bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Tall Wheatgrass Wind Barriers on Soil Drying1
Authors: Aase J. K. , Siddoway F. H. 
Published: July 2010

AbstractVirtually no direct measurements have been made to determine if wind barriers, in fact, do affect evaporation from bare soils. Our objective, therefore, was to quantify the effect of a tall wheatgrass (Agropyron elongatum) wind barrier system on soil drying from fallow soil compared with open‐field fallow. The experiment was done on a Williams loam soil (fine‐loamy, mixed, frigid family of Typic Argiborolls) near Sidney, Mont. We applied a 3.8‐cm irrigation and sampled for soil water content at half‐hour intervals and small depth increments to 10 cm. Ancillary data collected included wind in the barrier interval and in the open, plus global radiation, air temperature, and humidity in the open. The north‐south oriented system consisted of 8 double‐row tall wheatgrass barriers 1.2 m tall, 183 m long, with seven 15 m wide cropping intervals. For the study, we selected three locations in the third interval from the east, along with a location on an unprotected (check) area outside the influence of the barriers. The surface 4 cm of soil inside the barrier system remained wetter for about 3 days after the irrigation as compared with the check area. The drying rate remained constant at all four locations until approximately noon the day after irrigation. Thereafter, drying rate was influenced by exposure to wind. There are many periods of small, intermittent precipitation events during April and May when tall wheatgrass barriers could benefit a crop by creating a suitable soil water environment for seed germination, plant emergence and establishment, and soil resistance to wind erosion.
Seedcoat Structure in Coronilla varia and its Relations to Hard Seed1
Authors: McKee G. W. , Peiffer R. A. , Mohsenin N. N. 
Published: July 2010

AbstractHard seeds are common in some seedlots of crownvetch (Coronilla varia L.); such seeds are impermeable to water and require scarification before planting. However, unless carefully performed, scarification can lead to seedcoat injury with consequent loss of vigor and germinability. To locate the region or regions responsible for impermetability in ‘Penngift’ crownvetch, sized and known hard seeds were pierced to known depths and subsequently tested for imbibition of water and germination. All seeds punctured to a depth of 98 μm or more germinated rapidly while only 5% of those punctured to a depth of 47 μam or less subsequently germinated. Measurements of cross sections of crownvetch seeds indicated that the macrosclerid cells extended to a mean depth of 45 to 50 μm. In addition, an inner integument at an average depth of 73 μm also had to be pierced before germination occurred. Colors developed after staining with safranin and fast green indicated that the cuticle, macrosclerids and inner integument were lignified. Extensive deposits of tannin‐like materials were noted just below the inner integument.
Effects of Topping Pima Cotton on Lint Yield and Boll Retention1
Authors: Kittock D. L. , Fry K. E. 
Published: July 2010

AbstractSubstantial mid‐ and late‐season topping of American Pima cotton (Gossypium barbadense L.) plants occurs in field plantings. Lygus bug (Lygus hesperus Knight) feeding is the apparent cause of topping. The effects of mid to late‐season topping on lint yield and several yield components of ‘Pima S‐4’ cotton were examined. Topping of Pima S‐4 cotton in mid‐July, early‐August, and mid‐August reduced plant height, reduced the number of main stem nodes, increased boll set on top fruiting branches, and resulted in additional branch nodes on top fruiting branches. Plants topped 17 July produced 300%, 100%, and 60% more bolls on the first, second, and third branch, respectively, below the point of topping than did the check plants. The effect was less when topping was later in the season. The yield patterns in lower branches were not different from the checks. Topping did not affect: 1) lint yield (3 years), 2) number of bolls set, 3) seed/boll, 4) lint/boll, 5) lint/seed, 6) seed weight, 7) days to boll maturity, or 8) pink bollworm infestation. Fruit set was not delayed by topping. Fruiting points, which aborted on normal plants, produced bolls on topped plants up to the potential for the cultivar and environment. This has important implications for studies on insect damage to plants and for efforts to increase lint yield by reducing boll abscission.
Comprehensive Nitrogen Fertilizer Management Model for Winter Wheat1
Authors: Jackson Grant D. , Sims James R. 
Published: July 2010

