles of Na removed per unit leachate volume) were measured and compared from four noncropped and four cropped treatments applied in duplicate to 1.0 m deep sodic calcareous silt loam in lysimeters. Treatments included a check, gypsum, chopped alfalfa (Medicago sativa L.), fresh manure, alfalfa, sorghum (Sorghum bicolor), Sudan grass (Sorghum Sudanese) hybrid (which will be called sorghum hybrid for simplicity), sorghum hybrid + leaching, and cotton (Gossypium hirsutum L.). The sorghum hybrid + leaching treatment soil was leached with tap water until 0.5 pore volume of leachate was collected from lysimeter bottoms, and then sorghum hybrid was planted. Sorghum hybrid was the most efficient treatment in reclaiming Na‐affected soil. All four non‐cropped soils eventually became dispersed in the lower part of the profile and hydraulic conductivity became very low. Cropped treatments continued to conduct water at a satisfactory rate for reclamation; however, due to low water use, cotton treatment produced a low total Na removal. Sorghum hybrid shows promise as a crop that could be used to speed reclamation of sodic calcareous soils. The treatments producing the highest sodium removal efficiencies also produced the highest soil atmosphere CO2 concentrations. By selecting crops, amendments, and water application rates and timing, calcareous sodic soil reclamation can very likely be accomplished faster and more economically than in the past.
Field Evaluation of Urease Inhibitors for Corn Production1
Authors: Schlegel A. J. , Nelson D. W. , Sommers L. E. 
Published: July 2010

AbstractPhosphoroamide urease inhibitors were evaluated for their ability to increase N uptake and grain yield of corn (Zea mays L.) when added to surface‐applied urea fertilizers. Six urease inhibitors [trichloroethyl phosphorodiamidate, diethyl phosphoric triamide, dimethyl phosphoric triamide, N‐(diaminophosphinyl)‐cyclohexylamine, N‐benzyl‐N‐methyl phosphoric triamide, and phenylphosphorodiamide (PPD)] were evaluated. Urea prills, urea solution, and urea–ammonium nitrate (UAN) solution were broadcast, and UAN solution was banded onto the surface of conventional till (CT) Chalmers silty clay loam (Typic Haplaquoll) and no‐till (NT) Raub silt loam (Aquic Argiudoll) in 1983. Two urease inhibitors [PPD and N‐(n‐butyl)‐thiophosphoric triamide (TPT)] were broadcast with urea prills and UAN solution (60, 120, and 180 kg N ha−1) onto CT and NT Chalmers and NT Avonburg silt loam (Aeric Fragiaqualf) soils in 1984. With both tillage systems in 1983, urea prills produced greater grain yield and tissue N content than did UAN solution, although no differences between broadcasted and banded UAN or between fertilizers with and without urease inhibitors were observed. In 1984, urease inhibitors increased grain yield and N uptake of NT corn when applied with urea prills, but not with UAN solution. When conditions existed for substantial NH3 loss, TPT performed as well or better than PPD. Urease inhibitors will be most beneficial when added to urea that is surface‐applied to soils with large amounts of residue cover under conditions of adequate moisture to promote urea hydrolysis and ammonia volatilization but without sufficient precipitation to move the urea into the soil.
Phenology of Dent Corn and Popcorn. I. Analysis of Repeated Measurements from Phenology Experiments1
Authors: Stevens E. J. , Eskridge K. M. , Stevens S. J. , Flowerday A. D. , Gardner C. O. 
Published: July 2010

