bluuebunny/crossref_metadata_2025 huggingface dataset:
Soybean Plant Damage and Yields as Affected by Metribuzin and Seed Quality1
Authors: Gossett B. J. , Morgan L. F. , Murphy T. R.
Published: July 2010

Crop safety is a concern when metribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐as‐triazin‐5(4H)‐one] is used as a preemergence for weed control in soybeans [Glycine max (L.) Merr.] on coarse textured soils having a low organic matter content. Six field experiments were conducted on soils that were Typic Hapludults, Typic Udifluvents, and Typic Paleudults. In each experiment three soybean cultivars were used to determine if excessive metribuzin rates interact with various seed quality factors to influence the margin of safety to soybean plants. The cultivars were ‘Bragg’, ‘Bossier’, and ‘Hampton 266A’. Seed quality factors included 1 and 2‐year‐old seed with different germination percentages, physically damaged vs. nondamaged seed, and large vs. small seed sizes. Metribuzin was applied at 0.0, 0.84, and 1.68 kg/ha to the soil surface immediately after planting.

In most experiments, both metribuzin and seed quality factors affected plant damage ratings, final stands, mature plant heights, and grain yields. In seed germination and seed damage experiments, none of the seed quality ✕ metribuzin interactions were significant for any of the measured parameters. However, in the seed size experiments, metribuzin caused more plant damage and a greater reduction in final stands and heights of plants from small than from large seed, but grain yields were not affected. From a practical standpoint, this may be of little or no importance since seed size extremes in these studies probably do not occur in normal seed lots, and plant performance differences did not appear to warrant separating specific seed sizes from a given lot. Our results suggest that metribuzin ✕ seed quality interactions do not frequently result in increased plant damage, reduced stands and height of plants, and lower grain yields, but their effects are additive. Therefore, uneven stands and apparent herbicide damage symptoms may be diagnosed only as herbicide damage when actually seed quality factors may be contributing to the problem.
Kentucky Bluegrass Seed Production Characteristics as Affected by Residue Management1
Authors: Hickey V. G. , Ensign R. D.
Published: July 2010

Seed productivity of Kentucky bluegrass (Poa pratensis L.) is usually improved by open field burning of post‐harvest residue. This field study compared the effects of field burning and mechanical removal of post‐harvest residue on Kentucky bluegrass plant growth and seed yields. ‘Merion’, ‘Nugget’, ‘Baron’, ‘Glade’, and ‘South Dakota’ Kentucky bluegrass cultivars were seeded on a Latahco soil, (fine‐silty, mixed, frigid argiaquic Agrialboll) in 1976. Residue removal treatments were stripped across the cultivars in 1977, 1978, 1979, and 1980. Seed yields where residue was removed by burning were 1.5 times greater in 1979,1.6 times greater in 1980, and 1.7 times greater in 1981 than yields where residue was mechanically removed to 2.5 cm. Seed yields where residue was removed by burning were 2.0 times greater in 1979, 1.9 times greater in 1980, and 2.6 times greater in 1981 than yields from plants where residue was mechanically removed to 7.6 cm. Panicle and tiller numbers were reduced where residue was mechanically removed to 2.5 or 7.6 cm compared to panicle and tiller numbers where residue was burned. Tiller leaf sheath lengths were not different where residue was burned or removed to 2.5 cm and were shorter than where residue was removed to 7.6 cm. Rhizome weights were reduced where residue was burned compared to weights where residue was clipped at 2.5 or 7.6 cm height in both 1980 and 1981. Root weights, when averaged across all five cultivars, were not affected by residue removal method. A significant cultivar × treatment interaction was noted for Glade, which produced more roots when clipped to 2.5 cm than when burned or clipped to 7.6 cm in both years. Significant cultivar × treatment interactions occurred in 1980 in tiller number which were reflected in panicle numbers and seed yields for Glade and South Dakota. Increased tiller production was associated with decreased rhizome weights. Since tiller apices have been found to control the upturning of rhizomes to produce new tillers, it was concluded that burning functions to reduce tiller apical control of rhizomes. The increased length of tiller leaf sheaths under decreasing heights of residue removal was concluded to be in response to decreased light penetration into the canopy.
Yield and Quality of Soybean Hay as Influenced by Stage of Growth and Plant Density1
Authors: Munoz A. E. , Holt E. C. , Weaver R. W.
Published: July 2010

Soybeans [Glycine max (L.) Merr.] are known to have potential for hay production but additional cultural and harvest practice information is needed to optimize production and forage quality. Nodulating ‘Lee’ cv. of soybeans was grown on Ships clay (very fine, thermic, Udertic Haplustolls) at densities of 97,100, 194,200 and 291,300 plants/ha in 68‐cm row widths to evaluate the effect of stage of maturity at harvest and planting density on the quality (percent digestibility and crude protein) and dry matter yield of the soybean hay. The plant tops were separated into leaflets, stems plus petioles, and pods plus grain. Dry weight, in vitro dry matter digestibility (IVDMD) and crude protein (percent N ✕ 6.25) were determined for each sample. Plant density had a small negative effect on IVDMD, a large positive effect on dry matter (DM) yield and no significant effect on the percent crude protein of the soybean plant. Age had a significant effect on the proportion and DM production of plant components, IVDMD of leaves and stems but not pods and total plant, and protein content. When the pods were filled and leaves were beginning to turn yellow, the percentages of leaves, stems, and pods were 28, 36, and 36, respectively with a total DM yield of 12.4 metric ton/ha. The highest protein (20.2%) and IVDMD (62.2%) values for the total plant were at the pod‐filled stage. For optimum yield, crude protein and digestibility, the best time to cut soybean for hay appears to be when pods are filled and some leaves are starting to turn yellow.
Automated Seeding Rate Selector1
Authors: Stewart B. A.
Published: July 2010

