bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Nitrogen‐15 Microplot Design for Measuring Plant and Soil Recovery of Fertilizer Nitrogen Applied to Corn1
Authors: Jokela W. E. , Randall G. W. 
Published: July 2010

AbstractApplication of the stable isotope I5N to a small area, or microplot, within a larger field plot reduces the cost of measuring plant uptake and soil recovery of fertilizer‐derived N (FN). The objective of this study was to evaluate a specific microplot design for corn (Zea mays L.), including determining maximum plant sampling area. Nitrogen as (NH4)2SO4 was applied to 6‐ by 9‐m plots of corn at rates of 200 and 150 kg N ha−1 on a Webster clay loam (fine‐loamy, mixed, mesic Typic Haplaquoll) and a Mt. Carroll silt loam (fine‐silty, mixed, mesic Mollic Hapludalf), respectively, in 1982 and 1983. Enriched 15N was applied to 1.52‐ by 2.29‐m microplots located in opposite halves of the large plot in each year of the study. This allowed separate measurement of plant and soil recovery of FN for the two application years as well as for residual years. Each microplot was centered lengthwise on one row and bordered by the two adjacent rows, so that the center row was 0.76 m from each side of the microplot and the adjacent rows were on the microplot edge. To assure incorporation and uniform distribution, labeled N solution was injected with a syringe to a depth of 0.08 m on a grid pattern with 0.19‐m spacings. Grain and stover samples and soil samples to a 0.4‐m depth were taken at maturity from various positions within and outside the microplots, and percentage of N derived from fertilizer was determined. Results showed that this microplot design provided reliable FN recovery data for corn in 0.76‐m rows when plant samples were taken from the center row at least 0.38 m from the end of the microplot and when soil was sampled from a 0.76‐ by 1.14‐m area in the center of the microplot. Measurement of FN in plants from the two edge rows indicated that use of a microplot 0.76 m in width would not always provide reliable FN data.
Thatch and Quality of Tifway Bermudagrass Turf in Relation to Fertility and Cultivation1
Authors: Carrow R. N. , Johnson B. J. , Burns R. E. 
Published: July 2010

AbstractSecondary cultural practices, such as core aeration, vertical mowing, and topdressing, are being used on homelawn turf to a greater extent, even though specific problems may not warrant their application. In a field study (clayey, kaolinitic, thermic Typic Hapludult soil), we applied secondary cultural practices on ‘Tifway’ bermudagrass [Cynodon dactylon (L.) Pers. ✕ C. transvaalensis (Burtt‐Davis)] in conjunction with annual N rates of 98, 196, and 296 kg ha−1 and K at 49, 98, and 196 kg ha−1. Neither N nor K influenced thatch accumulation, but a minimum of 196 kg N ha−1 was necessary for adequate shoot density and color. The 49 kg K ha−1 resulted in as good or better shoot density and color than did higher K rates. Three to four times more dollar spot (Moellerodiscus spp. and Lanzia spp.) occurred at the lowest N rate, while K had much less influence on disease incidence. Core aeration applied once or twice per year caused a loss of stand density and did not reduce thatch accumulation regardless of whether cores were removed or returned. Vertical mowing twice per year decreased thatch by 8% but shoot density was adversely affected. At the end of 4 yr, topdressing with sand reduced thatch by 44 to 62% for one or two applications, respectively, while maintaining adequate shoot density and color. Increasing N or K did not offset the adverse effects of core aeration or vertical mowing. Thus, under homelawn conditions, core aeration and vertical mowing should only be used if a specific problem exists and not as routine practices to prevent thatch accumulation.
Dormant‐Season Irrigation: Grain Yield, Water Use, and Water Loss1
Authors: Stone L. R. , Gwin R. E. , Gallagher P. J. , Hattendorf M. J. 
Published: July 2010

