bluuebunny/crossref_metadata_2025_split huggingface dataset:
Yield and Quality of Birdsfoot Trefoil Stockpiled for Summer Utilization1
Authors: Collins Michael 
Published: July 2010

AbstractPasture production is generally lower during summer than during spring and autumn in the midwestern and eastern states of the USA. Forage stockpiled during spring could increase the carrying capacity of pastures during summer. The objective of this experiment was to study the use of birdsfoot trefoil (Lotus corniculatus L.) to provide stockpiled forage for utilization during summer.Small plots (1.5 ✕ 5.8 m) of ‘Empire’ birdsfoot trefoil on Plano silt loam soil (fine‐silty, mixed, mesic Typic Argiudoll) were managed according to eight cutting treatments (T) in 1979 and 10 treatments in 1980. Harvest dates in 1979 were; (T1) 30 May, 16 July, and 10 October, (T2) 30 May, 1 August, and 10 October, (T3) 30 May, 15 August, and 10 October, (T4) 28 June, 16 July, and 10 October, (T5) 28 June, 1 August, and 10 October, (T6) 28 June, 15 August, and 10 October, (T7) 30 May, 28 June, 1 August, and 10 October, and (T8) 30 May, 28 June, 15 August, and 10 October. Harvest dates in 1980 were: (T1) 28 May, 14 July, and 17 October, (T2) 28 May, 1 August, and 17 October, (T3) 28 May, 15 August, and 17 October, (T4) 13 June, 14 July, and 17 October, (T5) 13 June, 1 August, and 17 October, (T6) 13 June, 15 August, and 17 October, (T7) 28 May, 25 June, 1 August, and 17 October, (T8) 28 May, 25 June, 15 August, and 17 October, (T9) 14 July and 17 October, and (T10) 1 August and 17 October.Total seasonal matter yield was greatest in 1979 for plots left unharvested between late May and mid‐July (T1, 5.9 metric tons/ha). An additional treatment in 1980 in which forage was left unharvested through the spring and harvested in early or mid‐August (T9 and T10) produced yields similar to that from T2, T3, T6, and T8. Stockpiling after mid or late June (T4 to T6) instead of late May (T1 to T3) reduced mid‐summer yields by approximately 50% in both years. Averaged over the 2 years, forage stockpiled from late May until early August (T2) averaged 62.8% in vitro dry matter disappearance (IVDMD) and 2.34% N. Birdsfoot trefoil stockpiled all spring and harvested in early August in 1981 (T10) had an IVDMD of 56.4 and 1.96% N. Shorter stockpiling periods resulted in higher IVDMD and lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) concentrations in the harvested forage, but also resulted in lower yields of stockpiled forage. These results indicate that birdsfoot trefoil can be managed to provide forage for summer use and that the length of the stockpiling period does influence both the yield and the composition of forage produced. The optimum management is dependent on the quality of forage required for a particular class of livestock.
Kentucky Bluegrass Tolerance to Consecutive Preemergence Herbicide Treatments1
Authors: Johnson B. J. 
Published: July 2010

AbstractHerbicides are one of several management practices necessary to maintain good quality, weed‐free turf. To be acceptable, they must control weeds without causing turfgrass injury. An experiment was conducted on Congaree loam (Fluventic Dystrochrepts) in the mountain region of Georgia to determine the effects of consecutive annual herbicide treatments on six Kentucky bluegrass (Poa pratensis L.) cultivars.Standard rates of DCPA (dimethyl tetrachloroterephthalate), bensulide [O,O‐diisopropyl phosphorodithioate S‐ester with N‐(2‐mercaptoethyl) benzenesulfonamide], benefin (N‐butyl‐N‐ethyl‐a,a,a‐trifluoro‐2,6‐dinitro‐p‐toluidine), or oxadiazon [2‐tert‐butyl‐4‐(2,4‐dichloro‐5‐isopropoxyphenyl)−Δ2−1 ,3,4‐oxadiazolin‐5‐one] affected the quality and stand of Kentucky bluegrass cultivars very little. However, oxadiazon applied at the 3X rate reduced the quality of all cultivars in early spring and the stands of ‘Victa’, ‘Merion’, and ‘common’ in late summer when compared with bensulide. Benefin applied at the 3X rate reduced the quality of ‘Adelphi’, ‘Vantage’, Victa, and ‘Fylking’, but not stand when compared with the recommended benefin treatment. Neither napropamide [2‐(a‐naphthoxy)‐N,N‐diethylpropionamide] or prosulfalin {N‐[[4‐(dipropylamino)‐3,5‐dinitrophenyl]sulfonyl]‐S‐S‐dimethylsulfilimine} should be applied to Kentucky bluegrass cultivars because of severe injury.
Relative Efficiency of Applied N and Soil Nitrate for Winter Wheat Production1
Authors: Haby V. A. , Simons C. , Stauber M. S. , Lund R. , Kresge P. O. 
Published: July 2010

