bluuebunny/crossref_metadata_2025_split huggingface dataset:
Minimum‐Tillage Forage Turnip and Rape Production on Hill Land as Influenced by Sod Suppression and Fertilizer1
Authors: Jung G. A. , Kocher R. E. , Glica Anna 
Published: July 2010

AbstractInsufficient herbage during the fall in the temperate areas of the world has long been a serious limitation in animal production. The purpose of this research was to determine the feasibility of producing Brassicaspp. forage crops for fall grazing of sheep on hill land. The experiment was conducted near Waynesburg, Pa., in a 4‐ha hill pasture, predominantly Dormont silt loam (fine‐loamy, mixed, mesic Ultic Hapludalf) on the sideslopes and Culleoka loam (fine‐loamy, mixed, mesic Ultic Hapludalf) on the ridge. A split‐plot block arrangement was used with blocks of ‘Sirius’ turnip, (Brassica rapaL.) ‘Fora’ rape, (B. napusL.), and ‘Perko P.V.H.’ winter rape (B. rapaL.) randomized in each of six blocks. Competition from the existing species was suppressed with paraquat (l,l′‐dimethyl‐4,4′‐bipyridinium ion) or glyphosphate [isopropylamine salt of N‐(phosphonomethyl)glycine] at 1.1 kg a.i. ha−1. Nitrogen and P fertilizer treatments were assigned to subplots in a randomized complete block design. Fertilizer was applied before seeding in 1978 and 1979 to provide 0, 33, 66, 99, or 132 kg N ha−1and 0, 15, 30, 45, or 60 kg P ha−1in a 52factorial arrangement. The crops were minimumtillage (min‐till) planted on 10 Aug. 1978 and 25 July 1979. Dry matter (DM) yields were determined 60 and 90 days after planting. Select samples were taken to determine crude protein, in vitro dry matter disappearance (IVDMD), and mineral element composition. Mean crop yields were similar for the two herbicide treatments in 1978 but were−35 to 75% higher on glyphosate‐treated plots than on paraquat‐treated plots in 1979. Grass yield in the Brassicaplots in 1979 were twice as high in the paraquat‐treated plots as in the glyphosate‐treated plots. At the higher rates of applied N and P, DM yield exceeded 7000 kg ha−1in 1978 and 9000 kg ha−1in 1979. Crop yield responses were quadratic functions for N fertilizer rates and linear functions for P fertilizer rates for both harvests in 1978. In 1979, yield responses were linear functions for N fertilizer rates for both harvests and for P fertilizer rates for the 60‐day harvest; and were quadratic for P rates for the 90‐day harvest. Yield of turnip and rape was affected more by P fertilizer before the 60‐day harvest than afterwards. Crude protein concentration ranged from 60 to 250 g kg−1. Nitrogen and P fertilizers differentially affected the crude protein concentration of forage turnip and rapes. Mean IVDMD was 950 and 900 g kg−1for turnip tops and roots, respectively, 910 g kg−1for Fora rape, and 930 g kg−1for Perko rape. Yield of digestible DM of turnip was up to 67% higher than that of stockpiled orchardgrass. The Brassicaspp. had different DM mineral element compositions, and concentrations of P, K, Ca, Mg, and Zn generally were higher in Brassicaspp. than in orchardgrass checks.
Photosynthesis and Stomatal Conductance with CO2‐Enrichment of Containerand Field‐Grown Soybeans1
Authors: Sionit N. , Rogers H. H. , Bingham G. E. , Strain B. R. 
Published: July 2010

