bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects and Treatments of Petroleum Spills on Bermudagrass Turf1
Authors: Johns D. , Beard J. B. 
Published: July 2010

AbstractDue to the frequency of petroleum spill damage to turfgrass areas, a field study was conducted on ‘Tifgreen’ bermudagrass (Cynodon L. spp.) to determine the injury symptoms and subsequent recovery rates from petroleum spill damage. Five petroleum products commonly used in turfgrass maintenance equipment were applied as spill treatments to the turf growing on Lufkin fine sandy loam (fine, montmorillonitic, thermic, Vertic Albaqualf). Injury symptoms of the turf were documented following the three replicate spray applications of gasoline, motor oil, hydraulic fluid, and brake fluid, and following direct spreading of grease over 1 m2 plots. Calcined clay fines, activated charcoal, and detergent were evaluated as potential corrective treatments. Each corrective treatment was applied within 20 minutes of each spill in three replications.The injury symptom varied among the petroleum spill treatments. Detergent proved effective in enhancing bermudagrass recovery (3 to 4 weeks) from motor oil, hydraulic fluid, and brake fluid damage. None of the corrective treatments were effective on either the gasoline or grease‐damaged turf. The bermudagrass recovered rapidly (3 to 4 weeks) from gasoline spills without corrective procedures. More than 10 weeks were required for recovery from grease spills.
Fertilizer Management with Drip Irrigation in an Oxisol1
Authors: Keng J. C. W. , Scott T. W. , Lugo‐Lopez M. A. 
Published: July 2010

AbstractOxisols are the dominant soils of the continental shields in the tropics under permanently moist and alternately wet and dry climates. Oxisols have a low cation exchange capacity, high permeability, but low available waterholding capacity. Some have a low pH, which can cause Al3* toxicity to many crops. Together with erratic rainfall patterns, special management methods of soil‐water and plant nutrients for Oxisols are yet to be carefully studied. The relatively recent development of combined high frequency irrigation and fertilizer techniques, “drip fertilization,” may be one of the solutions for intensive production of food crops on Oxisols.A drip irrigation system using porous plastic tubing was designed for a field experiment to study the feasibility and operational techniques of drip irrigation and fertilization management in a highly weathered, acid Oxisol (Coto clay). Green pepper (Capsicum annuum L.), ‘Blanco del Pais’ was the test crop. A randomized, completeblock design was chosen to compare different fertilization techniques. In addition to the check plot, the three other treatments were: fertigation (drip irrigation and drip application of N and K, banded P); drip irrigation with banded N, P, and K; and drip irrigation with broadcast N, P, and K. All treatments, except the control plot, received a total amount of fertilizer equal to 56.8 g of 10‐10‐10 commercially available fertilizer per plant and all treatments were uniformly drip irrigated according to pan evaporation data.Different moisture profiles during the wet (June‐November) and dry (December‐May) seasons were observed. Nutrient movement profiles suggested that the distribution of fertilizer under drip irrigation depended on the method of fertilizer placement. Root development patterns indicated that more than half of the root system (dry weight) was developed in the 5 to 15 cm layer. More fibrous roots were developed toward the porous drip tubing which supplied moisture and nutrients. Yield were significantly different among all treatments during the dry season and the fertigation, broadcast, and control during the wet season. Yields from broadcast fertilizer treatments were 15.8% lower than from fertigation, and 12.3% lower than from banded fertilizer. The results of this research indicates drip fertigation can be a promising alternative to currently used water‐nutrient management methods for Oxisols in the wet‐dry tropics.
Nitrogen Fertilization and Mowing Height Effects on Tensile Strength of Bermudagrass Sod1
Authors: Mitchell C. H. , Dickens Ray 
Published: July 2010

