bluuebunny/crossref_metadata_2025_split huggingface dataset:
Forage Production and N Contents, and Soil Changes During 25 Years of Continuous White Clover‐Pensacola Bahiagrass Growth on a Florida Spodosol1
Authors: Blue W. G. 
Published: July 2010

AbstractThis experiment was established in 1952 with white clover (Trifolium repens L.) and Pensacola bahiagrass (Paspalum notatum Flugge) on virgin Myakka fine sand (sandy, siliceous, hyperthermic Aeric Haplaquod) at the Beef Research Unit near Gainesville, Fla., to evaluate the effects of lime and micronutrients on white clover‐grass production and N fixation, the persistence of this combination of plants under good management, and their effects on the soil. Initial treatments consisted of one without lime and nine with calcitic lime at 5 metric tons/ha incorporated into the soil to a depth of 15 cm. Two of the limed treatments were without micronutrients; the remaining seven included a variety of B sources and experimental frit materials. The experimental area was seeded to Pensacola bahiagrass in July and overseeded with white clover in October. Nitrogen, P, and K were uniformly applied to all plot areas through 1957; subsequently only P and K were applied. Micronutrients were reapplied periodically to plots which received them initially and lime was surface applied as needed. All forage was removed from the experimental area.Oven‐dry forage was increased by lime from 3,870 to 9,660 kg/ha per year. The percentage increase in forage N was similar even though N was applied to all treatments during the first 5 years. Forage yield and N content were increased additionally by micronutrient treatments.Soil organic matter was approximately twice as high in 1977 as in 1953. Total soil N increased from 1,180 to 2,560 kg/ha where lime was applied. Where lime was omitted and white clover did not grow, soil N still increased by approximately 800 kg/ha. Exchangeable A1 was eliminated by liming, but was reduced only slightly by phosphate additions. Cation exchange capacity determined by NH4,OAc (pH 7.0) was 2 meq/100 g for each percent of organic matter in soils collected in 1953. In 1977, it was 1.36 and 1.68 meq/100 g for each percent organic matter in unlimed and limed soils, respectively. Very little K accumulated even in unlimed soil where removal by plants was small.
Cotton Cultivar Response to Propazine and Atrazine1
Authors: Abernathy J. R. , Keeling J. W. , Ray L. L. 
Published: July 2010

AbstractForty‐eight cotton (Gossypium hirsutum L.) cultivars were evaluated in field studies over a 2‐year period to determine tolerance to phytotoxic soil residue levels of propazine [2‐chloro‐4,6‐bis (isopropylamine)‐s‐triazine] and atrazine [2‐chloro‐4‐(ethylamino)‐6‐isopropylami)‐s‐triazine] present after use in rotational grain crops. After planting, preemergence, broadcast applications of atrazine and propazine at 0.56 kg/ha were applied to an Amarillo sandy clay loam soil (a member of the fine‐loamy, mixed thermic family of Aridic Paleustalfs). Cotton cultivars injury ratings were obtained 6 to 8 weeks after planting, In another study, propazine rates of 0.56 and 1.12 kg/ha were applied preemergence to test yield differences between tolerant and susceptible cotton cultivars.Injury ranged from 8 to 80%, and 3 to 53% among varieties subjected to atrazine and propazine, respectively. In the propazine yield test, where a tolerant cotton cultivar (‘Paymaster 303’), was compared to a sensitive cotton cultivar (‘Paymaster lllA’), the tolerant cultivar produced 210 kg/ha more than the sensitive cultivar. In the absence of the herbicide, there were no differences in the yield of the two cultivars. This research indicates that choice of cultivar can significantly limit injury to cotton and the likelihood of reduced yields.
Root Elongation and Plant Growth in a Basal Till Compact Soil Treated with 3,5‐Diiodo‐4‐Hydroxybenzoic Acid and Gibberellic Acid1
Authors: Saini G. R. 
Published: July 2010

