bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uptake and Assimilation of Ammonium‐N and Nitrate‐N and Their Influence on the Growth of Corn (Zea mays L.)1
Authors: Schrader L. E. , Domska D. , Jung P. E. , Peterson L. A. 
Published: July 2010

AbstractVariations in response to ammonium and nitrate by different plant species including corn (Zea mays L.) quires further definition. Corn was grown in nutrient solutions under greenhouse conditions to investigate (1) uptake of ammonium and nitrate from the solutions and (2) the effect of ammonium and nitrate on growth, nitrate reductase activity, and accumulation of total N and nitrate in leaves, stems, and roots at four stages of development (21, 28, 40, and 47 days after planting). Uptake was determined by following the disappearance of ammonium‐N and nitrate‐N from nutrient solutions in which N was supplied in various combinations and rates. The nutrient solution treatments were as follows (ppm NO3‐‐N/ ppm NH4+‐N): 0/50, 0/100, 0/150, 50/0, 100/0, 150/0, 25/75, 50/50 and 75/25.Fresh and dry weights per plant generally increased more rapidly when plants were provided 100 ppm of N as a combination of nitrate‐N and ammonium‐N (25/75, 50/50, or 75/25) than wherein 100 ppm of either nitrate‐N (100/0) or ammonium‐N (0/100) was supplied alone.When both nitrate‐N and ammonium‐N were supplied, uptake rates of the two forms were similar. Uptake of nitrate was not retarded by the presence of ammonium, but assimilation of nitrate into organic N was retarded by ammonium. When both forms of N were absorbed, ammonium was used preferentially for synthesis of amino acids and protein.Nitrate reductase activity was localized principally in the leaf blades and tended to be highest in plants provided a combination of nitrate‐N and ammonium‐N. Total N in the leaf and root tissues generally was higher in plants grown on ammonium alone or in combination with nitrate than in plants grown on nitrate alone. More nitrate accumulated in stem tissue than in leaf or root tissues. Amino acid composition of leaf tissue was not affected by the N treatments.
Recovery and Nutrient Content of Sandblasted Soybean Seedlings1
Authors: Armbrust D. V. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.] seedlings were exposed to a 13.4‐m/sec wind velocity and wind plus sand (<1.17 mm diameter) for 0, 5, 10, and 15 min at 6 g/cm width/min to study the effect of wind and sandblast injury on their growth and nutrient content. Soybeans can tolerate a soil loss of 6 g/cm width for 5 min without a significant (5% level) reduction in vegetative yield. Exposures to wind or wind plus sand increased the nitratenitrogen concentration 443 ppm for the 5‐min wind treatment to 1,390 ppm for the 15‐min wind plus sand treatment. Iron concentration was increased only where vegetative production was unaffected, i.e., 5‐min wind, 5‐min wind plus sand, and 10‐min wind. Other nutrient concentrations were unaffected by the treatments. Sandblast injury can change a plant's metabolic processes before there is any visual damage.
Influence of Irrigation on the Yield and Persistence of Forage Legumes1
Authors: Wahab Hashim A. , Chamblee Douglas S. 
Published: July 2010