AbstractThe present experiment was an attempt to study the differences between photosynthetic responses of pot‐grown and field‐grown soybean [Glycine max(L.) Merr., ‘Bragg’] plants to atmospheric CO2enrichment at six levels of irradiance and four leaf temperatures. Plants were grown in field soil or in pots containing an artificial substrate at five elevated atmospheric CO2levels and two water regimes in open top field chambers. Under well‐watered conditions plants grown in the pots had lower stomatal conductances and lower rates of net photosynthesis than plants grown in the field. However, the field‐grown plants responded to a less extent to increasing atmospheric CO2concentration than pot‐grown plants. The photosynthesis‐ irrdiance relationships were linear in the field‐grown plants and curvilinear in the pot‐grown plants. At the highest irradiance level tested (1400 µmol m−2s−1), the field‐grown plants had maximum net photosynthetic rates of 43 and 48 mg CO2dm−2h−1at 332 and 623 µL L−1CO2respectively. The pot‐grown plants were irradiance saturated at a level of 700 µmol m−2s−1and net leaf photosynthetic rates were 18 and 28 mg CO2dm−2h−1at 332 and 623 µL L−1CO2, respectively. Water stress caused a reduction in both stomatal conductance and net photosynthetic rate in the leaves of pot‐grown plants. The effect of leaf temperature on net photosynthethis and stomatal conductance depended upon the atmospheric CO2concentration and rooting media. High temperature increased net photosynthetic response to CO2enrichment at high CO2concentrations but not at low CO2concentrations.
Influence of Seed Size and Planting Date on the Performance of Austrian Winter Field Peas1
Authors: Murray G. A. , Swensen J. B. , Auld D. L. 
Published: July 2010

AbstractProduction of Austrian winter field pea [Pisum sativum spp. arvense (L.) Poir] is limited by a lack of information on cultural practices and potential productivity. Field studies were conducted to determine the influence of seed size and planting date upon spring seedling vigor, seed yield, and seed weight of several Austrian winter field pea cultivars. The Moscow studies were situated on a Palouse silt loam soil (fine‐silty, mixed, mesic, pachic Ultic Haploxeroll) and the Grangeville study on a Chicane silt loam (fine, montmorillonitic, mesic Xeric Argialboll). Small‐sized seed (<5.2 mm diam) significantly reduced spring seedling vigor of Austrian winter field pea planted in October under cool, wet conditions. Seed yields of Austrian winter field pea planted in October under cool, wet conditions in 1977 at Grangeville, Idaho, and in October under dry conditions in 1978 at Moscow, Idaho were reduced by 742 and 255 kg ha−1, respectively when Austrian winter field peas were established from small vs large‐sized seed. Improved seedling vigor of Austrian winter field pea from large‐sized seed did not improve yield of Austrian winter field peas planted at locations, planting dates, and environments favorable for pea growth. At Grangeville in 1977, the Austrian winter field peas planted in September produced 1298 kg ha−1 more seed than October‐planted Austrian winter field pea. September and early October planting dates had no influence on seed yield at Moscow, but Austrian winter field peas planted in late October failed to establish economic stands in both years, probably because of low October precipitation in both years and very low winter temperatures in 1978 to 1979. Seed weight of most Austrian winter field pea lines declined an average of 1.6 g 100−1 seed as seeding date was delayed from September until October. Reduced seed weight accounted for part of the seed yield reduction observed at Grangeville. Seed weight of a semi‐dwarf Austrian winter field pea increased significantly as seeding date was delayed from September until October. ‘Melrose’ had the best seedling vigor and ‘Common’ the worst seedling vigor of all cultivars tested. No differences in seed yield were observed between ‘Fenn’, Melrose, and Common at either location.
Effect of Moisture Stress on Seed Growth in Soybeans1
Authors: Meckel L. , Egli D. B. , Phillips R. E. , Radcliffe D. , Leggett J. E. 
Published: July 2010

AbstractThe growth of an individual soybean [Glycine max (L.) Merr.] seed is an important part of the yield production process. An understanding of the effect of environmental factors on the growth of individual seeds is needed to enhance our understanding of the effect of the environment on yield. Soybeans were grown in the field on a Maury silt loam soil (fine, mixed, mesic Typic Paleudalfs) for 3 years (1979 to 1981) and subjected to varying levels of moisture stress to investigate the effect of moisture stress on seed growth. Irrigated controls were compared with moisture stress treatments from planting to beginning seed fill (growth stage RS), during seed filling (growth stage R5 to R7) or from planting to maturity (severe stress). Fruits were tagged at beginning seed fill and sampled at weekly intervals to estimate the seed growth rate and the effective filling period (EFP). Although the stress treatments reduced yield and vegetative growth, the rate of seed growth (mg seed−1 day−1) was not affected. The seed‐filling period (estimated as days from growth stage R5 to R7 or EFP) was shortened by the severe stress treatment in 1979 and 1981 (statistically significant only in 1979), and there was a trend for the period of R5 to R7 to be shortened by late stress in 1980 and 1981. The data suggest that the rate of individual seed growth is less sensitive to moisture stress than other plant processes. The seed filling period was more sensitive to moisture stress than seed growth rate and the effect of moisture stress on the duration of seed fill may be one way that stress reduces soybean yield.
Foliar Applications of Nutrients on Maize. I. Yield and N Content of Grain and Stover1
Authors: Below F. E. , Lambert R. J. , Hageman R. H. 
Published: July 2010

