bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Soil Mixtures and Irrigation Methods on Leaching of N in Golf Greens1
Authors: Mitchell W. H. , Morehart A. L. , Cotnoir L. J. , Hesseltine B. B. , Langston D. N. 
Published: July 2010

AbstractUtilization of applied N by ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.) is of special interest because of the cost and availability of N and the potential environmental problems resulting from its deep percolation. The influence of soil mixtures, irrigation systems, and N sources on N leaching was studied in experimental, though functional, golf greens from 1973 to 1976. Sprinkler irrigation was compared with subsurface irrigation using porous irrigation tubing constructed from spun‐bonded olefin. Soil mixtures contained from 60 to 80% sand and variable amounts of silt loam topsoil, calcined clay and humus. Nitrogen treatments included activated sewage sludge, ureaform, ammonium nitrate, 30% N solution, anhydrous ammonia and nitrapyrin. Nitrogen solutions were applied through the subsurface irrigation system while other N carriers were surface applied. Each soil × irrigation treatment was underlain by a drainage line placed in pea stone at a depth of about 46 cm. Water samples were collected periodically from drainage lines and analyzed for NH4‐ and NO3‐N.Nitrogen leached primarily as NO3‐N with a reduced rate of loss associated with slow release N sources and the onset of low seasonal temperatures. Even though about 75% of the added was NH4‐N, N solution (30% N) applied through the subsurface irrigation system caused a sharp increase in NO3‐N in the drainage water. Anhydrous ammonia with or without nitrapyrin reduced NO3‐N leaching losses for 1 to 2 weeks but had little effect on the average NO3‐N concentration over a 47‐day period.Subsurface irrigation stimulated turfgrass growth in bands about 20 cm wide located above the irrigation lines. Appearance of growth bands was associated with low temperatures and increased levels of NO3‐N in proximity to the irrigation lines. Banding was most apparent in soil mixtures containing low levels of residual soil N and absent when turfgrass was adequately fertilized with N.
Analysis of Potato Growth under Differing P Regimes. I. Tuber Yields and Allocation of Dry Matter and P1
Authors: McCollum R. E. 
Published: July 2010

AbstractHigh rates of P fertilization for potatoes (Solarium tuberosum L.) over many years have resulted in significant increases in total and extractable soil‐P reserves. While fertilization practices for other crops grown in rotation with potatoes reflect both plant demand and soil‐test P, many producers continue to fertilize potatoes with little regard to crop requirements nor to existing soil‐P levels. If neither potatoes nor crops grown in rotation with them require such high rates of directly‐applied P, a considerable saving in fertilizer costs could be realized. This hypothesis was tested in two field experiments (on a Typic Umbraquult, fine‐loamy, mixed, thermic soil) designed to measure tuber yields and trace patterns of dry matter and P accumulation by ‘Pungo’ potatoes in response to row‐applied fertilizer P[FP (1969) = 0, 24, 48, and 72 kg/ha; FP (1970) = 0, 28, and 56] on soil with 35, 66, and 110 kg of extractable soil P/ha. The latter objectives were accomplished by weekly samplings and appropriate analyses of tops and tubers during tuber bulking. When soil P was low (35 kg) or medium (66 kg), row‐applied P increased yields by 38 and 22%, respectively; but no response to fertilizer P was obtained if initial soil P was high (110 kg). At tuber initiation, P concentration in whole plants ranged from 0.20% under severest deficiency to 0.45% under optimal nutrition; it dropped to less than 0.20% at harvest, regardless of treatment. On low‐P regimes (SP < 66, FP = 0) rates of dry matter and P accumulation were still positive at 84 days after emergence; but plants on other treatments had lost most of their leaves—and many haulms were dead—at 79 days. At tuber initiation, plants with and without row‐applied P had accumulated 20 and 10%, respectively, of their 72‐day total P. Dry matter at tuber initiation was about 10% of the 72‐day total for all treatments. About 75% of the total accumulated P and 70‐75% of total dry matter was in tubers at harvest. While massive P applications to these low P soils are needed to make them productive, my results suggest that even high‐demand crops like potatoes require relatively modest amounts of row applied P to maintain maximal productivity once the initial deficiency is eliminated.
Management of Irrigated Soybeans on a Moderately Coarse‐textured Soil in the Upper Midwest1
Authors: Cassel D. K. , Bauer Armand , Whited D. A. 
Published: July 2010