AbstractThe fertilizer N recommendation for a given yield of dryland winter wheat (Triticum aestivum L.) is lowered by the amount of nitrate‐nitrogen (NO3‐N) measured in the upper 1.2 m soil profile. This implies that soil NO3‐N substitutes for fertilizer N on an equal basis. The study was designed to compare the effectiveness of soil NO3‐N in the 1.2 m depth with fertilizer N for wheat production. Data were from 19 siteyears of N, P, and K rate combinations in 23 treatments planned to fit the nested‐cube statistical design. A response function for grain yield was estimated using fertilizer N, P, and K, soil NO3‐N, P, and water plus seasonal (April‐July) precipitation in a nonlinear regression model. All explanatory variables except fertilizer N and soil NO3‐N were set at fixed values to derive the yield response function. Marginal rates of substitution (MRS) of soil NO3‐N for fertilizer N were derived from representative yield levels. Results indicate that soil NO3‐N in the 1.2 m surface depth is not as efficient (approximately one‐third) as fertilizer N for grain production. Substantial differences in economic returns exist between comparisons of fertilizer recommendations made using the response surface vs an accepted one‐to‐one substitution. Differences are greatest in the range of 75 to 150 kg of soil NO3‐N/ha; the maximum difference, $44.36/ha occurs at a NO3‐N level of 100 kg/ha. Additional research is needed on the N supplying ability of soil NO3‐N for plant growth based on its zones of concentration within the soil profile.
Semiautomated X‐Y‐Plotter‐Based Method for Measuring Root Lenghts1
Authors: Wilhelm W. W. , Norman J. M. , Newell R. L. 
Published: July 2010

AbstractRoot‐length measurements are an important aspect of many agronomic research programs. Several automated systems have been reported which use modifications of the line‐intersect technique to estimate root length; however, most of these systems are very costly. This paper describes an inexpensive automated system using a modified line‐intersect technique to estimate root length. An X‐Y plotter was used to move a light sensor in a grid pattern through the projected photographic image of a root system, recording intersections with an event counter. Compared to manual counting using the line‐intersect technique, the system described accurately estimated root length of samples up to 10 m in length (r2 = 0.98). The advantage of our system is that costs are reduced by using equipment that is readily available at most laboratories: X‐Y plotter and slide projector. The cost of additional items was less than $600. Each determination of root length required 50 sec. The accuracy of the system was comparable to others that are based on the line‐intersect technique.
Foliar Fertilization of Soybeans. II. Effect of Biuret and Application Time of Day1
Authors: Poole W. D. , Randall G. W. , Ham G. E. 
Published: July 2010

AbstractNegative yield results from the foliar application of NPKS solutions to soybeans [Glycine max (L.) Merr.] at the podfilling stage have been reported recently. Many of these studies have cited phytotoxicity and leaf burn as a causal factor. The purpose of this study was to investigate two factors which may contribute to these yield decreases: (1) biuret in the urea and (2) time of day of application. Biuret, a contaminant in fertilizer‐grade urea, was added to a base NPKS solution containing biuret‐free urea at the rates of 0, 0.25, 0.50, 1.0, 2.0, and 4.0% of the weight of the urea in the fertilizer material. Application of the biuret containing fertilizer solutions either one or three times did not reduce soybean yield and seed weights at three sites in the 2 study years. To determine the effect of application time of day, an NPKS solution containing 24 + 2.4 + 7.2 + 1.2 kg N + P + K + S/ha was applied to soybeans at 0300, 0600, 0900, 1200, 1500, 1800, 2100, and 2400 hours four times at 7 to 10 day intervals during podfilling. Under the climatic conditions encountered in the 2 years of this study, soybean yields were not significantly (P=O.lO level) affected by the time of application. However, consistent trends toward lower yields with midday applications allow us to suggest that the application of foliar fertilizer before 0800 or after 1700 hours will minimize chances of foliar injury and may improve chances of a positive response.
Seasonal Zn, Cu, Mn, and Fe Levels of Western Wheatgrass and Green Needlegrass as Affected by N Fertilization1
Authors: Halvorson A. D. , White L. M. 
Published: July 2010

