bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water Balance and Profile Moisture Loss Patterns of an Alfisol1
Authors: Singh Piara , Russell M. B. 
Published: July 2010

AbstractIn order to match the water availability with the crop water requirement in the semi‐arid tropical (SAT) areas of the world, the distribution and magnitude of various water balance components and the moisture dynamics in the soil profile during crop growth periods need to be understood. Since Alfisols (fine, clayey mixed udic Rhodustalf) constitute the major soil group of SAT areas, its water balance and water loss pattern in sorghum (S. bicolor L. Moench) was studied during both the monsoon and post‐monsoon season of 1977 to 1978.During the monsoon season, water losses as evaporation, transpiration, and drainage constituted 21, 35, and 29%, respectively, of the total seasonal available water (Rainfall + irrigation + profile available water to 127 cm depth). In the post‐monsoon season, the only unproductive loss of water was soil evaporation which formed about one‐fourth of the total seasonal available water. The major amount of moisture depletion during the postmonsoon season was confined to the top 90 cm profile depth.The data obtained on water balance and the ability of Alfisols to supply water to crops suggest the need for better water management by adopting improved cultural practices, like water harvesting, and improved cropping patterns for optimizing water availability and its use for crop production in the SAT.
Utilization of Labeled‐N Fertilizer by Silage Corn Under Conventional and No‐till Culture1
Authors: Legg J. O. , Stanford George , Bennett O. L. 
Published: July 2010

AbstractThe influence of tillage methods on the utilization of N from soil and fertilizer sources by crops has not been investigated previously by tracer methods to any great extent. The objectives of this study were to compare yields and N utilization of silage corn (Zea mays L.) in conventional and no‐till culture, using a double‐cropping system of corn and smooth bromegrass (Bromus inermis Leyss.). The experiment was initiated in 1974 on a Wharton‐Cookport (Aquic Hapludults‐Aquic Fragiudults) silt loam soil with an established stand of smooth bromegrass in West Virginia. Labeled (15N‐depleted) ammonium sulfate was surface‐applied annually at rates of 85, 170, and 340 kg N/ha over a 4‐year period. Herbicides (2.2 kg/ha atrazine; 1.1 kg/ha paraquat) were applied annually to the grassed and plowed plots to suppress the grass sod but allow bromegrass to resume growth after corn silage was harvested. The grass was not harvested for hay, but left as a cover crop for erosion control. Yields of corn plants were determined at midseason (11 to 12 leaf stage) and at the silage stage. The proportions of total N uptake contributed by the soil and fertilizer were determined by mass spectrometry.In 1974 and 1977 when soil water regimes were most favorable, total dry matter (TDM) yields were similar under the two systems of tillage, but in the intervening years of subnormal rainfall, yields were substantially higher from no‐till than from plowed plots. Amounts of available water in the surface 30 cm of soil were consistently higher in no‐till than in tilled plots during the growing season, but differences were not discernible in the underlying 30 an layer. The 4‐year average yields of silage TDM for all N rates were 13,400 and 11,570 kg/ha, respectively, for no tillage and conventional tillage. Because of the lower attainable yields on plowed plots in 1975 and 1976, the corresponding average amount of applied N required for near‐maximum yield under conventional tillage was about one‐half that required for no‐tillage. Soil N uptake tended to decrease with increasing rate of N applied, generally was unaffected by method of tillage, and differences among years were relatively small. For both samplings and all N rates in 1975 and 1976, uptake and recovery of fertilizer N were substantially higher under no‐tillage than under conventional tillage. In 1974 and 1977, enhanced recovery under no‐tillage was evident only at the highest N rate. Four‐year midseason recoveries from 85, 170, and 340 kg N/ha, respectively, were 42, 32, and 26% for no‐till and 35, 27 and 16% for conventional tillage. Corresponding average annual recoveries at silage harvest were 46, 53, and 46% for no‐till, and 53, 55, and 347, for conventional tillage.
Seed Set and d2 Gene Effects on Pearl Millet Forage Quality1
Authors: Hanna W. W. , Gaines T. P. , Monson W. G. 
Published: July 2010