AbstractIncreased availability of water for supplemental irrigation in the upper Midwest has enhanced an interest in growing soybeans [Glycine max (L.) Merr.] on moderately coarse‐textured soils where they have not previously been introduced. The objectives of this study were to determine the yield potential of supplementally irrigated soybeans on these soils and to develop an irrigation schedule for efficient water management. The study, conducted on Maddock sandy loam from 1972 to 1974, employed a splitsplit plot design with water level as the main block and N fertility rates (0, 56, 112, and 224 kg/ha) as sub‐plots. Water levels were Wl (dryland), W2 (under‐irrigation), W3 (optimum) and W4 (over‐irrigation). Sub‐sub plots were planting dates in 1972 and cultivars in 1973 and 1974. Soil samples were collected from 15 to 30 cm intervals to depths of 90, 150, or 270 cm throughout the study and analyzed for NO3‐N in the soil profile under irrigated conditions. Grain yields were significantly different for water levels during each of the 3 years. Threeyear yield means were 543, 1,823, 2,428, and 2,164 kg/ha for Wl, W2, W3 and W4, respectively. The application of 24 kg/ha N fertilizer in 1972 increased grain yield at the 0.95 probability level. The seed was not inoculated that year but was inoculated in 1973 and 1974. Soybeans planted 10 May 1972, outyielded soybeans planted 6 June by 356 kg/ha. ‘Anoka’ outyielded the ‘SRF‐100’ cultivar by 137 kg/ha in both 1973 and 1974. An irrigation schedule based upon tensiometers placed at the 30 cm depth until 15 July (growth stage R2) and at the 45 cm depth after 15 July proved effective in applying irrigation water. Analysis of NO3‐N in the soil profile at different dates during the 3‐year period showed that under heavy fertilizer NO3‐N applications, the NO3‐N moved below the crop rooting zone when excess water was applied. Based upon results of this study, soybeans can be seriously considered as a crop to be included in cropping systems for irrigated, moderately coarse‐textured soils in the Upper Midwest.
Wheat Seed Germination under Low Temperature and Moisture Stress1
Authors: Ashraf C. M. , Abu‐Shakra S. 
Published: July 2010

AbstractCultivate differ inherently in their response towards drought. Only those adapted to arid and semiarid conditions become established into uniform and vigorous stands during germination under moisture stress and suboptimal temperature. Seed germination of four wheat cultivars, ‘Najah’ and ‘Mexi‐pak’ (Triticum aestivum L.), and ‘Hurani’ and ‘Jori’ (Triticum durum L.), were compared under suboptimal temperatures and various levels of simulated moisture stress. Components of water uptake, germination percentage, speed of germination, root growth, respiration rate, and germination recovery from stress were measured. The rate of water uptake decreased and the time required for germination increased when the seeds were incubated at 6 atm and higher. Seeds of the four cultivars germinated when their moisture content was approximately 50% on a fresh weight basis. Total germination was not affected by moisture stress levels up to 12 atm but was significantly reduced at 15 and 18 atm osmotic tensions. Rate of root growth, speed of germination, and respiration rates were inversely related to moisture stress. Low moisture stress (3 atm) did not inhibit root growth. Significant differences were found among cultivars in the parameters studied. Perforating the pericarps did not eliminate the differences in water uptake and respiration rates between cultivars. Prolonged exposure of ungerminated seed to high osmotic tensions at low temperatures showed high seed germination recovery. These data suggest that any of the germination criteria used can be effective in selecting droughtresistant cultivars.
Competitive Effects of Several Grass Species and Weeds on the Establishment of Birdsfoot Trefoil1
Authors: Laskey B. C. , Wakefield R. C. 
Published: July 2010

