bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residual Effects of N Fertilization on Dryland Spring Wheat in the Northern Plains. I. Wheat Yield and Water Use1
Authors: Alessi J. , Power J. F. 
Published: July 2010

AbstractData are frequently lacking to quantify the residual effects of fertilizer applications on soil nutrient availability, especially in regions of limited rainfall. Therefore, the effects of fertilizer N on yields of continuous dryland spring wheat (Triticum aestivum L.) grown on Typic haploboroll soil were determined in a field study at Mandan, North Dakota. Rates up to 540 kg N/ha applied either (i) all in 1 year, (ii) one‐third of the total rate in each of 3 years, or (iii) one‐sixth of the total rate each year for 6 years of the experiment. Average dry matter (1967–1972) at different stages of growth and average grain yields were increased significantly by increased N rate, but only dry matter at tillering was significantly affected by rate × timing interaction. With 270 and 540 kg N/ha applied in only the first year, residual effects significantly increased grain production in 4 of the following 5 years. At total rates of 135 kg N/ha or above, total grain yield for the 6‐year period was greatest for the 6‐year fertilization treatment and least for the 1‐year treatment. Average annual grain yields for the 540 kg N/ha rates were 1,700, 1,660 and 1,880 kg/ha for the 1, 3, and 6‐year treatments, respectively, and 1,050 kg/ha for the zero‐N treatment. Weight of grain produced per kilogram of fertilizer N applied usually decreased as N rate increased. At the 135 kg N/ha rate or higher, grain production per unit of fertilizer applied was greatest for the 6‐year treatments (annual fertilization). Root weight and development in the 6th year were related to the availability of soil N as reflected by fertilizer treatment.Total water use was significantly influenced by N rate or frequency of fertilization in only 2 of the 6 years. Water use efficiency (WUE) increased as N rate increased, irrespective of fertilization frequency. Highest WUE was obtained by 6‐year fertilization treatment and for most treatments WUE decreased .when annual fertilization ceased. Although residual N derived from previous fertilization seems to be very important for subsequent crop production, availability of N from residual sources was not sufficient to maintain maximum crop production over a number of years.
Effect of Phosphorus Nutrition on Response of Perennial Ryegrass Cultivars to Maleic Hydrazide1
Authors: Nittler L. W. , Kenny T. J. 
Published: July 2010

AbstractPreviously perennial ryegrass, Lolium perenne L., cultivars were found to differ in response to soil treated with maleic hydrazide (l,2‐dihydro‐3,6‐pyridazinedione). However, several cultivars were similar in response to the chemical and results varied from one experiment to the next. The investigation reported here was conducted to improve precision and reliability of cultivar purity tests in which maleic hydrazide (MH) is used. Sand‐nutrient culture was used to eleminate soil type as a variable. Every 4th day seedlings were supplied either with a complete nutrient solution or with a solution lacking phosphorus. After the first 12 days, flats on which the solution lacking P was used were supplied with a complete nutrient solution. Starting 18 days after planting, a 300 ppm MH solution was applied to the sand every 4th day. Photoperiods were 8 hours and temperature was 25 C during light periods and 16 C during dark periods. Upper leaf blades started to become chlorotic 12 days after MH treatment was started and cultivars differed markedly. Cultivar differences were greater for plants grown without P the first 12 days than for plants grown with complete solution the entire experiment. The upper leaf blade of most ‘NK‐200’ plants became yellow but the next lower leaf blade remained green. In contrast, both upper and second leaf blades of ‘Manhattan’ plants tended to remain green. Second leaf blades of ‘Pennfine’ plants tended to become chlorotic at about the same rate as upper leaf blades. This procedure resulted in greater contrast between cultivars than was obtained in previous experiments. A series of ten experiments demonstrated that very similar results can be obtained from one experiment to the next.
Effect of Vel 4207 and Dicamba on Bermudagrass and Broadleaf Weeds1
Authors: Johnson B. J. 
Published: July 2010