AbstractThe influence of N fertilization practices and mowing management on sod formation is of interest because both are important economic inputs in commercial sod production. Field experiments were conducted to determine the effects of mowing height, rate, and frequency of N applications on the sod tensile strength of ‘Tifway’ and ‘Tifgreen’ bermudagrass (Cynodon dactylon L. Pers. ✕ C. transvaalensis Burt‐Davy) grown on a Marvyn sl (typic Hapludult).Results of the 3‐year study showed that N rates of 0.25 kg/are produce sod tensile strengths equal or superior to those obtained from rates as high as 1.0 kg/are. Applications of N made at 2‐week intervals produced sods with lower tensile strength than when applications were spaced 4 weeks apart. There were no significant interactions between N rates and application intervals. Both cultivars responded similarly; however, sod strengths for Tifway ranged from 30 to 50% greater than for Tifgreen in all tests. Varying mowing height from 1.25 to 2.50 an did not materially affect sod strength of either cultivar.
Soybean Yield Compensation with Different Populations and Missing Plant Patterns1
Authors: Stivers R. K. , Swearingin M. L. 
Published: July 2010

AbstractSoybean [Glycine max (L) Merr.] populations are sometimes uneven because of skips or missing plants in a section of row. The relative amount of anticipated yield loss and compensation can be valuable in deciding to replant or not. This research compares soybean yields and yield components associated with skips of different lengths and arrangements using two cultivars in 76‐cm rows for two cropping years in northwest Indiana. Four‐row plots were used in two experiments having a randomized, complete‐block design with four replications. Skips in rows were made by removing plants before the V‐3 stage was reached. Skips were made in one interior row in the first experiment. Yields of the skip row declined as skips became longer. Several short skips reduced yields less than one long skip of the same total length. In an adjacent interior row with no skips, yields increased 0.4 to 18.3% over that of the check (3,712 kg/ha) adjacent to 0.76‐m and 3.05‐m skips, respectively. The ‘Woodworth’ cultivar yielded relatively more than ‘Wells’ in one year, particularly where longer (>0.30 m) skips occupied 50% of the total row length, mainly because Woodworth had more pods per plant. In the second experiment, where three of the treatments had different populations (10.5, 14.1, and 18.0 plants/m, yields remained the same (3,839 to 3,893 kg/ha). In the seven treatments with alternate skips in each row, yield reductions varied from 1.1% with 0.30.m skips to 15.3% with 1.22‐m skips in 50% of the entire row length. The constant yield in the three populations and relatively small decline in yield for the longer skips (0.61, 0.92, 1.22‐m) either in one‐fourth or one‐half of the total row length was due to compensation resulting from increases in numbers of branches per plant, increases in numbers of pods on branches and on the main stem, and increases in numbers of seeds per pod on branches as each plant was given more space. Increasing weight per seed played a small role.
Effect of Nitrogen and Phosphorus Fertilizers on a Bromegrass and Alfalfa Mixture Grown Under Two Systems of Pasture Management. I. Yield, Percentage Legume in Sward, and Soil Tests1
Authors: Nuttall W. F. , Cooke D. A. , Waddington J. , Robertson J. A. 
Published: July 2010

AbstractBromegrass (Bromus inermis L.) and alfalfa (Medicago media Pers.) herbage production in western Canada can be increased by the application of N and P fertilizers on soils deficient in these elements. This study was conducted to determine optimum pasture production, changes in botanical composition of the sward, and changes in nutrient concentration of Melfort silty clay soil (Typic cryoborolls) from the application of N‐P fertilizers on a 4‐year‐old stand of bromegrass and alfalfa under two pasture management systems. N fertilizer was applied at 0, 45, 90, 135, and 180 kg N/ha each year from 1970 to 1973 in combination with P fertilizer applied to one‐half of each plot at 0 and 20 kg P/ha from 1971 to 1973.Total yield of bromegrass and alfalfa herbage expressed as a percentage of a control was significantly related to the application of N and P fertilizers and available soil P by regression analyses (R2 = 60.4%). Yields were as high as 251% of controls and ranged from 1,919 to 10,518 kg dry matter per ha. Higher herbage yields were obtained on pastures in which supplementary barlay (Hordeum vulgare L.) was fed to growing animals than on pastures with a “Put and Take” stocking system. The percentage of alfalfa in the sward was significantly reduced as much as 29.4% by N‐P fertilizers. A higher proportion of alfalfa in the sward was measured under the “Put and Take” treatment (36.9%) than the supplementary barley system (23.5%). Percentage alfalfa in the sward ranged from 13.8 to 54.8% (1972 to 1973, ranges C and A).Nitrogen applied at 180 kg N/ha each year to pasture increased nitrate‐N in the soil profile to 31.5 µg N/g of soil at the 30 to 60‐cm depth. As a result of residual N and P fertilizer, increased herbage yields were obtained 3 years after fertilizer was applied. After this 3‐year period, nitrate‐N was low, 1.8 µg N/g soil or less, in the soil profile at all depths.Nitrogen fertilizer at 90 kg N/ha and P at 20 kg P/ha produced an average increase in herbage yield of 74% or a total yield of 6,129 kg/ha. These rates gave the most economical return on fertilizer invested and did not increase nitrate‐N in the soil profile significantly.
Relationships Among Stalk Length, Leaf Area, and Dry Biomass of Sugarcane1
Authors: Shih S. F. , Gascho G. J. 
Published: July 2010