AbstractEstablishment of legume‐grass mixtures on highway rights‐of‐way is complicated by the requirement that seedings be made over an extended period as construction proceeds and erosion control become critical. Permanent seedings are frequently required during the late spring‐early summer period and the late summer‐early fall period when weather conditions are likely to be critical and competition from grasses and weeds may severely retard legume growth. Studies were conducted to determine the competitive effects of three grasses, perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), red fescue (Festuca rubra L.) and also weeds on establishment of birdsfoot trefoil (Lotus corniculatus L.) in the field at four times of the year, September, April, May and June. Plots were established on Enfield silt loam (mixed Typic Distrochrepts). Birdsfoot trefoil plant counts at the seedling and bloom stages showed that ryegrass was the most and red fescue the least competitive grass. Plant establishment of birdsfoot trefoil was significantly higher for the April seeding than for other seeding dates. Growth of birdsfoot trefoil was greater when seeded with Kentucky bluegrass or red fescue than when seeded with ryegrass. Weed competition reduced establishment of birdsfoot trefoil and growth of the legume at all seeding dates. When birdsfoot trefoil was grown alone, weeds produced more competing growth than grasses. However, grasses virtually eliminated weed growth. Reduced stands and yields of birdsfoot trefoil when grown with perennial ryegrass appeared to be due to rapid seedling emergence of the grass at a critical stage in the early growth and development of birdsfoot trefoil. The slower growing grasses, Kentucky bluegrass and red fescue, did not inhibit growth of birdsfoot trefoil since yields were comparable to the legume grown alone. An exception was the September seeding when winter‐killing severely depleted stands of birdsfoot trefoil grown alone.
Investigation and Treatment of Localized Dry Spots on Sand Golf Greens1
Authors: Wilkinson J. F. , Miller R. H. 
Published: July 2010

AbstractSeveral experimental sand golf greens were seeded in 1972 to ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.) in Columbus. Localized dry spots became serious problem during the summer of 1974. Despite heavy, frequent irrigation the soil remained hydrophobic, resulting in patches of dead or severely wilted turf. The turf and thatch would wet, but water would not penetrate the thatch/soil interface. Infiltration rate within the dry spots was studied in the laboratory using a permeameter, and by placing water droplets along horizontally positioned soil cores. Several wetting agent and soil cultivation treatments were utilized in a field study to alleviate the dry spots. The cause of the dry spots was investigated by observing individual sand particles under a scanning electron microscope.The hydrophobic condition was restricted to the upper 2 cm of soil. Infiltration rate within the dry spots was 20% of that for normal turf. Hydro‐Wet and Aqua‐Gro reduced the severity of the dry spots, but a combination of coring plus wetting agent proved most beneficial. Maintaining moist soil conditions was the best defense against the dry spots. Allowing the soil to become dry makes the hydrophobic condition worse.Scanning electron micrographs provided evidence of a coating surrounding individual sand particles. The coating had the appearance of fungal mycelium and was organic and acidic in nature. No specific fungus was isolated that could be shown to be the cause of the dry spots.
Effect of Lime Application on No‐Tillage and Conventionally Tilled Corn1
Authors: Blevins R. L. , Murdock L. W. , Thomas G. W. 
Published: July 2010

AbstractSoil management to control soil acidity resulting from surface applied N fertilizer is an important factor in continuous no‐tillage corn (Zea mays L.) production. The objective of this study was to evaluate the effectiveness of surface‐applied lime in maintaining a favorable soil pH level under continuous no‐tillage and conventional tillage corn systems.Experiment 1 was established in 1971 on a moderately well‐drained Tilsit silt loam (Typic Fragiudults) soil. Lime treatments for both no‐tillage and conventional tillage included: (1) 0 (check), (2) 3.36 mt/ha, (3) 10.08 (4) 3.36 initially + 1.12 mt/ha applied each year, (5) 3.36 initially + 2.24 mt/ha applied every year, and (6) 3.36 initially + 3.36 mt/ha applied after 3 years. After 5 years of continuous no‐tillage corn production the soil surface receiving no lime became extremely acid, pH 4.6. In the no‐tillage plots lime additions resulted in a statistically significant increase in grain yield. Little difference was observed for yield or soil pH changes for the lime treatments that included different frequencies of application. The lime rate based on a soil buffer test recommendation of 3.36 mt/ha was effective in maintaining favorable soil pH and yield levels.Comparison of limed and unlimed treatments in Experiment 2 on deep, well‐drained Maury (Typic Paleu‐ dalfs) soil showed increased yields for liming no‐tillage plots as N‐rates increased, but no significant yield response for lime on conventionally tilled treatments. The surface soil pH level decreased to pH 4.3 on unlimed, no‐ tillage treatments receiving 336 kg N/ha after 7 years of continuous corn. It is concluded that surface liming without incorporation is an efficient way to overcome soil acidity caused by N fertilization of no‐tillage corn.
Effects of Shading on the N2‐Fixation, Yield, and Plant Composition of Field‐Grown Soybeans1
Authors: Wahua T. A. T. , Miller D. A. 
Published: July 2010