AbstractThe primary purpose of this study was to investigate the effect of irrigation on the yield and persistence of certain legumes as related to disease incidence. The effect of irrigation on the yield of three alfalfa (Medicago sativa L.) varieties, crownvetch (Coronilla varia L.), and ladino clover (Trifolium repens L.) was studied in the field over a 2‐year period. The nonirrigated plants received natural precipitation, whereas the irrigated legumes were supplied with supplemental water in addition to the rainfall whenever soil moisture was depleted to approximately 50% of the available water‐holding capacity. At the first harvest after irrigation in the 1st year, superior growth of all legumes was obtained by the use of supplemental water. The benefits of irrigation to some species and varieties ended at this point. Yields of alfalfa were sharply reduced in mid‐ and late summer of the 2nd year as a result of irrigation. Irrigation of the three alfalfa varieties resulted in an overall decrease in yield of 76% at the last harvest. The alfalfa varieties responded differentially to irrigation. Most of the stand of crownvetch was lost following the first cut on the irrigated plots.In contrast to other legumes, irrigation increased the yields of ladino clover by approximately 19%.Severe infestation by several diseases was probably a primary factor in the severe stand loss and low yields of alfalfa and crownvetch under irrigation. Excessive soil moisture due to precipitation soon after irrigation also possibly contributed to the loss of alfalfa stands.
Germination and Emergence of Crownvetch as Affected by Seed Maturity and Depth of Planting1
Authors: Peiffer R. A. , McKee G. W. , Risius M. L. 
Published: July 2010

AbstractBecause of the indeterminate flowering habit of crownvetch (Coronilla varia L.) some seedlots contain appreciable amounts of immature seed. Our objectives were (i) to study the relationship of seed maturity in ‘Penngift’ crownvetch as indicated by seedcoat and seedpod color to germination and emergence and (ii) to compare the emergence of ‘Chemung,’ ‘Emerald,’ and ‘Penngitt’ crownvetch; ‘Saranac’ alfalfa (Medicago sativa L.); ‘Pennscott’ red clover (Trifolium pratense L.); and ‘Empire’ birdsfoot trefoil (Lotus corniculatus L.). The development of Penngift crownvetch seed required 7 to 9 weeks with seedpods progressing through a sequence of color changes: green (3 to 4 weeks), greenish‐purple (1 to 2 weeks), greenish‐brown (1 to 2 weeks), tan and dull brown (1 to 2 weeks), and reddish‐brown (full maturity). Seedcoat color paralleled seedpod color. The total germination percentages (normal seedlings plus hard seeds) of seeds with greenish‐brown (immature), tan or dull brown, and reddish‐brown (mature) seedcoats were respectively, 30, 64, and 92. Immature seeds produced significantly fewer emergent seedlings from depths of 6, 13, and 25 mm than did more mature seeds. Emergence of seedlings of three cultivars of crownvetch from 19, 25, and 38 mm was 97, 98, and 76% of emergence from 13 mm. Crownvetch required 5 weeks for maximum seedling emergence, compared to 3 weeks for birdsfoot trefoil, red clover, and alfalfa. While under most field conditions the optimum planting depth for crownvetch is 6 to 13 mm, vigorous seedlings can emerge from depths of 25 to 38 mm.
Effect of Crust Rigidity and Osmotic Potential on Emergence of Six Grass Species1
Authors: Frelich James R. , Jensen E. H. , Gifford R. O. 
Published: July 2010

AbstractNonporous wax crusts were used to compare seedling emergence of tall wheatgrass (Agropyrun elongatum Host), pubescent wheatgrass [Agropyron trichophorum (Link) Richt.], basin wildrye (Elymus cinereus Scribn. and Merr.), Russian wildrye (Elymus junceus Fisch.), tall fescue (Festuca arundinacea Schreb.) and smooth bromegrass (Bromus inermus Leyss.). Seedlings were grown at O, −2.3, −4.4, −6.7, and −8.4 bars osmotic potential under soft, medium, and hard wax crusts, 3 mm thick. The treatments were designed to simulate the separate and combined effects of salty soils and crusts as limiting factors in seedling establishment in arid regions. The germination and emergence phases were separated by using only seeds that germinated as a basis for percent emergence.Emergence of all six species was lower under hard crust than under soft wax crust. Pubescent wheatgrass and smooth bromegrass were most affected by the crust hardness. In the range of osmotic potential used, there was no reduction in emergence as osmotic potential was reduced when the emergence was taken at 2 weeks; however, reduction in osmotic potential did delay emergence. The delay was slightly longer for hard crust than for soft crust.Although osmotic potential did not reduce emergence under soft crusts, a combination of low osmotic potential and hard crust did reduce the emergence of tall wheatgrass, basin wildrye, and Russian wildrye. The emergence of pubescent wheatgrass smooth bromegrass, and tall fescue was reduced principally by the hardness of the crust. Tall fescue was least able to penetrate the crust.The results indicate that osmotic potential may be less important in reducing emergence of field seedlings than is the presence of a crust. In a field situation the slower rate of emergence and low osmotic potential may involve additional crust strength as the soil surface dries.
Iron Utilization by Efficient and Inefficient Sorghum Lines1
Authors: Mikesell M. E. , Paulsen G. M. , Ellis R. , Casady A. J. 
Published: July 2010