AbstractRepeated observations are commonly made on individual or multiple plant samples in order to generate data suitable for developing linear regression models with growth stage as the dependent variable. Most studies using regression, including those conducted at the University of Nebraska, Lincoln (UNL), have implicitly assumed that the data adhere to standard regression assumptions even though these assumptions may be tenuous. Misleading conclusions can be made if basic regression assumptions are not reasonably satisfied. Pilot studies may be used as a strategy for completing preliminary analyses of representative data from a larger phenology study to develop appropriate regression models and substantiate basic regression assumptions. The objectives of this research were to (i) validate regression models used in an interactive agrometeorology (AGNET) offered by UNL (ii) correctly specify thermal‐photoperiod regression models of corn phenology using hourly data generated by an automated weather station, (iii) investigate the validity of underlying assumptions of models developed, and (iv) investigate the application of growth curve analysis as a statistical procedure for comparing response profiles of different treatment effects in corn phenology experiments. A 2‐yr phenology study incorporating three planting dates, one dent corn cultivar (B73 ✕ Mo17), and three differently maturing popcorn cultivars (P410, P609, and Iopop 12) was conducted in eastern Nebraska during 1982‐1983. Climate records from an automated weather data network were used to develop daily and hourly heat sums. Corn growth was described using both current and modified staging procedures. Serious violations of standard regression assumptions were identified in the UNL‐AGNET corn phenology model and were commonly associated with one or more of the following conditions: (i) using incorrectly specified models, (ii) heterogeneity of error variance, and (iii) nonindependence of errors. Violations were considered serious since they were suspected of producing biased mean squares and regression estimates, indicating a need for further refinement of model definitions and growth staging procedures. Alternative regression models were developed and tested using a modified staging procedure combined with partitioning and modeling phenological sequences as pre‐ and post‐anthesis development. When applied to these data, growth curve analysis demonstrated a curvilinear response of corn phenology to planting date (daylength) within the range of 14.3 to 15.2 h, and provided a useful alternative to standard regression techniques for statistically analyzing data from corn phenology experiments.
Herbicide Compatibility and Phytotoxicity When Mixed with Liquid Fertilizers1
Authors: Sander Kip W. , Burnside Orvin C. , Bucy John I. 
Published: July 2010

AbstractThe need for growers to conserve energy, labor, and money has stimulated the joint application of herbicides and liquid fertilizers. Chemical and physical reactions between herbicides and liquid fertilizers may affect the compatibility or herbicidal performance of a combination. The objective of this research was to determine the compatibility and phytotoxic characteristics of 10 common herbicides when individually mixed with each of six liquid fertilizers. Of the 60 herbicide‐liquid fertilizer combinations tested, 87% were compatible and 13% were incompatible. Attapulgite clay suspensions were the most compatible of the liquid fertilizers tested. Atrazine (6‐chloro‐N‐ethyl‐N'‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine] and metribuzin [4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazin‐5(4H)‐one] were least compatible with the liquid fertilizers. Phytotoxicity of the herbicide, when combined with the liquid fertilizers, increased in 21%, decreased in 32%, and was equal to the herbicide‐water check in 47% of the combinations. Glyphosate [N‐(phosphonomethyl)glycine] and paraquat (1,1'‐dimethyl‐4,4'‐bipyridinium ion) showed the highest occurrence of decreased phytotoxicity, whereas acifluorfen {5‐[2‐chloro‐4‐(trifluoromethyl)phenoxyl‐2‐nitrobenzoic acid} and bentazon [3‐(1‐methylethyl)‐(1H)‐2,1,3‐benzothiadiazin‐4(3H)‐one 2,2‐dioxide] showed the highest occurrence of increased phytotoxicity when mixed with liquid fertilizers. Agitation was necessary to prevent separation in 52% of the compatible mixtures. Duration of contact between herbicide and liquid fertilizer did affect herbicidal phytotoxicity with certain combinations and especially with butylate [S‐ethyl bis(2‐methylpropyl) carbamothioate]‐liquid fertilizer mixtures.
Mefluidide Applications for Annual Bluegrass Seedhead Suppression Based on Degree‐Day Accumulation1
Authors: Danneberger T. K. , Branham B. E. , Vargas J. M. 
Published: July 2010

AbstractMefluidide [N‐(2,4‐dimethyl‐5‐{[(trifluoromethyl)sulfonyl] amino}phenyl) acetamide] is an effective growth regulator for annual bluegrass [Poa annua var. reptans (Hauskins) Timm.] seedhead suppression. The effectiveness of mefluidide is dependent on the rate and timing of application. The objective of this field study was to determine the lowest effective rate and the proper time for mefluidide application based on growing degree‐days (GDD). Soil types were a fine, mixed, mesic Aeric Ochraqualf and fine‐loamy, mixed, mesic Typic Glossoboric Hapludalfs for Columbus, OH, and East Lansing, MI, respectively. The rates evaluated were 0.140, 0.070, and 0.035 kg ha−1 of mefluidide. The applications were made at 15, 25, 30, and 45 GDD. Degree‐days were accumulated using a sine curve as an approximation of the diurnal temperature curve. The base temperature used was 13°C. Mefluidide applied between 15 and 30 GDD at 0.140 kg ha−1 gave excellent seedhead suppression. Mefluidide applied between 15 and 30 GDD at 0.070 kg ha−1 gave moderate seedhead suppression. Applications of mefluidide at 45 GDD or at the 0.035 kg ha−1 rate were unacceptable.
Fungal Endophyte Infection‐Loline Derivative Alkaloid Concentration of Grazed Tall Fescue1
Authors: Belesky D. P. , Robbins J. D. , Stuedemann J. A. , Wilkinson S. R. , Devine O. J. 
Published: July 2010

