bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient and Inefficient Use of Iron by Two Soybean Genotypes and Their Isolines1
Authors: Brown J. C. , Weber C. R. , Caldwell B. E. 
Published: July 2010

AbstractIron‐efficient ‘Hawkeye’ and iron‐inefficient PI‐54619‐5‐1 soybean genotypes and their isolines A62‐9 (iron efficient) and A62‐10 (iron inefficient) were grown comparatively on soils and solution cultures. There was a differental response in the iron‐efficient soybeans. A62‐9 was less efficient than Hawkeye. This loss in efficiency was related to a loss in the ability of A62‐9 to reduce Fe+++ to Fe++ at the root. The four genotypes differed in their ability to reduce iron: Hawkeye > A62‐9 > PI 54619‐5‐1 ≥ A62‐10.A lowered pH of the growth medium, a concomitant release of reducing substance by the roots, and the subsequent reduction of iron at the root are associated with the absorption and translocation of iron. Translocation of citrate in the stem exudate of the four genotypes relates most nearly to the available iron supply.
Studies of Water Requirements of Horticultural Crops: II. Influence of Drought at Different Growth Stages of Onion1
Authors: de Lis B. R. , Ponce I. , Cavagnaro J. B. , Tizio R. M. 
Published: July 2010

AbstractTwo years of field experiments with onion crops (Allium cepa, L.) show that this plant is differentially sensitive to drought in each stage of its vegetative cycle. Drought at the seedling stage increases the rate of foliar emergence, produces a greater number of leaves, accelerates bulb formation by 15 days, and increases the final weight as compared with the check (no significant difference). When drought occurs at the beginning of the bulb formation, it causes a delay in foliar emergence, a smaller number of leaves, and a decrease in bulb weight (a significant difference as compared with the check). In other stages of the cycle (post‐transplanting, and 50 and 100% of the bb's weight), the drought does not cause significant damage to the plant's growth.
The No‐Tillage System for Corn (Zea mays L.)1
Authors: Jones J. N. , Moody J. E. , Shear G. M. , Moschler W. W. , Lillard J. H. 
Published: July 2010

AbstractCorn (Zea mays L.) grown under the no‐tillage system was compared with that grown under (1) systems involving increased amounts of tillage for 2 years, and (2) conventional turnplow tillage over a 6‐year period.Plant growth and yield of corn generally increased with decreasing degrees of tillage in the 2‐year test. Yields from no tillage during the 6‐year period were comparable to or ranged from 18 to 39% above yields from conventional turnplow tillage. Soil moisture measurements indicated that the dead sod mulch provided by the no‐tillage procedure was highly effective in reducing evaporation and runoff from the soil surface.
Effects of Clipping Compared to Grazing of Ladino Clover‐Orchardgrass and Alfalfa‐Orchardgrass Mixtures1
Authors: Bryant H. T. , Blaser R. E. 
Published: July 2010

AbstractClipped and grazed plots with similar defoliation intensities were sampled with a sickle bar mower for yield on the same day. The clipped plots were trimmed with the mower and the grazed plots grazed by cows the same day yield samples were taken. After each grazing the manure was removed and the ungrazed forage around urine spots trimmedd with a hand sickle.Herbage yields were higher under clipping than under grazing. Grazing had less effect on yield of alfalfa‐orchardgrass than on yield of Ladino clover‐orchardgrass. The harmful effect of grazing was not permanent. Higher yields of Ladino‐clover‐orchardgrass were obtained under both clipping and grazing by defoliating to 1.9 cm compared to 6.4 cm. Highest and lowest yields of alfalfa‐orchardgrass were obtained on the least and most frequently defoliated plots, respectively, under both clipping and grazing.Estimating potential grazing yields by clipping may lead to predicting inflated yields. The grazing technique used appears suitable for studying how the animal affects plants under different grazing pressures.
Effect of Corn (Zea mays L.) Stover Mulch on No‐Tillage Corn Yield and Water Infiltration1
Authors: Triplett G. B. , Van Doren D. M. , Schmidt B. L. 
Published: July 2010

AbstractCorn was grown for 3 years on Wooster silt loam, a soil on which the yield response of corn to cultivation exceeds that attributable to weed control. Treatments included conventional preplant tillage (plowing, disking) and no preplant tillage with three corn stover residue levels, 5% cover (stover removed), 45% cover (stover left in place), and 70% cover (double level of stover). Except for the first year when the tilled plots were not cultivated, grain yields with 45% cover (6,170 kg/ha) equalled the tilled check (5,970 kg/ha). Yields of treatments with 5% cover were significantly lower (4,770 kg/ha) than the tilled treatment and significantly higher with 70% cover (6,625 kg/ha). Soil moisture determined with gypsum blocks during the last 2 years was greater with increasing amounts of soil cover during the growing season. Soil cover did not increase during the experiment, even on treatments receiving double residue. At the end of the third year, water infiltration as determined with a sprinkling infiltrometer was significantly greater with 80% cover than for the other treatments. Results from these experiments indicate that mulch protection which may be readily available from previous crop residues is necessary to maintain no‐tillage corn grain yields on this and similar areas of Wooster silt loam. The beneficial effects of the mulch seem to be associated with increased soil moisture.
Influence of Row Spacing and Nitrogen Fertilization on Grass Seed Production1
Authors: Canode C. L. 
Published: July 2010