AbstractControlling weeds in turfgrasses without injuring the turf and surrounding plants in turf areas is a major concern. Dicamba (3,6‐dichloro‐o‐anisic acid) has been widely used for broadleaf weed control in turfgrass. Since dicamba leaches through the soil it is likely to cause chemical damage to other than turf plants in the area. These field studies were initiated to determine if Vel 4207 [N‐phenyldiethanolamine bis (2‐methoxy‐3,6‐dichlorobenzoate)] which leaches less in the soil than dicamba would give comparable weed control and without serious injury to turf. The soil types were Cecil sandy loam (Typic Hapludult), Pacolet sandy loam (Typic Hapludult), Gwinnett sandy clay loam (Typic Rhodudult), Durham sandy clay loam (Typic Hapludult) and David sandy clay loam (Rhodic Paleudult) in the weed experiments and Appling sandy clay loam (Typic Hapludult) in the turfgrass tolerance experiment. Dicamba and Vel 4207 at 1.1 and 2.2 kg/ha were applied as single and repeated treatments for comparison of weed control in dormant bermudagrass [Cynodon dactylon (L.) Pers.] and to determine the effects of these chemicals on quality of five actively growing bermudagrass cultivars. There was no difference in control of common chickweed [Stellaria media (L.) Cyrillo] with either Vel 4207 or dicamba. Two applications of Vel 4207 at 1.1 kg/ha were required for satisfactory control of spur weed (Soliva sessilis P.&K.) and henbit (Lamium amplexicaule L.) while similar control was obtained with a single dicamba treatment. One application of dicamba at 2.2 kg/ha controlled a higher percentage of corn speedwell (Veronica arvensis L.) than Vel 4207 applied at the same rate. However, the control was equal when each was applied in two applications at 2.2 kg/ha. Vel 4207 did not control parsley‐piert (Alchemilla microcorpa Boissier Reuter) satisfactorily while two applications of dicamba at 2.2 kg/ha resulted in acceptable control. When Vel 4207 was applied to actively growing bermudagrasses, the turf tolerance varied with cultivars. It was just as safe as dicamba treatments, however, and there was no difference in quality of turf in treated or untreated plots by 7 weeks after treatment. These results suggest that Vel 4207 can possibly be substituted for dicamba for the control of selected winter annuals.
Minimum vs. Conventional Tillage in Commercial Sugarbeet Production1
Authors: Glenn D. M. , Dotzenko A. D. 
Published: July 2010

AbstractIn recent years, minimum tillage practices have been applied to sugarbeet (Beta vulgaris L.) production in northeastern Colorado to reduce soil erosion and fuel demands. The objective of this study was to compare the effectiveness of rotary‐strip, no‐plow minimum tillage to conventional plow‐based tillage on commercial sugarbeet fields under center‐pivot sprinkler irrigation relative to soil nitrate movement, weed control, stand establishment, soil compaction, field operations, yield and quality. Minimum tillage was compared to conventional plow‐based tillage in 16 center‐plot‐irrigated fields in eastern Colorado. A 0.10‐ha study site was located in a representative portion of each field. Soils were aridic Argiustoll members of the fine montmorillinitic mesic family. In the spring and midsummer, stand counts and weed counts were conducted to determine stand establishment and the effects of tillage systems on weed populations. Five‐foot deep soil cores were collected in June, July, and November to monitor nitrate movement in each field. After all field operations were completed prior to harvest, water infiltration, soil compaction, soil aggregate distribution, and aggregate stability studies were conducted to determine any differences due to tillage system. Minimum‐tilled sites had significantly lower proportions of furrow soil aggregates 6.4 mm and less in diam but had a higher percentage of aggregates 12.7 to 38.0 mm in diam. Minimum tillage significantly reduced the percentage and stability of row soil aggregates 0.84 to 6.4 mm in diameter. The stability of row and furrow aggregates decreased with increasing size. Nitrate movement was greater and larger concentrations of nitrate were moved to a depth of 75 cm under minimum tillage. The method of tillage had no effect on row and furrow bulk density, water infiltration rate, weed populations, emergence percentage, final stand, yield, quality, or recoverable sucrose. The results demonstrate that minimum tillage produced a sugarbeet crop of comparable tonnage and quality to that of conventional tillage while significantly reducing the number of field operations by 40%.
Chlorotic Dieback in Flax1
Authors: Moraghan J. T. 
Published: July 2010

