bluuebunny/crossref_metadata_2025_split huggingface dataset:
Orientation of Leaves of Winter Wheat Planted in North‐South or East‐West Rows1
Authors: Kirkham M. B. 
Published: July 2010

AbstractThe objective of the present experiment was to determine if, and to what extent, leaves of winter wheat (Triticum aestivum L. em. Thell.), oriented in two row directions, received different amounts of light. At times distributed over two growing seasons, including fall, winter, and spring months, values of I/IO (intensity of received direct‐beam radiation to incident direct‐beam radiation) were calculated from solar‐noon sun angles for leaves of winter wheat (cv. ‘Osage’), planted in north‐south (NS) and east‐west (EW) rows. Another objective of this research was to determine leaf disposition, area, width, and length, regardless of light intensity received, for fall, winter, and spring months. In addition, climatic data were collected.Results for the winter growth period were significant. The winter results showed that I/IO values for leaves in NS and EW rows differed markedly during the slow‐growing winter season. Furthermore, on cold, windy days, it was found that leaves in NS rows were prostrate and leaves in EW rows were erect, apparently because the plants in the EW rows were protected in the winter from the prevailing northerly winds by ridges made at planting. The leaf measurements showed that leaves in EW rows were long and narrow and leaves in NS rows were short and wide. Also, plants in NS and EW rows had most leaves pointing southerly and easterly, respectively, for all seasons; fewest leaves pointed northeasterly in both NS and EW rows. There were more living leaves in NS rows than in EW rows. The leaf measurements and I/IO calculations showed that, during winter, the leaves in EW rows, which were generally erect and not prostrate (horizontal), were oriented in many directions and had the full range of I/IO values (range: 0 to 1.00), while leaves in NS rows, which were often not erect, but prostrate, despite wind, had a range of values of I/IO from 0.18 to 0.76, independent of leaf direction.
Sunflower Nutrient Uptake, Growth, and Yield as Affected by Nitrogen or Manure, and Plant Population1
Authors: Mathers A. C. , Stewart B. A. 
Published: July 2010

AbstractSunflower (Helianthus annuus L.) is a new crop in the Southern High Plains. It was grown on Pullman clay loam (Torrertic Paleustoll) in an experiment designed to determine the effects of N, plant population, and row spacing on growth, yield, and nutrient uptake. Fertility treatments were 0, 84, and 168 kg N/ha and residue from three annual applications of 22 and 67 metric tons of manure/ha (wet wt.). Populations of 37, 62, and 99 thousand plants/ha were grown in a bed‐furrow irrigation system in two row spacings (one and two rows 30 cm apart) per bed. Beds were spaced 1 m apart. The crop was irrigated to provide adequate water. Beginning about 7 weeks after planting, samples were taken at 2‐week intervals for dry matter yields and chemical analyses. Seed and oil yields were taken at maturity.In 1975, the seed yield on the unfertilized treatment was 1,950 kg/ha, whereas all other treatments produced similar yields averaging 2,850 kg/ha. In 1976, yields were similar on the unfertilized and inorganic N treatments (avg. 2,000 kg/ha) and similar on the manure treatments (avg. 2,330 kg/ha). Lower sunflower yield in 1976 than in 1975 is attributed to higher temperatures during the seed filling period in 1976. Both N fertilizer and manure reduced oil percentage in seed. Even though statistically significant effects were found in 1975, yields were not affected to a large degree by differential row spacings and plant population treatments. Dry matter and nutrient yield curves showed that adequately fertilized sunflower produced about 10 metric tons of dry matter/ha containing 200 kg N, 35 kg P, 450 kg K, 180 kg Ca, and 45 kg Mg/ha.The 84 kg N/ha rate supplied sufficient N for maximum sunflower yields. Apparently, manure supplied some needed element or condition not supplied by inorganic N. That factor was not identified. Plant populations from 37 to 99 thousand/ha gave satisfactory yields.
Austrian Winter and Spring Peas as Green Manure Crops in Northern Idaho1
Authors: Auld D. L. , Bettis B. L. , Dial M. J. , Murray G. A. 
Published: July 2010