There are instances when crop production could be enhanced if the plant population was changed within the field to correspond with changes in water or nutrient availability. Therefore, a device for changing seeding rates during planting operations was designed and tested. The device reported allows for three seeding rates, but the number could be changed to meet specific needs. The rate is changed by simply dialing an electric switch which engages the respective electromagnetic clutches. There is no need to stop or slow the planter to make the desired change. while the need that led to the equipment was to reduce plant densities down the field to correspond with decreased amounts of irrigation water, there are many other potential uses. Plant population studies could be more easily and precisely implemented. The concept could also be used to change fertilizer or pesticide rates in instances where the materials are applied by chain‐ or belt‐driven assemblies. The device can be readily constructed at moderate cost.
First Harvest Phenological Stage Effects on Production of Eight Irrigated Grasses1
Authors: Fairboura Merie L.
Published: July 2010

Phenological development stage at the first harvest affects seasonal dry matter production of some grass species. This field experiment was done to determine the effect first harvest phenological stage has on seasonal dry matter production of eight grasses under irrigation on the Central High Plains. Grasses were ‘Latar’ orchardgrass (Dactylis glomerata L.), ‘Fawn’ tall fescue (Festuca arundinacea Schreb.), ‘Regar’ bromegrass ( Bromus biebersteinii Roem. and Schult.), ‘Manchar’ bromegrass (B. inermis Leyss.), ‘Garrson’ creeping foxtail (Alopecurusarundinaceus Poir.), meadow foxtail (A. pratensis L.), ‘Luna’ pubescent wheatgrass Agropyron trichophorum (Link) Richt.], and ‘Greenar’ intermediate wheatgrass p. [intermedium (Host) Beauv.]. Soil of the study area was an Altvan fine sandy clay loam, an Aridic Argiustoll. First harvests of the grasses were made at the vegetative, boot‐heading, and anthesis stages of development. In 24 species by year combinations, dry matter production was greater for first harvest at the boot‐heading stage than for vegetative and anthesis stages by eight and five harvests, respectively. First harvest at the anthesis stage had greater dry matter production than for boot‐heading in only one instance. First harvest at the vegetative stage depressed seasonal dry matter production. Crude protein and in vitro dry matter digestability (IVDMD) production generally followed the dry matter yields of the forages. Since the foxtail grasses have an indeterminate heading stage, a forage height of 25 to 30 cm appeared to be the best guide for first harvest of the growing season. The foxtail grasses, Latar orchardgrass, Fawn tall fescue, and Regar meadow bromegrass gave consistent season long production. The wheatgrasses and Manchar smooth bromegrass produced little regrowth and can be used to the best advantage in a forage program where hay harvest at the flowering stage is practiced.
Russian Wildrye Nutritional Adequacy and Chemical Composition1
Authors: Karn J. F. , Hofmann L. , Lorenz R. J.
Published: July 2010

Apparent metabolic problems were observed in yearling steers grazing Russian wildrye (Elymus junceus Fisch.) in spring or early summer. This study was initiated to determine what factors were involved in these metabolic problems. Forage samples were obtained from small plots established in an existing 10‐year‐old stand of Russian wildrye, growing on Temvik silt loam (flne‐silty, mixed Typic Haploborolls) soils. The objective of the experiment was to examine the effect of sampling dates and N, P, and K fertilization on the chemical composition and subsequent nutritional adequacy of this forage for grazing cattle. Levels of N, P, K, and in vitro digestible organic matter (IVDOM) in Russian wildrye declined consistently between weekly sampling dates both years. Forage Ca and Mg levels increased (P < 0.05) between initial and final sample dates, but weekly changes were not consistent between years. The tetany hazard to cattle grazing Russian wildrye appeared greater when evaluated by the ratio of forage K/(Ca + Mg) than when evaluated by estimated blood serum Mg data. Regrowth forage, although morphologically similar to early cut forage, appeared quite different chemically. Nitrogen fertilization increased (P < 0.05) forage N and K and consequently the K/(Ca + Mg) ratio. Nitrogen fertilization decreased (P < 0.05) forage P, but the decrease was not progressive with higher N levels. Fertilization with P increased (P < 0.05) forage P, but effects on other parameters were inconsistent. Potassium fertilizer had little effect on any parameters measured. The data indicated substantial differences in forage chemical composition as affected by year, season, and fertility, but the results did not suggest a cause of the severe scours, excessive urination and depressed weight gains which had been exhibited by yearling steers.
Irrigation Regime Effects on Some Physiological Responses of Potato1
Authors: Shimshi D. , Shalhevet J. , Meir T.
Published: July 2010

