bluuebunny/crossref_metadata_2025_split huggingface dataset:
Establishment of Alfalfa by Conventional and Minimum‐Tillage Seeding Techniques in a Quackgrass‐Dominant Sward1
Authors: Mueller‐Warrant G. W. , Koch D. W. 
Published: July 2010

AbstractMinimum‐tillage establishment of forages offers potential advantages over the conventional method in terms of reducing energy and labor requirements, erosion hazard, and improving flexibility, and timeliness of operation. Our objective was to compare these methods of establishing alfalfa (Medicago sativa L.) with various herbicides, time intervals between herbicide application and seeding, and seeding dates. The seedings were established on a Charlton fine sandy loam (Entic Haplorthod) of high fertility in a sward dominated by quackgrass (Agropyron repens L.). Conventional renovation consisted of plowing, disking, cultipacking, and seeding; minimum‐tillage renovation consisted of mowing and seeding with a J. D. Powrtill seeder.Delaying application of glyphosate IN‐(phosphonomethyl) glycine] from 2 to 16 May had no apparent effect upon quackgrass control, but did lead to a significant reduction (52%) in densities of alfalfa seedlings and, subsequently, of second year alfalfa plants in plots seeded 21 May 1977 by minimum‐tillage. At the first harvest of the seeding year, a delay in glyphosate application resulted in significantly lower forage yield (1.84 vs. 2.82 metric tons/ha) and higher percent crude protein (20.0 vs. 16.8%) for the 21 May and 4 June minimum‐tillage seedings. In subsequent harvests, there were no yield differences due to glyphosate application date for alfalfa established by minimum‐tillage. Date of glyphosate treatment did not affect plant densities, forage yield, or quality of conventionally‐seeded alfalfa.For glyphosate treatments, conventional seeding resulted in an average of 0.6 metric tons/ha more alfalfa than minimum‐tillage during the seeding year. Yields of total forage and alfalfa seeded by the two techniques after glyphosate treatment were similar during the second year, except that yields for conventional seeding continued to be higher than for minimum‐tillage for the 4 June seeding (9.2 vs. 8.5 metric tons/ha of alfalfa).In terms of alfalfa and total forage yields, glyphosate was more important for minimum‐tillage than for conventional seedings. EPTC (S‐ethyldipropylthiocarbamate) produced yields similar to glyphosate with conventional seeding, while with paraquat (l,l'‐dimethyl‐4,4'‐ bipyridinium ion) yields were similar to those with glyphosate only at the earliest minimum‐tillage seeding. Seeding without herbicide led to substantial yield reductions, especially with minimum‐tillage seedings.
Forage Quality of selected Warm−Season Weed Species1
Authors: Bosworth S. C. , Hoveland C. S. , Buchanan G. A. , Anthony W. B. 
Published: July 2010

AbstractAlthough weeds are a common component of pasture, hay, and silage, limited information is available on forage quality of warm−season weeds. Forage quality of 17 warm−season weeds and two cultivated forage species seeded in pure stands was determined at vegetative, flowering, and fruiting development stages to ascertain nutritive value for ruminants. At the vegetative stage, 16 of the 17 weed species had greater in vitro dry matter digestibility (IVDMD) than ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] or ‘Millex 23’ pearlmillet [Pennisetum typhoides (Burm) Staph & C. E. Hubb.]. The majority of forbs had crude protein (CP) concentrations of 20% or more at the vegetative stage. Generally, IVDMD declined as plants matured. Some grass weeds were lower in CP and comparable to pearlmillet and bermudagrass. Crude protein concentrations generally declined as plants matured. All weed and forage species had nutritionally adequate amounts of Ca, Mg, and K. Phosphorus levels were sub−optimum for high producing ruminants in seven forbs and had high Ca:P ratios which could cause metabolic disorders in ruminants if used as a sole feed source. Many of these warm−season weed species at the vegetative stage can offer ruminants a nutrient level comparable to that of cultivated grasses such as Coastal bermudagrass and pearlmillet.
Phosphorus Requirements of Soybean and Cowpea as Affected by Mode of N Nutrition1
Authors: Cassman K. G. , Whitney A. S. , Fox R. L. 
Published: July 2010