AbstractResearch results are lacking that compare the yield benefit from a limited amount of irrigation water applied off‐season vs. in‐season. Also lacking is a partitioning of field water losses during winter into the profile drainage and evaporation components. The objectives of this work were: (i) to examine grain yield and water use of corn (Zea mays L.) and Winter what (Triticum aestivum L.) in irrigation schemes that use fall vs. spring irrigations; and (ii) to partition field water loss during winter into the profile drainage and evaporation components. The field work was done near Tribune, KS, on a Ulysses silt loam soil (fine‐silty, mixed, mesic Aridic Haplustoll). Timing of the off‐season irrigation (fall vs. spring) did not influence corn grain yield. In irrigation schemes identical except that off‐season irrigation was or was not applied, off‐season irrigation did not influence corn grain yield significantly. Maximum grain yield benefit in corn from irrigation was achieved when water was applied in‐season. In winter wheat receiving only one irrigation, fall irrigated wheat yielded 2055 kg ha−1 more grain (3‐yr mean) than wheat irrigated only in spring. Among the irrigation schemes containing fall irrigation, there was no significant difference in winter wheat grain yield, even though the total irrigation amount ranged from 152 to 456 mm. Drainage losses during winter were less than 5% as much as evaporation losses at mean profile water contents during winter of less than 50% available soil water. At greater than 50% available soil water, the relative contribution of drainage in profile water loss increased with increasing profile water content. Drainage losses equalled evaporation losses at a mean profile water content during winter of 0.57 m (80% available soil water). Off‐season irrigation of corn was not a water efficient practice. Fall irrigation of winter wheat was a water efficient practice that allowed continuous cropping in a region where some rotation that includes fallow is the dryland alternative.
Effects of Cover Inoculation of Soybean on Nodulation, Nitrogen Fixation, and Yield1
Authors: Ciafardini G. , Barbieri C. 
Published: July 2010

AbstractIn clay soils with no indigenous Bradyrhizobium japonicum, seed or soil implant inoculation of soybean [Glycine max (L.) Merr.] often results in nodules distributed mainly on the primary root and the initial portions of the secondary root, due to the poor mobility of B. japonicum in soil. To increase nodulation of soybean in silty clay loam soil (Vertic Xerothent), we used B. japonicum (USDA strain 122) cover‐inoculated with 100 m3 of irrigation water at the third node (V3) stage. Inoculation treatments included: (i) seed inoculation; (ii) seed and cover inoculation; and (iii) a control without inoculation. Two soybean cultivars were used. Seed plus cover inoculation doubled the biomass of the nodules compared to plants with seed inoculation only. Nodules produced after cover inoculation were very active in nitrogen fixation and showed increased nitrogenase activity during the reproductive stage of the plant. As a consequence, there was an increase in the N concentration in the stem, in seed protein (+6.7% in ‘Evans’, +16.0% in ‘Swift’), and in seed production per hectare (+16.1% in Evans, +10.5% in Swift).
Water Use, Yield, and Dry Matter Accumulation by Determinate Soybean Grown in a Humid Region1
Authors: Scott H. D. , Ferguson J. A. , Wood L. S. 
Published: July 2010

AbstractPlanning of irrigation strategies for soybean [Glycine max (L.) Merr.] requires a knowledge of the year‐to‐year variability associated with water use, dry matter accumulation, and seed yield. This study was undertaken to determine the relationships and variability among these plant responses at the end of vegetative and reproductive growth for irrigated (I) and nonirrigated (N) soybean grown in the field during five seasons under humid climatic conditions. Water balance components were determined by computer simulation based on actual soil, plant, and meteorological data. The soil was a Crowley silt loam (fine, montmorillonitic, thermic Typic Albaqualf). For the N soybean, seed yields ranged from 1.07 to 2.74 Mg ha−1, and dry matter ranged from 4.76 to 9.12 Mg ha−1 as the seasonal rainfall ranged from 290 to 570 mm. Variability of dry matter production was greater at the end of vegetative growth than at the end of reproductive growth. Five‐year mean cumulative values of evapotranspiration (ET) during vegetative growth were 237 and 215 mm for I and N treatments, respectively. At the end of the season the 5‐yr mean ET, transpiration (T), and evaporation (E) from the I soybean were 497,327, and 170 mm, respectively. These corresponding values were greater than those of N soybean of 382, 231, and 151 mm, respectively. However, when the data from the wet season were removed, the variability of ET, T, and E from the I soybean were lower than from N soybean. Under I conditions, the lowest seasonal ET (370 mm) was found in the wetter‐than‐normal season and the highest ET (539 mm) was found in the drier seasons. Under N conditions, ET during the wet season (370 mm) was similar to the 5‐yr mean (382 mm). The year‐to‐year variability in this humid environment depended on soil‐water management as well as the climatic conditions.
Forage Nutritive Value and Palatability of Perennial Weeds
Authors: Marten G. C. , Sheaffer C. C. , Wyse D. L. 
Published: July 2010