AbstractSugarcane (Saccharum spp.) is a leading contender in comparisons of biomass energy systems, however, scientific information on growth factors affecting biomass is limited and precludes establishing valid interrelationships for predicting biomass production. With that objective in mind, two sugarcane experiments were conducted at lysimeter and field sites to study the relationships among stalk length, leaf area index, and dry biomass. Three replications of five cultivars ‘CP 63‐588,’ ‘CP 56‐59,’ ‘CP 65‐357,’ ‘C1 54‐378,’ and ‘C1 54‐336’ were planted in six lysimeters where water tables were maintained at 30, 60, and 90 cm. Cultivar ‘CP 65‐357’ was planted in the field at 0.5 and 1.5 m row spacings. Leaf area and the stalk length were measured. Two equations involving leaf area were developed. The first equation estimated leaf area (Y) from stalk length (X) by an exponential‐hyperbolic function; i.e. Y = Exp [X/(1.140 + 0.111X + 0.177 ✕ 10−4 X2)]. The second equation predicted dry biomass (DB) from the cumulative time interaction with leaf area index (CTXLAI), i.e. DB = Exp [CTXLAI/(0.388 + 0.280 CTXLAI)]. The relationships developed should be useful for easily estimating sugarcane biomass.
In Situ Study of Corn Seedling Root and Shoot Growth by Neutron Radiography1
Authors: Couchat Ph. , Moutonnet P. , Houelle M. , Picard D. 
Published: July 2010

AbstractIn corn (Zea mays L.) root and shoot studies particular attention has been paid to environmental and soil influence on seedling root growth. Experimentation in this field has been limited by the difficulty in investigating root elongation, since no nondestructive in situ method was available other than glass‐sided boxes. The purpose of this study was to show that the neutron radiography is capable of supplying in situ root images permitting qualitative and quantitative interpretation so that comparative root and shoot growth may now be analyzed in a new way.The experiments consisted of shoot and root growth studies up to 21 days for two corn seeds sown at depths of 1 and 6 cm. The plants were grown in a growth chamber in a 2‐cm‐thick aluminum box containing coarse sand maintained at 8% volumetric water content. Daily neutron radiographs were made by the direct method using the 3.2° diverging thermal neutron beam of the MIRENE reactor at Valduc, France.The images obtained allowed a qualitative interpretation not only for seminal root but also for laterals. Root development was not harmed visibly by irradiation and repeated environmental changes due to neutron radiography experiments. The seminal root elongation rate was analysed vs. the plant age. Quantitative data show that the root growth was greater during the day than at night. Root and shoot lengths were related in a linear manner between 7 and 15 days after sowing.
Residual Effects of Labeled N in Field Trials1
Authors: Broadbent F. E. 
Published: July 2010