Potato is relatively sensitive to water stress, and therefore indices for characterizing the degree of water stress and its relation to tuber yield are sought. During a series of field irrigation experiments on potatoes (Solanum tuberosum L.) conducted on a calcic haploxeralf in the Negev region of Israel, data were collected on leaf permeability (LP), leaf and tuber water potential (Ψ1 and Ψ1, respectively) and photosynthetic rate, with the aim of relating the variables to a range of water stresses caused by the ratio irrigation/evaporation (Kp). Leaf permeability was linearly related to Ψ1, which ranged from −0.7 kJ kg−1 in well irrigated plants to −1.4 kJ kg−1 in severely water‐stressed plants. Tuber water potential, Ψ1, was higher by 0.4 to 0.7 kJ kg−1 than Ψ1, the difference increasing with water stress. In trickle‐irrigated plants, Ψ1 of tubers growing in dry soil was lower by 0.06 to 0.12 kJ kg−1 than Ψ1 of tubers growing in wet soil, even though the tubers were attached to the same stem. Photosynthesis increased with LP up to 0.8 mg CO2 m−2sec−1 and declined with plant age independently of LP. Marketable yield was well related to both seasonal LP and Ψ1, all three variables decreased when Kp dropped below 1.0. Leaf permeability seems to be a better index than leaf water potential for the characterization of water stress of potato in the field.
Grain Protein Response to Phosphorus Nutrition of Wheat1
Authors: Porter Michael A. , Paulsen Gary M.
Published: July 2010

Efficacy of N fertilizer in increasing wheat (Triticum aestivum L.) grain protein is well recognized, but effects of P nutrition are unclear. Phosphorus nutrition of wheat in relationship to grain protein was investigated to ascertain differences among cultivars and interactions of P with N and K. Five hard winter wheat genotypes that differed in grain protein concentration were grown at two Kansas locations on Smolan Pachic Agriustolls and Parsons Mollic Albaqualfs soils with three P levels (0, 56, 112 kg P ha−1) as superphosphate and three K levels (0, 112,224 kg ha−1) as KCL to elucidate effects of P nutrition. Hydroponic studies with 0.005, 0.01, 0.05, 0.1, and 0.5 mM NaH2PO4, 5, 10, and 15 mM NaNO3, and 0.05, 0.5, and 5.0 mM KCI determined effects and interactions of P on nitrate reductase activity and soluble protein in seedling leaves. Other hydroponic studies determined effect of 0.01, 0.1, and 1.0 mM NaH232PO4 on grain yield, protein concentration, and 32P distribution. Field application of 56 and 112 kg P ha−1 increased mean grain yield 150 and 314 kg ha−1, respectively, over both locations and decreased grain protein 0.2 and 0.4% , respectively, at one location, an effect attributed to dilution of grain protein. Nitrate reductase activity of hydroponically grown seedlings was highest with 0.1 mM P and lowest with 0.005 and 0.5 mM P, whereas soluble protein was highest at the lowest P level. In plants grown to maturity in hydroponic cultures, 0.1 and 1.0 mM P increased plant tillers, vegetative N and P concentrations, grain yield, and grain protein and P concentrations. Time of application of 32P did not influence grain 32P concentration. We concluded that P fertilizer had no intrinsically detrimental effect on N metabolism and grain protein in wheat, but that it might indirectly affect grain protein concentration by influencing yield.
Fertilizer Nitrogen Utilization by Corn, Tomato, and Sugarbeet1
Authors: Hills F. J. , Broadbent F. E. , Lorenz O. A.
Published: July 2010

Differences in the abilities of crops to utilize fertilizer and soil N can contribute to the establishment of rotation systems to improve the efficiency of fertilizer use and reduce nitrate pollution groundwater. Field studies show considerable site variability in the utilization of fertilizer by individual crops. To compare fertilizer N use by corn (Zea mays L.), sugarbeet (Beta vulgaris L.), and tomato (Lycopersicon esculentum Mill.), several rates of fertilizer N were applied to replicated plots of each crop in the same field at Davis, Calif. A 2nd year study involved only corn and sugarbeet. The experiments were conducted at different sites, but both on the same soil, Yolo silt loam (a fine‐silty, mixed, nonacid, thermic, Typic Xerorthent). Nitrogen‐15 depleted ammonium sulfate was used as a labeled N source in the three‐crop experiment and ammonium nitrate of normal isotopic ratio was used for the two‐crop experiment. In both experiments, N was applied in bands on both sides of crop rows after seedling emergence in 56 kg increments from 0 to 280 kg N/ha. Fertilizer N required for maximum commercial yield in 1979 was: corn 194, tomato 131, and sugarbeet 92 kg N/ha; and in 1980: corn 280 and sugarbeet 70 kg N/ha. Average recoveries of labeled N from fertilizer in 1979 were: corn 57%, and tomato and sugarbeet 27%; and in 1980 without labeled N the apparent recoveries were: corn 52% and sugarbeet 37%. The ratios of fertilizer to soil N in the crops at fertilizer rates giving maximum commercial yields in 1979 were: corn 45/55, tomato 25/75, and sugarbeet 15/85; and in 1980 were estimated by the difference method to be: corn 54/46 and sugarbeet 10/90. Thus corn relied most heavily on fertilizer N, followed by tomato then sugarbeet. On average, over the 2 years, sugarbeet took up 95% more soil N than corn. These data indicate that fertilizer use efficiency may be improved by growing corn when residual N is lowest and tomato or sugarbeet when residual N is highest. With care to avoid residual N too high for depletion prior to harvest, sugarbeet can be used to scavenge soil N and thus conserve the use of fertilizer N.
Phosphorus Uptake by Six Plant Species as Related to Root Hairs1
Authors: Itoh Sumio , Barber S. A.
Published: July 2010