AbstractA field experiment was conducted on a tropical soil (Humoxic Tropohumult) with a high P sorption capacity to compare the critical external and internal P requirements of soybean (Glycine max (L.) Merr.) and cowpea (Vigna unguiculata (L.) Walp.) as affected by the predominant mode of N nutrition during crop growth. The experiment had a split‐plot design with two N‐level subplots established within each of six P‐level mainplots. Phosphorus treatment ranged from 0.0015 (unamended soil) to 0.08 (1,880 kg P/ha) µg P/ml in 0.01M CaCl2 solutions equilibrated with soil for 6 days. Nitrogen levels were either deficient (plants primarily dependent on N fixation) or sufficient (N fertilizer supplied at rates sufficient to satisfy the crop N requirement). Nitrogen‐fixing soybeans required 750 kg P/ha to obtain a 90% relative yield which was 320 kg P/ha more than that required by N‐supplied plants to obtain a comparable relative yield. The P concentration of N‐fixing soybean plants was significantly lower than that of N‐supplied plants at all levels of applied P fertilizer. The external P requirement and tissue P concentration of cowpea were unaffected by soil N level. The data show that cowpea was more tolerant of P stress than soybean, especially when dependent on N fixation. The cowpea cultivar grown without P or N fertilizer yielded 72% of the maximum yield obtained at optimum P levels while the comparable relative yield for the soybean cultivar was 28%. We conclude that (i) some N‐fixing grain legumes can make respectable yields with little or no P fertilizer while others might not and, (ii) screening N‐fixing grain legumes for tolerance to nutrient stress should be conducted on N‐deficient soil to Insure that nutritional requirements are assessed for the N‐fixing plant, especially on the highly weathered soils of the tropics.
Aluminum Tolerance of Triticale and Wheat Cultivars Developed in Different Regions1
Authors: Mugwira L. M. , Sapra V. T. , Patel S. U. , Choudry M. A. 
Published: July 2010

AbstractThe differential tolerance of crop varieties to high Al is often related to the amounts of labile Al in the soils in which the plants were developed. The objective of this study was to evaluate the Al tolerances of triticale (X Triticosecale, Wittmack) and wheat (Triticum aestivum L.) developed in different regions. Twenty‐seven triticale and 37 wheat cultivars were tested in growth chambers and under greenhouse conditions for Al tolerance in 1/5‐strength Steinberg solution containing 0 or 6 ppm Al, highly Al‐toxic Bladen soil ((Typic Albaquult), and mildly Al‐toxic Dothan soil (Typic Paleudult). The Bladen soil had a pH of 4.6 and KCl‐extractable Al of 3.75 me.e/100 g. The corresponding values for the Dothan soil were 4.5 and 1.45, respectively. Each cultivar was also grown in soils limed to pH 5.8. The relative root lengths (A1/no A1) of two triticale and six wheat checks in the nutrient solutions were correlated to their relative top growth (unlimed/limed) in the Bladen soil but not in the Dothan soil. When grown in nutrient solutions, Al tolerance of the triticales followed the order Canada and Mexico > California > Alabama > Oregon while in the Bladen soil Alabama triticales had higher Al tolerance than Canadian triticales. On the average, Brazilian wheats had higher A1 tolerance than U.S. wheats. Wheat varieties from Indiana and the Plains States were more sensitive to A1 than those developed in the Eastern States. There were large differences in the A1 tolerances of triticale cultivars from each region probably reflecting differences in the A1 tolerances of the parent species. More work should be conducted with triticales from stable and non‐segregating lines.
Seasonal Nitrogen Fixation and Dry Matter Accumulation by Peanuts1
Authors: Tonn W. H. , Weaver R. W. 
Published: July 2010