AbstractIron‐efficient and Fe‐inefficient sorghum [Sorghum bicolor (L.) Moench.] inbred lines and their F1 hybrid differed in response to Fe deficiency. These lines were used in growth chamber studies with a soil and with several liquid‐nutrient media to determine Fe‐use efficiency. An Fe‐deficient Colby silt loam soil (5.2 ppm DTPA extractable Fe) with 22.4 kg Fe/ha and without added Fe was used for a potted‐soil, growth study. In the remaining studies seedlings were grown in Hoagland nutrient solution to induce Fe deficiency, to determine effects of P levels and Fe sources, and to measure root reduction potential. The respective solutions used were: (i) 0.2‐strength solution with no Fe; 2.0 μM Fe and 3.0 mg CaCO3/ liter; 2.0 μM Fe and 5.0 mM P; 2.0 M Fe and 2.5, 25.0, and 10.0 μM Cu, Mn, and Zn, respectively; (ii) 0.5‐strength solution with 10.0 μM Fe at O, 0.5, 1.0, 2.5, and 5.0 mM levels of P; (iii) 0.5‐strength solution with 10.0 μM ferric and ferrous Fe; (iv) 0.2‐strength solution containing 2.0 μM Fe with the last 24 hours' growth in a ferrichloride‐ferricyanide solution.Plants from all studies were separated to roots and shoots, wet‐ash digested, and assayed for Fe, Cu, Mn, Zn, Ca, and Mg by atomic absorption spectrophotometry. Phosphorus was determined by the vanadomolybdophosphoric method.The Fe‐efficient inbred usually maintained lower P concentrations in shoots and commonly in roots under Fedeficient conditions. Antagonism from other nutrients except P was not involved consistently in differential response of Fe‐efficient and Fe‐inefficient lines. Root reduction potential for ferrichloride‐ferricyanide was lower for sorghum than for other crops, but did not differ between inbred lines. Shoot and root growth was always greater with ferrous than with ferric Fe. Efficiency of Fe use by sorghum apparently was not inherited by the hybrid. Iron efficiency in sorghum probably can be improved by accumulating genes that increase uptake of Fe, or by decreasing interference of P in utilization of Fe.
Effects of Date and Depth of Planting on the Establishment of Three Range Grasses1
Authors: McGinnes William J. 
Published: July 2010