AbstractTall and dwarf pearl millet [Pennisetum americanum (L.) Leeke.] hybrids are commercially available and can be either cytoplasmic‐genic male‐sterile or fertile depending on whether the male parent is a restorer line. No information is available on the effects of seed set on forage quality in the tall and dwarf pearl millet hybrids. The purpose of this research was to study effects of seed set and the d2 (dwarf) gene in in vitro dry matter digestibility (IVDMD) and total nonstructural carbohydrates (TNC) in pearl millet forage at anthesis and at 2 and 4 weeks after anthesis. In 1976 and 1977, forage samples were taken from pollinated and unpollinated cytoplasmicgenic male sterile tall and dwarf pearl millet growing in the field. Seed set did not affect IVDMD of the whole plant and leaf or stem components at 2 and 4 weeks after anthesis. Seed set reduced total sugars at 4 weeks after anthesis because of conversion of sugars to starch. Forage from dwarf plants was significantly higher in IVDMD than forage from tall plants; however, there were no differences in the leaf and stem components, which indicates that after anthesis, the higher IVDMD of the dwarf forage is due to the higher leaf percentage of the dwarf. Forage from tall pearl millet had significantly higher levels of total sugar, but significantly lower IVDMD than dwarf pearl millet, which indicates that the nonstructural carbohydrates were not responsible for the higher quality of forage from dwarf pearl millet.
Effects of Mycorrhizae on Establishment and Performance of Forage Species in Mine Spoil1
Authors: Lambert D. H. , Cole H. 
Published: July 2010

AbstractMine soil not containing topsoil usually lacks the normal endomycorrhizal fungi which improve the P uptake of many plants. The establishment of mycorrhizae might be useful for low‐cost, low‐maintenance revegetation of abandoned strip mines or other mineral wastes low in available P. The value of establishing endomycorrhizae to improve the growth of forage grasses and legumes on a low‐P strip mine spoil (Schlickig udispolent) was investigated using 1‐cm layers of field soil as mycorrhizal inoculum. In replicated l‐m2 field plots receiving lime but not fertilizer, yields of flatpea (Lathyrus sylvestris L.), crownvetch (Coronilla varia L.), and birdsfoot trefoil (Lotus corniculatus L.) after two seasons were 7, 13, and 18‐fold greater, respectively, in mycorrhizal treatments. Survival after two winters averaged 51 vs. 6% for nonmycorrhizal treatments. In 0.25 m2 plots receiving 0, 41, 81, and 162 kg/ha P or mycorrhizal inoculum at the two low rates of P, the yields of mycorrhizal and nonmycorrhizal plants converged as P was increased. The response of mycorrhizal trefoil improved over 2 years relative to nonmycorrhizal treatments receiving only initial applications of P. Growth of tall fescue (Festuca arundinacea Schreb.) and perennial ryegrass (Lolium perenne L.) in 600‐ml pots in the greenhouse was not significantly improved by mycorrhizae. Mycorrhizal fungi from different sources varied in their adaptation to low‐pH mine spoil. The establishment of mycorrhizae in mining wastes is useful if indigenous inoculum is absent or nonadapted, if available P is low, and if the plant species used for revegetation responds to mycorrhizae. Under these conditions, mycorrhizal plants are more persistant and less affected by the immobilization of fertilizer P.
Stand Thinning in Seed Production of ‘Cougar’ Kentucky Bluegrass1
Authors: Evans David W. 
Published: July 2010

AbstractKentucky bluegrass (Poa pratensis L.) seed production typically decreases as the stand ages. Eliminating or reducing this decrease would greatly benefit growers. In earlier research, stand thinning by gapping (removing sections of sad from the row) increased Kentucky bluegrass seed yield for one season where stands were fertilized with low to moderate rates of N. The present study was conducted to determine the effects of single and repeated gapping on seed yield, seed yield components, and the age‐associated seed yield decline in Kentucky bluegrass fertilized with different rates of N.‘Cougar’ Kentucky bluegrass was grown in rows under sprinkler irrigation and fertilized yearly with 100, 200, or 300 kg N/ha. Alternate 23‐cm sections of the row were removed after harvest in 2 consecutive years, in the 1st year only and in the 2nd year only. Also, alternate 23‐cm sections of ungapped rows were clipped for 2 consecutive years to remove panicles at panicle emergence.Gapping increased seed weight per panicle by 12% the 1st year and panicles per meter of row and seed yield by up to 39 and 32%, respectively, the 2nd year. Repeated gapping was as effective as first‐time gapping in either year. Clipping, while it decreased panicle numbers and seed yield, increased seed weight per panicle by 20% or more each year and 1,000‐seed weight by 5 to 8%. Seed production was highest for 200 kg N/ha in 1969 and 1970 and for 100 kg N/ha in 1971. Nitrogen rates did not affect gapping or clipping responses.Density of panicle production within the bluegrass sod was the principal factor affected by gapping. Gapping consistently increased panicle density. Density was increased as much by repeated as by first‐time gapping.Results of the study indicate that appropriate sod management can increase seed yield and reduce the rate of age‐associated seed yield decline.
Biochemical and Morphological Responses of Cannabis sativa L. to Postemergent Applications of Paraquat1
Authors: Coffman C. B. , Gentner W. A. 
Published: July 2010