AbstractSoybeans (Glycine max L. Merr.) are becoming important in cropping systems that increase competition for light among crops. One of the products of N2‐fixation is protein production. A field study was conducted to determine the effects of various degrees of shading (0,20,47, 63, 80, and 93%) on soybean No‐fixation, grain yield, and plant composition. The soil was a Flanagan series, a fine, montmorillonitic, mesic Aquic Argiudoll. Ambient illumination was 124.2 klux. Various degrees of shading were obtained by using different screens. Acetylene‐ethylene assay was used to determine N2‐fixation.Shading accelerated the rate of loss of total nodule N2‐fixing activity (TNA) as plants developed. The average TNA and dry weight of plant tops were highest at 20% shade (99.3 Klux) and decreased curvilinearly as shading increased, while specific nodule activity decreased linearly. Grain yields under 20, 47, 63, 80, and 93% shade were 90, 75, 48, 18, and 2% of unshaded plants. Seed percent protein and oil content of the seed were virtually unaffected between 20 and 80% shade. The highest percent protein and lowest percent oil occurred at 93% shade. Number of pods per plant percent leaf N, total stem N, TNA, and grain yield were highly correlated with shading and may be good selection indices for soybean shade tolerance. Soybean N2‐fixation was positively correlated with seed protein content (r = 0.77) but negatively correlated with seed protein (r = −0.44). Cropping practices should allow at least 80% ambient illumination measured at the height of 50 cm for substantial soybean No‐fixation.
Influence of K on the Uptake, Translocation, and Reduction of Nitrate by Barley Seedlings1
Authors: Blevins Dale G. , Hiatt A. J. , Lowe R. H. , Leggett J. E. 
Published: July 2010

AbstractThe absorption, translocation, and metabolism of N is influenced by the source of N and by the availability and mobility of counter ions for transport. The purpose of this study was to determine the influence of K or Ca on nitrate uptake, translocation, and reduction in barley seedlings (Hordeum vulgare. cv. Compana). Six‐day‐old barley seedlings were grown for 2 to 36 hours in solutions of 1.0 meq/liter KNO3 or Ca(NO3)2, each containing 0.4 meq/liter of CaSO4. Experiments were conducted in a growth chamber at 27 C with a photosynthetic irradiance of 5.3 mW cm−2. Seedlings treated with Ca(NO3)2 (low K) had lower levels of nitrate uptake, nitrate reductase activity, and lower organic acid concentrations than seedlings treated with 1 mM KNO3. The solution pH and the expressed sap pH of roots and shoots of the low K seedlings increased during the experiment. The shoots of the low‐K seedlings had much lower nitrate concentrations and lower levels of nitrate reductase activity than the roots, suggesting that K plays a major role in nitrate translocation. These results support the hypothesis that potassium malate is cycled from the tops to the roots where decarboxylation occurs, providing a source of HCO3‐ for exchange with NO3‐ during absorption.
Role of Minimum and Maximum Environmental Temperature on Maturation Period of the Cotton Boll1
Authors: Yfoulis A. , Fasoulas A. 
Published: July 2010

AbstractTemperature is critical in boll formation, and in temperate climates earliness is one of the main breeding objectives. The effect of night and day temperature on the boll maturation period of five genetically divergent cultivars of cotton (Gossypium hirsutum L.) was studied in a 3‐year field experiment at Sindos, Greece. Under a 24‐hour cycle (mean temperature 18 to 32 C) night temperature shortened the boll period up to five times more than day temperature. Under a range of 16 to 30 C, day temperature favored boll maturation four to six times greater than night temperature did. The favorable or adverse effect of mean day and night temperature depended on the maximum and minimum temperatures.
Illustration of a Cluster Analysis Method for Mean Separation1
Authors: Gates C. E. , Bilbro J. D. 
Published: July 2010