AbstractYield improvement of peanut (Arachis hypogaea L.) is partially dependent on N nutrition. The differential ability of peanut cultivars to fix N symbiotically and best utilize this N supply are traits that may be useful in plant breeding. Four peanut cultivars representing Spanish and Virginia subspecies var. vulgaris and var. hypogaea, respectively, were grown for 1 year on a sandy soil to determine seasonal patterns of nodulation, acetylene reduction, and N accumulation in pods, leaves, and stems. The two Virginia cultivars ‘Florunner’ and ‘Florigiant’ accumulated more N in vegetative organs than the Spanish cultivars ‘Tamnut 74’ and ‘Starr’. The Virginia cultivar also maintained a higher percentage N in the leaves throughout the season than did the Spanish cultivars. The Virginia cultivar tended to accumulate N in fruit at a faster rate than the Spanish cultivars. Nodule mass on the Virginia cultivars was more than 50% greater than on the Spanish cultivars at midseason. Acetylene reduction was also substantially higher for the Virginia cultivars at midseason. Conclusions are restricted because severe insect damage to plants terminated the experiment approximately 3 weeks before the normal harvest date. The result suggest that the Virginia cultivars have greater N fixing capability than Spanish cultivars.
The Influence of Sorghum‐Sudangrass Roots on Nutrient Leaching1
Authors: Long F. Leslie 
Published: July 2010

AbstractAn active root system can reduce leaching by taking up water and nutrients and transporting them to the aboveground portion of the plant, but little is known concerning the quantitative influence of roots on leaching. This study was conducted to determine the influence of sorghum‐sudangrass (Sorghum bicolor [L.] Moench ✕ S. sudanense (Piper) Stapf) roots on the movement of NO3, K, Ca, and Mg in a simulated field soil profile of Dothan loamy sand (Plinthic Paleudults) in the Auburn rhizotron.Two rates of N (250 and 500 kg/ha) and one rate of K (63 kg/ha), Ca (50 kg/ha), and Mg (25 kg/ha) were applied. Nutrient movement was monitored by analysis of soil solution samples taken at 48 to 72‐hour intervals over a 132‐day period from depths of 20, 40, 60, 80, 100, 120, 140, and 180 cm. Soil water status was determined by tensiometers and the neutron‐scattering technique. Rainfall and supplemental irrigation maintained soil water tension generally less than 0.3 bar. Sorghum‐sudangrass roots proliferated the soil profile to 160 cm and reached a maximum density of 3 cm root length per cm8 of soil in the Ap horizon, with lesser amounts in the A2 and B horizons. Roots took up NO3 and did not allow any appreciable leaching below 80 cm at 250 kg of N/ha or below 100 cm at 500 kg of N/ha. Root uptake of K was sufficient to prevent any appreciable accumulation of K at any depth measured. Uptake of Ca and Mg was sufficient to virtually prevent leaching of these nutrients below 40 cm at 250 kg of N/ha or below 80 cm at 500 kg of N/ha. From the results of this study, it is evident that nutrient leaching through soil can be virtually eliminated by the natural mechanism of root uptake, thereby preventing any possible pollution of groundwater.
Glyphosate Timing Effects on Establishment of Sod‐Seeded Legumes and Grasses1
Authors: Welty L. E. , Anderson R. L. , Delaney R. H. , Hensleigh P. F. 
Published: July 2010

AbstractSod‐seeding establishment of small‐seeded legumes and grasses has great potential for increasing forage production on previously non‐tillable lands. However, consistently successful stand establishment has been difficult to achieve via sod‐seeding. Even when adequate stands are obtained, they often lack the vigor associated with conventional establishment. A delay between the spraying of a non‐selective chemical for sod control and seeding with a minimum‐till drill has been suggested to improve sod‐seeding stand establishment. We conducted two field experiments to determine the optimum time interval needed between spraying glyphosate [N‐(phosphonomethyl) glycine] and sod‐seeding various grass and legume species with minimum‐till drills. The soils were classified as Cumulic Haploborolls and Ustic Tomfluvents in the first experiment and Udic Haploborolls and Typic Eutrochrepts in the second.A 14 day interval between spraying glyphosate and sodseeding alfalfa (Medicago sativa L.), alsike clover (Trifolium hybridum L.), and tall fescue (Festuca arundinacea Schreb.) with either the John Deere Powr‐till drill or the Melroe 701 No‐till drill was needed for adequate establishment at Laramie, Wyoming in 1978. In 1979, a 7 to 14 day spray‐plant interval was needed for adequate establishment of alfalfa, alsike clover, creeping meadow foxtail (Alopecurus mundinaceus Poir.), and meadow bromegrass (Bromus biebersteinii Roem. & Schult.) when seeding with the John Deere drill. When seeding with the Melroe drill in 1979, no differences among spray‐plant intervals were obtained for the same species.At Kalipell, Montana in 1978, a 28 day delay between spraying glyphosate and sod‐seeding alfalfa with the John Deere drill was needed for adequate establishment; whereas ladino clover (Trifolium repens L.) required a 14 day interval between spraying and seeding. In 1979 at Kalispell, a 28 day spray‐plant interval was needed for adequate establishment of alfalfa. Ladino clover establiihment was very poor for all spray‐plant intervals. Inadequate legume establishment was associated with slug (Agriolimax reticulatum Müller) predation. Spraying 28 days prior to seeding allowed sufficient time for grass desiccation. This permitted sunlight to penetrate the canopy which dried out the furrow thereby providing a less favorable slug environment.
Determining Soil‐Induced Plant Water Potential Depressions in Alfalfa by Means of Infrared Thermometry1
Authors: Idso S. B. , Reginato R. J. , Reicosky D. C. , Hatfield J. L. 
Published: July 2010