AbstractSystems for predicting fertilizer N rates on dryland winter wheat (Triticum aestivum L.) in Montana have needed refinement for several years. The objective of this study was to develop a comprehensive N fertilizer management model for dryland winter wheat based on soil properties and climatic factors. Data for multiple regression analysis were gathered from 47 locations rep resenting 4 growing seasons. A stepwise multiple linear regression technique was used to generate equations for predicting optimum grain yield, grain protein content at optimum yield levels, N fertilizer rate needed to achieve optimum yield, post‐harvest soil NO3‐N in surface 30 cm of soil, and grain yield and protein content without N fertilization. Statistically significant equations were developed for all functions except post‐harvest NO3‐N when excessive N fertilizer rates were used. Growing season rainfall, pan evaporation rate, soil temperature, initial soil NO3‐N, soil organic matter content, available soil water, grain yield, and grain protein content were the important variables.
Influence of No‐tillage and Nitrogen Fertilization on Certain Soil Properties after 5 Years of Continuous Corn1
Authors: Blevins R. L. , Thomas G. W. , Cornelius P. L. 
Published: July 2010

AbstractIn no‐tillage management systems for row crop production, plant residues, lime, and fertilizer are not incorporated into the soil. A major concern in continuous no‐tillage farming is what effect not incorporating these materials will have on soil properties and nutrient availability. The purpose of this study was to compare the effects of 5 years of continuous no‐tillage and conventional‐tillage of corn (Zea mays, L.) on certain chemical and physical properties of the soil. A field experiment was initiated in 1970 on a Maury silt loam (Typic Paleudalfs) soil. The experimental site had been in bluegrass (Poa pratensis, L.) for the past 50 years. A split‐block design with four replications of treatments of 0, 84, 168, and 336 kg N/ha was used in combination with no‐tillage and conventional‐tillage. After 5 years of continuous corn production, soil samples from all treatments were analyzed for selected chemical and physical properties. Neither tillage treatment or N treatment had a statistically significant effect on soil density. Exchangeable Ca decreased with increasing rates of N but tillage methods did not significantly effect exchangeable Ca. Exchangeable Al increased with N rates and was higher under no‐tillage than under conventional‐tillage. The soil pH was lowered by increasing N rates and was lower with no‐tillage than with conventional‐tillage. Organic C was significantly higher under no‐tillage and increased with increasing N rates. Organic soil N followed the same trends as organic C. Exchangeable Mg decreased under both tillage methods. No tillage with moderate rates of N most nearly preserved the soil chemical characteristics found under the original bluegrass sod.
Factors Determining Germination of Indian Ricegrass Seeds1
Authors: McDonald M. B. , Khan A. A. 
Published: July 2010

AbstractIndian ricegrass, Oryzopsis hymenoides (Roem. & Shult.) Ricker is an important forage crop in the western United States. The seeds of this species are dormant at harvest and even following several years of storage. In spite of several attempts by various workers to uncover the factors responsible for dormancy, little progress has been made to date. The present investigation was undertaken to reexamine in detail the nature of dormancy in these seeds with emphasis on the effects and possible roles of hormones in release of dormancy. The seed coats of Indian ricegrass seeds prevented germination and were shown to delay the uptake of water, gibberellic acid, and tetrazolium salts by the seed. The acid scarification proved the only effective method of breaking dormancy imposed by the seed coats. One‐year‐old scarified Indian ricegrass seeds were also shown to exhibit a post‐harvest dormancy which was overcome by 10 μM gibberellic acid and 10 μM kinetin. Intact seeds contained abscisic acid and the level of this inhibitor decreased following scarification. Gibberellic acid was incorporated into scarified Indian ricegrass seeds by acetone permeation suggesting a commercial preparation for these seeds.
Giant Foxtail and Velvetleaf Control in Sweet Corn1
Authors: Harvey Robert G. , Andrew Robert H. , Ruscoe Alfred W. 
Published: July 2010