AbstractCrop yield response to foliar fertilization has been variable, but few studies have utilized detailed plant analyses of field grown maize (Zea maysL.) hybrids known to differ in C and N metabolism and content to establish a role for foliar fertilization especially in plant and grain development. Field studies were conducted in 1981 and 1982 to determine whether foliar application of N would delay the remobilization of leaf N and leaf senescence thereby maintaining photosynthesis and increasing productivity. In 1981, N‐P‐K‐S (12 kg N ha−1per treatment) was applied to plants of five hybrids at 7 days before and 12 days after anthesis. In 1982, urea (two equal applications for a total of 67 kg N ha−1) was applied to three hybrids (B73 × Mo17, Pioneer brand 3382, and Farm Services brand 854) at 12 and 6 days before anthesis and 9 and 15, and 25 and 32 days after anthesis to give treatments 1, 2, and 3, respectively. Soil type was Drummer silt loam (fine‐silty, mixed, mesic Typic Haplaquoll) in 1981 and a Flanigan silt loam (fine, montmorillonitic, mesic Aquic Arqiudoll) in 1982. In 1981, grain yield and N content, and the accumulation of dry weight and reduced N by the whole plant were unaffected by the spray treatments. In 1982, increases in whole plant N at physiological maturity in response to urea sprays were 0.1, 0.1, and 0.4 g N plant−1for the first spray, 0.5, 0.4, and 1.0 g N plant−1for the second spray and 0.4, 0.5, and 0.5 g N plant−1for the third spray for P3382, B73 × Mo17, and FS854, respectively. Grain yields of all hybrids were not affected by any treatment and significant increases in whole plant dry weight and grain yield of erect plants were noted only for FS854 (second treatment). Grain N of all hybrids was increased significantly by the third treatment and for FS54 by the second treatment. Adverse effects of urea treatments were that stalk lodging was increased, and that the harvest indices for dry weight and N were not altered. Foliar application of N did not delay the remobilization of N from the leaves, and had little consistent effect on net photosynthesis or productivity. The use of foliar N sprays for increasing grain yield of maize grown at soil N levels commonly used for commercial production is not recommended.
Comparison of N Balance and 15N Isotope Dilution to Quantify N2Fixation in Field‐Grown Legumes1
Authors: Rennie R. J. 
Published: July 2010

AbstractTwo techniques are commonly used to estimate N2fixation integrated over the growing season in field‐grown legumes: total N balance (NB) (the classical difference method), and methods based on the principle of 15N isotope dilution. Many researchers do not have access to 15N or to isotope ratio mass spectrometers and thus rely on the NB method. A comparison of these two techniques of estimating N2fixation in several experiments over 3 years showed that the NB method generally resulted in a lower estimate of N2fixation and was consistently less precise (higher experimental error). Good agreement existed between the two methods in 70% of the experiments for estimating the amount of N2fixed but in only 60% of the experiments for percentage N2fixed. Even when high correlation coefficients were found, the unacceptable characteristics of the regression equations (i.e., deviation from a slope of unity and a y‐intercept of zero) made predictions difficult. Nitrogen balance was most reliable in experiments when soil N was low, so that non‐fixing plants showed signs of N deficiency by anthesis. Still, it was not possible to determine when NB would agree with 15N isotope dilution for estimates of N2fixation. Negative values for fixing systems or positive values for non‐fixing systems for N2fixation were found when using NB. In only one circumstance will NB accurately quantify N2fixation: when the fertilizer use efficiency (or, in unfertilized experiments, soil N uptake) of the fixing system is identical to that of the non‐fixing system. Since this occurs sporadically, NB cannot be used with confidence to estimate N2fixation in field‐grown legumes.
Estimation of Spring Wheat Leaf Growth Rates and Anthesis from Air Temperature1
Authors: Bauer Armand , Frank A. B. , Black A. L. 
Published: July 2010