AbstractNitrogen fertilization has been used to increase forage production of range grasses in the northern Great Plains; however, little information is available as to how N fertilization affects minor element composition of range forage. Our objectives were to determine the effects of N fertilization on Zn, Cu, Fe, and Mn concentrations in vegetative and floral tillers of western wheatgrass (Agropyron smithii Rydh.) and green needlegrass (Stipa viridula Trin.) throughout the growing season. Nitrogen fertilizer (0,40,80,160,320, and 640 kg N/ha) was applied in a completely randomized design to each grass species growing on a calcareous silt loam (Typic Haploborolls). Plants were collected on 10 and 11 sampling dates in 1973 and 1974, respectively. Nitrogen fertilization significantly increased the level of Zn, Cu, and Mn in green needlegrass and Zn and Mn in western wheatgrass forage. Absolute changes in mineral composition caused by N fertilization were very small and of little practical significance. Forage Zn and Cu levels declined throughout the growing season and were generally below recommended allowances (less than 20 to 30 πg/g Zn and 4 πg/g Cu) for proper cattle nutrition by mid‐June. Therefore, supplemental Zn and Cu may be required in diets of cattle being fed or grazing western wheatgrass or green needlegrass grown in the northern Great Plains after mid‐June. Forage Fe and Mn levels decreased as the growing season progressed until maximum forage yield was reached in June. Iron then started accumulating in the forage while Mn remained relatively constant during the remainder of the growing season. Iron (>80 πg/g) and Mn (>35 πg/g) were well above the recommended minimum levels for proper cattle nutrition. Floral tillers of both grasses had lower concentrations of Zn, Fe, Mn, and Cu than did vegetative tillers. In general, the earlier the harvest, the better the forage quality of western wheatgrass and green needlegrass will be with respect to Zn and Cu nutrition of cattle. Maintaining the grasses in the vegetative rather than floral growth stage would also improve forage quality
Wheat Development as Affected by Deficit, High Frequency Sprinkler Irrigation1
Authors: Hang An N. , Miller D. E. 
Published: July 2010

AbstractAn important limitation to wheat production worldwide is insufficient water. Therefore, it is important to know how the crop responds physiologically to water stress. The present study was conducted to determine the effect of various irrigation rates on wheat development. Variable irrigation treatments were initiated at pre‐ or early‐boot stage of Fielder spring and Nugaines winter wheat (Triticum aestivum L. em. Thell.) grown on sandy (mixed, mesic, Xeric Torripasamments) and loam (coarsesilty, mixed, mesic Xerollic Camborthids) soils. Different amounts of irrigation water were applied by the line source technique. Daily irrigation near the line source was equivalent to 1.00 (loam) or 1.15 (sand) times estimated evapotranspiration (ET). Pan evaporation (EP) was used to estimate ET as ET = 0.95 EP. On sandy soil, stress symptoms were first observed in plants receiving the least irrigation water (23 % estimated ET) 2 weeks after treatments were initiated. Symptoms included decreased number of green leaves, shorter plants, fewer heads, increased specific leaf weight and increased leaf‐stem dry weight ratios. Head growth rates were from 8.2 to 15.6 mg·head−1day−1, at the lowest and highest applications, respectively. Reproductive growth rate, crop growth rate, and partitioning to reproductive growth increased with increased irrigation. Effects of decreased irrigation were less on loam soil than on sandy soil. Stress symptoms did not appear until late in the growing season. There were significant differences in plant height, total plant weight, and head weight between the plots receiving highest and lowest irrigation rates (100 vs. 20 % estimated ET). Results indicate that normal growth and yield of wheat grown on sandy soil require irrigations that approach ET. However, on loam soil irrigation amounts can be decreased 40 to 50 % without affecting developing of plant parts.
Placement of Molybdenum Fertilizer in the Transplant Solution of Burley Tobacco1
Authors: Sims J. L. , Suchy M. E. , Cornelius P. L. 
Published: July 2010

