bluuebunny/crossref_metadata_2025_split huggingface dataset:
Remobilization of Pre‐Anthesis Assimilates to the Grain for Grain Only and Dual‐Purpose (Forage and Grain) Triticale
Authors: Royo Conxita , Voltas Jordi , Romagosa Ignacio 
Published: July 2010

AbstractIn Mediterranean environments, translocation of pre‐anthesis assimilates to the grain is an important source of photosynthates. In this work, the effect of forage removal at the beginning of jointing on the amount of dry matter (DM) accumulated before anthesis and remobilized during grain filling was studied in five spring and five winter triticale genotypes (×Triticosecale Wittmack). Field experiments were conducted in 1992 and 1993 in northeastern Spain. Two harvesting treatments were used: (i) grain production only and (ii) cutting the crop for forage at the beginning of jointing and harvesting the grain produced after regrowth. Pre‐anthesis storage of carbohydrates was very important to grain filling in triticale, both for grain and for dual‐purpose. Contribution of pre‐anthesis assimilates to grain yield in the uncut plots was 46% in spring triticale genotypes and 65% in winter genotypes, as the later‐maturity winter triticale genotypes were more affected by terminal abiotic stresses. Reductions in DM accumulated at anthesis after forage removal were more pronounced in winter genotypes (39%) than in spring genotypes (20%), where an earlier development allowed for a longer recovery period after cutting; DM reductions were similar to grain yield decreases. The effect of forage removal on translocation depended on the growth hbit of the genotype and environmental conditions. Most differences were associated with changes in crop phenology. In spring types, with early jointing, DM translocation and the contribution of pre‐anthesis assimilates to grain were not affected by forage removal, whereas both traits were drastically reduced in winter triticale. Most differences in 13C/12C carbon isotope discrimination (Δ) in grains were also phenology driven.
Switchgrass Seedling Development as Affected by Seed Size
Authors: Smart Alexander J. , Moser Lowell E. 
Published: July 2010

AbstractSeed size has been associated with early seedling vigor (i.e., germination rate, emergence rate, and growth) in grasses. This study was conducted to compare seedling development over a 60‐d period in the field as affected by heavy seed (HS) (0.19 to 0.21 g 100 seed−1) and light seed (LS) (0.13 to 0.16 g 100 seed−1) of ‘Blackwell’ and ‘Trailblazer’ switchgrass (Panicum virgatum L.). The experiment was conducted in 1995 and 1996 at Lincoln, NE, on a Kennebec silt loam (fine‐silty, mixed, superactive, mesic Cumulic Hapludolls). The experimental design was a randomized complete block with four replicates. Seed was separated into two sizes using a South Dakota seed blower. Seed was planted into rows at a rate of 100 pure live seed per meter of row. Plants were excavated and evaluated for shoot weight, leaf area, and root weight. Shoot and root systems were morphologically staged four times during the summer. Seed size differences in switchgrass appeared to produce only slight differences in morphological development of shoot and root systems, leaf area, shoot weight, and adventitious root weight from seedling emergence to 6 wk of growth. Adventitious roots formed more quickly on seedlings from heavier than lighter seed, but the advantage to seedling establishment was minimal even when soil moisture appeared to be lacking. By 8 to 10 wk after emergence, growth and development of LS seedlings were similar to HS seedlings. Once seedlings formed two or more adventitious roots, seed size no longer affected establishment and growth. Seed size in switchgrass appears to have a minimal long‐term effect on growth and development of seedlings.
Chicory Effects on Lamb Weight Gain and Rate of In Vitro Organic Matter and Fiber Disappearance
Authors: Turner Kenneth E. , Belesky David P. , Fedders James M. 
Published: July 2010