AbstractThe seed production capabilities of five species of cool‐season grasses as influenced by three row spacings and three nitrogen rates were determined for a 5‐yr period. The conclusions here are based on the 4‐ or 5‐yr cumulative average seed yields.Kentucky bluegrass produced more seed in 30‐ and 60‐cm rows. Crested wheatgrass and smooth bromegrass seed production was higher in 60‐cm rows, but for smooth bromegrass the difference in seed yield for the 60‐cm rows was not significantly higher than those of the 90‐cm rows. Orchardgrass produced more seed in the 90‐cm rows. Row spacing did not influence the seed yields of red fescue.Kentucky bluegrass and orchardgrass responded with more seed when fertilized with nitrogen at 90 or 112 kg/ha. Crested wheatgrass produced more seed with 112 kg/ha of nitrogen, but the differences were only significant in the 4‐yr average yields. Nitrogen rates over 67 kg/ha did not increase the seed yields of red fescue and smooth bromegrass.The 90‐cm rows resulted in heavier seed than that produced in 60‐ and 30‐cm rows. The 112 kg/ha of nitrogen increased seed weight in red fescue, but decreased seed weight of smooth bromegrass. Nitrogen rates did not influence the weight of crested wheatgrass seed.
Influences of Several Management Practices on Growth Characteristics and Available Carbohydrate Content of Smooth Bromegrass1
Authors: Paulsen Gary M. , Smith Dale 
Published: July 2010

AbstractHerbage yields of bromegrass (Bromus inermis Leyss.) grown without alfalfa were favored by infrequent cutting (3 cuts) primarily because spring growth yields were increased. Nitrogen fertilizer (168 kg/ha) increased bromegrass yields by increasing the number of tillers and rapidity of regrowth after cutting. Herbage yields of bromegrass plants grown with alfalfa were favored by frequent cutting (5 cuts) because fewer shoot apices were removed by frequent cutting and because alfalfa was less competitive.Frequent cutting decreased slightly the percentage of total available carbohydrates (TAC) accumulated between cuttings in the stem bases of bromegrass. Nitrogen fertilizer increased depletion of TAC after cutting, but did not affect the maximum level accumulated. Association with alfalfa decreased markedly the percentage of TAC in bromegrass during the growing season. High levels of TAC were present under all the treatments when growth ceased during late autumn.
Effect of Nitrogen to Phosphorus Atom Ratio of Ammonium Phosphates on Emergence of Wheat (Triticum vulgare)1
Authors: Stevenson C. K. , Bates T. E. 
Published: July 2010

AbstractAmmonium phosphates providing five N:P atom ratios (1.00, 1.25, 1.50, 1.75, and 2.00:1) were applied in solution in the row with wheat seed at planting in greenhouse experiments. The soils used were Oneida clay loam (CEC 18.3 meq/100 g) and Fox sandy loam (CEC 8.2 meq/100 g) each adjusted to pH levels ranging from 5.4 to 7.4. Soil pH, over the range studied, had no effect on emergence with any of the ammonium phosphate materials tested. Neither early nor final emergence changed when the N:P atom ratio was varied in the clay loam soil when the molarity of the fertilizer solution was held constant (equal rates of P but varying rates of N). In the sandy loam soil early emergence was markedly lower with high N:P atom ratio materials than with low ratio materials. Final emergence showed the same trend as early emergence with the sandy loam soil but differences between materials were much smaller. The difference in results between the two soils is attributed to the effect of cation exchange capacity on the toxicity of ammonia in the soil.
Corn Yield and Economic Optima for Nitrogen Treatments and Plant Population Over a Seven‐Year Period1
Authors: Colyer Dale , Kroth Earl M. 
Published: July 2010

AbstractResponse of corn (Zea Mays L.) yield to nitrogen applications at various planting rates were determined for two soil types over a seven‐year period. Regression analysis was used to determine response surfaces, maximum and economic optimal treatments and yields. Response curves and production surfaces were constructed from the regression data. Significant differences in responses and optimal treatments were found from year to year and between sites. Optimal nitrogen treatments varied from 21.4 to 202.1 kg/ha and optimal planting rates from 12,189 to 54,135 plants/ha. A function from data aggregated over seven years indicated that the optimal rates would be 120 kg/ha of N and 37,787 plants/ha.
A Precision Weighing Lysimeter for Row Crop Water Use Studies1
Authors: Ritchie Joe T. , Burnett Earl 
Published: July 2010