AbstractSeasonal variability in climate within and between the major spring wheat (Triticum aestivumL.) growing regions of the world causes large differences in plant development patterns. A major need of models attempting to describe crop growth as a dynamic process is an evaluation of phenological development. Researchers modeling growth and yield would benefit from a meteorologically‐based phenological index that accurately and reliably predicts the development stage. The objective of this study was to develop capability to estimate leaf growth rate and crop growth stage from planting to anthesis under variable management and climatic conditions. Aboveground morphological entities of 16 hard red spring (HRS) and 3 durum (T. durumDesf.) wheats were rated in Haun scale designations in seven field trials grown on Williams loam (fine‐loamy, mixed Typic Argiboroll). These designations were regressed with growing degree‐days (GDD), photothermal units (PTU), and days (DAYS) after emergence. Time to emergence did not differ among cultivars within a trial. Among the seven trials, emergence occurred 7 to 15 days after planting; accumulated GDD ranged from 94 to 138, and averaged 106. Eighteen of the cultivars produced eight leaves, ‘James’ produced seven. Main‐stem phyllochron interval was 73 GDD for the HRS cvs. Butte and Waldron combined for analysis, and about 81 GDD for either “other” eight‐leaved HRS cultivars or for the durums combined for analysis, and for James. The R2value for any combined analysis was no less than 0.970**, significant at the 0.01 level. Soil water level and fertilizer N rate had no effect on main stem development rate, but did affect the maximum number of tillers produced per plant. The GDD accumulated per plant growth unit from emergence to anthesis (leaves plus four stages after expansion of the flag leaf) was the same as from emergence through full expansion of the flag leaf. Precision of estimating growth rates and stages with GDD was the same as with PTU, and both were superior to DAYS.
Seasonal Response of Uninoculated Alfalfa to N Fertilizer: Soil N, Nodule Turnover, and Symbiotic Effectiveness of Rhizobium meliloti1
Authors: Jenkins M. B. , Bottomley P. J. 
Published: July 2010

AbstractInformation exists on the effects of fertilizer N upon alfalfa (Medicago sativa L.) grown either in the greenhouse or during the establishment year in the case of field‐grown plants. Very little information has been obtained by using fertilizer N as a means to assess the performance of symbiotic N, fixation during postestablishment growing seasons. ‘Anchor’ alfalfa was established from uninoculated seed on three soils (two Xerollic Durargids and one Xerollic Camborthid) of limited depth (0.6 m) in central Oregon. After the year of establishment, alfalfa was harvested annually in three cuttings. Fertilizer N (NH4NO3,) was applied at rates of up to 230 kg N ha−1 In mid‐April and immediately after the first and second harvests. Most of the responses to added Noccurred in the third harvest. Significant increases were observed in dry weight in three of seven cuttings, in total reduced N in four of seven cuttings, and in the percentage of reduced N in the herbage in two of seven cuttings. At least one of these responses was enhanced with added N in five of the seven third harvest cuttings. Increases were not seen in the first harvest cuttings and only in two of seven second harvest cuttings. Mineral N levels in the soil profiles under the non‐fertilized plants at two of the sites declined during the growing season. This decline (35 and 40 kg N ha−1) approximated the difference between the total reduced N in the herbage of N‐fertilized and non‐fertilized plants in five of six cases (40 to 70 kg N ha−1). Symbiotic effectiveness tests of isolates of Rhizobium meliloti taken from nodules of 10‐week‐old plants during the establishment year showed that 20% of the isolates were ineffective, 16% were of intermediate effectiveness, and 64% were highly effective. In the 3rd year, although no ineffective nodule isolates were recovered, nodule numbers declined from 66 to 11 per plant between the first and third harvest and no isolates recovered from nodules at the third harvest were highly effective. The influence of nodule turnover, nodule occupants of suboptimum effectiveness, and the contribution of soil N on alfalfa production during postestablishment seasons requires more attention.
Bloom and Pod Set in Determinate and Indeterminate Soybeans Grown in China1
Authors: Gai Junyi , Palmer R. G. , Fehr W. R. 
Published: July 2010