AbstractImpaired animal performance on tall fescue (Festuca arundinacea, Schreb.) pasture has been associated with the presence of a fungal endophyte (Acremonium coenophialum). A number of alkaloids, including the loline derivatives N‐formyl and N‐acetyl loline, occur in endophyte infected tall fescue. A study was conducted at Watkinsville, GA, on a Cecil sandy loam (Typic hapludult) to examine the influence of N fertilization and season on endophyte infection frequency (EIF) and loline derivative alkaloid concentration (LDA) of grazed low and high endophyte tall fescue. Paddocks (0.7 ha) established with low and high endophyte status ‘Ky‐31’ tall fescue seed were fertilized with 134 and 336 kg N ha−1 (22 factorial) and replicated three times. Endophyte infection frequency was greater in high than low fungus paddocks during the 3‐yr study. Endophyte infection frequency means within a given paddock, i.e., high or low fungus, remained relatively constant in 1983 and 1984 but increased by 50% in high and 100% in low fungus paddocks in 1985. Endophyte infection frequency was not affected by N nor did infection frequency vary significantly within a growing season. Loline derivative alkaloid concentration and EIF were significantly correlated (positive) in each growing season. High fungus paddocks had significantly greater (100%) LDA than low fungus paddocks. The ratio of LDA to EIF was greater under high N and high fungus conditions in the fall of 1983 and in 1984. Periods of LDA production may be more closely associated with short‐term weather conditions than absolute EIF. The relationship between LDA and EIF may not be simply defined in continuously grazed tall fescue, especially under moderate EIF.
Temperature Effects on Leaf Anatomy, Phenolic Acids, and Tissue Digestibility in Tall Fescue1
Authors: Akin D. E. , Fales S. L. , Rigsby L. L. , Snook M. E. 
Published: July 2010

AbstractIncreasing growth temperature lowers digestibility of tall fescue (Festuca arundinacea Schreb.) cell walls, but specific tissue responses have not been fully elucidated. The objectives of our research were to determine the effect of increasing growth temperature on leaf anatomy, histological reactions for lignin, alkali‐extractable phenolic acids, and the digestion of different tissue types by rumen microorganisms after 4, 10, 24, or 48 h. Plant material was grown in a controlled environment in which temperature was changed sequentially from 13/10°C (T1), to 20/18°C (T2), to 30/27°C (T3), and back to 13/10°C (T4). Two consecutive harvests of uppermost leaf blades following 28 days growth were made at each temperature, and analyses were performed on leaf blades. Histological reactions for lignin and leaf anatomy were similar for all treatments but with higher amounts of lignified vascular tissue in T3. At incubation times less than 48 h, leaf tissues from plants grown at T1 or T4 were degraded, as determined by scanning electron microscopy, to a greater extent than those at T2 or T3. However, after 48 h, tissues from plants grown at T2 were clearly the most degraded, and the order for all digestible tissues was as follows: T2 > T4 > T1 > T3. From 786 to 854 g kg−1 of the phenolic acids extracted from forage with 1 M NaOH were trans‐p‐coumaric and trans‐ferulic acids. Increases in growth temperature tended to increase levels of these and other phenolic acids, with T3 resulting in the highest level; amounts at T1 were lower (P≤10.05) than those at T2 through T4. Increased temperature resulted in a lower digestibility of easily degraded tissues without causing a marked change in leaf anatomy or histological reaction for lignin. Increased levels of p‐coumaric and ferulic acids up to T3 suggest that these compounds may contribute to limiting the digestibility of leaf blade tissues at higher temperatures.
Variation in Seed Size in Soybean1
Authors: Egli D. B. , Wiralaga R. A. , Ramseur E. L. 
Published: July 2010

AbstractSeed size (mass per seed) is an important yield component in soybean [Glycine max (L.) Merr.]; however, little is known of the variation in seed size within a seed lot. Consequently, the variation in seed size within seed lots collected from greenhouse and field experiments was investigated. Treatment variables included in the experiments were planting dates, cultivars (determinate and indeterminate), and source‐sink alterations applied during seed filling. Seed size distributions were determined using round‐hole screens ranging from 3.2 to 8.7 mm in diameter at intervals of 0.8 mm. All seed lots investigated exhibited a wide range in seed size from approximately 90 to greater than 200 mg seed−1. However, 40 to 80% of the seeds stayed on a single screen. The seed size of seeds on a single screen varied significantly among cultivars, planting dates, and years. Determinate cultivars tended to have a greater proportion of the seed on a single screen, but the range in seed size was similar to that exhibited by indeterminate cultivars. Treatments that altered mean seed size usually affected the proportions of the various sized seeds in the lot, more than the range in seed size. Variations in seed size within a seed lot were not associated with differences in seed density, specific seed coat mass, or seed N concentration. The data indicate that variation in mean seed size can be caused by variations in the proportion of the various sized seed in the seed lot, with relatively small changes in the range in seed size.
Effects of Tillage Practices on Cotton Double Cropped with Wheat1
Authors: Baker Shelby H. 
Published: July 2010