Plant species vary in the amounts of P they obtain from the soil. It was hypothesized that investigation of the differences among species with a mathematical model describing the processes involved in P uptake from soil, would both show why species varied and provide a more rigorous test of a model verified for corn (Zea mays L.). A controlled climate chamber experiment was conducted with six plant species varying in ability to grow in soils at low levels of soil P. The soil and plant parameters required to operate the model were measured and the agreement between predicted P uptake and observed P uptake evaluated. When the roots were considered to be smooth cylinders absorbing P from soil solution, several species absorbed more P than predicted by the model. The species varied widely in root hair length and density. When the contribution of root hairs to P uptake was included, predicted P uptake agreed with observed uptake. A linear regression gave an r of 0.89 and a slope of 0.89. In addition to root hairs, P uptake efficiency of the plant species was influenced by amount of root surface per gram of plant, rate of plant growth, and the P influx kinetics of the root.
Toxic Nitro Compounds in Lotus1
Authors: Williams M. C.
Published: July 2010

Toxic aliphatic nitro compounds were recently detected in species of the genus Lotus. Nitro‐bearing species, if used as forage, might be harmful to livestock. Therefore, this investigation was initiated in the greenhouse and laboratory to study the distribution, types, and concentration of nitro compounds in species of Lotus, and to determine the toxicity of cultivars of L. pedunculatus Cav. to 1‐week‐old chicks. Leaves of 83 species of Lotus, collected from herbarium specimens or plants grown in soil (Dagor series of fine‐loamy, mixed, mesic family of Cumulic Haploxeroll) in the greenhouse, were analyzed for nitro compounds. Nitro‐bearing species for which sufficient material was available were analyzed chromatographically for the type of nitro metabolite. The toxicity of cultivars of L. pedunculatus was determined by feeding dried plant and aqueous extracts of the foliage to 1‐week‐old chicks. Nitro compounds were detected in 17 of 83 species of Lotus. No nitro compounds were detected in three commercial cultivars of L. corniculatus L. Hydrolysis of nitro compounds yielded only 3‐nitropropionic acid (3‐NPA). Nitro levels in leaflets of L. pedunculatus averaged 27 to 29 mg NO2/g of plant. Dried plant or extracts of three cultivars of L. pedunculatus produced nitro poisoning in 1‐week‐old chicks. The data indicate that several species of Lotus synthesize toxic nitro compounds that yield 3‐NPA upon hydrolysis. Species of Lotus should be screened for nitro compounds before developing cultivars to prevent the seeding of potentially poisonous plants on grazing land.
Manganese Deficiency and Toxicity Effects on Growth, Development, and Nutrient Composition in Wheat1
Authors: Ohki K.
Published: July 2010

Wheat (Triticum aestivumL.) production areas have expanded to soils low in available Mn and to low pH soils with excess available Mn. The purpose of this study was to determine the effect of Mn deficiency and toxicity effects on ‘Stacy’ wheat growth components and to determine the Mn critical deficiency level (CDL) and critical toxicity level (CTL) in specific plant tissue in relation to top dry weight. The critical deficiency and toxicity values could be used as guidelines in tissue analysis to diagnose Mn deficiency and toxicity. Wheat plants were grown in nutrient solution containing 10 Mn rates from 0.09 μMto 9.1 mMin the greenhouse. Plants were harvested 26 days following treatment with Mn and tissue samples were analyzed for Mn and other elements in the wet ashed extract. Manganese deficiency and toxicity reduced top dry weight, root dry weight, plant height, and tiller number compared with plants supplied at adequate Mn levels. The CDL and CTL defined as the elemental concentration in the tissue associated with a 10% reduction in growth due to a deficiency or toxicity, respectively, were determined from the relationship of Mn concentrations in the tissue and top dry weight. The Mn CDL values for blades 1, 2, 3, and stem of Stacy wheat were 13,39,82, and 12 μg g‐1, respectively. Blade 1 is recommended for tissue sampling since the transition zone in the response curve is narrow and blade 1 is metabolically active and the most recently matured blade with a developed ligule. The Mn CTL values of the sampled tissues were 380, 900, 1100, and 200 μg g‐1for blades 1, 2, 3, and stem tissue, respectively. Maximum growth would be expected when tissue Mn concentrations are within the CDL and CTL of a specific plant tissue. The Mn concentration in tissues increased as Mn supply was increased. A reciprocal Fe/Mn and P/Mn concentrations existed in blade 1. Manganese deficiency and toxicity reduced K, Ca, and Mg concentrations.
Agronomic, Chemical, Physical, and Visual Characteristics of Hand‐Suckered vs. Maleic Hydrazide‐Treated Flue‐Cured and Burley Tobaccos1
Authors: Seltmann Heinz , Nichols Beryl C.
Published: July 2010