AbstractTwo field experiments were conducted at Lexington, Ky. on Maury silt loam soil (fine, mixed, mesic Typic Paleudalf) to determine the effect of placing molybdenum (Mo) fertilizer as a solution in the root zone (band) at transplanting on growth, yield, and Mo concentration of burley tobacco (Nicotiana tabacum L. cv. KY 14). In one experiment on soil with initial pH of 5.5 that had received application of Mo in each of the 2 previous years, adding Mo as a transplant solution significantly increased plant Mo concentration, nitrate reductase activity, and cured leaf yields. Response to added Mo as a transplant solution was generally greater in plots previously amended with little or no Mo. This plant response to transplant applications is in contrast to previous studies showing little or no response to broadcast applications in soils of relatively low pH. In a second experiment on soil with pH of 6.2, plant Mo concentrations increased linearly as rate of Mo increased for both broadcast and transplant solution Mo applications. However, the slope of the regression line was greater for transplant Mo fertilization. The data indicate that Mo applied as a transplant solution is more effective than broadcast Mo. This will permit the use of lower rates when Mo is added at transplanting.
Effects of Increasing the Rates of Potassium and Nitrapyrin on Nitrogen Uptake by Corn1
Authors: Lueking M. A. , Johnson J. W. , Himes F. L. 
Published: July 2010

AbstractPlant uptake of NH+4 is competitive with the uptake of K+. This relationship is of interest because fertilizer N is commonly applied in the NH+4 form and K is either present in large quantities in the soil or is applied as fertilizer. This study was conducted to determine the effects of high K rates and a nitrification inhibitor on the uptake of N and yields of corn (Zea mays L.). Corn (Landmark C747X) was grown in a field experiment during 2 years. Anhydrous ammonia was applied to all plots at 112 kg N/ha. Treatments consisted of three rates of KCI (0, 90, and 360 kg K/ha) applied in all combinations with three rates of nitrapyrin [2‐chloro‐6‐(trichloromethyl) pyridine] (0, 0.56, and 2.24 kg/ha) to a Kokomo silty clay loam soil (fine, mixed, mesic Typic Argiaquoll). Plant samples were taken 1 week after tasseling during one growing season for chemical analysis. Grain yields and N analyses of leaf tissue at harvest were averaged over 2 years. Soil samples were collected from the surface, 30 cm of soil surrounding the anhydrous ammonia band at 2‐week intervals for 12 weeks. The soil was analyzed for inorganic N to monitor the predominant ionic form available to the plants. Nitrapyrin application kept a higher concentration of NH+4 in the soil as compared to the checks for 4 to 6 weeks. Increased rates of K decreased yields and decreased the percent total N in leaves 6 through 10 at 12 weeks. Total N in grain was not affected by K rate or nitrapyrin rate, however, it was very low (0.95%) indicating an N deficiency in all treatments. Total nutrient analysis indicated that the concentration of Ca, Mg, Cu, and P decreased as K rate increased. The study indicated that increasing K rates may decrease yields if N is a limiting factor, due to a competition for uptake. The competition was confirmed by low total N in the grain and the decreased total N in leaves 6 through 10 at tasseling as K rate increased.
The “Ammoniator”: a Device to Enrich Waste Solutions with Nitrogen1
Authors: Huber D. M. , Karamesines P. D. , Nelson D. W. 
Published: July 2010

AbstractUtilization of liquid wastes as fertilizers is sometimes limited by the large volumes (due to low N concentrations), which must be applied to provide optimum N rates for crops. A device (ammoniator) is described which facilitates the enrichment of waste slurries with anhydrous ammonia (or other concentrated liquid N sources) to improve the value of the wastes as nutrient sources for crop production. The ammoniator is inexpensive to construct, simple and safe to operate with ordinary precautions for NH3, use, and efficient in increasing the plant‐available N concentration in waste slurries two‐ to three‐fold. The device is adaptable for use in liquid manure tanker wagons or in pits and holding tanks.
Forage Residue Filtration, In Vitro Forage Digestion, and Elemental Solution Concentrations as Influenced by Soil Type and Concentration1
Authors: Cherney J. H. , Robinson D. L. , Ray D. J. 
Published: July 2010