AbstractSoils developed on basal till have very dense compact subsoil, which may extend many meters below the topsoil. To improve their moisture storage and other physical conditions, deep subsoiling is usually practiced. In most instances, the beneficial effect of subsoiling is short‐lived and the operation has to be repeated every few years. The spiralling costs of fossil fuel may make repeated subsoiling operations prohibitive. Therefore, as an alternative management technique, the use of small quantities of 3,5‐diiodo‐4‐hydroxybenzoic acid (DIHB) and gibberellic acid (GA3) in the top‐soil to promote root elongation and enhance crop yields was compared with loosening the sub‐soil and also with incorporating limestone in the subsoil after loosening.A growth chamber study showed that roots of alfalfa (Medicago saliva L.) ‘Saranac’ penetrated the dense subsoil, bulk density 1.9 g cm−3, of a poorly drained basal till soil (Fera Luvic Gleysol) when 1,700 g topsoil was treated with 200 ml of 10−2M DIHB or with GA3. However, the roots in loosened subsoil and to which limestone at 11.2 metric ton/ha had been added and incorporated went deeper. The treatments in order of their superiority were: loosened sub‐soil plus limestone > loosened sub‐soil > top‐soil treated with DIHB > topsoil treated with GA3 > control. Mean root lengths of the alfalfa plants in the various treatments were 66.3, 61.0, 51.2, 49.0, and 33.2 cm, respectively. Corresponding mean dry weight yields of shoots in each treatment were 7.05, 6.08, 5.59, 4.65, and 3.08 g.Should the spiraling costs of energy make periodic subsoiling operations uneconomical, the use of small quantities of DIHB in the topsoil may provide an alternate management technique for agricultural lands with dense subsoil.
Foliage Injury, Nutrient Intake, and Yield of Soybeans as Influenced by Foliar Fertilization1
Authors: Parker M. B. , Boswell F. C. 
Published: July 2010

AbstractYield response to foliar fertilization (N, P, K, S, solution) of soybeans [Glycine max (L.) Merr.] in Iowa has stimulated interest in the use of the same or similar materials in other soybean production areas. Inconsistent yield increases were obtained in Iowa, and it is unknown whether foliar fertilization is feasible where environmental conditions, type of soybeans, and other factors are different from those in Iowa. Field experiments were conducted on a Tifton sl (fine‐loamy, siliceous, thermic, Plinthic Paleudult) and on a Norfolk sl (siliceous, thermic, Typic Paleudult) in the Coastal Plain region of Georgia. Urea K‐polyphosphate mix (urea, K‐polyphosphate, and K2SO4) and NH4‐polyphosphate mix (urea, NH4‐polyphosphate, KCl, and K2SO4) treatments were foliar sprayed on soybeans during the seed filling period. All spray treatments damaged the foliage and suppressed yields with the greatest damage to foliage occurring with repeated application of foliar fertilizer. Three sprayings of a mixture containing 28, 2.9, 9.5, and 1.7 kg N, P, K, and S/ha resulted in an average (two sites) yield decrease of 10.9% for the K‐polyphosphate mix and 17.6% for the NH4‐polyphosphate mix. Weight of pods, whole plants, or seeds, and seed quality were not affected by spray treatments. Absorption of applied nutrients into leaf tissue and translocation to reproductive tissue were detected only in a few instances. Increased N levels were detected only in seeds, and P levels increased only in leaves, while K levels were not changed. Under the conditions of this study, foliar N, P, K, and S fertilization of soybeans does not appear practicable for increasing yields.
Soybean Nodulation as Influenced by Seedling Vigor1
Authors: Smith R. S. , Ellis M. A. 
Published: July 2010

abstractNodulation in soybeans [Glycine max (L.) Merr.] is influenced by environmental, rhizobial, and host symbiont factors. This investigation was conducted to determine the effects of seedling vigor on early soybean nodulation. Seed quality of three soybean cultivars was adjusted using the accelerated aging technique in order to provide seed lots with a high degree of variation in seedling vigor. Seedling vigor was defined as the number of days from planting to emergence. Aged seeds planted in both a sandbench and the field were uniformly inoculated in the furrow with a Rhizobium japonicum liquid inoculum. Days to seedling emergence was negatively correlated with plant top weight, number of tap root nodules, total number of nodules, and nodule dry weight per plant. Significant decreases in the number of tap root nodules and total number of nodules were observed in a sandbench trial between each of the three earliest emerging treatments (4, 5, and 6 days after planting). In all cases, the first plants to emerge had significantly more tap root nodules than the last plants to emerge. Significance in number of nodules/plant and nodule weight/plant between these two treatments was observed in six of the eight instances.The results suggest that soybean nodulation may be influenced by seedling vigor and that seedlings with uniform vigor should be utilized when conducting nodulation evaluations.
Yield Variability in Proso Millet Due to Plot Size1
Authors: Nelson L. A. 
Published: July 2010