AbstractVelvetleaf (Abutilon theophrasti Medic.) and giant foxtail (Setaria faberi Herrm.) are among the most serious weed problems in sweet corn (Zea mays L.) grown in the north central U.S. While several herbicide treatments have been used to partially control these weeds, the treatments frequently leave soil residues which can injure susceptible crops commonly grown in rotation with sweet corn. Consequently, studies were conducted over a 3‐year period on fields (Plano silt loam, 3.5 to 4% organic matter, Typic Argindoll fine silty mixed mesic) heavily infested with velvetleaf and giant foxtail to compare the effectiveness of 10 herbicides applied alone and in 36 combinations in controlling these weeds. Visual observations of sweet corn injury and weed control were obtained and the sweet corn was harvested to determine the effects on yields. Oats (cv. ‘Lodi’) and peas (cv. ‘NK‐692’), which commonly follow sweet corn in a crop rotation and which are susceptible to residues of common herbicides, were grown over the plot areas the year following sweet corn and evaluated for carryover injury. Of the herbicide treatments included in the study, the best overall weed control and the largest average sweet corn yields were produced by a sequential application of 2.2 kg/ha alachlor [2‐chloro‐2',6'‐diethyl‐N‐(methoxymethyl) acetanilide] applied premergence and 1.1 kg/ha bentazon [3‐isopropyl‐1H‐2,1,3‐benzo‐thiadiazin‐(4)3H‐one 2,2‐dioxide] applied postemergence and by a preemergence combination of 2.2 kg/ha alachlor and 0.6 kg/ha metribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐as‐triazin‐5 (4H) one]. Preplant incorporated combinations of butylate (S‐ethyl diisobutylthiocarbamate) with atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] or cyanazine [2‐([4‐chloro‐6‐(ethylamino)‐s‐triazin‐2‐yl] amino)‐2‐methyl‐propionitrile] and preemergence combinations of alachlor with atrazine or cyanazine provided good weed control and satisfactory yields in 2 of the 3 test years. Three‐way combinations of atrazine, cyanazine, and butylate, as well as preemergence combinations of alachlor with bifenox (methyl 5‐(2,4‐dichlorophenoxy)‐2‐nitrobenzoate) or dicamba (3,6‐dichloro‐o‐anisic acid) and a preemergence and postemergence split treatment of cyanazine also showed promise. Preemergence treatments failed to control velvetleaf adquately in 1973 when insufficient rainfall was received, but preplant‐incorporated treatments failed similarly in 1974 following excessive rainfall. Postemergence treatments were typically best for controlling velvetleaf but did not satisfactorily control giant foxtail. The only injury to oats (Avena sativa L.) or peas (Pisum sativum L.) from soil residues persisting until the spring following sweet corn, occurred from atrazine applied at 3.4 kg/ha preplant‐incorporated in combination with butylate.
Detection of the Green and Brown Wave in Hardwood Canopy Covers Using Multidate, Multispectral Data from LANDSAT‐11
Authors: Blair B. O. , Baumgardner M. F. 
Published: July 2010

AbstractPhenologic events which may be related to yields of economic plant species in humid and sub‐humid temperate regions are difficult and expensive to observe and measure. Sequential multispectral reflectance data obtained by an orbiting satellite (LANDSAT‐1) over 14 preselected sites in central and eastern United States during a 14‐month period were examined. Analysis of data from four reflectance bands (0.5 to 1.1 μm) indicated that foliage color, leaf senescence, and regrowth differences among hardwood timber stands can be detected and quantified. The results suggest the need for continued development of these monitoring techniques for use in detecting and quantifying conditions of economic plants which may affect yield.
Renovation of Tall Fescue Pasture with Lime‐Pelleted Legume Seed1
Authors: Olsen F. J. , Elkins D. M. 
Published: July 2010

AbstractLime pelleting of legume seed might protect Rhizobium and aid nodulation by providing a favorable microenvironment near developing seedling. The objective of this investigation was to determine if lime pelleting seed of selected forage legumes would aid renovation of tall fescue (Festuca arundinaceae Schreb.) pasture on an acid soil in Southern Illinois. This work was conducted on a Stoy silt loam soil classified as an Aquic Hapludalfs with a pH of 4.7. Seedbeds were prepared for oversowing legumes in tall fescue sod, by disking, and by chemical means plus disking. Seed treatments used were a) inoculation only and b) inoculation plus gum arabic and lime pelleting. They were applied to each of three forage legumes, alfalfa (Medicago sativa L.), ladino clover (Trifolium repens L.), and red clover (Trifolium pratense L.). With limited exceptions, lime pelleting of legume seed did not enhance early stand of legume seedlings, plant height, or legume ground cover. Dry matter herbage yields of legumes were not increased significantly by seed pelleting; however, tall fescue growth was stimulated by the introduction of legumes into the sward. The yield from most legume renovation treatments exceeded that of grass alone.
Rear‐Mounted Planter for Small Grain Yield Trials1
Authors: Cobb D. L. , Doyle B. L. , Webster J. A. , Smith D. H. , Ries D. K. 
Published: July 2010