AbstractIn modern forage systems, there is increased emphasis on use of nontraditional forages to supply nutrients to livestock. Field and laboratory experiments were conducted to evaluate the utility and nutritive value of chicory (Cichorium intybus L.; CHIC) as a component of hill‐land pastures in Appalachia. In 1995, lamb (Ovis aries) gain was 56.1 kg ha−1 on orchardgrass (Dactylis glomerata L.; OG), while those grazing OG + CHIC lost 24.2 kg ha−1 during the 44‐d midsummer grazing period (P < 0.05). In 1996, while weight gains were not different (P > 0.10), total lamb production per hectare was 14% less on OG + CHIC (258 kg ha−1) than on OG only (300 kg ha−1) for the 79‐d grazing period. In 1997, total weight gained for the season was not different (P > 0.10); lambs grazed OG or OG + CHIC for 110 d and production was 362 and 351 kg ha−1, respectively. Laboratory mixtures of 40:60 or 60:40 OG:CHIC had higher (P < 0.05) in vitro organic matter disappearance (IVOMD), compared with 100% OG or 100% CHIC. There was a synergism in mixtures with orchardgrass that increased IVOMD relative to pure samples. Another laboratory experiment suggested that as total N increased in chicory herbage, rate of in vitro neutral‐detergent fiber (NDF) disappearance decreased. More information on the influence of soil type and management on chicory growth in pure stands and mixtures with other plant species is needed to optimize productivity of systems that include chicory.
Effects of Mechanical Conditioning on Wilting of Alfalfa and Italian Ryegrass for Ensiling
Authors: Borreani Giorgio , Tabacco Ernesto , Ciotti Angelo 
Published: July 2010

AbstractConditioning may greatly increase the drying rate of cut forage during the initial stages of drying. Such results may be particularly useful for silage systems (as opposed to haymaking). This study was conducted to determine the drying rate and losses in six field wilting trials on pure stands of alfalfa (Medicago sativa L.) and Italian rye‐grass (Lolium multiflorum Lam.) when treated with different types of mower‐conditioners (rubber rolls; plastic or steel flails). Drying was measured by calculating the water loss rate from two subsequent hourly weights of swath portions placed on trays. Dry matter (DM) losses were estimated on 1.2‐m lengths of swaths immediately after cutting. The steel flail conditioner provided faster drying than the other conditioning types for both crops. The effect of the rubber roll conditioner was limited due to the swath structure, especially with forage surface densities higher than 0.7 kg DM m−2. Tedding positively interacted with the conditioning treatment to increase the drying rate, especially when forage was conditioned with the rubber roll machine. Shatter losses from alfalfa were higher for the flail conditioner, ranging from 3.6 to 10.2%, and with greater loss of crude protein. The DM losses were always lower than 2.5% for Italian ryegrass. The most severe conditioning (steel flails) followed by tedding is appropriate for grass, as it significantly reduces the wilting time without affecting DM loss. However, a less severe conditioning (rubber rolls) without tedding is more appropriate for wilting alfalfa, to avoid excessive leaf and protein loss.
Demography of Wild Oat in Barley Crops: Effect of Crop, Sowing Rate, and Herbicide Treatment
Authors: Scursoni Julio , Benech‐Arnold Roberto , Hirchoren Hernán 
Published: July 2010

AbstractWild oat (Avena fatua L.) is a major weed in barley (Hordeum vulgare L.) in Argentina. During 1993, 1994, 1995, and 1996, demographic studies of wild oat in barley crops were conducted to assess the effect of herbicide treatment, crop, and sowing rate on the demographic processes of seedling establishment, survival rate, reproductive performance, preharvest seed dispersal rate, and fate of seed in the soil during the fallow period. The herbicide was diclofop‐methyl: methyl 2‐[4‐(2,4‐dichlorophenoxy)phenoxy]propanoic acid. Increasing barley sowing rate from 160 plants m−2 to 280 plants m−2 effectively reduced the amount of wild oat seeds that entered the soil seed bank by 50% through lowering fecundity. Diclofop‐methyl reduced the number of seeds that entered the soil seed bank sevenfold (1050 vs. 140 seeds m−2) through a reduction in both seedling survivor rate and reproductive output. In addition, the diclofop‐methyl treatment delayed the onset of seed maturity and reduced the dormancy level of the seeds produced by the surviving plants. Half the number of wild oat seeds entered the seed bank in a barley than in a wheat (Triticum aestivum L.) crop. This was through a lower wild oat reproductive output and a higher rate of seed dispersal related to the later harvest time of wheat relative to barley. These data indicate that integrated control of wild oat should include herbicide treatment, crop selection, and sowing rate.
Some Factors Affecting Soil Sampling
Authors: Welch C. D. , Fitts J. W. 
Published: July 2010