AbstractThe increasing cost of N fertilizers has caused a renewed interest in the utilization of Austrian winter peas [Pisum sativum ssp. arvense (L.) Poir] as a green manure crop. From 1977 to 1980 field experiments on a palouse silt loam (fine, montmorillonitic, mesic Xeric Argialboll) were conducted in northern Idaho to determine the planting date, harvest date, and cultivar of Austrian winter peas that produced the maximum yield of organic matter (OM) and N in the vines. Organic matter yield was determined by harvesting and weighing the vines from four‐row plots (1.3 m2). A 1‐kg sample from each plot was dried and wet weights were adjusted to an oven dry basis. Vine N was determined using either micro‐Kjeldahl or a Technicon Autoanalyzer II System.Austrian winter peas seeded in early September produced the highest yields of OM and vine N. Delaying seeding until early October reduced OM production and vine N by over 50% at both locations. Vine N was increased only 28 kg/ha by delaying harvest from early bloom to late pod filling but OM yield was increased by 4.9 metric tons/ha.‘Melrose’ produced the most OM (13.9 metric tons/ha) and vine N (321 kg/ha) of the five winter pea lines evaluated. All of the lines accumulated in excess of 250 kg of vine N/ha averaged over both test years.The four long‐vined Austrian winter pea lines yielded an average of 13.0 metric tons of OM/ha when fall planted but only 6.9 metric tons/ha when planted in the spring. Six spring pea cultivars (P. sativum L.) averaged 12.1 metric tons/ha but late maturity would have prevented plow‐down under dryland conditions.In northern Idaho, Austrian winter peas could produce in excess of 10 metric tons/ha of OM which would contain a minimum of 175 kg/ha of vine N. The inclusion of Austrian winter peas as a green manure crop in crop rotations could have a significant impact on the total N budget of the soils in this region.
Mulching and Green Manure Applications for Continuous Crop Production in the Amazon Basin1
Authors: Wade M. K. , Sanchez P. A. 
Published: July 2010

AbstractKudzu (Pueraria phaseoloides) and guineagrass (Panicum maximum) cuttings were each used as mulch or incorporated as green manures under three fertilizer treatments in a Typic Paleudult soil at Yurimaguas, Peru to evaluate their potential as organic additions for continuous crop production in the Amazon Basin. Mulching with guineagrass decreased topsoil temperatures by 5 C prior to the establishment of a crop canopy, conserved soil moisture in the top 5 cm during dry weather, prevented surface crusting and decreased weed growth. Mulching had. little effect in increasing the availability of N, K, Ca, and Mg. The use of mulches without chemical inputs produced an average of 75% of the crop yields achieved with completely fertilized, bare plots. For five consecutive crops, incorporating kudzu at the rate of 8 tons fresh material/ha/crop produced yields which were 90% of the crops receiving complete inorganic fertilization and liming. Guineagrass incorporation was also beneficial but generally less so than kudzu. The beneficial effects of incorporating kudzu as green manure were associated with the amounts of N, P, K, Ca, and Mg released from the decomposing material, decreased AI saturation, and possibly enhanced nutrient accumulation due to less moisture stress and lower bulk density. No response to organic additions were found when recommended amounts of lime and fertilizers were supplied.
Phosphorus Requirements of Alfalfa‐Smooth Bromegrass‐Orchardgrass and Reed Canarygrass Pastures under Two Grazing Pressures1
Authors: Mallarino A. P. , Wedin W. F. , Voss R. D. , West C. P. 
Published: July 2010