AbstractA four‐row single cone planter that could be easily detached from a tractor was needed for off‐station cereal leaf beetle (Oulema melanopus (L.)) research plots. The grain box and three disk openers were removed from a small seven‐row drill equipped with a three‐point hitch and a cone seeder with a four‐row divider was installed. A fertilizer attachment was also installed. The length of plots can be easily changed from 2 to 15 m with a variable speed drive which is part of the commercial cone unit. The planter has been successfully used in planting plots of wheat (Triticum aestivum L. em. Thell.), barley (Hordeum vulgare L.), and oats (Avena sativa L.)
Time and Rate of Fertilization on Seeded Warm‐Season and Bluegrass Pastures. II. Quality and Nutrient Content1
Authors: Rehm G. W. , Sorensen R. C. , Moline W. J. 
Published: July 2010

AbstractThere is relatively limited available information to be found which pertains to the effect of fertilizer application on the quality and nutrient concentration of seeded warm‐season as well as bluegrass pastures grown under more arid conditions. Therefore, this study was designed to measure the influence of the application of N and P fertilizers in early (mid‐April) and late (late May) spring on the quality (protein and in vitro dry matter disappearance) and nutrient (NO8−‐N, P, K, Ca, Mg) concentration of seeded warm‐season and bluegrass (Poa pratensis L.) pastures from 1971 through 1974. Applications of N (0, 45, 90, 135, and 180 kg/ha) and P (0, 8.5, 17, 25.5 and 34 kg/ha) were repeated in each of the 4 years. Whole‐plant samples were collected from each plot at harvest. These samples were analyzed for in vitro dry matter disappearance (IVDMD) and protein percentage. In addition, whole‐plant samples were collected from all plots approximately 30 days after fertilizer application in both 1973 and 1974. These samples were analyzed for NO3‐N, protein‐N, P, K, Ca, and Mg.Fertilization with both N and P had no consistent effect on the IVDMD percentage of mature forage. The protein percentage of the mature forage increased linearly with rate of fertilizer N. Kentucky bluegrass forage had a higher percentage of protein than the mixture of warm season prairie grasses which consisted of big bluestem (Andropogon gerardi Vitman.), switchgrass (Panicum virgatum L.), indiangrass (Sorghastrum nutans (L.) Nash.), and sideoats grama (Bouteloua curtipendula (Michx.) Tarr.). Protein production from the bluegrass pasture was increased eight‐fold by application of both N and P. There was a six‐fold increase in protein production from the warm‐season prairie grasses when adequate rates of both N and P were applied. The concentration of P in samples collected at harvest as well as those collected 30 days after fertilizer application increased linearly with rate of applied P in all cases.The ratio, , exceeded the critical value of 2.2 only when N and P were applied to the warm season grasses in early spring of 1974. The concentration of NO3−‐N in forage from both pastures was increased by applied N but did not approach the 2,000 ppm level generally considered to be lethal to livestock.
Effects of Preharvest Desiccation with Glyphosate on Grain Sorghum Seed1
Authors: Baur J. R. , Miller F. R. , Bovey R. W. 
Published: July 2010

AbstractThe preharvest application of chemical desiccants to reduce moisture content of grain sorghum (Sorghum bicolor (L.) Moench) may make it possible to eliminate costly mechanical drying of harvested grain. The objective of these experiments was to evaluate the effect of glyphosate on the viability of seed from field‐treated plants. Seed from grain sorghum plants desiccated with 1.12, 2.24 and 4.48 kg/ha glyphosate [(N‐phosphonomethyl) glycine] produced a high percentage of abnormal seedlings with varying amounts of interveinal areas completely devoid of chlorophyll. Mildly affected seedlings recovered from the symptoms and produced normal plants with normally appearing, viable seed. Severely varlegated plants died. Seed damage was greatest when treatments were applied 25 days after flowering when the grain had a moisture content of 30 to 40%. Damage decreased as time of treatment after flowering (30, 35, and 40 days) increased. The number of abnormal seedlings observed in standard germination tests corresponded to the number of variegated seedlings observed in growth evaluation studies. Similar effects were noted for genotypes ‘Top Hand’, BT− 399, and RT− 2536. The last two genotypes are similar to the female and male parents of Top Hand. Rate and time of treatment had no effect on yield of Top Hand.
Influence of Soil Organic Matter on Cowpea's Response to N Fertilizer
Authors: Agboola Akinola A. 
Published: July 2010