AbstractRuminant animals may ingest large quantities of soil at certain times during the grazing season, but the effect of ingested soil on the mineral nutrition of ruminants is not clear. Our objectives were to determine the effects of soil on elemental concentrations in solution in an active in vitro system to estimate matter digestibility (IVDMD), rate and extent of cell wall digestion, and neutral detergent fiber (NDF) concentrations. Elemental concentrations were determined with an emission spectrophotometer immediately after the in vitro incubation of soil (0 to 300 g kg−1 forage) with annual ryegrass (Lolium multiflorum Lam.) for 6 to 48 h. The effect of soil on IVDMD was studied by adding three levels of soil (0, 75, and 150 g kg−1) to ryegrass samples prior to digestion. Four levels of soil (0, 100, 200, and 300 g kg−1) were combined with ryegrass samples to determine the effect of soil on NDF residue filtration. Increased soil levels in annual ryegrass forage samples resulted in linear increases in solution concentrations of Ca, Mg, Fe, Mn, and Zn, but no measurable Al or Ti in solution. Soil type had only small influences on Mg and Ca concentration in solution, with values ranging from 41.9 to 42.9 and 41.7 to 47.4 mg kg−1, respectively. Iron concentrations among soil types ranged from 0.93 to 1.81 mg kg−1, while Mn concentrations among soil types varied by nearly nine‐fold, from 0.25 to 2.24 mg kg−1. When soil was not present in the in vitro system, Ca, Mg, and Fe concentrations increased linearly with increased incubation time. However, solution concentrations of each of these elements responded differently to soil additions with increased incubation time. Soil had no apparent effect on the in vitro digestion process itself, but may lead to decreases in IVDMD values by interfering with filtration of sample residues. There was a linear increase in NDF values with increased soil additions to the forage samples, after correction with soil blanks. Neutral detergent fiber was significantly affected (P < 0.05) by filtration method, with mean values of 491 g kg−1 for sintered glass and 475 g kg−1 for glass wool plus sintered glass. The effect of soil contamination on forage quality analyses, resulting from inadequate filtration through sintered glass filters, cannot be overcome by expressing values on an ash‐free basis.
Effect of Crop Cover on Temperature Regime of an Alfisol in the Tropics1
Authors: Ghuman B.S. , Lal R. 
Published: July 2010

AbstractEffect of maize (Zea mays L.) and cowpea (Vigna unguiculata L. Walp) canopies on the thermal regime of an Alfisol was investigated in flat and ridged seedbeds. An interaction was observed between canopy characteristics and soil moisture availability that influenced the soil temperature. When the soil moisture was >0.08 cm3 cm−3 (suction <0.64 bar), plants were protected against temporary wilting in the second half of the day and the 5‐cm soil temperature decreased with an increase of maize and cowpea canopies. However, when the soil moisture was ≤0.0.8 cm3 cm−3 (observed on 53rd day after seeding of crops in 1980), the 5‐cm maximum soil temperature under maize and cowpea crops was higher by 3 and 0.2°C, respectively, than in an uncropped flat seedbed, and by 7 and 3.9°C, respectively, than in uncropped ridges. The 5‐cm soil temperature under maize was slightly lower in the early growth stages than under cowpea irrespective of the method of seedbed preparation. However, the reverse was true towards the crop's maturity. In addition to percent ground cover, soil moisture deficit, and the possible change in thermal conductivity were responsible for this reversal in soil temperature observed at the maturity stage. Soil temperature regime is strongly influenced by the interaction between canopy cover and soil moisture regime, on the one hand, and canopy height and density and wind velocity, on the other. The effect of increasing crop canopy on soil temperature on a given day (that provided an identical radiation for all plots) was studied for the flat seedbed by staggering the seeding dates of crops in the first season of 1981. On the 16th June (at approximately 50,40, and 20 days after seeding), and when the crops were not under moisture stress, an increase of maize canopy from 0 to 59.7% decreased the soil temperature range from 10.6 to 4.3°C at 1 cm and from 3.2 to 1.6°C at 20 cm depth. Similarly, an increase of cowpea cover from 0 to 100% decreased the temperature range from 10.6 to 1.7°C at 1 cm and from 3.2 to 0.6°C at 20 cm depth. Empirical models were developed that describe the effects of canopy cover, soil moisture, and radiation on maximum and mean soil temperatures at 1, 5, and 20 cm depths.