Abstract“Chlorotic dieback” of flax (Linum usitatissimum L.) is characterized by leaf chlorosis, dieback of terminal buds, and development of lateral branches; its occurrence is most frequent under cool soil conditions. The cause of this disease was studied under greenhouse conditions. Flax was grown on a calcareous soil (Calciaquoll) at three soil temperatures (7, 16, and 24 C) in the presence and absence of different levels of FeEDDHA and ZnSO4. The dieback syndrome occurred in the absence of Zn at 16 and especially 7 C but not at 24 C. Zinc accumulation in plant tops for a given fertilizer treatment dcreased progressively as soil temperature was reduced from 24 to 7 C. Zinc deficiency in mature plants was associated with plant Zn levels less than approximately 20 ppm, and its severity was inversely related to soil temperature. FeEDDHA decreased Zn and Mn accumulation in plant tops and, in the absence of added Zn, increased degree of Zn deficiency. FeEDDHA with added Zn eliminated leaf chlorosis and spotting of older leaves and increased Fe concentration in young plants. Dieback of main stems and subsequent branch development from the cotyledonary node, the chief features of “chlorotic dieback”, were found to result from Zn deficiency; however, the leaf chlorosis aspect of the disease was influenced by available soil Fe. Apical dominance in flax was decreased by Zn deficiency; soil temperature indirectly affected this characteristic through its influence on plant Zn accumulation. However, the influence of soil temperature on apical dominance was more complex since lateral branch development even in the presence of added Zn was greatly affected by soil temperature. Phosphorus accumulation in flax was markedly decreased by low soil temperatures.
Fragmentation of Cotton Bract and a Technique for Detecting Bract in Cotton Dust1
Authors: Morey P. R. , Raymer P. L. 
Published: July 2010

AbstractBract fragments are thought to be a major component of the respirable dust generated during the processing of cotton (Gossypium sp.) lint in textile mills. Byssinosis is an occupational disease affecting susceptible textile workers exposed to respirable dust. Procedures designed to reduce mill dust require that the dust components be identified. The cotton bract is a candidate component. The objectives of this study were (A) to determine if changes occur in the friability and structure of bract during postanthesis development and (B) to develop a tracer technique suitable for following the micronization of this plant part. Whole bracts were collected from greenhouse‐grown cotton, ‘Tamcot SP21’. Bract friability was determined by placing whole bracts in porcelain jars and abrading these plants with porcelain cylinders for ½‐hour on a roller mill. Whole anthesis bracts were broken apart to the extent that 6% of their weight was collected in a particle size fraction < 250 μm. By contrast, in bracts collected from 20 to 120 days postanthesis there was a trend toward a greater percent of the bract to be broken apart to a particle size of < 250 μm by the same procedure. Observation of tissue sections prepared from bracts showed that this change in friability was associated with an increased number of lignified bundle sheath parenchyma cells and tracheary elements in bract veins. Other anatomical changes accompanying bract senescence included significant decreases in epidermal, mesophyll, and lamina thickness at or shortly after the time of capsule dehiscence. Four fluorescent dyes and two fluorescent brightening agents were applied separately in aqueous solution to cotton bract and leaf trash. Colour Index Basic Yellow 37 was found to be the most suitable dyeing agent. Two‐ to 10‐μm diameter particles obtained from the pulverized remains of dyed bract were distinguished from undyed bract particles of the same size by observation with an epifluorescence microscope using a 334‐ to 365‐nm exciter beam at a magnification of 625 ✕. Significant differences in friability of dyed and undyed bract were not observed by roller mill tests. It is reasonable to conclude that these tracer procedures will identify the bract component in respirable cotton mill dust.
Maintaining Tall Fescue Stands in Association with Bahiagrass1
Authors: Hoveland C. S. , McCormick R. F. , Carden E. L. , Rodriguez‐Kabana R. , Shelton J. T. 
Published: July 2010