AbstractA study was conducted to obtain information as to the effects of tools used and depth of sampling on results of soil analysis. All samples were analyzed for pH, phosphorus, potassium, and organic. matter. Some of the principle findings were as follows:There was no significant difference between results of analysis for samples collected with a tube, spade, or trowel. The pH and organic matter values were significantly lower for samples collected with the auger as compared to the other tools. There was no significant difference between analyses for duplicate samples collected in a bucket.There was a significant decrease in the pH of soil with depth from the 0 to 3 to the 3 to 6 to the 6 to 9 inch layers of soil in fields seeded to sod crops. The difference was not significant for comparable fields used for row crops. The amount of phosphorus, potassium and organic matter decreased with depth in fields used for sod crops as well as those in row crops.The soil analyses results for pH, phosphorus, and potassium and organic matter were significantly lower for samples composited from 0 to 6‐inch cores as compared to 0 to 3‐inch cores for fields in sod crops in the Coastal Plains as well as the Piedmont and Mountains. Samples from 0 to 6‐inch cores in fields used for row crops showed significantly lower results than those from 0 to 3‐inches for pH, potassium, and organic matter in the Piedmont and Mountains but only for organic matter in the Coastal Plains.
Factors Affecting Mass Movement of Four Soils in the Western Cascades of Oregon
Authors: Paeth R. C. , Harward M. E. , Knox E. G. , Dyrness C. T. 
Published: July 2010

AbstractFour soils derived from tuffaceous rock in the Western Cascades were studied to determine relationships to slope stability. Two of the soils derived from greenish tuff and breccia were prone to slope failure. The other two soils were derived from yellowish and reddish tuff and breccia and were more stable.Soils prone to slope failure were characterized by high amounts of smectite clay, absence of kaolin, and moderate amounts of free iron oxide. The more stable soils contained kaolin, more chlorite and chloritic intergrades, less smectite, and higher amounts of free iron oxide.Pseudomorphs of clay were the major component of silt and sand fractions. The pseudomorphs seem to function mechanically as primary soil particles but the clay contributes to cation exchange and moisture retention. The ratio of clay calculated from 15‐bar moisture retention to measured clay was highest for the most stable soils.Stability of these soils did not appear to correlate with clay content, content of amorphous clay, or proportions of exchangeable cations. Color of the soils and of their source rocks was correlated with clay mineralogy, content of iron oxides, and landscape stability.
Artificial Weathering of Oxidized Biotite: I. Potassium Removal by Sodium Chloride and Sodium Tetraphenylboron Solutions
Authors: Gilkes R. J. , Young R. C. , Quirk J. P. 
Published: July 2010

AbstractThe rate of release of interlayer potassium from biotite to NaCl and NaCl/sodium tetraphenylboron solutions is determined by the oxidation state of octahedral iron. Octahedral cation vacancies are generated when octahedral iron is oxidized resulting in a change of orientation of hydroxyl from perpendicular to the mica layer to parallel. This in turn produces a more stable environment for interlayer potassium. Infrared absorption measurements show that the abundance of inclined hydroxyl bears a negative linear relation with the amount of potassium removed by leaching.
Layer Charge Decrease by Tetrahedral Cation Removal and Silicon Incorporation during Natural Weathering of Phlogopite to Saponite
Authors: Sridhar K. , Jackson M. L. 
Published: July 2010

AbstractA substantial layer charge decrease, from 210 to 140 meq/100 g, occurred during the natural weathering of phlogopite through vermiculite to saponite in Kansas. A comparison of the Fe2+ content and layer charge of the coarse fraction (72% phlogopite) and the fine fraction (71% saponite) indicated that iron oxidation cannot account for the layer charge decrease during the transformation. Control studies on iron oxidation during vermiculitization of biotites and lepidomelane did not correlate with layer charge decrease.Elemental analysis of the coarse and fine fractions revealed gains and losses of cations during the weathering of the mica flakes to fine particles. The Si4+ and Mg2+ increased by 2.66 and 0.84%, respectively, while Al3+ and total Fe3+ plus Fe2+ decreased by 0.34 and 1.21%, respectively, in the two fine fractions compared to the macroflakes. The elemental analyses also revealed the unique nature of this phlogopite which contained fewer moles of Al3+ than K+; the presence of some isomorphously substituted tetrahedral Fe3+ contributed 17% of the total negative layer charge. Loss of layer charge was found to be a result of the loss of isomorphically substituted tetrahedral Al3+ and Fe3+ by authigenic recrystallization with an increase in tetrahedral Si4+. In control studies, removal of isomorphously substituted tetrahedral Al3+ from Ontario phlogopitic vermiculite and Transvaal micaceous vermiculite by citrate chelation also resulted in an equivalent layer charge decrease.
Surface Properties and Forces Holding Water in Allophane Soils
Authors: Rousseaux J. M. , Warkentin B. P. 
Published: July 2010