AbstractField experimentation with a new crop requires determination of optimum plot size to minimize variability and obtain an unbiased yield estimate. Plot size influences the planting and harvesting equipment, and the amount of land needed to conduct a research trial. Variability in proso millet (Panicum miliaceum L.) yields due to number of rows planted and harvested in field experimentation was compared using four cultivars for 4 years on Typic argiustoll soils. Plot size combinations selected were: plant one row, harvest one row; plant two rows, harvest two rows; plant three rows, harvest one row; plant four rows, harvest two rows; plant six rows, harvest two rows; plant six rows harvest four rows.The results of this experiment indicated: 1) three harvest rows were optimum to minimize variance based on the best quadratic fit, 2) the number of rows harvested had a greater effect on variance than the number of rows planted, 3) plots having one border row of their own genotype on each side produced higher yields than plots with either zero or two border rows on each side, and 4) adding border rows of the same cultivar on each side of the harvested row did not decrease variance. The optimum plot size combinations for testing proso cultivars in field experiments appears to be planting five rows and harvesting the center three rows.
Use of Computer Graphics in the Development and Evaluation of Response Surfaces1
Authors: Schoney Richard A. , Bay Ted F. , Moncrief John F. 
Published: July 2010

AbstractVarious statistical measures and prior knowledge of functional relationships have traditionally been the main guides in developing crop response equations. Computer graphics provide a valuable addition to this developmental process. Through graphics, the distribution, physical response, and interaction characteristics of a large volume of data can be visually analyzed. In addition, the physical characteristics of alternative functional forms can more easily be compared to the original data. This paper demonstrates the use of computer graphics in the analysis of field data and the comparison of three alternative functional forms developed from the data.
Corn Physiology in Short Season and Low Temperature Environments1
Authors: Lee S. S. , Estes G. O. 
Published: July 2010

AbstractNorthern areas seeking to expand corn (Zea mays L.) production and thereby reduce feed costs for livestock require early plantings of short season hybrids with good seedling vigor. The association between physiological behavior of corn to low temperature and its field performance could be important in selecting hybrids adaptable to such areas.Twenty corn hybrids of commercial importance in New Hampshire which varied in maturity were planted 21 April and 19 May at the Univ. of New Hampshire Agronomy Research Station, Madhury, NH; nine selections from the above were also grown at three other locations in the state with widely differing growing conditions. The effect of controlled temperature on chloroplast structure and photosynthetic activity was also determined using the earliest and one of the latest maturing hybrids which differed in early development under field conditions.Low temperatures following the early planting of 21 April did not adversely affect stand density of hybrids; seedling growth of the two earliest maturing hybrids was superior to all other selections. At the normal planting date of 19 May seedling growth of the 20 hybrids was negatively correlated with their maturity rank; seedling growth was greatest in the earliest hybrids.Yield of total dry matter (TDM) at maturity was not related to seedling growth. In field studies in the southern and middle part of New Hampshire with a growing degree days (GDD) range of 1,100 to 1,300, TDM yields of the earliest corn hybrids were lower than yields of the later maturing corn. At the northern locations, with GDD < 1,100, yield of TDM was not significantly different among hybrids although % DM was higher in early maturing corn. A greater decline in photosynthesis and altered chloroplast ultrastructure in the leaves of a late‐maturing corn following exposure to controlled day/night temperatures of 15/10 C in the greenhouse was observed; no such changes occurred at 15/10 C either in the earliest hybrid, which had shown superior seedling performance under field conditions, or in either hybrid when grown at 10/15 C.
Deleterious Effects on Yield of Drilling Fertilizer into Established Alfalfa Stands1
Authors: Leyshon A. J. 
Published: July 2010