AbstractThe optimum depth of planting for cool‐season introduced grasses under field conditions on range lands, particularly on the Central Great Plains, has received limited study. Whereas most previous studies on date of planting have been with fall planting, the author has had considerable success for 15 years with spring experimental plantings in northern Colorado. The following experiment was conducted to determine the optimum spring planting date, to find the optimum depth for spring seeding, and to evaluate date and depth of seeding interactions.Crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.], pubescent wheatgrass [A. trichophorum (Link) Richt.] and Russian wildrye (Elymus junceus Fisch.) were planted at depths of 1.3, 2.5, 3.8, and 5.1 cm on average dates of planting of April 4, April 18, May 4, May 20, and June 9, 1967 through 1970 north of Fort Collins, Colo. Crested wheatgrass and Russian wildrye were also planted at the same depths on average dates of planting of April 20, May 3, May 18, and June 8, 1968 through 1970 on Central Plains Experimental Range (CPER) near Nunn, Colo. Establishment was evaluated from seedling counts made in September of the year of planting. At Fort Collins the greatest average number of seedlings was obtained from the April 18, May 4, and May 20 dates of seeding. Although year‐to‐year variations were great, the most reliable establishment was from the April 18 planting. At CPER, establishment from the June 8 planting was markedly poorer than for the three earlier dates of planting. Number of seedlings per meter of row was essentially the same for 1.3‐ and 2.5‐cm planting depths within species and locations except that crested wheatgrass averaged 12% more seedlings from 1.3‐ than from 2.5‐cm depths at Fort Collins. At 3.8 cm, numbers declined to about 50% of those in the shallower depths and declined still more at 5.1 cm. The decline was about 50% as much for pubescent wheatgrass as for crested wheatgrass and Russian wildrye, Soil moisture in the zone 2.5 to 5.1 cm deep appeared to be most critical for establishment. When moisture at this soil depth averaged less than 12% following seeding, stands contained only 53% as many seedlings as when the soil moisture averaged above 12%.
Yields and Magnesium Uptake by Plants as Affected by Soil pH and Calcium Levels1
Authors: Christenson D. R. , White R. P. , Doll E. C. 
Published: July 2010

AbstractLiming of acid soils may influence Mg uptake either because of associated pH factors or because of Ca level as the result of liming. This study was conducted to determine the effect of Ca levels and soil pH on the yield and uptake of Mg by oats (Avena sativa, cultivar ‘Gary’).Treatments in one experiment included a control, 118 ppm Al as Al2(SO4)3, 506 ppm Ca as CaCO3, 506 ppm Ca as CaCO3 plus 506 ppm Ca as CaSO4, and 1,012 ppm Ca as CaCO3. In a second experiment two Mg levels (0 and 12 ppm Mg as MgSO4·7H20) were applied in combination with two Ca sources at two Ca levels (0 ppm Ca, 800 ppm Ca as CaSO4, and 800 ppm Ca as CaCO3).Uptake of Mg was not increased by the addition of CaSO4 either in combination with Al2(SO4)3 or CaCO3. Uptake of Mg was significantly greater (5% level) when 800 ppm Ca as CaCO3 was applied than when 800 ppm Ca as CaSO4 was applied.Application of Mg significantly (5% level) increased Mg uptake regardless of Ca level or source.These results suggest that soil pH level affected Mg uptake more than did Ca level.
Distribution of Nutrients in the Rice Plant and Effect of Two Nitrogen Levels1
Authors: Westfall D. G. , Flinchum W. T. , Stansel J. W. 
Published: July 2010

AbstractThe use of plant analysis as an aid in making fertilizer recommendations and diagnosing nutritional disorders in rice (Oryza sativa L.) has potential as a production tool. This field experiment was designed to study the distribution of N, P, K, Ca, Mg, Mn, Fe, and Zn in rice plant parts at the panicle differentiation stage of plant development when grown under recommended (134 kg N/ha) and inadequate (67 kg N/ha) N fertility in order to determine the effects of these factors on plant analysis results.Rice plants grown with inadequate N fertility were lower in N, Mg, Mn, Fe, and Ca in most plant parts analyzed than their counterparts grown with recommended N fertility. The concentration of P was not influenced by N fertility rate. The concentration of plant nutrients varied with plant part and leaf age. The concentrations of N, P, and K were highest in the younger, fully matured leaves and decreased with leaf age. The concentrations of N, Ca, Mg, and Fe in the second leaf were higher than in the whole plant samples.Both plant parts analyzed and N fertility level in which plants were grown influenced nutrient analysis. The second leaf appears to be more closely correlated with the nutrient needs of the plant at panicle differentiation. As a production tool, the second leaf, or the most recently fully expanded leaf, is recommended to be collected for tissue analysis.
Yield and Protein Responses to Nitrogen Fertilizer of Two Winter Wheat Varieties Differing in Inherent Protein Content of Their Grain1
Authors: Johnson V. A. , Dreier A. F. , Grabouski P. H. 
Published: July 2010