AbstractField trials utilizing 15N‐depleted fertilizer were conducted over a 6‐year period at two locations for the purpose of providing as complete an accounting as possible of N in the soil‐plant‐water system under conditions of irrigated agriculture. These trials permitted measurement of residual effects while continuing a constant rate of N application, and also after applications were discontinued. On Yolo fine sandy loam (Typic xerorthent) residual value of the previous year's fertilizer varied from negligible to 23% of the total crop uptake depending on N rate and amount of irrigation water applied. These values were equivalent to 5 to 91 kg N/ha of a current year's N application. In Hanford sandy loam (Typic xerorthent) 51 to 60% of the N in a corn (Zea mays L.) crop was labeled N in the year following discontinuance of N application and about 32% in the second year. Most of the residual N subsequently utilized by a crop was in the inorganic form. There was little evidence of remineralization of labeled organic N.At fertilizer rates that were adequate, but not excessive, for maximum grain yield coupled with adequate irrigation water the residual N was equivalent to 3 to 24 kg/ha. It is concluded that with efficient management which avoids overfertilization, the value of residual N is not sufficient to affect application rates. Substantial quantities of residual N reflected overfertilization and/or insufficient irrigation water in previous years.
Physiological Aspects of Yield Improvement in Soybeans1
Authors: Gay Scott , Egli D. B. , Reicosky D. A. 
Published: July 2010

AbstractAn understanding of the physiological changes that have occurred in cultivar development in the past would be helpful in the continued production of high yielding cultivars of the various crop species. Field experiments using conventional cultural practices with supplemental irrigation were conducted in 1976 to determine the physiological basis for yield differences between old, low yielding soybean [Glycine max (L.) Merr.] cultivars (Lincoln' and ‘Dorman’) and new high yielding cultivars (‘Williams’ and ‘Essex’). Mechanical support was used to prevent lodging for comparison to control plots with no mechanical support. There was no lodging in Lincoln and Williams (Maturity Group III); whereas, in maturity group V, Dorman lodged significantly more than Essex in the control plots. However, there was no relationship between lodging and yield. Williams produced 34% more yield than Lincoln, primarily because of larger seed. Essex produced 88% more yield than Dorman, primarily because of more seed per unit area.Yield differences were not correlated with total shoot weights or CO2 uptake rates of a single leaf during vegetative or early reproductive growth. Rates of acetylene reduction were similar for Williams and Lincoln, but Essex had a higher rate than Dorman. The yield advantage of Williams resulted partially from a longer filling period (12%), which was associated with higher CO2 uptake and acetylene reduction rates late in the filling period. Essex and Dorman produced similar total shoot weights late in the filling period, so the yield advantage for Essex resulted from partitioning more photosynthate to the seed. The data suggest that yield improvement in the future may be possible by lengthening the filling period. It may not be possible to increase seed yields by increasing the partitioning of photosynthate to the seed if the partitioning in current cultivars is approaching the maximum.
Tests to determine Wheat Straw Decomposition1
Authors: Armbrust D. V. 
Published: July 2010

AbstractCrop residues are important for erosion control and maintaining soil fertility, but these residues could also be used for other pnrposes. To determine the amount of excess residues available for other uses, we need a simple, accurate method to measure residue decomposition. Three methods were evaluated to determine residue losses by decomposition. Wheat (Triticum aestivum L.) straw was enclosed in nylon envelopes, buried 6 cm deep in a loam soil in greenhouse benches, and recovered periodically during 9 months. Assays for acriflavine (acriflavine hydrochloride) adsorption on 0.1 N NaOH‐extractable humic materials, light absorption of the extracted humic materials, and the force necessary to break the straw were compared with weight loss by decompositionLight absorption and break force were linearly related to residue loss with regression coefficients of − 0.95 and − 0.92, respectively. Break force approached zero after 2 months. Acriflavine adsorption was poorly related to straw loss. The light‐absorption technique may be used to measure decomposition of crop residues freely mixed Within the soil once the relationships between percent transmittance and loss by decomposition are established.
Forage Quality Response of Tall Fescue, Orchardgrass, and Phalaris to Soil Fertility Level1
Authors: Odom J. W. , Haaland R. L. , Hoveland C. S. , Anthony W. B. 
Published: July 2010