AbstractDrilling fertilizer into an established forage crop has been suggested as a means of increasing fertilizer availability. Experiments were conducted at Swift Current, Saskatchewan on an orthic Brown chernozem (aridic haploboroll) to investigate the effects of fertilizer rate and placement depth on the yield of an established dryland alfalfa (Medicago ✕ vuriu Martyn) stand. In one experiment phosphorus fertilizer at rates of up to 64 kg P/ha was drilled‐in to depths of 0, 5, and 10 cm and in a second experiment, N fertilizer at rates of up to 200 kg N/ha was drilled‐in to the same depths. Fertilizer rate did not affect yields in either experiment and there were no interactions between depth of placement and fertilizer rate. However, in both experiments, increasing the depth of placement decreased yields between 12 and 20% in the first year and in both experiments the yield decreases persisted for 2 or more years. In a third experiment the soil 30 cm from the row of an old established stand of alfalfa was disturbed at four depths (0, 2.5, 5 and 10 cm) with a tractor‐drawn spike to simulate a fertilizer drill. A 20% decrease in yield was observed when the soil was disturbed below 2.5 cm. It is suggested that the reduced yields were a result of mechanical damage to roots and that the persistence of the effect was due to an inability of the root to regrow in the dry topsoil common to southwest Saskatchewan. It is recommended that for established alfalfa stands all fertilizer be surface applied.
Drought Response of Sorghum Hybrids under a Sprinkler Irrigation Gradient System1
Authors: O'Neill M. K. , Hofmann W. , Dobrenz A. K. , Marcarian V. 
Published: July 2010

AbstractReliable techniques for identification of drought‐resistant germplasm are essential if new lines and hybrids are to be developed for arid and semiarid areas of the world. This experiment was designed to evaluate the irrigation gradient system as a mechanism for evaluating drought tolerance in sorghum [Sorghum bicolor (L.) Moencb.] in the field. Fifty sorghum hybrids which were developed with A‐lines ‘CK‐60’ and ‘Redlan’ were planted perpendicular to the mainline of the sprinkler irrigation gradient system at Yuma, Ariz. in 1979 and 1980. The soil was a superstition sand (sandy, mixed, hyperthermic Typic Calciorthid) with an average available soil moisture of 3.6 % . Characteristics including panicle rank, anthesis date, plant height, panicle and peduncle length, crown diameter, and plant weight were measured on plants of each hybrid grown in the high and low water areas of the gradient system. The distance from the line source to the last grain‐producing panicle in the low water area of the gradient was also measured on each hybrid. Hybrids developed with CK‐60 were able to produce seed‐producing panicles in drier areas of the gradient compared to hybrids developed with Redlan. The average distance from the sprinkler Line source was 14.4 m for CK‐60 hybrids and 11.3 m for Redlan hybrids over both years. Days to anthesis, panicle and peduncle length of plants in the stressed area of the gradient may be potential indicators of drought resistance. The irrigation gradient system is a useful tool for evaluating drought resistance and the selection of parental lines over a wide range of available soil moisture conditions.
Weed Control in a Winter Wheat – Corn – Ecofarming Rotation1
Authors: Vorst P. B. Vander , Wicks G. A. , Burnside O. C. 
Published: July 2010

AbstractAdequate information is not available regarding the influence of row spacing, seeding rate of winter wheat (Triticum aestivum L.), and time of herbicide application on weed control following wheat harvest and in the succeeding corn (Zea Mays L.) crop. Field experiments, conducted during 1977 through 1980 on a Holdrege silt loam (fine‐silty, mixed, mesic Typic Argiustoll) at North Platte, Nebr. determined that narrow‐row spacing (17 vs. 35 cm) and seeding rates of 67 or 100 kg/ha vs. 33 kg/ha of winter wheat significantly improved weed control in a wheat – Corn – fallow rotation. Wheat grain yield did not differ between row spacings. Wheat yielded 15% more grain when seeded at 67 or 100 kg/ha than at 33 kg/ha in 1978. Weed yield and grass weed panicle production in wheat stuhhle increased as atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] + paraquat (1,1'‐dimethyl‐4,4'‐bipyridinium ion) application was delayed from 5 to 25, 45, or 260 days after harvest, but atrazine persistence was not sufficient to maintain better weed control when planted to corn the following year. Atrazine applied 260 days after wheat harvest provided the best weed control in the following corn crop. However, corn yield was reduced 22% in 1978, because weed growth between wheat harvest and herbicide spraying used soil water needed for the corn. Narrow‐row spacing and high seeding rate of wheat the year prior to corn reduced weed populations during the fallow period the year following corn. Reduction of weed seed production is essential during the entire rotational sequence in order to prevent the buildup of weed populations.
Effect of Sulfur Fertilization on Three Annual Range Species I. Laughlin Soil Experiment1
Authors: Shock Clinton C. , Jones Milton B. , Williams William A. , Center D. Michael 
Published: July 2010