AbstractPrecise description of soybean [Glycine max (L.) Merr.] blooming and pod set characteristics are necessary for proper utilization of these characteristics in crop improvement. Seven determinate and five indeterminate soybean land cultivars from the lower Yangtze and Hwai Valleys (31° to 35°N 115° to 122°E) were examined in Nanjing, China (32°N 118°48'E) to describe the blooming habit and estimate the percentages of bloom and pod set. The plants had main raceme and subraceme (including subbranch) subdivisions on the floral nodes at the top, and primary branch and secondary branch subdivisions on the branch nodes at the bottom. In both determinate and indeterminate cultivars, the most important sectors in producing flowers and pods were the main raceme and the primary branch subdivisions. With a similar maturity, the determinate type had fewer main racemes, more subracemes, more primary and secondary branches, and more flowers per main raceme at a corresponding node than did the indeterminate type. The peak blooming period of a plant was from the 4th to the 14th day after first flowering. For the two stem‐termination types, on each subdivision, the flowering order was basically from the lower flowers to the upper ones, with the subraceme beginning to flower about the time that the main raceme at the same node finished blooming. For both stem‐termination types, the percentage of pod set was negatively correlated with maturity date and number of flowers. The percentage of pod set was relatively high on the terminal raceme for the determinate type. Percentage pod set of subracemes tended to decrease from the lower nodes to the upper ones for both types, but, at corresponding nodes, the percentage pod set of the determinate type was higher than that of the indeterminate type.
Luxury Water Use by Bermudagrass Turf
Authors: Kneebone W. R. , Pepper I. L. 
Published: July 2010

AbstractIn an earlier study of the effectiveness of turf‐soil filters for tertiary treatment of sewage effluent, we irrigated with effluent at very high application rates, and noticed that water use increased with application rate. This study investigates luxury water use by bermudagrass, and the effect of high application rate on evapotranspiration (ET). The primary objective of this study was to measure the effects of three high irrigation levels (114, 243, and 364 mm 7 days−1) on ET from seeded certified bermudagrass (Cynodon dactylon L. Pers.) turf growing on three sand‐soil substrates (19:1, 18:2, and 16:4) mixed with Pima clay loam (fine‐silty, mixed, thermic Typic Torrifluvent). The data used were derived from a study of the effectiveness of bermudagrass turf growing in sand‐soil mixes irrigated with secondary treated sewage effluent. Percolation lysimeters were irrigated twice each week with effluent. Leachate was collected and measured each week. The difference between applied effluent and recovered leachate measured ET. The lysimeters were arranged in three complete blocks. In each block, the nine treatment combinations of sandsoil mixes and irrigation levels were assigned at random. As irrigation levels increased, ET levels increased. Mean values at the three rates averaged over sand‐soil mixes were 31,49, and 53 mm 7 days−1. Evapotranspiration levels were highest on substrates highest in soil, and values averaged over all rates were 36, 44, and 53 mm 7 days−1. Differences due to irrigation levels and to sand‐soil mixes were significant at the 0.001 level. Overall rates of irrigation were 254, 540, and 808% of Class A pan evaporation during the 1 year study period. Corresponding ET values were 68, 109, and 119% of Class A pan. Fluctuations in ET paralleled pan evaporation but the ratios of ET to pan were higher during periods of low pan evaporation in winter and spring. Calculations based on solar radiation showed that advective heat from nearby streets and bare ground was a component of the latent heat represented in ET levels measured.
Measurement of Viable Plant Roots with the Image Analyzing Computer1
Authors: Ottman M. J. , Timm H. 
Published: July 2010

AbstractInvestigation of the spatial arrangement of plant roots in soils is limited by the time required to remove the roots from the soil and measure the viable roots. A root measurement technique is reported which includes differentially staining viable root tissue and extraneous organic matter with trypan blue, photographing the roots, and presenting the photographic negatives to an Image Analyzing Computer, which can predict root length or area in seconds. The staining procedure did differentially stain the viable roots and organic matter since addition of dried organic matter did not increase the Image Analyzer estimation of length or surface area. The photographic process, however, contributed to lower and more variable Image Analyzer estimates of root surface area when comparing specimens presented as photograhic negatives or in bulk without photography. The Image Analyzer provides reliable estimates of surface areas for root and wire samples presented in bulk with a coefficient of variation of 3.3 and 1.2%, respectively. This technique is relatively rapid and can be used to measure plant root systems sampled by soil cores.