AbstractNew statistical methods of separating means into different groups should be brought to the attention of researchers so they can decide if the new methods can be used advantageously in their research programs. Our objective was to illustrate the use of a cluster analysis method (which we have called the Scott‐Knott method after the developers) and compare it to the commonly used Duncan's multiple range test. We applied the two methods to four sets of data. The results showed that the smaller the variance of the treatment means, the more similar were the separation groupings produced by the respective methods. However, in contrast to Duncart's procedure, the Scott‐Knott method never produced overlapping mean separation groups and distinct groups of non‐overlapping means are often desired by the researcher. The Scott‐Knott method has more complex calculations than Duncan's method, but it is readily programmable for computers and many desk top electronic calculators.
Irrigation Effects on Vegetative and Reproductive Development of Three Soybean Cultivars1
Authors: Ashley D. A. , Ethridge W. J. 
Published: July 2010

AbstractPrevious investigations have demonstrated a response in soybean [Glycine max (L.) Merr.] yields to supplemental water applications during reproductive development, but few have described the effects of irrigation during different development periods on fruiting patterns and vegetative development in relation to yields. Variables included in this field experiment were four moisture regimes — unirrigated, full season irrigation, irrigation begun at bloom stage, and irrigation begun at pod fill stage — and three cultivars, ‘Ransom’, ‘Hamptom 266A’, and ‘Coker 102’. Data were collected for seed yield, pod number and dry weight, dry weight of vegetative components during reproductive development and seasonal soil moisture status. The soil was a sandy loam (Rhodic Paleudult, clayey, kaolinitic, thermic family). Full season and bloom stage irrigation treatments produced higher yields than the unirrigated check except for Hamptom 266A in 1974. Yields from plants receiving the podfill stage irrigation treatment were higher than the unirrigated check in drier seasons of 1972 and 1973 but not in 1974. Irrigation beginning at pod fill produced yields equal to the full season and bloom stage treatments in some cases and somewhat lower yields in other cases. Higher yields and greater response to irrigation was obtained from shorter, less vegetative Ransom plants than the other two cultivars. Water applications prior to blooming greatly increased vegetative dry weight, and number as well as dry weight of pods. Beginning irrigation during reproductive development had little effect on vegetative dry weight, but usually resulted in a greater number of pods late in the season than the unirrigated check.
Effect of Fertilizers on the Yield and Botanical Composition of Pastures in South Sulawesi, Indonesia1
Authors: Blair Graeme J. , Pualillin Phylipus , Samosir Solo 
Published: July 2010

AbstractInformation on the nutrient status of soils of the outer Islands of the Indonesian Archipeligo is limited. Attempts are being made to establish a cattle industry based on legume pastures, and this work has created a need for detailed nutrient investigations. Legumes have generally failed to produce and persist in large areas of South Sulawesi which are presently covered by Imperata cylindrica. A series of field experiments were conducted to investigate the nutrient status of a Glossudalf soil. Such soils cover large areas of upland country in Sulawesi that are used for cattle grazing. P, K, S, Mo, Cu, and Zn containing fertilizers were broadcast onto field plots that were oversown with Centrosema pubescence. Nutrient responses were measured during a 1‐year period by cutting quadrats from the plots. Responses to S, applied as either elemental S (brimstone) or as sulfate (in superphosphate), and Mo were recorded. In one experiment elemental S, applied at 13 kg/ha, lifted the yield of Centro from 4,068 kg/ha (green) to 10,491 kg/ha (green) over a 17‐week period. The increase in Centro production lead to a decline in the production of Imperata cylindrica.
Relationship Between Leaf Area and Dry Matter in Winter Wheat1
Authors: Aase J. K. 
Published: July 2010

AbstractModels of plant growth and plant water use often require leaf‐area measurements, a potentially time‐consuming and costly process. The objective of this study was to determine if by establishing a relationship between leaf area and dry matter in winter wheat (Triticum aestivum L. em Thell), that dry matter can be substituted for leaf area. Four cultivars of winter wheat were seeded on Dooley sandy loam and Williams loam (fine‐loamy, mixed, Typic Argiborolls) in northeastern Montana in three divergent growing seasons. Leaf area and dry matter determinations, from random 30‐cm row plant samples cut at ground level, were made weekly throughout the season. Leaf area and leaf dry matter were closely correlated (r2= 0.951). Leaf area vs. plant dry matter also was closely correlated (r2 = 0.948) through the fifth growth stage (leaf sheaths strongly erect, tillering complete). Thus it appears that in studies and modeling efforts where leaf area indices are needed, at least for winter wheat, leaf dry matter may be substituted for leaf area index.