AbstractThere are divergent views on N application to legumes, especially cowpea. Results of various investigations in the tropics, especially Nigeria, have indicated either no response or a significant response to about 20 kg N/ ha. In Nigeria, a starter N is usually recommended irrespective of the cropping history of the field. As a result of these conflicting reports three field and one greenhouse experiments were carried out over a period of 4 years to investigate the effect of different levels of N, soil organic matter (O.M.), and split application of N on grain yield and performance of cowpea. Ife‐Brown, an improved variety of cowpea, was used as the test crop. The soils of the fields used were moderately to strongly leached luvisols, derived from metamorphic and igneous basement complex rocks under forest vegetation. The experimental design for each field experiment was a randomized, complete‐block design, while the greenhouse investigations was laid out in a split plot design. Cowpea was grown on fields having different cropping histories and levels of O.M. with various levels of N including no nitrogen as control. Cowpeas responded to N fertilizer; however, the level of O.M. affected the response. On soils having 0.5% O.M., grain yield was increased from 800 kg on the check to 1,850 kg dry grain per hectare, where 20 kg N/ha was applied, whereas on soils with 2% or more O.M. there was no constant response to N fertilizer.In the greenhouse, N fertilizer did not effect the time of flowering and pod initiation of cowpea but the total number of flowers and pods were significantly affected. When 33.6 kg N/ha was applied at planting or split into two equal applications applied 2 and 4 weeks after planting, there was a significant increase in dry matter accumulation but low grain yield. In the latter treatment the cowpea fixed 33.07 mg N per pot compared with 40.10 mg N when 33.6 kg N/ha was applied at planting. The treatment that produced the highest grain yield fixed the lowest N. Application of N at planting and 2 weeks after planting depressed nodule number up till the 4th week, but 10 weeks the highest number of nodules was observed on cowpeas from the plots where N was applied at planting. It is concluded, therefore, that starter N should be used in soils having less than 2% O.M. Such starter N should be applied not later than 2 weeks after planting. Time of N application affects nodulation and N fixation.
Yield and Quality of Cicer Milkvetch Forage as Influenced by Cutting Frequency1
Authors: Townsend C. E. , Christensen D. K. , Dotzenko A. D. 
Published: July 2010

AbstractCicer milkvetch (Astragalus cicer L.) is a potentially valuable forage crop for irrigated pastures, but little information is available concerning the effects of management practices on forage production. Therefore, the objective of this field study was to evaluate the effect of six harvest treatments on yield, forage quality, weed invasion, and persistence of stand. The study was conducted under irrigation on a Nunn clay loam soil (aridic Argiustoll). The treatments consisted of clipping the forage two, three, four, five, six, and seven times annually for 3 years to a height of 7.5 cm. Forage yields and weed counts were taken for 3 years, and seven quality factors and four mineral elements were evaluated for 2 years. Total nonstructural carbohydrates in the rhizomes were measured at the end of the 3rd harvest year. There were significant differences in yield among harvest treatments in 2 of 3 years and for the 3‐year average. In general, the two‐ and three‐cut treatments were the most productive with 3‐year average yields of 10.5 and 10.7 metric tons/ha, respectively. Considerably more weeds were present in the five‐, six‐, and seven‐cut treatments than in the two‐, three‐, and four‐cut treatments. Annual weeds were most prevalent during the first 2 years, but by the 3rd year dandeloins (Taraxacum spp.) were the most common. Although there were significant differences among treatments for total nonstructural carbohydrates in the rhizomes, the differences were not associated with persistence because persistence of stands was excellent for all treatments. In vitro dry matter digestibility (IVDMD) and all chemical constituents evaluated, with the exception of magnesium and potassium, differed significantly among treatments each year. In general, cell wall constituents (CWC) and cellulose decreased with an increase in the frequency of cutting. Protein, IVDMD, and phosphorus increased as the number of cuttings increased. Lignin, hemicellulose, silica, calcium, magnesium, and potassium varied among cutting treatments. The quality of cicer milkvetch forage was high for all cutting treatments. Based on yield, quality, and stand persistence cicer milkvetch has the attributes of a desirable forage species.