AbstractMost recommendations for P fertilization of pastures are based on data from small plots from which the herbage is clipped and removed. This may overestimate the sward growth responses to fertilizer P because of the absence of trampling and nutrient cycling by grazing animals. In a beef‐steer grazing study conducted on Aquic Argiudoll‐Typic Argiaquoll soils in Iowa we determined the effect of fertilizer P applied to two pasture types under two grazing pressures. Pasture types were: (1) ‘Pioneer 520’ alfalfa (Medicago sativa L.)‐‘Baylor’ smooth bromegrass (Bromus inermis Leyss.)‐‘Napier’ orchardgrass (Dactylis glomerata L.), and (2) ‘Rise’ reed canarygrass (Phalaris arundinacea L.). The alfalfa‐grass pastures received no N fertilizer, whereas reed canarygrass pastures received 180 kg ha−1 year−1 of N. The 1.32‐ha pasture units were divided into three 0.44‐ha rotational grazing strips, upon which either 0, 20, or 40 kg ha−1 of P was topdressed in the spring of 1979. In 1980, three small plots were designated in each of the 0.44‐ha rotation strips to which the same three P treatments were randomly assigned. The grazing pressures were at 8 and 11 kg of available dry matter/steer‐day. No significant effects resulting from grazing pressure were detected for dry matter yield, plant P, or soil‐test P values. Herbage dry matter yield in 1979 was not influenced by P rate; however, in 1980, both pasture types exhibited a positive linear response to P where no P had been applied in 1979. In rotation strips that had received no P fertilizer in 1979, alfalfa‐grass dry matter yields in 1980 exhibited a quadratic relationship to soil‐test P levels, i.e., yield optimum at 25 ppm of soil‐test P (Bray 1). Reed canarygrass dry matter yields in 1980 exhibited a linear relationship to soil‐test P levels with an apparent leveling off of yield above soil‐test P of 20 ppm. We concluded that yield response to P topdressing is improbable at soil‐test P levels at or above 22 to 25 ppm (Bray 1) for alfalfa‐grass and 15 to 20 ppm for reed canarygrass pastures.
Growth and Seed Yield Characteristics of Birdsfoot Trefoil1
Authors: McGraw Robert L. , Beuselinck P. R. 
Published: July 2010

AbstractDifficulty in harvesting sufficient quantities of seed is a major factor limiting use and production of birdsfoot trefoil (Lotus corniculatus L.). A growth analysis of ‘Norcen’, ‘Viking’, and ‘Empire’ birdsfoot trefoil was conducted in the field at Roseau, Minn. in 1980 and 1981 to investigate physiological and morphological characteristics which limit seed yield potential. The soil was a Glyndon silt loam (coarse‐silty, calcareous Aeric Calciaquoll). Two major factors were largely responsible for low seed production: (1) low partitioning of assimilates to seed yield and (2) indeterminate flowering habit accompanied by dehiscent pods. Plants partitioned an average of about 40% of available assimilates to reproductive growth. Of the assimilates partitioned to reproductive growth, only about 30% became seed; the rest was distributed in peduncle, pedicel, and pod walls. Thus, only 12% of available assimilates was partitioned to seed. The stem component was the major sink for accumulation of dry matter until 2 weeks before final sampling when the umbels became the major sink. Plants flowered and new umbels were produced over a long period; consequently, umbel maturity varied widely on a single plant. Many umbels were still immature when the first dehisced pods were observed. At maximum pod maturity, about one‐third of the umbels contained either dehisced or immature pods. Genetic improvement or improved cultural or chemical methods that would increase partitioning to seed, produce a more determinate growth habit, or increase dehiscence resistance should help increase seed yields in birdsfoot trefoil.
Soil Contamination and Elemental Concentrations of Forages in Relation to Grass Tetany1
Authors: Cherney J. H. , Robinson D. L. , Kappel L. C. , Hembry F. G. , Ingraham R. H. 
Published: July 2010

AbstractRelationships among soil contamination of forages, elemental concentrations in forages samples, and grass tetany are not clear. Our objectives were to determine the extent and seasonal variation of soil contamination on annual ryegrass (Lolium multiflorum Lam.) samples, and to relate the contamination to various indicators of grass tetany. Seasonal variation of soil ingestion by grazing beef cattle was also investigated. Field experiments were conducted on a Tensas silty clay soil (fine, montmorillonitic, thermic Vertic Ochraqualf). Highly significant positive correlations were obtained among AI, Fe, and Ti concentrations within forage and rumen content samples. Concentrations of these elements occurred in the same ratios as in digested soil. Soil contamination during peak periods averaged approximately 70 g/kg in forage samples and 95 g/kg in rumen content samples. A washing procedure was ineffective in removing all of the soil contamination from forage samples. Forage samples taken in areas protected from grazing animals showed no apparent excessive uptake of AI by the plants at any time during the grazing season. The amount of soil contamination on forage plants and the amount of soil ingested by grazing animals increased with increased grazing pressure, decreased forage production, and saturated surface soils. A rapid decline in forage Mg and Ca concentrations may have been a major factor in the Occurrence of grass tetany, but was not associated with highest levels of soil contamination.
Sunflower Germination under Simulated Drought Stress1
Authors: Somers D. A. , Ullrich S. E. , Ramsay M. F. 
Published: July 2010