AbstractBahiagrass (Paspalum notatum Flugge) generally dominates the sward when grown in association with tall fescue (Festuca arundinacea Schreb.) in the lower southeastern U.S. If a management system could be devised to maintain tall fescue in association with bahiagrass, this mixture could provide grazing over a longer season than either of the two grasses when grown alone. The objective of this study was to determine the influence of rates and time of N application and stubble height on persistence and productivity of a tall fescue‐bahiagrass sward. ‘Pensacola’ bahiagrass was overseeded on established ‘Kentucky 31’ tall fescue at two field locations in central (typic hapludult, fine‐loamy siliceous soil) and southern (typic hapludult, coarse‐loamy, siliceous soil) Alabama. Five rates of winter and summer‐applied N were used in combination with summer rest and summer stubble heights of 10 and 4 cm over a 3‐year period to measure seasonal forage production and persistence. Winter application of 224 kg N/ha and summer resting or summer cutting at a 10 cm stubble resulted in best tall fescue persistence. Summer cutting to a 4‐cm stubble reduced tall fescue stands and production, regardless of N rates or time of application. Total forage yields were highest when bahiagrass dominated the sward. Tall fescue persisted better in central than in southern Alabama. Seasonal productivity of a tall fescue‐bahiagrass mixture during the third year was best with a winter N rate of 224 kg/ha N and summer stubble height of 10 cm. Both summer N and close clipping accelerated the shift from tall fescue to bahiagrass. This study emphasized the difficulty of maintaining tall fescue stands in association with bahiagrass. Nematode populations build to high levels in these sandy loam soils and seriously damage tall fescue while bahiagrass is relatively tolerant. Only under high rates of winter N fertilization and a high summer stubble height was it possible to maintain tall fescue in the mixture in central Alabama. Further south, bahiagrass can be expected to dominate the sward in a few years, regardless of management.
Time and Frequency of Irrigation in Relation to Growth Stages of Barley1
Authors: Sepaskhah A. R. 
Published: July 2010

AbstractCompetition of winter and summer annual crops for irrigation water is a vital problem in areas of short water supply. Proper time and frequency of irrigation are essential for the most effective use of water and optimum grain yield of barley (Hordeum vulgare L.). This experiment was conducted in a calciorthids clay loam soil and in a region with 10‐year average rainfall and evaporation of 252 and 1,453 mm, respectively. Complete randomized design was used to compare the effects of no irrigation (I0); one irrigation at either heading (I1), flowering (I2) or dough stage (I3); two irrigations at either heading and flowering (I12), heading and dough stage (I13) or flowering and dough stage (I23); and three irrigations at the heading, flowering, and dough stage (I123) on the grain yield, yield components and water use efficiency of Zarjo barley for 2 years. One irrigation at the flowering stage resulted in an average grain yield increase of 35% compared with no irrigation treatment and was found to be preferable to irrigations at any other stages of growth with respect to both grain yield production and water use efficiency. The lower grain yields at the no irrigation and the one irrigation at dough stage treatments were resulted mainly from the lower weight of 1,000‐seed. Flag leaf xylem water potential lower than −25.8 bars possibly reduced the translation of assimilates into the grain and caused the lower weight of 1,000‐seed. The straw yield was not affected by the irrigation treatments since they were imposed after completion of vegetative growth. One irrigation a the flowering period may be suggested for obtaining both higher water use efficiency and grain yield of barley as winter‐annual crop under irrigation in the southern region of Iran.
Effect of Peanut Hulls on the Performance of Corn1
Authors: Lutz J. A. , Jones G. D. 
Published: July 2010