AbstractParaquat (1,1'‐dimethyl‐4,4'‐bipyridinium ion) has been used to control illicit fields of Cannabis sativa L. (marihuana). Little is known concerning the effects of paraquat on the growth and cannabinoid concentrations of C. sativa. Therefore, three greenhouse experiments were conducted to 1) apply paraquat postemergent to C. sativa plants under controlled conditions; 2) evaluate the morphological responses of C. sativa to paraquat applications; and 3) determine the effect of paraquat applications on the concentrations of cannabidiol (CBD) and Δ9tetrahydrocannabinol (Δ9THC) in marihuana. Paraquat was applied at 0.07, 0.14, and 0.28 kg/ha. In the first experiment, plants were treated 51 days after seeding (DAS) and harvested 23 days after treatment. CBD and Δ9THC concentrations were reduced 70 and 67% respectively over all herbicide applications. Plants were treated 49 DAS in the second experiment and harvested 0, 1, 2, 4, and 8 hours and 1, 2, 4, 8, and 16 days after treatment. Delta‐9‐THC concentrations were significantly reduced by paraquat applications. Plants were treated with paraquat 25, 35, 65, and 75 DAS in the third experiment and harvested 10 days later. Plant growth, marihuana production, and Δ9THC concentrations were generally significantly lower for the herbicide‐treated plants relative to the untreated controls. These experiments revealed that Δ9THC concentrations in marihuana were generally reduced by the application of lethal or sub‐lethal rates of paraquat to C. sativa plants of varied chronologic and physiologic ages.
Plant Uptake and Leaching of Applied and Indigenous Potassium in Dothan Soils1
Authors: Sparks D. L. , Martens D. C. , Zelazny L. W. 
Published: July 2010

AbstractThe K fertilization requirement for corn (Zea mays L.) frequently is overestimated by soil test procedures for Atlantic Coastal Plain soils having sandy Ap horizons and high K concentrations in clayey subsoil. It seemed probable that the lack of response could reflect availability of subsoil K. This field and laboratory research was conducted to evaluate the availability and origin of subsoil K and the downward movement of K in two Dothan soils (Plinthic Paleudults). These soils had low CEC in the Ap, A2, and B21t horizons; fine sandy loam Ap horizons; higher clay contents in the B21t horizons than in the Ap horizons; and very acidic B21t horizons. Mineral suites in the clay‐sized fraction of the two soils were predominantly 14 A intergrade minerals, kaolinite, and quartz. The three horizons in these two soils contained high levels of total K ranging from 6.5 to 12.0 meq/100 g. Over 90% of the total K in the A2 and B21t horizons of the two soils was in feldspar and mica forms indicating that parent material, rather than leaching of applied K, was the main origin of K in these horizons. Decreases in exchangeable K occurred during the first growing season in the A2 and B21t horizons of control plots in field experiments on the two soils. These decreases in exchangeable K indicated K uptake by corn plants from the subsoil horizons. With time, two‐annual broadcast applications of 83 and 249 kg K/ha as KCl increased the exchangeable K in the A2 and B21t horizons of the two soils. These increases were ascribed to leaching of K into the subsoil horizons. This leaching of K suggests that downward movement of applied K could result in an accumulation of K in clayey subsoil. The K in subsoil, either from leaching of applied K or from genetic origin, would be available to plants unless root growth into the subsoil was restricted by adverse chemical and physical properties.
Small Plot Liquid Applicator1
Authors: Walker M. E. , Shannon J. E. 
Published: July 2010