AbstractGenes that increase the grain protein potential of wheat (Triticum aestivum L.) are known. The interaction of such genes with factors of the production environment, particularly soil nitrogen availability, determines their probable value and contribution to higher protein content in wheat.Two hard winter wheat varieties differing inherently in the protein content of their grain were grown in replicated plots at selected sites in Nebraska over a 3‐year period. Nitrogen fertilizer was applied at five rates in the 1st year and at seven rates in the 2nd and 3rd years. Data were recorded for yield, test weight, and protein content of the grain.Significant protein responses to nitrogen fertilizer occurred in all trials. Responses of both varieties were linear and positive. C.I.14016 maintained a protein advantage of 2 percentage points over ‘Lancer’ at all levels of fertilizer. The protein advantage of C.I.14016 over Lancer was independent of the relative yields of the two varieties. The feasibility of effectively increasing the grain protein content of wheat by breeding is indicated by the data.Statistically significant yield responses to fertilizer were recorded in 6 of 10 trials. Yield responses of both varieties were nonlinear with the second‐degree polynomial providing a good fit of the data. Less nitrogen fertilizer was required for maximum yield of Lancer, the lower protein variety, than for C.I.14016. Test weight responses of the varieties to fertilizer were negative and linear. The test weight of Lancer was higher than C.I.14016 at all fertilizer rates.
Use of Sprinklers to Study the Influence of Population Density Upon Seed Cotton Production in an Arid Area1
Authors: Robinson Frank E. , Cudney David 
Published: July 2010

AbstractThe growing period for cotton (Gossypium hirsutum L.) has been shortened by 2 months in the Imperial Valley because of an invasion by pink bollworm. The law now requires that cotton residue be incorporated into the soil early to lower the number of overwintering larvae. The shorter period for floral development led to reexamination of yield potential under different plant spacing. Defoliants, fertilizer, desiccants, and insecticides for pink bollworm control and water were applied through the sprinkler system. Randomized block designs of ‘Stoneville 213’ and ‘Paymaster 111A’ included plant densities of 15,000, 60,000, 242,000, and 969,000 plants/ha on a flat soil surface. Seeds were placed by hand at 2 per dibble in a square grid pattern. The bolls per plant were significantly affected by plant density. The effect of plant density on boll weight was significant on Paymaster 111A but not on the Stoneville 213. The highest seed cotton yield occurred where the plants produced the greatest number of bolls per hectare. For both varieties the highest yield occurred in the 242,000/ha treatment, with 4,870 kg/ha in Stoneville 213, and 4,228 kg/ha in Paymaster 111A. A trend of lower micronaire in the highest density was noted in each variety.
Variety and Row Spacing Effects on Recoverability of Soybeans from Simulated Hail Injury1
Authors: Burmood D. T. , Fehr W. R. 
Published: July 2010