AbstractTo ascertain the ability of a remote sensing technique to evaluate the soil‐induced component of plant water potential depressions in forage crops, field experiments were conducted to measure the air vapor pressure deficit and foliage‐air temperature differentials of well‐watered alfalfa (Medicago saliva L.) at five different sites throughout the United States. At two of these sites, data were also acquired for various degrees of stressed alfalfa along with concurrent measurements of total plant water potential. The temperature and vapor pressure data were used to construct a plant water stress index which was related to the plant water potential. Different results were obtained for the two sites studied; but after a procedure was developed to remove variable atmospheric effects, the remaining soil‐induced plant water potential depressions were found to be well described by a single function dependent upon the plant water stress index. These results demonstrate the ability of surface temperature measurement by means of infrared thermometry to rapidly assess large areas of cropped land for plant water potential depressions arising from shortage of soil moisture.
Grain Yields, Soil Water Storage, and Weed Growth in a Winter Wheat‐Corn‐Fallow Rotation1
Authors: Hoefer R. H. , Wicks G. A. , Burnside O. C. 
Published: July 2010

AbstractThis research involves factors affecting crop production in a no‐till crop rotation of winter wheat (Triticum aestivum L.)−corn (Zea mays L.)−fallow. Experiments were conducted in the field at North Platte, Nebr. during 1974 to 1977 on a Holdrege silt loam (fine−silty, mixed, mesic Typic Argiustolls) to determine the effect of weed control in growing winter wheat and stubble after harvest on annual weed growth, soil water storage, and winter wheat and corn yields. Winter wheat was an excellent competitor to weeds. Winter wheat allowed to grow until harvest (10 July) reduced weed weight taken 7 weeks after harvest (1 September) 56% as compared with plots where winter wheat and weeds were removed on 22 May. Weed competition reduced winter wheat yields by 15% in 1975 but not in 1976 when weeds succumbed to drought and competition from winter wheat. Glyphosate [N−(phosphonomethyl)glycine] applied after winter wheat harvest did not immediately kill weeds which resulted in unnecessary soil water loss when compared to plots receiving tillage. Volunteer wheat and weeds emerged after an application of glyphosate or one tillage after harvest. A residual herbicide should be applied to prevent these weeds from using soil water. Weeds in plots that were allowed to produce viable seed in the winter wheat or in the stubble after harvest significantly reduced weed control in corn planted the following spring as compared with plots in which weeds were not allowed to produce viable seed. Escaped weeds that produce seed during any period of a crop rotation will provide competition to subsequent crops. Standing stubble trapped snow which increased corn yields as compared to plots where tillage had knocked stubble down. Removal of winter wheat stubble after corn planting caused less brace root penetration, more lodging. and reduced corn yields 15% as compared to plots where stubble was left undisturbed.
Fallow Systems for Winter Wheat in Western Nebraska1
Authors: Fenster C. R. , Wicks G. A. 
Published: July 2010