AbstractKnowledge of forage quality of individual weed species is essential for making sound management decisions regarding the control of weeds that invade alfalfa (Medicago sativa L.). Our objective was to determine the nutritive value and palatability of nine perennial forb and grass weeds in comparison to alfalfa and smooth bromegrass (Bromus inermis Leyss.). Field trials were conducted on a fine‐silty over sandy skeletal, mixed, mesic Typic Hapludoll. We used a randomized complete block design with four replicates. Compared to alfalfa, smooth bromegrass and quackgrass [Agropyron repens (L.) Beauv.] consistently had more neutral detergent fiber (NDF), less crude protein (CP), and similar in vitro digestibility (IVDDM). Grasses consistently had more NDF than forbs. Nutritive value varied considerably among forbs. Jerusalem artichoke (Helianthus tuberosus L.), Canada thistle [Cirsium arvense (L.) Scop.], dandelion (Taraxacum officinale Weber in Wiggers), and perennial sowthistle (Sonchus arvnesis L.) had CP and IVDDM concentrations equal to or greater than those of alfalfa, while Jerusalem artichoke, dandelion, and curly dock (Rumex crispus L.) frequently had lower NDF concentrations than that of alfalfa. Forb weeds generally had lower palatability than alfalfa or smooth bromegrass, with several exceptions. Jerusalem artichoke, curly dock, hoary alyssum [Berteroa incana (L.) DC.], and Canada thistle were either completely or nearly completely rejected by grazing lambs (Ovis spp.). Palatability of a quackgrass biotype selected for wide leaves was equal or superior to smooth bromegrass and was equal to alfalfa in two of three trials. Common quackgrass consistently had lower palatability than smooth bromegrass or alfalfa. Because forage quality of perennial weeds varied considerably among species and was sometimes superior to that of alfalfa, we conclude that decisions on whether to implement weed control in established alfalfa should be specific for each situation
Comparative Water Use Characteristics of Six Row Crops
Authors: Hattendorf M. J. , Redelfs M. S. , Amos B. , Stone L. R. , Gwin R. E. 
Published: July 2010

AbstractTo help make decisions on shifting of crop species in water management strategies, information is needed on comparative water use characteristics of the principal row crops. The objective of this study was to compare the water use characteristics of six row crops grown in a replicated and randomized field experiment. Crops were corn (Zea mays L.), grain sorghum [Sorghum bicolor (L.) Moench], pearl millet [Pennisetum amerlcanum (L.) Leeke], pinto bean (Phaseolus vulgaris L.), soybean [Glycine max (L.) Merr.], and sunflower (Helianthus annuus L.). Crops were grown near Manhattan, KS, on Muir silt loam (Cumulic Haplustoll) in 1981 and on Eudora silt loam (Fluventic Hapludoll) in 1982, and near Tribune, KS, on Ulysses silt loam (Aridic Haplustoll) in both 1981 and 1982. Soil water content was determined to the 3.1‐m soil profile depth by the neutron attenuation method. Measured evapotranspiration (ET) was calculated as the sum of soil water depletion, rainfall, and irrigation. Reference ET was calculated by using the original Jensen‐Haise equation. The maximum value of measured ET/reference ET was greater for sunflower (1.35) than for the other five crops (ranged from 1.05 to 1.15). The mean daily water use rate of sunflower (6.1 mm d−1) was 22% greater than the mean of the other five crops (5.0 mm d−1). The mean dry matter water use efficiency was 17.5 Mg ha−1 m−1 for the group of C3 crops (pinto bean, soybean, and sunflower) and 33.3 Mg ha−1 m−1 for the group of C4 crops (corn, grain sorghum, and pearl millet). Sunflower depleted significantly more water from deeper soil depths (0.99‐1.60 m) than the other five crops at Manhattan in 1981 and 1982. Our findings consistently showed that sunflower had a greater daily water use rate than the other five crops.
Row Spacing, Plant Population, and Genotype × Row Spacing Interaction Effects on Yield and Yield Components of Dry Bean
Authors: Grafton K. F. , Schneiter A. A. , Nagle B. J. 
Published: July 2010