AbstractTo reduce production cost, reduce land erosion and increase profits per acre, double cropping and reduced tillage are becoming a part of production systems across the United States. Tillage studies with double crop (DC) wheat (Triticum aestivum L.) and cotton (Gossypium hirsutum L.) were conducted at two Georgia locations, Tifton (1982–1984) and Plains (1981–1984). At Tifton, continuous tillage treatments (same treatments on the same plot every year) were: a winter fallowed full‐season (FS) check; no‐tillage (NT), cotton planted into straw and stubble; burn no‐tillage (BNT), plots burned, no other tillage; maximum tillage (MXT), plots burned and bottom plowed; minimum tillage (MTH), plots burned and disc harrowed; and minimum tillage (MTRH), plots burned, subsoiled, and bedded (riphip). The treatments at Plains were non‐continuous (test rotated to new area each year) and did not include a FS or MTRH treatment. The DC cotton at Tifton showed a significant yield reduction when compared with the FS cotton, regardless of DC tillage treatment. Within tillage treatments, continuous MXT, MTH, or MTRH had no significant effect on cotton yield, but the average yield of the tilled treatments over years was significantly better than those of the NT and BNT treatments. In certain years the BNT treatment yield was equal to some of the tilled treatments. Yield of the BNT treatment was significantly better than the NT treatment. At Plains, the average yields of the BNT, MTH, and NT treatments were not significantly different, but the BNT was significantly better than the MXT treatment. The MXT and MTRH treatments produced a higher lint percent than FS, but there were no differences in the DC tillage treatments at Tifton. Boll size and fiber characteristics were similar for DC and FS cotton at Tifton. The MXT treatment at Plains produced larger bolls than did the other treatments, but there was no treatment effect for lint percent and fiber properties. Wheat yields at Tifton were not affected by cotton tillage treatments.
Response of a Rice‐Sugarcane Rotation to Calcium Silicate Slag on Everglades Histosols1
Authors: Anderson D. L. , Jones D. B. , Snyder G. H. 
Published: July 2010

AbstractRice (Oryza sativa L.) and sugarcane (Saccharum spp.), grown on organic soils of the Everglades, have been shown to respond favorably to the application of Si from calcium silicate slag. Since these crops may be grown in rotation, it is important to know if slag applied to one crop will benefit the second crop. The objective of the study was to determine the response of rice and sugarcane grown on a Terra Ceia muck (Euic, hyperthermic Typic Medisaprist) to calcium silicate slag applied prior to planting rice, and to slag applied before the planting of sugarcane. Five rates of slag were applied for production of a rice crop, after which time the same plots were planted to sugarcane. Other plots received the same rates of slag just prior to planting sugarcane. Slag applications increased both rice straw Si and sugarcane leaf Si concentrations. A single application of slag prior to planting rice increased production of both the rice and sugarcane crops in the rotation. The combined plant and ratoon rice grain yields were significantly increased 50% by slag application. Slag application also increased harvested cane (biomass) yields 23%, and sugar yields by 25%. Somewhat greater sugarcane plant responses were observed from slag applied immediately before planting than from slag applied before the rice and cane rotation treatment. On the average, slag applied at 20 Mg ha−1 before rice increased sugar yield by 16%, compared to a 21% increase when slag was applied before cane.
Comparison of Turnip‐Chinese Cabbage Hybrid, Rape, and Rye, Alone and in Combination with Annual Ryegrass and Crimson Clover1
Authors: Dunavin L. S. 
Published: July 2010