AbstractPoor steer performance was obtained on a tall fescue (Festuca arundinacea Schreb.) pasture on an acid soil while a nearby tall fescue pasture on a calcareous soil gave excellent steer performance. A greenhouse experiment using five soils was designed to test the effects of soil Ca and Mg levels on the digestibility and mineral composition of three cool season, perennial grasses. Soil Ca and Mg levels were associated with Ca and Mg concentrations in the herbage of tall fescue, orchardgrass (Dactylis glomerata L.) and phalaris (Phalaris aquatica L.) but concentration of Ca in the herbage had no effect on in vitro dry matter digestibility. Tall fescue had higher concentrations of Ca and Mg and lower concentrations of K than the other grass species grown on each of five soil.
Drought Adaptation of Cowpea. II. Influence of Drought on Plant Water Status and Relations with Seed Yield1
Authors: Turk Kenneth J. , Hall Anthony E. 
Published: July 2010

AbstractConcurrent studies described the drought resistance of cowpeas [Vigna unguiculata (L.) Walp.] during the vegetative stage, and susceptibility to drought during flowering and pod filling. The present field studies were conducted to examine possible mechanisms of cowpea adaptation to drought and relations between yield and plant water status to guide programs for the development of improved cultivars and irrigation practices.Two cowpea cultivars were subjected to different levels of irrigation at the vegetative, flowering, and pod filling stages using a line‐source sprinkler system during 2 years having contrasting weather patterns. The soil is an Arlington fine sandy loam (coarse‐loamy, mixed, thermic Haplic Durixeralf) with a high bulk density. Soil water content was determined with a neutron scattering device and plant water status measurements were made with a pressure chamber and thermocouple psychrometers. The plants exhibited extreme drought avoidance in the presence of soil water deficits or high evaporative demands with xylem pressure potential remaining above −18 bar. Drought avoidance by cowpeas appeared to be mainly due to several mechanisms for regulating water loss. Predawn xylem pressure potential was more consistently related to soil water deficits than afternoon values. Leaf solute potential was correlated with xylem pressure potential, becoming more negative in the afternoon than predawn. Solute potential also was more negative during periods of high evaporative demands but was only slightly reduced by soil water deficits.Seed yield was linearly correlated with seasonal cumulative xylem pressure potential measured either just before sunrise or in the afternoon. Consequently, the pressure chamber may provide guidelines for research on irrigation management and the selection of cultivars with improved drought tolerance. However, because of the large differences in seed yield associated with small differences in cumulative xylem pressure potential the pressure chamber may not be useful as an indicator for commercial irrigation of cowpeas.
Emergence Force by Cotton Seedlings1
Authors: Gerard C. J. 
Published: July 2010

AbstractEconomic returns from crops require establishment of a good plant stand. Soil crusting reduces seedling emergence and stands of many crops throughout the world. One of the most important crops adversely affected by crusting is cotton (Gossypium hirsutum L.). The force exerted by germinating plants such as cotton often determines the seedling's ability to rupture and emerge from under the soil crust. However, the force exerted by an emerging cotton seedling has not been determined. Studies were conducted in the laboratory to determine and better understand the emergence force of cotton seedlings.The force exerted by cotton seedlings under different soil moisture conditions and temperatures was determined using a force transducer. The transducer mv output, which is a linear function of the force exerted against the transducer button, was continuously monitored with a mv recorder.Emergence force was a linear function of volumetric soil moisture, number of seedlings, and cross‐sectional area of the emerging hypocotyls. The size of the hypocotyl was a function of soil moisture and temperature. Maximum diameters of the cotton hypocotyl at 22, 27, 32, and 40 C were 0.32, 0.41, 0.34, and 0.26 cm, respectively, and the maximum forces exerted were about 350, 600, 400, and 200 g, respectively. The time required for maximum exertion by the seedling was dependent upon temperature, ranging from 40 to 48 hours at 32 C and 50 to 60 hours at 27 C. These findings suggest that planting methods, planting dates, and cultivar improvement may offer possible ways to minimize or circumvent crusting effects and increase emergence.