Removal of the developing inflorescence (topping) in tobacco (Nicotiana tabacumL.) production will result in higher leaf yield and increased alkaloid content. Unfortunately, topping will remove axillary bud (sucker) inhibition. To achieve the higher yields and alkaloid content growers must control the development of suckers through manual or chemical means. Because hand‐suckering is a menial task, the use of maleic hydrazide (MH) rapidly became the cultural practice to control sucker growth, but its use was severely questioned by the industry. The Regional Tobacco Growth Regulator Committee was established in 1963 to evaluate tobacco treated with various experimental chemical sucker‐controlling agents as alternatives to MH. Regional committee test data accumulated from 1963 through 1981 by federal and state researchers were used to compare cured leaf from MH‐treated plants with hand‐suckered plants, the control treatments. Yield and value per hectare were higher from the use of MH while dollars per 100 kg were the same for both kinds of treatments in both classes of tobacco. Tobacco leaf experts were able to visually differentiate between MH‐treated and hand‐suckered flue‐cured but not burley tobaccos. Chemical analyses indicated that percent total alkaloids and percent total ash were less in MH‐treated flue‐cured and burley tobaccos. Alkalinity of water soluble ash increased from MH treatment. Total volatile bases minus nicotine (as ammonia) decreased significantly in flue‐cured tobacco from MH treatment while the increase found in burley from MH treatment was not. Maleic hydrazide treatment significantly increased per cent reducing sugars in flue‐cured tobacco, but had no effect on percent total N in burley. Physical analyses indicated that values for filling capacity were significantly lower and equilibrium moisture content significantly higher in MH‐treated tobaccos.
Leaf Area, Light Interception, and Yield Estimates from Spectral Components Analysis1
Authors: Wiegand C. L. , Richardson A. J.
Published: July 2010

Plants integrate the soil and aerial environments and express their development, stress response, and yield capabilities through the canopies achieved. The identities (1n LAI)/VI × Yield/(ln LAI) = Yield/VI [1] (1n LAI)/VI × IPAR/(ln LAI) = IPAR/VI, [2] where VI denotes any one of several spectral vegetation indices available; LAI is leaf area index; IPAR is intercepted photosynthetically active radiation; and yield is grain yield help interpret the information conveyed by canopies. Our objective herein was to test Eq. [1] and [2] term by term. LANDSAT multispectral scanner (MSS) spectral and field‐measured LAI data for 32 grain sorghum (Sorghum bicolor L. Moench) fields in Hidalgo County, Tex., for the years 1973,1975, and 1976 are the exemplary data used. The predominant soil types at the nonirrigated sites were McAllen (fine‐loamy, mixed, hyperthermic Aridic Ustochrepts) and Brennan (fine loamy, mixed, hyperthermic Aridic Haplustalfs) fine sandy loams, whereas the irrigated sites were typified by Hidalgo (fine‐loamy, mixed, hyperthermic Typic Calciustolls) sandy clay loam and Raymondville (fine, mixed, hyperthermic Vertic Calciustolls) clay loam. The IPAR vs LAI relation used was from the latest version of the sorghum growth and yield crop (SORGF) model. Each of the equation terms as well as the relation between yield and IPAR is illustrated. All were highly significant with coefficients of determination, r2, that ranged from 0.53 C 0.83. The IPAR vs LAI relations from the literature can be used in Eq. [1] to estimate IPAR from VI if LAI and VI were observed. The right hand side of Eq. [1] and [2] imply that even though the instantaneous VI relate to IPAR and yield, cumulative IPAR or cumulative VI for the season or for a period around maximum canopy development might relate even better. The fit of the relations to data from multiple weather years, irrigated and dryland plantings, across genotypes, and for differing planting configurations helps underscore the generality of the relationships and emphasizes the imformation inherent in crop canopy observations. Such spectral observations provide at alternative way of acquiring LAI or IPAR needed for large‐scale use of agrometeorological crop models and for independent estimates of phytomass and grain yield.
Tall Fescue Response and Soil Properties Following Soil Amendment with Tannery Wastes1
Authors: Stomberg A. L. , Hemphill D. D. , Volk V. V. , Wickliff C.
Published: July 2010

Field plots were established in 1978 and 1979 on a Willamette sil (fine‐silty, mixed, mesic pachic Ultic Argixeroll) in western Oregon to evalute the effects of chrome tannery wastes on tall fescue (Festuca arundinaceaSchreb.) and soil properties. Three rates of waste material were applied each year, N, Ca, Mg, Cu, Cr, Mn, and Zn in soils and plants were analyzed to relate plant elemental concentrations and yield to elemental application and availability. Soil and fescue Cu, Zn, and Mg concentrations varied only slightly with waste application in either year. Soil total Cr levels increased as much as sevenfold with waste treatment; however, fescue Cr concentrations increased only slightly or not at all with waste application. The Mn concentration of tall fescue grown on waste‐treated soils decreased compared to that of fescue grown on unamended soil in 1978 but increased with waste application in 1979, reflecting increased soil pH with waste application in 1978 but a decrease in 1979. Both fescue and soil Ca concentrations usually increased with waste application. Soil and fescue N concentrations and soil electroconductivity increased with waste application with the effect still observable 1 year after application. Fescue yields were greatest on soils treated with the highest rates of waste. Yields increased with waste treatment up to 3 years after application. With the exception of stand establishment problems, no detrimental effects of tannery waste on tall fescue were noted in 3 years of study.
Fall No‐Till Seeding of Alfalfa into Tall Fescue as Influenced by Time of Seeding and Grass and Insect Suppression1
Authors: Rogers D. D. , Chamblee D. S. , Mueller J. P. , Campbell W. V.
Published: July 2010