AbstractThe need for conservation of soil and water and the energy situation makes it imperative to develop more efficient fallow systems for controlling weeds, to utilize moisture efficiently, and maximize wheat production under limited rainfall.Research was conducted at North Platte and Sidney, Nebr. from 1972 through 1977 to develop a weed control program in a limited and no‐tillage winter wheat (Triticum aestivum L.)‐fallow rotation. The experimental areas in fallow were sprayed with glyphosate [N‐(phosphonomethyl)glycine] at 0.8 kg/ha after harvest to eliminate soil water loss from existing weeds in wheat stubble. Six tillage and/or herbicide treatments were applied to separate replicated plots the first few days of August, October, and April.Atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] + glyphosate at 0.8 + 0.8 kg/ha at Sidney and 1.3 + 0.8 kg/ha at North Platte was the most effective fallow weed control treatment but allowed too much weed growth 65 and 77 Mg/ha, respectively. Downy brome (Bromus tectorum L.) control at North Platte was unsatisfactory with August application of atrazine which left 40 plants/m2. Russian thistle (Salsola kali L. var. tenuifolia Tausch) and volunteer winter wheat were not always controlled in April by herbicides that were applied in August or October. The earlier the herbicides were applied during the fallow period the sooner subsequently emerging weeds appeared the following spring. Tillage reduced wheat residues 42% at Sidney and 78% at North Platte when compared to the no‐tillage plots. April tillage at North Platte had less weed growth because August and October tillage planted volunteer wheat and downy brome. Plots treated with residual herbicides stored 24 and 21% more soil water at Sidney and North Platte than tillage treatments. Wheat yields were increased 11% on no‐till plots only at North Platte when compared to tillage. Grain yields were not significantly different when comparing time of initial fallow treatments.
Influence of Mycorrhizae on the Mineral Contents of Cowpea and Soybean Grown in an Oxisol1
Authors: Yost R. S. , Fox R. L. 
Published: July 2010

AbstractCowpea (Vigna unguiculata) and soybean (Glycine max) were grown in the field on a Tropeptic Eutrustox which, for a period of 8 years, had been maintained at 10 different soil P levels by appropriate P fertilizer applications. Effects of methyl bromide fumigation of the soil on mycorrhizal infection and concentrations of P and other nutrients in the plants were compared. Plants grown on nonfumigated soils with soil P levels below 0.025 to 0.05 mg P/liter contained higher Ca and K percentages than plants grown on fumigated, low P‐status soils. Differences in Ca and K percentages in the plants were more closely related to crop growth rates than to vesicular arbuscular mycorrhizal infection levels. Differences in Ca and K percentages were small. In contrast, silicon percentages of mycorrhizal soybean plants were 0.5 to 0.9% Si while non‐mycorrhizal plants contained 0.2 to 0.3% Si. The pattern of Si percentages at different levels of soil P was different from that of other nutrients. The levels of Si in mycorrhizal soybean plants were greater than in non‐mycorrhizal plants at all levels of soil P, while with other nutrients, differences diminished with increasing soil P level. Crop growth rate and P absorption strongly affected the percentage composition of other nutrients with the notable exception of Si. If mycorrhizae consistently enhance Si uptake by plants such as soybean then Si uptake may indicate mycorrhizal activity. Silicon content of cowpea, however, was not altered by the presence or absence of mycorrhizae.
Growth and Yield Response of Chile Pepper to Trickle Irrigation1
Authors: Beese F. , Horton R. , Wierenga P. J. 
Published: July 2010

AbstractOptimizing rates of water application to irrigated crops is an important method for conserving water in arid areas. Trickle irrigation is one method of applying water to crops with minimal losses. This field study was conducted to determine chile (Capsicum annuum L.) growth and development when irrigated by trickle irrigation at different levels of water application. Chile peppers were grown on a 2‐ha field irrigated with a trickle irrigation system. Water application rates of 0.8, 1.2, and 1.4 times a control treatment were maintained from mid‐June (74 days after emergence) to maturation in September. Throughout the growing season measurements were made of leaf area index, and of the accumulation of dry matter in stems, leaves, roots, and pods. The data show a clear response of the rate of leaf area development and dry matter production to water application rates. From the start of treatments the dryer treatments had lower rates of leaf area development and dry matter production, resulting in lower final yields of above and below ground plant parts. However, water use efficiencies varied little and were between 8.1 and 8.2 cm actual ET per ton of dry mass production. The results indicate that limiting the water applied to chile during the period of rapid vegetative growth reduces final yield, but has limited effect on water use efficiency.