AbstractSmall grains, Italian ryegrass (Lolium multiflorum Lam.), and crimson clover (Trifolium incarnatum L.) have been used extensively for cool‐season pastures. Rape (Brassica napus L.), turnip (B. rapa L.), and hybrids thereof are possible alternatives that need investigating. A turnip‐Chinese cabbage hybrid [B. campestris var. rapa L. × B. pekinensis (Lour.) Rupr.], rape, rye (Secale cereale L.), ryegrass, and crimson clover were grown in a field experiment in monoculture and mixtures during 3 yr, on a Dothan fine sandy loam soil (fine‐loamy, siliceous, thermic Plinthic Paleudult). The mixtures and the ryegrass monoculture produced more dry matter (DM) and digestible organic matter (DOM) than the other monocultures. There was more variability between mixtures and monocultures with respect to crude protein (CP). The turnip hybrid was relatively unproductive for the whole season; however, when first‐harvest yields were considered, its value for early season production was apparent in that it was high producer of DM in all years and at the top in 2 yr for production of CP and DOM. The turnip hybrid‐ryegrassclover mixture, at the first harvest, was among the best in production of DM, DOM, and CP in 2 yr and was equal to the rye‐ryegrassclover mixture in production of DM, DOM, and CP at the first harvest in all years, The yield of DM, DOM, and CP from rape, at the first harvest, was equivalent to the high yield in only 1 yr. Rye was a top producer, at the first harvest, of DM, CP, and DOM, and ryegrass and clover had low first‐harvest yields. The turnip hybrid appears to be a reasonable alternative to rye in cool‐season mixtures with ryegrass and clover but less valuable than rape or rye in monoculture except for early season forage
Tall and Semidwarf Wheat Response to Dryland Planting Systems1
Authors: Winter S. R. , Welch A. D. 
Published: July 2010

AbstractDryland winter wheat (Triticum aestivum L.) yields on the Southern Great Plains are almost always limited by crop water deficits. This research was conducted to determine if a wide‐row planting system in combination with a high‐yielding, semidwarf wheat would increase plant height, leaf conductance, leaf water potential, and grain yield of dryland wheat. ‘Scout 66’, a tall wheat, and ‘TAM 105’, a semidwarf, were planted in five row‐spacing systems on Pullman clay loam soil (fine, mixed, thermic Torrertic Paleustoll) at Bushland, TX. Two narrow‐row systems (0.20‐ and 0.25‐m row spacing) and three wide‐row systems (0.51‐m single rows and 0.25/0.51‐m and 0.25/0.76‐m skip‐row systems) were studied. Total soil water depletion was not affected by row‐spacing system or cultivar in either year. Wide‐row systems were, however, effective in economizing usage of soil water before boot stage so more water was available in widerow systems during later growth stages in 1985. As a result, leaf conductance and leaf water potential at the boot stage in 1985 were increased from 2.21 mm s−1 and —1.38 MPa, respectively, in wheat growing in the 0.20‐m row‐spacing system, to 4.24 mm s−1 and —0.85 MPa in wheat growing in the 0.51‐m row‐spacing system. Wide‐row systems increased plant height of TAM 105 by 0.07 m. While using semidwarf wheat in wide‐row systems was successful in reducing crop water deficit and increasing plant height, grain yield was reduced in wide‐row systems compared to narrow‐row systems for both tall and semidwarf wheat.
Winter Wheat Production as Influenced by Fallow Method, Seeding Method, and Nitrogen Fertilization1
Authors: Tanaka D. L. , Aase J. K. 
Published: July 2010

AbstractUse of conservation tillage practices for erosion control retains more crop residue on the soil surface and alters plant environments. The objectives of a study conducted on a Williams loam (fine‐loamy, mixed Typic Argiboroll) were to determine the effects of fallow method, seeding method, and N rates on winter survival and production of winter wheat (Triticum aestivum L.). Factorial treatment combinations of fallow method (stubble mulch, reduced tillage, and chemical fallow) and seeding method (deep‐furrow and double‐disk) were whole plots, with N rates (0, 34, and 68 kg/ha) as subplots. Winter survival as determined from stand counts taken in late October and again in April was 100% for each year and treatment except in 1984 when deep‐furrow seeded wheat had a 13% reduction in stand. Winter soil temperatures at 30‐mm depth in deep‐furrow seeded plots were 1 to 3°C higher than in double‐disk seeded plots. Snow insulating effects were achieved with fallow methods that left residue erect, resulting in good winter survival on double‐disk seeded plots. Reduced tillage and chemical fallow reduced grain yields in 1981 but had no influence in the other years. Double‐disk seeded wheat yielded 200 to 400 kg/ha more grain than deep‐furrow seeded wheat. Grain N concentration was 0.9 to 1.8 g/kg less in double‐disk seeded wheat than in deep‐furrow seeded wheat. These data support use of conservation tillage methods to maintain crop productivity and to reduce soil erosion.