AbstractSurface area and micropore size distribution were calculated from measurements of adsorption of water vapor at 25°C on a group of allophane soils from the West Indies and from Japan. The changes in pore‐size distribution on drying were measured. Specific surface area varied between 100 and 400 m2/g, and the dominant pore radius was about 7Å. Cation‐exchange capacity measured with different cations also varied with pore‐size distribution.Water retention properties were interpreted in relation to the proportion of micropores, and the chemical composition of allophane component of the soils. Pore geometry and the chemical nature of surfaces determined water retention of these allophane soils. This is in contrast to soils containing crystalline clays where the magnitude of the surface area primarily determines water retention.
Decomposition of Fungal Mycelia and Humic‐type Polymers Containing Carbon‐14 from Ring and Side‐chain Labeled 2,4‐D and Chlorpropham
Authors: Wolf D. C. , Martin J. P. 
Published: July 2010

AbstractHendersonula toruloidea and Stachybotrys atra were grown on a liquid peptone‐dextrose medium containing 10 ppm ring‐ or side‐chain 2‐14C labeled 2,4‐D (2,4‐dichlorophenoxyacetic acid), or chlorpropham (isopropyl m‐chlorocarbanilate). Approximately 12% of the activity from ring‐14C 2,4‐D was present in the humic polymers produced by the fungi, and 4 to 16% was recovered in the mycelia. The mycelia of both fungi contained approximately 35% of the activity from either ring‐ or 2‐14C chlorpropham and the humic polymers from 3 to 24% of the added activity. The decomposition percentages of the 14C portions of H. toruloidea and S. atra from ring‐14C 2,4‐D were 15 and 35% and 13 and 35%, respectively, for the mycelia and humic polymers. The label from 2‐14C 2,4‐D was released as 14CO2 at rates greater than twice that for the ring‐14C 2,4‐D. Similarly, the carbon from ring‐14C chlorpropham associated with H. toruloidea and S. atra mycelia and humic polymers was more resistant to decomposition than that from 2‐14C chlorpropham. The results indicate that 2,4‐D and chlorpropham or more probably their partial degradation products may be incorporated into microbial cells or products, some of which are relatively resistant to microbial degradation.
Increased Selectivity of Naturally Weathered Biotites for Potassium
Authors: Tarzi J. G. , Protz R. 
Published: July 2010

AbstractMica particles from six residual soils were separated from different horizons and separated into three weathering classes. Potassium contents in the centers and in the edges of mica particles were determined by using electron probe microanalysis techniques. The results showed that biotites tended to regain K after an initial loss becoming more resistant to weathering. The regained K concentrated at the edges of weathered biotite particles.
Predicting Hysteretic Effects in Evaporation from Bare Soil
Authors: Staple W. J. 
Published: July 2010

AbstractEvaporation losses from initially dry soil moistened by simulated rainfall were computed on the assumption that the soil water pressure on drying was uniquely predicted by either the wetting or drying boundary curve of the hysteresis function. In other words, hysteretic effects involving detailed drying scanning curves were neglected. The results showed that computed evaporation losses based on the two unique curves were nearly equal, and that these losses were only about one‐half of those established previously both by evaporation measurement and by computations based on the appropriate scanning curves. It is concluded that hysteretic effects cannot be neglected or estimated by a simple averaging procedure in predicting water conservation in summerfallow under semiarid conditions.
Manganese Adsorption and Desorption in Calcareous Lebanese Soils
Authors: Curtin D. , Ryan J. , Chaudhary R. A. 
Published: July 2010