AbstractDry edible bean (Phaseolus vulgaris L.) production practices in the northern Great Plains have begun to shift from conventional wide (0.76‐m) to narrower row spacings for maximizing seed yields. Field experiments were conducted to determine row spacing and plant population effects for production of dry, edible bean in the northern Great Plains and also to determine if genotypes varied in their seed yield response to row spacing. Yield per hectare of the indeterminate pinto bean ‘UI‐114’ and the determinate navy bean ‘Seafarer’ increased by 52 and 44%, respectively, as row spacing was decreased from 0.75 to 0.25 m during 1977 and 1978. Seed yield of UI‐114 did not increase with increased plant populations, while yield of Seafarer increased as the plant population increased to 222 000 plants ha−1. Row spacing × plant population interaction for yield was nonsignificant for both cultivars. In another experiment, 10 navy bean genotypes were grown at 0.19−, 0.38−, and 0.76‐m row spacings in both 1984 and 1985. Significantly higher yields were obtained as row spacings decreased. Yields of seven genotypes were up to 57% higher when grown at 0.19− compared with 0.76‐m row spacings. Yield rank of the genotypes tested changed within the three row spacings. Genotype − row spacing interactions may necessitate the testing of breeding lines' potential production at specific row spacings.
Seasonal Changes in Smooth Bromegrass Top and Root Growth and Fate of Fertilizer Nitrogen
Authors: Power J. F. 
Published: July 2010

AbstractWhile information is available at the end of the growing season on the fate of fertilizer N applied to perennial grasslands, little detailed information is available on the transformations and translocation of N during a growing season. The purpose of this research was to measure the effect of N fertilization on time, quantities, and rates of dry‐matter accumulation by smooth bromegrass (Bromus inermis L.) tops and roots, water use, and fertilizer N transformations and uptake. Ammonium nitrate was surface broadcast at 0, 90, and 270 kg N ha−1 on established smooth bromegrass at Mandan, ND. At approximately 3‐wk intervals, top and root (0–900 mm) dry weights were measured, N uptake calculated, soil inorganic N concentrations determined, and apparent fertilizer N in tops, roots, and as soil inorganic N was calculated (fertilized minus check). Growth and N uptake of tops increased until physiological maturity in July, decreased during a midsummer drought, and increased after August rains. Fertilization greatly increased growth rate. For roots, growth stopped or even declined slightly at time of floral emergence in June, resumed until physiological maturity, remained constant or decreased slightly through the summer drought (when soil water reserves were depleted), then increased rapidly in September after fall rains. Dry matter accumulated at rates in excess of 300 kg ha−1 d−1 in May and September, when N uptake rates exceeded 4 kg ha−1 d−1. Over 40% of the fertilizer N at the 270 kg N rate was immobilized in organic forms other than root growth within 10 d after application, but by physiological maturity, 51% was in tops, 27% in roots, 3% as soil inorganic N, and only 19% was immobilized in other organic forms or lost by gaseous means (no leaching occurred). Results suggest that gaseous losses were no more than 10%. Nitrogen fertilization appeared to enhance three labile N pools—readily available (inorganic), highly labile (probably including microbial biomass), and moderately labile (possibly primarily grass roots).
Corn Growth with Foliar Nitrogen, Soil‐Applied Nitrogen, and Legume Intercrops
Authors: Tomar J. S. , MacKenzie A. F. , Mehuys G. R. , Alli I. 
Published: July 2010

AbstractCorn (Zea mays L.) production under current N fertilizer recommendations can result in soil degradation and N pollution of groundwater. Sources of N such as intercropped legumes or foliar spray might reduce fertilizer N requirements while improving soil quality through legume growth. The objective of this study was to compare corn growth using combinations of foliar and soil urea applications, as well as legume intercrops in combination with soil fertilizer N. Field experiments were conducted for 3 yr on two Typic Humaquepts, a Ste. Rosalie clay and an Ormstown silty clay. Foliar applications of 20 kg N ha−1 applied in late July or late August, or both, were compared at 0 and 140 kg N ha−1 of soil‐applied urea. The effects of a legume intercrop on corn yield were determined by planting legumes at the same time as corn, at three rates of added N (0, 70, and 140 kg N ha−1). Treatments were placed on the same plots each year, providing an assessment of cumulative effects. Plant dry‐matter yields and soil mineral N were determined. Plots were fall‐plowed each year and planted after conventional soil preparation. Foliar N increased yields only in one site‐year. Intercropping lowered corn yields by about 2 tonnes ha−1 in five site‐years, except for one wet year on the Ormstown site when intercrops did not affect corn yields. Added N increased corn yields independently of intercropping, indicating little cumulative effect of legumes on soil N supply. Legume intercropping and foliar‐applied urea were not effective alternatives to the use of soil‐applied urea N as far as grain corn yield is concerned.
Response of Solid‐Seeded Soybean to Flood Irrigation. II. Flood Duration
Authors: Griffin James L. , Saxton Arnold M. 
Published: July 2010