AbstractSunflower (Helianthus annuus L.) production is occurring and expanding under dryland conditions in many semiarid regions of the world. In some of these areas moisture stress may limit stand establishment. Germination of sunflower seeds in aqueous solutions of polyethylene glycol 20,000 (PEG) was evaluated as a screening technique for the selection of sunflower cultivars able to emerge under low soil moisture conditions. Germination of seed from four sunflower cultivars was determined at 0, −6, −11, −15, and −21 bars osmotic potential. No significant differences were observed among cultivars at 0 and −6 bars. Germination of three cultivars was significantly reduced at −11 bars. The germination of all cultivars was further reduced at −15 bars and completely inhibited at −21 bars. Emergence of the same cultivars from Palouse silt loam soil (fine‐silty, mixed, mesic Pachic Ultic Haploxeroll) adjusted to −4, −6, −7, −11, and −14 bars matric potential was not significantly different at −4, −6, and −7 bars for three cultivars, while one cultivar exhibited reduced emergence at all these matric potentials. The emergence of the seed of all cultivars was reduced at −11 bars and completely inhibited at −14 bars. Data from each analysis were pooled over all cultivars at each water potential for comparison of the two methods. Emergence from the soil was reduced at higher water potentials than germination in PEG solutions. However, the relationships of emergence to matric potential and germination to osmotic potential were similar indicating that PEG solutions may be useful in screening sunflower cultivars for improved emergence during moisture stress.
Retrev: a Software System for Managing Comprehensive Crop Survey1
Authors: Grube M. , Steinhorst R. K. , Wiese M. V. 
Published: July 2010

AbstractAnalyses of crop performance over a defined production area require the identification and quantification of yield determining variables coupled with measurements of yield. Because of the inherent complexity of most crop production ecosystems, analyses of crop performance usually necessitate the collection and interpretation of large amounts of data describing yield and yield constraints and proponents. In this light, a software system called RETREV was developed to manage comprehensive crop survey data and assist with yield loss assessments. RETREV flexibly files survey data by crop, year, sample site, sample date, and variable name. It provides definition, indexing, storage, retrieval, and subsetting of data sets and accommodates single and multiple measurements of discrete (alphanumeric) and continuous variables. The FORTRAN program also preprocesses data for use in subsequent programs or analysis packages to generate univariate and multivariate yield analyses, crop yield models, and written reports. RETREV currently is used in an evaluation of regional yields of peas (Pisum sativum L.), wheat (Triticum aestivum L.), and sugarbeets (Beta vulgaris L.) relative to pest, weather, soil, and management data.
Basic Cation Saturation Ratios as a Basis for Fertilizing and Liming Agronomic Crops. II. Field Studies1
Authors: McLean E. O. , Hartwig R. C. , Eckert D. J. , Triplett G. B. 
Published: July 2010