AbstractThe application of liquid fertilizer and other solutions to small experimental areas creates a problem because most equipment is constructed for farm application. There was a need for a small plot applicator that would accurately dispense liquid fertilizer 10‐34‐0, as well as other solutions. A two‐row cultivator (Pittsburg) frame was equipped with a system activated by carbon dioxide. A 19‐liter stainless steel tank (Firestone) was used for mixing chemical solutions.This system allows surface and subsurface application of fertilizer solution and can easily be converted to a sprayer for application of solutions to plant foliage. Various combinations of solutions, rate, and pressure are available to meet the applicator's specifications.
Greenhouse Evaluations of Strains of Rhizobium for Peanuts1
Authors: Wynne J. C. , Elkan G. H. , Meisner C. M. , Schneeweis T. J. , Ligon J. M. 
Published: July 2010

AbstractThe use of effective strains of Rhizobium can increase the yield of peanuts (Arachis hypogaea L.) substantially. Preliminary screening of rhizobial strains for effectiveness in leguminous crops is generally done in greenhouse tests. This study was conducted to develop reliable greenhouse procedures for the evaluation of rhizobial strains for peanuts and to determine the variability in N‐fixing ability of rhizobial strains in symbiosis with genetically diverse peanut hosts.Using ‘Argentine’ (a Spanish genotype) and ‘NC 4’ (a Virginia genotype), 18 rhizobial strains, 9 in each of two tests, were compared with an uninoculated control for N‐fixing ability. Strains of Rhizobium varied in their N‐fixing ability in both tests as evaluated by nodulation, nitrogenase activity, plant color and weight and N content. Plants of NC 4 were larger and greener and had larger nodules, greater nitrogenase activity and higher N content than plants of Argentine. Host‐strain specificity was found for several traits indicative of N‐fixing activity.Nodulation, plant color and weight, nitrogenase activity, and N content were significantly correlated. The high significant correlation of total nitrogen and plant dry weight (r = 0.99** and r = 0.97**) and total nitrogen and plant color (r = —0.95** and —0.97**) indicates that either plant color and/or plant dry weight can be used as a measure of strain effectiveness in preliminary tests.Greenhouse screening of rhizobia for effectiveness on peanuts using plant weight or color was determined to be an excellent initial evaluation of strain efficiency. Because of host differences and host‐strain specificities, the peanut genotype should also be considered in rhizobial testing.
Germination of Three Species of Atrifilex1
Authors: Young J. A. , Kay B. L. , George Harry , Evans R. A. 
Published: July 2010

AbstractTrailing saltbush (Atriplex semibaccata R. Br.), quailbush [A. lentiformis (Torr.) Wats.], and fat‐hen [A. patula ssp. hastata (L.) Hall & Clem.] are adapted for growth in saline‐alkaline areas and provide valuable cover, browse, and/or feed for waterfowl. We undertook this study to evaluate the germination characteristics of these species which have potential as artifically‐seeded revegetation species. Germination tests were conducted at 55 constant and alternating temperatures. The constant temperatures were 0, 2, and 5 C and in 5° increments through 40 C. Alternating temperature regimes consisted of 16 hours at each constant and 8 hours daily at each higher constant temperature. Tests were conducted in both lighted and dark germinators for entries that responded to light at six constant temperatures. In addition, tests were conducted with presoaked seeds at eight constant temperatures. Germination was evaluated on sand, loam, and clay textured substrates. The optimum germination for all three species tended to occur with alternating rather than constant temperatures. Fat‐hen was the only species whose germination was enhanced by light during the warm period. Seeds of this species were highly germinable with optimum germination averaging 96%. ‘Corto’ trailing saltbush and quailbush seeds were also highly germinable. However, overall mean germination and optimum germination were somewhat lower than those observed for fathen. Presoaking and rinsing the false‐fruits increased the germination of the other two species at some incubation temperatures, but not the germination of fat‐hen. The species differed in requirements for seed burial with fat‐hen germinating on the surface of sand, loam, and clay soils but quailbush largely requiring burial. Trailing saltbush exhibited intermediate germination requirements relative to seed burial. Although each species had a different germination profile, seedbed temperatures within moderate ranges will not be limiting to their use as revegetation species.
Soybean Cyst Nematode and Rhizobium Strain Influences on Soybean Nodulation and N2‐fixation1
Authors: McGinnity P. J. , Kapusta George , Myers Oval 
Published: July 2010