Higher nitrogen and pasture renovation costs have increased interest in no‐till seeding of legumes into grass pastures, but improved technology is needed for direct establishment of legumes in grass sods. This study was undertaken to quantify and evaluate the effects of seeding date, sward suppression, and insect pests on fall no‐till establishment of alfalfa (Medicago sativa L. cv. Arc) into tall fescue (Festuca arundinacea Schreb.)‐dominant swards. Six field experiments of 1 year duration each were conducted during a 5‐year period on either a Typic Hapludult or Ultic Hapludalf soil in the Piedmont of North Carolina. Paraquat (1,1′‐dimethyl‐4,4′‐bipyridinium ion) for grass suppression and granular carbofuran (2,3‐dihydro‐2,2‐dimethyl‐7‐benzofuranyl methylcarbarnate) for insect control either were not applied or were applied at 0.28 and 3.7 kg active ingredient (a.i.) ha−1, respectively, at two seeding dates (early September and mid‐October) in a 23 factorial combination. Three additional sodsuppression treatments (two trials) included (1) application of paraquat to 13 cm‐wide bands over 25.4‐cm rows at 0.28 kg a.i. ha−1, (2) broadcast application of glyphosate [N‐(phosphonomethyl) glycine] at 3.4 kg a.i. ha−1, and (3) post‐sowing clipping and removal of the fescue regrowth. Insects prevalent during establishment were identified and measurements were made of alfalfa stands, insect damage, winter survival, and dry matter production. Seasonal yields of September seeded alfalfa were increased 76 and 20% by sward and insect suppression during establishment, respectively (average six experiments). Insect damage was greater in early September plantings than in mid‐October plantings. Sward suppression and insect control interacted accumulatively under conditions of intensive insect feeding and moisture stress during establishment. Even though 50 to 100% of October‐seeded alfalfa in control plots had not advanced beyond the two‐trifoliolate‐leaf stage of development by early December, good winter survival occurred. We conclude that suppression of tall fescue was essential for best establishment and 1st‐year production of alfalfa and that insect control must be practiced in September no‐till plantings of alfalfa in some years.
Transpiration Efficiency in Relation to Nutrient Status1
Authors: Walker G. K. , Richards J. E.
Published: July 2010

Many experiments have shown a linear relationship between plant biomass and water use. Despite this, it is thought that general nutrient deficiency lowers transpiration efficiency. Since little attention has been given to the effects of specific nutrients, a study was designed to examine the effects of a single nutrient, K, on the transpiration efficiency of alfalfa (Medicago sativa L.). In addition, maize (Zea mays L.) biomass and water‐use data obtained in 1911 by Montgomery and Kiesselbach, at a range of nutrient levels, were reanalyzed to further assess nutrient effects on transpiration efficiency. In a greenhouse study, ‘Banner’ alfalfa was grown, in pots, in a range of soils varying widely in K status but otherwise adequately fertilized. A sand mulch was used to minimize evaporation from the pots. Evapotranspiration (determined by weighing) and biomass data were collected over seven regrowth cycles. At every harvest there was a wide range in tissue K status, but only at harvest four did transpiration efficiency appear reduced by restricted K supply. Biomass and evapotranspiration remained well correlated and linearly related for every harvest, despite the increasing occurrence of severe K deficiency as the experiment progressed. Transpiration efficiency did fall substantially for the last two harvests, possibly in response to the lower (winter) light regime under which those harvests were made. Although not applicable to a specific nutrient, Montgomery and Kiesselbach's maize data yield similar results, and do not suggest that nutrient deficiency leads to lower transpiration efficiency.
Chaff Feed Quality of Winter Wheat, Spring Wheat, Barley, and Oat Cultivars1
Authors: White Larry M. , Bergman Jerald W.
Published: July 2010

Little data exist regarding differences in chaff (i.e., glums, lemma, palea, and awns when present) feed quality among cultivars of small grains although large amounts are fed to livestock each year. This study was conducted to determine if in vitro organic matter disappearance (IVOMD), and concentration (conc) of ash, crude protein (CP), and P differed significantly among chaff from 19, 22, and 17 cultivars of spring wheat (Triticum aestivum L. and T. durum Desf.), barley (Hordeum vulgare L.), and oat (Avena sativa L.), respectively, grown on an irrigated site ( fine montmorillonitic soil, Typic Argiborolls) and among 16 cultivars of winter wheat grown on a dryland site (fine‐loamy, mixed Typic Argiborolls) near Sidney, MT for 2 years. Correlation of heading date, plant height, grain test weight, and grain yield with chaff IVOMD were calculated to determine if high chaff IVOMD was negatively correlated with agronomic traits important in grain production. Typical chaff piles were also sampled to determine the content of true chaff, weed seed, and grain in them. Chaff IVOMD, ash, and CP levels differed as much or more among cultivars of each species as between the 2 years. Chaff IVOMD differed by 84,136, 106, and 56 g kg−1; chaff ash by 45, 68, 52, and 49 g kg−1; chaff CP by 17, 25, 41, and 26 g kg−1 among cultivars of winter wheat, spring wheat, barley, and oat, respectively. The chaff P (without high P fertilization) conc differed by 0.3, 1.7, 1.7, and 2.4 g kg−1 among cultivars of winter wheat, spring wheat, barley, and oat, respectively. High P fertilization and variation between years increased chaff P conc of barley, spring wheat, and oat 0.5,1.5, and 2.5 times, respectively. High chaff IVOMD was generally not negatively correlated with agronomic traits important in grain production. Typical chaff piles of winter wheat, spring wheat, barley, and oat consisted of 898, 58, and 44 g kg−1 of true chaff, weed seed, and cereal grain, respectively.
Dris Norms for 11 Nutrients in Corn Leaves1
Authors: Elwali A. M. O. , Gascho G. J. , Sumner M. E.
Published: July 2010