AbstractA field experiment was conducted over a period of six cropping years to determine the relative merits of basic cation saturation ratio (BCSR) and of sufficiency level of available nutrients (SLAN) as bases for a p plying lime (Ca and Mg) and fertilizer K for crops. The study involved an acid Loudonville silt loam soil (Ulfic Hapludalf, fine‐loamy, mixed, mesic) which had been adjusted to 3 pH (Ca), 3 Mg, and 2 K levels, in all combinations. The sequentially grown crops were: corn (Zea mays L.), corn, soybeans (Glycine max L. Merr.), wheat (Triticum aestivum L.), alfalfa (Medicago sativa L.), and alfalfa. The treatment variables for pH were: 5.0, 6.0, and 6.5; for percent Mg saturation of soil CEC were: 4, 6, and 10; and for percent K saturation of CEC were 2.4 and 4.3. Both yields and crop compositions were measured. The treatment variables resulted in an average soil Ca/Mg ratio range of 2.3 to 26.8 and an average soil Mg/K ratio range of 0.6 to 3.6. Direct correlation or association of crop yields with basic cation saturation ratios (BCSR) were quite low. Also, the treatments producing the five highest yields for each crop gave rather wide ranges in both Ca/Mg and Mg/K ratios which were to a large extent also common to those ratios associated with the five lowest yielding treatments. Thus, finding no evidence to support the validity of the BCSR concept as a basis for providing maximum crop yield conditions, the direct response of the crops to the basic nutrient cations (SLAN) concept was examined. Although yield responses to increased levels of the cations were not obtained in all cases, the results obtained were reasonable; and compositions of Ca, Mg, and K were in almost all cases increased as the levels of the respective cations were increased. The results strongly suggest that for maximum crop yields, emphasis should be placed on providing sufficient, but nonexcessive levels of each basic cation rather than attempting to attain a favorable BCSR which evidently does not exist.
Nitrogen Fixing Activity of Water Stressed Siratro1
Authors: Ismaili Mohammed , Briske D. D. , Weaver R. W. 
Published: July 2010

AbstractSiratro [Macroptilium atropurpureum (DC.) Urb. cv. siratro] is grown in tropical and subtropical environments characterized by frequent periods of drought and is dependent on N2 fixation for its N. These investigations were conducted to relate leaf and nodule water potentials to N2 (C2H2) fixing activity and determine the capability of nodules to recover N2 (C2H2) fixing activity following water stress. Plants were grown in pots containing vermiculite under controlled environment conditions. Forty‐two days after planting four water treatments were imposed by withholding water for increasing periods of time. Water treatments created a decrease in leaf and nodule water potentials corresponding to the period of time water was withheld. However, when water potentials decreased below −1.5 MPa, nodule water potentials became more negative than leaf water potentials. A similar decrease in water potential suppressed growth of both nodules and shoots. In the longer duration, water withholding treatments nodule and shoot weights decreased as a result of nodule sloughing and leaf shedding. All water withholding treatments reduced the rate of N2 (C2H2) fixing activity.Nodules with water potentials of −1.5 MPa or greater were able to regain much of their N2 (C2H2) fixing activity within 2 d following rewatering. The specific activity of nodules surviving the most severe level of water stress (−1.9 MPa) were only about 60 % as active as the control 6 d following rewatering. Nodules were irreversibly inactivated by water stress more severe than −3.0 MPa but in approximately 12 d following rewatering new nodules developed. Regrowth of siratro following water stress may be delayed while the capacity for N2 fixation recovers.
Ammonium Uptake by Wheat Varieties Differing in Al Tolerance1
Authors: Fleming A. L. 
Published: July 2010

AbstractPrevious studies have indicated that wheat (Triticum aestivum L.) cultivars absorbed nutrients more efficiently and induced a higher pH in the root zone than Al sensitive cultivars. In many of these studies, plants were screened on acid soils fertilized with NH4NO3 or in nutrient solutions containing up to 15% NH+4‐N. The research reported in this paper was conducted to determine the impact of NH+4‐N nutrition on the response of wheat varieties to Al and to define the relationship between plant‐induced pH changes in nutrient solutions and the utilization of NH+4‐N. ‘Atlas’ and ‘Redcoat’ wheat were grown in nutrient solutions that contained variable ratios of NO‐3‐N and NH+4‐N (100/0, 90/10, 80/20, and 70/30) with or without Al. In the absence of NH+4‐N and Al, both Atlas 66 (Al‐tolerant) and Redcoat (Al‐sensitive) wheats increased the pH of the nutrient solution at equal rates. With NH+4‐N (10 to 30% of the total N), Atlas 66 achieved a higher equilibrium pH than Redcoat. The Al treatments with NH+4‐N inhibited the uptake of NO‐3‐N, reduced the rate of pH increase and injured Redcoat more than Atlas. Aluminum injury was intensified by increasing the concentration of NH+4‐N in the solution. It was concluded that NH+4‐N uptake by Redcoat, with the coincident pH decrease and interference with NO‐3‐N metabolism, was a major determinent of sensitivity to Al.