AbstractThe spread of the soybean cyst nematode (SCN) (Heterodera glycines Ichinhoe) has required the breeding of resistant soybean [Glycine max (L.) Merr.] cultivars. The SCN causes a reduction in nodulation and N2‐fixation which may explain part of the yield reductions associated with SCN infestations. This study was designed to determine the interaction effects of SCN resistant and susceptible cultivars, Rhizobium japonicum (Kirch.) Buchanan strains, and SCN races on nodulation and N2‐fixation.The susceptible cultivar ‘Williams’ and resistant cultivars ‘Bedford’, ‘Forrest’, and ‘Franklin’ were grown on sterile sand culture in the greenhouse and inoculated with all possible combinations of SCN races 3 and 4 and R. japonicum strains 3, 110, and 123. Bedford and Forrest inoculated with strain 110 had the highest specific N2(C2H2)‐fixation activity (SA), but Bedford, Forrest, and Franklin inoculated with strain 123 had the largest nodule mass (NM). SCN race 3 did not reduce NM, but reduced both total N2(C2H2)‐fixation activity (TA) and SA. Race 4 did not influence TA and was inconsistent in its influence on SA and NM.Total N2(C2H2)‐fixation activity and SA was estimated at the R2 (determinate) and R4 (indeterminate) stages on several field‐grown soybean cultivars. The number of SCN cysts per 250 cc of soil (cyst index) also was determined. Resistant cultivars had low cyst indices and high N2‐fixation potentials. Susceptible cultivars had higher cyst indices and generally lower N2‐fixation rates but ‘Williams’, ‘Wayne’, and ‘York’ exhibited high fixation potentials despite high cyst indices. Nodule serology indicated a significant cultivar ✕ strain interaction which may account for the TA and SA differences.These results indicate that nodulation and N2‐fixation are influenced by cultivar ✕ Rhizobium strain and SCN race interactions and that the SCN is not equally deleterious to all susceptible cultivars. Williams and Wayne may be especially valuable in breeding resistant cultivars since they exhibited good nodulation and N2‐fixation despite high cyst indices.
Yield Reduction from Defoliation of Irrigated and Non‐Irrigated Soybeans1
Authors: Caviness C. E. , Thomas J. D. 
Published: July 2010

AbstractHail adjusters, entomologists, and others frequently use defoliation percentages to estimate soybean [Glycine max (L.) Merr.] yield loss caused by hail, insects, or diseases. Little information is available on the percent yield loss from defoliation under drought stress and adequate moisture. Thus, the objective of this research was to measure yield response of a determinate soybean cultivar ‘Lee 74’ to different levels of defoliation under irrigated and non‐irrigated conditions. Field experiments were conducted on a Crowley silt loam (fine, montmorillonitic, thermic Typic Albaqualfs) at Stuttgart, Ark., during a 3‐year period to study effects of four levels of defoliation (0, 50, 75, and 100%) applied at three stages of development (V5, R2, and R4) in 1974 and 1975 and two stages (V3 and R5) in 1976 on yield of irrigated and nonirrigated soybeans.Irrigation significantly increased yield 7% in 1974, 38% in 1975, and 51% in 1976. Mean squares for levels of defoliation, stages of treatment, and the defoliation × stage interaction were highly significant each year. The least reduction in yield occurred when plants were defoliated at vegetative stages, V3 and V5, and the most at reproductive stages, R4 (full pod) and R5 (beginning seed). Average yield reductions for 50, 75, and 100% defoliation were 11, 17, and 37%, respectively.Percent yield reductions under irrigated and non‐irrigated conditions were similar because all interactions with irrigation treatments were non‐significant. This same pattern existed regardless of whether the season was extremely dry as hi 1975 and 1976 or moderately dry as in 1974. Reduction in number of pods appeared to be the yield component primarily responsible for yield losses from defoliation. Results from these experiments indicated that percent reduction in yield from defoliation is similar for soybeans grown with adequate moisture or under drought stress.
A Small Plot Drag for Use on Bermudagrass or Similar Sods1
Authors: Keisling T. C. , Holt Edwin 
Published: July 2010

AbstractMany types of drags and spike tooth harrows have been used in pasture work. Most are not suitable for small plot work with bermudagrass because of lack of uniformity resulting from the dragging operation, fouling and clogging of the teeth with plant parts, and their cumbersome operation. This note describes a small unit which drags a plot uniformly, exhibits essentially no fouling or clogging of the teeth and is easily maneuverable around and through a plot area.