AbstractFlood‐irrigated soybean [Glycine max (L.) Merr.] can be exposed to extended periods of soil‐saturated conditions, depending on the producers method of application, watering capacity, and field size. Field studies were conducted on a Crowley silt loam (fine, montmorillonitic, thermic Typic Albaqualf) soil in southwest Louisiana during 1982 to 1984 to evaluate the effects of flood duration on solidseeded (i.e., nonbedded narrow rows) ‘Ransom’ soybean. Soybean was flooded at the V6 (vegetative), R2 (bloom), or R2 + R5 (bloom and pod fill) growth stages. Within each timing treatment, water was applied to a standing depth of 0.076 m and allowed to stand for 0 (nonflooded control), 1, 2, 4, or 8 d. Soybean stand density did not change as flood duration increased. Yields for individual timing treatments were generally similar when flood periods were 0, 1, or 2 d. When water was held longer than 2 d postflowering, significant yield reductions were noted in all years and were as much as 1390 and 1520 kg ha−1 in 1982, when water was applied at R2 or R2 + R5, respectively. In 1982 and 1984, when water was applied at R2 + R5, average yield reductions associated with increasing flood duration from 2 to 4 d and from 2 to 8 d were 20 and 10% higher, respectively, compared with R2 only. Increasing flood duration at V6 from 4 to 8 d decreased yields in 1982 and 1984 an average of only 340 kg ha−1. For those 2 yr, with flood periods of 4 or 8 d, yields for soybean flooded at V6 were substantially higher than yields from the R2 or R2 + R5 treatments. Increased numbers of both seeds per pod and seeds per plant accounted for the higher yields in the V6 treatment. When flood irrigating solid‐seeded soybean after flowering, attempts should be made to remove standing water within 2 d to avoid yield reductions.
Spring Defoliation to Improve Summer Supply and Quality of Switchgrass
Authors: George J. R. , Obermann Doug 
Published: July 2010

AbstractSwitchgrass (Panicum virgatum L.) normally is lower in forage quality by the time cool‐season forage species are less productive in early summer. The objective of this study was to determine if the major supply of switchgrass herbage could be delayed by use of partial spring defoliation and still maintain adequate herbage quality. Switchgrass plots were fertilized with 0 or 120 kg N ha−1 and defoliated at six time‐intensity combinations. Yield and quality of initial spring and 6‐wk regrowth were measured. Initial 1984 spring defoliation treatments were 1 June at 15 cm; a multiple defoliation at 15, 20, and 25 cm over 1‐wk intervals beginning on 1 June; 15 June at 6 or 20 cm; and 29 June at 6 or 20 cm. All 1985 treatments were 9 d earlier. Fertilization with N increased 6‐wk regrowth dry matter (DM) yields by 79 to 92% for 1 June treatments and by only 38 to 54% for 29 June treatments. Close defoliation on 29 June produced the greatest total seasonal DM yield of 10.5 Mg ha−1 and IVDDM yield of 5.79 Mg ha−1, but only 30% of this was harvested in midsummer after 6 wk of regrowth. Total season DM yield and IVDDM yield were about 20 to 35% less for both 1 June treatments when compared with close defoliation on 29 June, but the 6‐wk regrowth yield accounted for about 75 to 85% of total season DM and IVDDM yields. Little or no difference in leaf or stem IVDDM of the 6‐wk regrowth was observed among defoliation treatments, so partial spring defoliation can delay the major supply of switchgrass herbage with no serious reduction in herbage quality. We conclude that a short period of moderate defoliation of switchgrass in early to mid‐June could benefit grazing programs by providing (i) some very high‐quality switchgrass herbage during early to mid‐June; (ii) a brief rest and regrowth period for the cool‐season pasture; and (iii) relatively high summer yields of quality switchgrass when it is most needed.