AbstractAdsorption data for 20 calcareous soils, obtained by equilibrating soil samples with 9 different concentrations of Manganese, were evaluated using Langmuir adsorption equations. When the data were plotted according to the conventional Langmuir equation, the isotherms were curvilinear at low Mn concentrations and linear at higher concentrations. Where the data were fitted to a “competitive” Langmuir equation, the isotherms were again found to be nonlinear, indicating that more than one population of adsorption sites existed in these soils. Manganese adsorption maxima, estimated from the linear parts of the conventional Langmuir isotherms, were highly correlated with the cation exchange capacity (CEC) of the soils but not with values of organic matter content, calcium carbonate equivalent or free iron. A desorption study confirmed that part of the adsorbed Mn was held quite tightly.
Effect of Exchangeable Sodium on Soil Electrical Conductivity‐Salinity Calibrations
Authors: Bottraud Jean‐Christophe , Rhoades J. D. 
Published: July 2010

AbstractThis study was undertaken to ascertain if soil sodicity significantly influences soil electrical conductivity (σa) — salinity calibrations. Laboratory columns of Fallbrook (Typic Haploxeralfs) and Yolo (Typic Xerorthents) soils were adjusted to various levels of salinity and sodicity by leaching them with solutions varying in electrical conductivity (σw) and sodium adsorption ratio (SAR); then σa was measured using four‐electrode techniques. Calibrations obtained between σw and σa over the σw range 2 to 20 were compared at different levels of SAR ranging between 0 to 80 or 400. The calibrations between σw and σa were found to be insignificantly influenced by variations in SAR over the range studied. Normal variations in the exchangeable Na contents of typical saline, arid‐land soils should not cause any serious misdiagnosis of soil salinity based on measurements of bulk σa and use of σw‐σa calibrations.
Erosion‐sedimentation in a Closed Drainage Basin in Northwest Indiana
Authors: Norton L. Darrell 
Published: July 2010

AbstractA closed drainage basin representing a catchment for eroded sediment was studied to determine the amount of erosion since cultivation began, and to determine the spatial relationships of the erosion‐sedimentation process that had occurred during 145 yr of agriculture. Post‐settlement alluvium (PSA) thickness was easily determined in the field as light‐colored mineral soil overlying highly decomposed (sapric) organics in the depression. A detailed field study of the PSA, other geologic sediments, loess, and the original till surface in the watershed demonstrated a reduction in the original relief. The mass of PSA served as a measure of the amount of soil eroded from peripheral slopes. The long term average soil loss was > 26 Mg ha−1 yr−1, which represented an average removal of over 24 cm of soil from the entire watershed in 145 yr. The maximum slope in the watershed was 5%. The loess thickness on the surrounding slopes was used as an indication of the spatial variation of erosion processes. Summit positions and convex slope shapes having divergent runoff had the most erosion while concave shapes with convergent runoff exhibited more sedimentation. These results are essentially opposite to those predicted by the Universal Soil Loss Equation (USLE). Accurate prediction models in the future should consider the dynamic aspects of erosion‐sedimentation on landscapes.
Estimating the Variability of Unsaturated Soil Hydraulic Conductivity Using Simple Equations
Authors: Wagenet R. J. , Addiscott T. M. 
Published: July 2010

AbstractDescription of transient water flow requires knowledge, or estimation, of the relationship between the unsaturated soil hydraulic conductivity, K, and volumetric water content. A variety of studies have related K(θ) to the saturated conductivity Ko by equations involving the volumetric water content, θ, and its value at saturation, θo. The relationship is expressed here in terms of either the difference between θ and θo or the ratio of θ to θo, so that K(θ) is obtained by multiplying Ko by exp[β(θ − θo)] or by [θ/θo]2b + 3 respectively, with β and b being constants for any one sampling point. The quantity β in the equation involving (θ − θo) can be obtained from field data by four different mathematical methods. When this equation was used to compute distributions of lnK(θ) from measured distributions of lnKo and lnβ, the first four moments of the resulting distributions of lnK(θ) all differed considerably according to the mathematical method used, although Ko and β were derived in each case from the same set of field data. When both equations were used to estimate lnK(θ), using the same distributions of lnKo and appropriate distributions of lnβ or lnb, there were large differences between them in the moments of the resulting distributions. The estimate of lnK(θ) from the equation using θ/θo had much the larger variance, mainly because the variance of lnb was about three times that of lnβ.