AbstractDisposal of peanut (Arachis hypogaea L.) hulls, after separation from the seed, is a serious problem in the peanut production areas of southeastern Virginia. Limited amounts of peanut hulls are used for mulch around shrubbery, but commercial use is limited, resulting in a large volume being burned, thus contributing to the pollution hazard. Became of their chemical composition and potential use as a mulching material, it is thought that they may be of considerable importance in corn (Zea mays L.) production. The objective of this investigation was to evaluate the effect of peanut hulls on the growth, yield, and chemical composition of corn, and on soil moisture. The experiment was conducted for 2 consecutive years on Tatum (Typic Hapludults, clayey, mixed, thermic) silt loam at Orange, Virginia. Hulls were applied at rates of 0, 21, 42, and 84 metric tons/ha on unfertilized plots and on plots that received 112 kg N/ha, 49 kg P/ha, and 93 kg K/ha. Hulls increased the growth and yield of corn by increasing the available moisture content in the 0‐ to 15‐cm soil depth. Hulls also increased the K concentrations of corn silage from 0.99 to 1.77% on unfertilized plots and from 1.32 to 2.04% on fertilized plots. The Mg concentration was decreased from 0.43 to 0.25% on unfertilized plots and from 0.35 to 0.29% on fertilized plots. The N, P, and Ca concentrations of corn silage were not significantly affected by peanut hull applications. Hulls did not increase the number of nematodes in the soil. Results of this experiment indicate that peanut hulls can be used effectively in corn production.
Effect of Nitrapyrin on Nitrification of Fall and Spring‐Applied Anhydrous Ammonia1
Authors: Touchton J. T. , Hoeft R. G. , Welch L. F. 
Published: July 2010

AbstractNitrification of ammonium fertilizers in late fall and early spring and subsequent nitrate losses through leaching and denitrification are a continuing economical and environmental concern. To evaluate the effects of nitrapyrin on nitrification, anhydrous ammonia with and without nitrapyrin was applied in the fall and spring to poorly drained soils in southern, central, and northern Illinois. Nitrogen and nitrapyrin rates ranged from 0 to 268 and 0 to 1.12 kg/ha, respectively. Detailed sampling from ammonia retention zones was conducted throughout the fall, spring, and summer. Effects of nitrapyrin on nitrification varied with time of application, nitrapyrin rate, and soil type. In central Illinois, nitrification of fall‐applied N, with or without nitrapyrin, was relatively rapid in a silty clay loam soil until the soil temperature dropped below 10 C, but less nitrification occurred when nitrapyrin was applied. On similar soil in the northern part of the state, when the soil temperature was below 10 C at application, nitrapyrin was more effective in controlling nitrification. Time required for amonium‐N in soil to drop to levels equal to that in the control (no N or no nitrapyrin) increased with N and nitrapyrin rates except with spring‐applied N in central Illinois in 1975 where increasing nitrapyrin rates above 0.28 kg/ha had no additional effect on inhibition of nitrification rates. Nitrapyrin applied to a silt loam soil in southern Illinois in the spring or fall of 1975 had no significant effect on nitrification, but nitrapyrin used with spring‐applied N in 1976 was effective in controlling nitrification through early June.
Analysis of Fallow‐Farming Systems in Semi‐Arid Africa Using a Model to Simulate the Hydrologic Budget1
Authors: Hall Anthony E. , Dancette Claude 
Published: July 2010

AbstractA model was developed to predict bare soil evaporation, crop water use, and the distribution of water in the soil. Comparisons with hydrologic budget data obtained in the field with bare soil, cowpeas (Vigna unguiculata (I.,) Walp.), and millet (Pennisetum typhoides (Burm. f.) S. and W.) indicated that the models performed adequately for the conditions and objectives of the study. Simulations of annual fallow, predicted that the amounts of water conserved in the soil would rapidly decrease with decreases in annual rainfall. Simulations of partial year fallow, achieved by weed removal after harvest of 90‐day or 75‐day millets were evaluated through an 8‐ year period of wet, dry, wet, and dry years having an average, monomodal rainfall of 502 mm. The simulations predicted that substantial quantities of water may be conserved in the soil by partial fallow during wetter years. More soil moisture would be conserved with the shorter cycle variety, but the longer cycle variety would have greater need for this moisture in this climatic zone during dry years, indicating a possible advantage of rotations involving short cycle, and long cycle crops. Shorter cycle varieties and partial fallow could also increase ground water recharge. The simulations predicted that present varieties may only use a small proportion of the moisture that may be stored below 150 cm depth in the soil by partial fallow, indicating a possible need for developing varieties with faster growing, deeper, root systems.