Fertilizer accounts for nearly one‐half of the total cash expenses of growing corn (zea mays L.) in Georgia. Recommendations are usually made with the assumption of favorable climatic conditions, a practice that can result in serious problems to farmers in years of unfavorable climatic conditions. This is especially true on deep sands where nutrient‐holding capacity is low. One possible way of reducing the risk and increasing fertilizer efficiency is to apply moderate amounts of fertilizer initially and make corrections in the growing season as indicated by foliar analysis. Results of foliar analyses are usually interpreted on the basis of the Critical Nutrient Level (CNL) approach. Recently, the Diagnosis and Recommendation Integrated System (DRIS) was found to be an effective approach for interpreting foliar values and guiding corrections in the growing season for sugarcane (trispecies hybrid of Saccharum). The present study was conducted to determine the DRIS reference norms for 11 nutrients (N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, and B). A data base of approximately 10 000 observations of leaf nutrient concentrations and yield of corn grown in several states and countries was used to establish the norms on corn leaves. They should be useful in diagnosis of nutrient imbalance in order to make adjustments in the nutritional status of corn plants.
Soil Moisture Effect on Potassium Uptake by Corn1
Authors: Mackay A. D. , Barber S. A.
Published: July 2010

Soil moisture influences K uptake by corn (Zea maysL.) by affecting root growth rate and the rate of K diffusion in soil. The extent each affects K uptake has not been resolved. The objective of this study was to determine the effect of soil moisture on each of the parameters of a mechanistic‐mathematical model that simulates K uptake by corn. Corn was grown for 7, 14, and 21 days at three volumetric soil moisture levels, 0.22 (M0), 0.27 (M1), and 0.32 (M2), the water held at potentials of −7.5, −33, and −170 kPa, respectively, with three soils (S0and S1, Raub, fine‐silty, mixed, mesic Aquic Argiudolls, and S2, Chalmers, fine‐silty, mixed, mesic Typic Haplaquolls, silt loams; S0was low in K, S1and S2were medium in K), in 3‐L pots in a controlled‐climate chamber. Root growth and K uptake by corn were measured. Raising soil moisture from M0to M1increased shoot K uptake by 81, 70, and 68%, with the S0,, S1, and S2soils, respectively. Raising soil moisture further, from M1to M2resulted in a further increase of 13% in K uptake by corn with the S0soil but small decreases of 13 and 8%, with the S1and S2soils, respectively. Raising moisture from M0to M1also increased root growth, however a further increase to M2decreased root growth. There was a relation between root surface area and K uptake, but this varied with soil. The relation between mean K influx and K uptake (r= 0.85**, significant at the 0.01 level), however, was independent of soil. Soil moisture did not significantly (P<0.05) affect K influx. Raising soil moisture from M0to M2, increased the effective diffusion coefficient, De, for K an average of 2.1 times across the three soils. When all the data were used in the simulation model, calculated K uptake (y) in mmol pot−1agreed with observed K uptake (x) by corn (y= 0.9x‐ 0.08; r= 0.95**), indicating that the model is a useful method for studying the effect of soil moisture on each of the mechanisms involved in K uptake by corn.
Conventional and No‐Till Establishment of Ladino Clover as Influenced by Time of Seeding and Insect and Grass Suppression1
Authors: Rogers D. D. , Chamblee D. S. , Mueller J. P. , Campbell W. V.
Published: July 2010

Requirements for establishing ladino clover (Trifolium repensL.) into pastures may differ markedly between conventional and no‐till systems. Objectives of this study were to compare effects of pesticides and seeding date on fall establishment of ‘Tillman’ ladino clover seeded with tall fescue (Festuca arundinaceaSchreb.) in conventionally prepared seedbeds and sod‐seeded into tall fescue‐dominant swards on a Typic Hapludult soil in Piedmont North Carolina. Effects of grass suppression were studied in no‐till plantings by either applying or not applying paraquat (1,1'‐dimethyl‐4,4'‐bipyridinium ion). Carbofuran (2,3‐dihydro‐2, 2‐dimethyl‐7‐benzofuranyl methylcarbamate) either was not applied or was applied for insect control at two seeding dates (early September and mid‐October) in four trials and at one seeding date (31 August) in a fifth trial. Clover stand reductions by insect and/or mollusk pests were much greater in notill plantings than in conventional plantings. Clover stands from notill seedings in late August were destroyed in one trial by slugs (Derocerus laeveMull.), but were largely unaffected in prepared seedbeds. Insecticide moderately increased clover densities and yields of September conventional plantings in three of five trials. September‐seeded clover damaged by insect and/or mollusk pests 10 to 15 days after emergence averaged 67 and 23% in no‐till and conventional plantings, respectively. Insecticide alone or with paraquat was required in September no‐till plantings to produce clover yields approximately equal to or exceeding those of the check in September conventional plantings. Mid‐October conventional plantings of clover usually failed to survive the winter due to frost heaving, yet survived well in the no‐till plantings. We conclude that insecticides are usually necessary for successful establishment of ladino into tall fescue swards in early September, but may not be needed as often in prepared seedbeds.
Soybean Response to Rhizobium japonicumStrain, Row Orientation, and Irrigation1
Authors: Hunt P. G. , Sojka R. E. , Matheny T. A. , Wollum A. G.
Published: July 2010