AbstractThe fate of a single application of sodium sulfate and its effect on three range species grown alone and in pairs in free‐draining lysimeters containing Laughlin loam soil (fine‐loamy, mixed, mesic Ultic Haploxerolls) was monitored during two growing seasons. Plant growth responses to added S were small because the soil released considerable S during the course of the experiment, equivalent to more than half of the S application. However, the growth of subclover (Trifolium subterraneum L.) and its mixtures with fllaree [Erodium botrys (Cav.) Bertol.] and soft chess (Bromus mollis L.) was increased by S fertilization (P = 0.06). The botanical composition shifted towards subclover with added S. On the lysimeters where S was applied, subclover and filaree obtained more of their S from the applied fertilizer (55 and 55%) than did soft chess (44%). Total plant recovery of fertilizer sulfur in the 1st year was greater in pure stands of subclover (20%) than for soft chess (11 %) and filaree (7%). Total sulfur uptake was greatest on S fertilized lysimeters of subclover or sublover plus filaree. Leachate losses of S in the 1st year were positively related to the amount of S applied and volume of leachate and negatively related to S uptake by the plants. In the 2nd year leachate losses of S were positively related to the calculated S status of the soil at the end of the 1st year and negatively to plant S uptake. A greater leachate volume was lost from lysimeters containing filaree than containing soft chess or subterranean clover, and mixtures were intermediate. Leachate volume was not related to dry matter production. Sulfur application did not affect N uptake by the nonlegumes, but subclover N2 fixation was increased by 60% during the 1st year. The percentage of subclover N coming from N2 fixation was enhanced by the presence of nonlegumes. Estimates of recovery of fertilizer S were significantly less by calculations based on 35S and than on total S differences suggesting that the labile 35S is diluted in the soil solution by the release of non‐labeled S from decomposition of organic matter.
Nutritive Value of Seven Tropical Weed Species During the Dry Season1
Authors: Nuwanyakpa M. Y. , Bolsen K. K. , Posler G. L. , Diaz M. Q. , Rivera F. R. 
Published: July 2010

AbstractProliferatiion of weeds is a major constraint in pasture management, especially in the tropics, where fertilizers are rarely used and where poor grazing management is common. Nonetheless, grassland weed control should not be initiated indiscriminately without an evaluation of the palatability and nutritive value of the species present. One objective of a grazing trial conducted at Pichilingue, Ecuador, was to compare the palatability, in vitro dry matter digestibility, crude protein (CP) content, cell wall components, mineral and nitrate contents of seven weed species and four cultivated forages during the dry season. The weed species were Alternanthera gullensis (Mart.) Griseb (chaff flower), Amaranthus spinosus L. (spiny amaranth), Digitaria sanguinalis (L.) Scop. (large crabgrass), Eleusine indica (L.) Gaerth. (goosegrass), Momordica charanria L. (balsam apple), Sida acuta Burm. f. (southern sida), and Sida rhombifolia L. (arrowleaf sida).Weeds were more digestible than cultivated forages, higher in CP and acid‐detergent lignin, and lower in neutral‐detergent fiber, acid‐detergent fiber, and silica. The Ca:P ratios in cultivated forages were close to the recommended 1:1 to 2:1 ratio. The only weed with a favorable Ca:P ratio was D. sanguinalis. The remaining weeds had Ca:P ratios of 3 to 7:1. During the dry season cattle were reluctant to graze the increasingly fibrous and protein‐deficient cultivated forages, so they consumed A. gullensis and A. spinosus, despite the very spiny texture of the latter. With the exception of D. sanguinalis for which palatability observations were not possible, cattle did not consume the other weeds. There were no symptoms of mineral imbalance or nitrate toxicity in cattle from grazing weeds. The practical implication of this study is that some weed species may be useful as feeds for grazing livestock during periods of limited feed supply, and should not be removed indiscriminately. Based on this study, A. gullensis and A. spinosus should not be removed from pastures during the dry season.