AbstractTwo soybean [Glycine max (L.) Merr.] cultivars were grown in 100‐ and 50‐cm rows to evaluate the influence of cultivar and row spacing on recoverability from hail injury. ‘Hawkeye’ and ‘Hark’ soybeans were treated at three stages of plant development with 0, 25, and 50% stand reduction and 0, 25, and 50% stem cut‐off at ½ height.The experiment was conducted at Ames, Iowa for 3 consecutive years. The percentage yield loss averaged across years and treatments was the same (7%) for both row spacings of Hark and only 1 percentage point different (3% for 100‐cm and 4% for 50‐cm rows) for Hawkeye. No significant row spacings ✕treatments or row spacings ✕treatments ✕cultivars interactions were observed. Row spacing does not appear to warrant consideration in adjustment of soybeans for recoverability from hail injury.Average yield loss for Hark (7.0%) was more than for Hawkeye (3.5%) when averaged across years, treatments, and row spacings. The cultivars ✕stem cut‐offs interaction was not significant, but the cultivars ✕stand reductions interaction was significant at the 1% probability level. Hark had greater yield loss due to stand reduction than Hawkeye, primarily at the 50% level of stand reduction. Although small differences for recoverability did occur between cultivars, the differences were not great enough to justify the evaluation of all commercial soybean cultivars for their recovery potential. Such an evaluation would be necessary if cultivar is to be considered in the adjustment of hail losses.
Response of Three Corn Hybrids to Low Levels of Soil Moisture Tension in the Plow Layer1
Authors: Rhoads F. M. , Stanley R. L. 
Published: July 2010

AbstractFertilizer materials are generally mixed with the soil to plow depth and as a result, concentration of corn (Zea mays L.) roots is usually greatest in the surface soil; therefore, water demand is expected to be highest in the plow layer.The objective of these experiments was to evaluate the response of three corn hybrids to irrigation treatments that were designed to maintain soil moisture tension at low levels (less than 1‐bar) in the plow layer rather than the entire root zone. Flowering date, plant height, and grain yield were used as indexes of response.Irrigation was applied at four levels (0.3, 0.6, 2.0, and 5.0 bars) of soil moisture tension in 1970 and at three levels (0.2, 0.4, and 0.6 bar) in 1971. Nitrogen was applied at 336 and 560 kg/ha, in 1971, to treatments irrigated at 0.2 bar of soil moisture tension. Each irrigation treatment was replicated four times and consisted of applying water at a selected value of soil moisture tension. A tensiometer was placed in each plot to in irrigated at soil moisture tensions below 1 bar in order to monitor soil moisture tension at a depth of 15 cm. Electrical resistance units were used in 1970 to monitor soil moisture tension in plots irrigated at tensions above 1 bar.Flowering occurred earlier and plant height increased as soil moisture tension at irrigation decreased. Grain yields were increased significantly (5% level) each year when plots were irrigated at 0.2 or 0.3 bar soil moisture tension instead of 0.6 bar. Irrigation at 0.6 bar did not increase grain yields in comparison with no irrigation in 1970. Each corn variety gave an inverse linear grain yield response to soil moisture tension values between 0.2 and 0.6 bar in 1971. There was a significant difference (5% level) between varieties in magnitude of grain yield response to irrigation in 1971. Highest grain yields were produced each year when soil moisture tension in the plow layer was maintained below 1/3 bar.
Influence of Cultivar, Row Spacing, and Number of Rows on Yield of Wheat Plots1
Authors: Rich Pat A. 
Published: July 2010

AbstractCultivar competition in wheat (Triticum aestivum L.) yield plots has been acknowledged for more than 50 years. However, measurements of the effects of possible interactions of cultivars and row spacings in two‐, four‐, and six‐row plots have not been investigated together in planned experiments. The objective of this study was to study the influence of two‐, four‐, and six‐row plots with 15‐, 20‐, 25‐, 30‐cm row spacings on the yield of a normal height wheat (‘Riley 67’) and a semi‐dwarf wheat (‘Sturdy’) in 4 ✕ 3 ✕ 2 factorial experiments. Marked cultivar ✕ rows per plot interactions indicated cultivar competition. The yield of Sturdy was linear function of rows per plot but the yield of Riley 67 was an inverse linear function. Sturdy plot yields were (i) larger than Riley 67's in six‐row plots, (ii) not different from Riley 67's in four‐row plots, and (iii) less than Riley 67's in two‐row plots. The data indicate that six‐row plots with 15‐, 20‐, 25‐, or 30‐cm row spacings are needed for valid yield evaluation in perennial experiments, but in annual experiments six‐row plots with 30‐cm row spacing should be used.