Stresses or environmental differences associated with soybean [Glycine max(L.) Merr.] row configuration and drought could affect selection and symbiotic performance of Rhizobium japonicumstrains and subsequent growth and yield of soybean. The present field studies were conducted in 1981, 1982, and 1983 to assess the response of soybean nodulation, growth, and yield to R. japonicumstrains, row orientation, and irrigation. Strains USDA3I1b110 (110), NC1004 (04), and B587 (587) of R. japonicumwere compared to indigenous populations in a Norfolk loamy sand (fine loamy, siliceous, thermic, Typic Paleudult). Soybean cultivars ‘Davis,’ ‘Braxton,’ and ‘Coker 338’ were grown with and without irrigation, with east/west and north/south row orientations, and with inoculation variables. The seasonal weather was different for air temperature, rainfall, and solar radiation; and soil temperatures were generally 1 to 5 °C lower for north/south‐oriented than east/west‐oriented rows at depths of 5 and 15 cm. Nodular occupancies of inoculated strains were increased by inoculation in 1981 and 1982, but not in 1983. No significant differences in N concentration or total N of soybean shoots were found in any year. Yet, a strain ✕ row orientation interaction occurred for seed yield in all 3 yr, and a strain by irrigation interaction occurred in 1983. Seed yield of soybean inoculated with strain 04 or 110 were significantly different for row orientation; differences ranged from 0.24 to 0.43 Mg ha−1for irrigated soybean. Soybean inoculated with 587 was not significantly different in seed yield for row orientation. It was concluded that environmental differences induced by row orientation influence some R. juponicumstrains in soybean more than others, particularly under irrigated conditions.
Soybean Growth as Influenced by Planting Date, Cultivation, and Weed Removal1
Authors: Horn Paul W. , Burnside Orvin C.
Published: July 2010

Knowledge of weed interference is important for designing weed control systems for agronomic crops. Research was initiated to determine the critical periods of weed interference in soybean [Glycine max(L.) Merr.] and the minimum weed removal requirements needed to achieve optimum seed yields. In a field infested with mainly broadleaf weeds, a 4‐week weed‐free period after planting was needed to achieve optimum yields in early and late planted soybean grown on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudoll). Plots cultivated about 3 and 5 weeks after planting required only one handhoeing 2 weeks after planting to obtain optimum soybean yields. Weeds left 4 weeks before removal, but not 6 weeks, did not reduce soybean yields in early or late planted soybean. Results indicate that if soybeans are kept weed‐free the first 4 weeks after planting or if weeds are not left undisturbed longer than 4 weeks after planting, optimum soybean yields should occur.
Estimating Ammonia Flux: A Comparison Between the Integrated Horizontal Flux Method and Theoretical Solutions of the Diffusion Profile1
Authors: McInnes K. J. , Kissel D. E. , Kanemasu E. T.
Published: July 2010

Estimating the loss of N fertilizer as ammonia from the ground to the atmosphere via the integrated horizontal flux method (IHF) generally requires measurement of the mean atmospheric ammonia density and the mean wind speed at five or more heights. Using acid traps as a means of measuring ammonia density at that many heights over long periods of time proves laborious, and a way of reducing the number of heights is desirable. This paper presents an application of an analytical solution of the diffusion equation for local advection to the estimation of the loss of ammonia from a small circular (20 m radius) plot fertilized with 200 kg N/ha urea‐ammonium nitrate solution. Predicted ammonia density profile shapes agree well with those measured at the center of the plot. The estimated fluxes obtained from the “theoretical profile shape” solution (TPSP) show much less variation than those from a recently proposed single‐height method (TPSW), when compared with estimates from the IHF method using mean wind speed and mean ammonia density at five heights. The ratios of FTPSP/FIHFwere found to be generally > 1 under unstable atmospheric conditions and < 1 under stable conditions. The advantages of TPSP over TPSW are that samples may be taken where the error to magnitude of measurement ratio is smaller and the solution is simple to calculate for any size plot, provided an estimate of atmospheric stability may be made.
Cassava‐Cowpea and Cassava‐Peanut Intercropping. II. Leaf Area Index and Dry Matter Accumulation1
Authors: Mason S. C. , Leihner D. E. , Vorst J. J. , Salazar E.
Published: July 2010

Cassva (Manihot esculentaCrantz) is comonly intercropped with cowpea [Vigna unguiculata(L.) Walp] and peanut (Arachis hypogaeaL.) in the tropics. Little is known about the influence of intercropping on leaf area index, dry matter production, or partitioning of dry matter to the harvestable plant part. The objectives were to determine (i) the leaf area index (LAI) and (ii) the dry matter accumulation of the whole plant and harvestable plant part for cassava, cowpea, and peanut when grown in intercropping and sole cropping systems. Cassava, cowpea, and peanut were grown in sole and intercropping systems on a Typic Dystropept soil at Santander de Quilichao, Colombia in 1981 and 1982. Between 30 and 65 days after planting (DAP), the intercropping systems produced LAI's 0.6 to 1.9 greater than those produced in the cassava sole cropping system. In 1981, the intercropping systems produced LAI's that were 0.8 to 1.0 lower than those of sole cropped cassava 150 DAP. The cassava‐cowpea and cassava‐peanut intercropping systems produced 42 to 250 g m−2more dry matter than did the sole cropped cassava between 50 and 105 DAP. However, dry matter production at the end of the 11‐month growing season was similar for intercropping systems and sole cropped cassava. Intercropping did not influence cassava total plant or storage root dry matter accumulation at final harvest except when intercropped with peanut in 1982. In this case, a reduction in LAI of 0.8 was associated with production of 4.4 fewer storage roots per plant. These data indicate that rapidly growing cowpea and peanut were able to use space between rows of cassava during the first 100 DAP with minimal effect on cassava growth.