AbstractA relatively simple and economical weighing lysimeter specifically designed for evaluating hourly row crop water use under dryland conditions has been developed and tested. The lysimeter soil container is 1.83 m (6.0 ft) square by 1.22 m (4.0 ft) deep. This allows a representative rooting profile for two rows of crop spaced 0.92 m (3.0 ft) apart and also allows normal soil shrinkage cracks to form within the soil mass. The thin soil container and retaining tank walls are separated by a 10‐mm air gap, resulting in a surface disturbance of only 4.5% of the lysimeter area. Soil water suction at the bottom of the soil container is controlled. A commercially available floor stand tank scale lever assembly is used to transfer up to 600 kg of the total lysimeter weight to a precision strain gauge load cell, the remainder being counter‐balanced under the lysimeter. The sensitivity of the system (± 0.025 mm equivalent water weight change) is adequate for short‐period evaporative flux measurements. The electrical output signal from the load cell can be measured remotely, minimizing site disturbance. The weighing mechanism has suitable utility for other weighing lysimeter applications.
Management of Land Diverted from Crop Production. I. Perennial Forages1
Authors: Robinson R. G. 
Published: July 2010

abstractAlaflfa (Medicago sativa L.), alfalfa‐brome (Bromus inermis Leyss.), red clover (Trifolium pratense L.), red clover‐timothy (Phleum pratense L.), sweetclover (Melilotus alba Desr.), and sweetclover‐timothy were maintained at Rosemount, Minn. under three management systems— removal of forage from the plots, mowing and leaving forage, and chopping and leaving forage. Within each management system, comparisons were made of one, two, and three cuttings per year. Uncut plots were included in each replicate. After 2 to 5 years of the management and cutting treatments, corn (Zea mays, L.) was grown for 2 years to determine residual effect of treatments on corn production using seven methods of land preparation.Comparison of forage removal with nonremoval—Removal reduced stands of timothy but not those of other forages, slightly increased weed control, reduced soil fertility, and reduced grain production 636 to 1168 kg/ha in the first 2 years of corn.Comparison of mowing with chopping—Mowing and chopping effects were similar on forage stand, forage growth, weed control, and corn yield except that chopping sweetclover resulted in higher corn yields than mowing.Comparison of cutting treatments—Cutting favored growth of alfalfa, red clover, and foxtail (Setaria glauca (L.) Beauv. and viridis (L.) Beauv.) and injured bromegrass, timothy, and quackgrass (Agropyron repens (L.) Beauv.). Uncut bromegrass‐alfalfa gave the densest ground cover and best weed control. Without bromegrass or timothy present, cutting was essential for weed control, and two cuttings were best.Comparison of herbicide‐tillage methods of land preparation for corn—Plowing in July and spraying in September gave best weed control.
Comparison of Growth Stages of Sorghum Forage Types as to Yield and Chemical Composition
Authors: Worker George F. , Marble Vern L. 
Published: July 2010

AbstractA 2‐year study of harvesting three types of forage sorghum — sudangrass, sorghum‐sudangrass hybrids, and sorgo — at pasture, boot, flower, and soft‐dough stages was undertaken to evaluate dry‐matter production, chemical composition, and digestibility predicted from chemical analyses.Dry‐matter yields generally increased in all types as harvest was delayed, with sorgo making the largest increase at the soft‐dough stage.Percent ash, crude protein, and fat decreased as harvest was delayed with little difference occurring between forage types. All cultivars declined in fiber when harvested after the flower stage. Total sugar percent increased as harvest was delayed for all forage types.Sudangrass and sorghum‐sudangrass TDN percent was lowest when cut at flower stage of maturity, whereas the sorgo steadily increased from the earliest harvest to the latest.Forage quality, except for crude protein which decreased sharply as harvest was delayed, was approximately equal for all forage types. Dry‐matter production varied considerably by forage types and stage of harvest indicating the utilization of sudangrass for pasture or green chop; sorghum‐sudangrass hybrid for pasture, green chop, or silage; and sorgo for silage.
Influence of Crop Sequence, Nitrogen Fertilizer and Herbicides on Weed Seed Populations in Sugar Beet Fields1
Authors: Dotzenko A. D. , Ozkan M. , Storer K. R. 
Published: July 2010

AbstractThe crop sequence in which sugar beets followed beans had lower weed seed populations than did sugar beets following barley and corn. The rate and time of application of nitrogen fertilizer had a significant effect on weed seed numbers in sugar beet fields. Where high levels of N were applied, high densities of weed seed occurred. Chemical weed control treatments significantly reduced populations of all weeds studied when compared to mechanical cultivation treatments. Significant differences between interactions were found for N fertilizer and crop sequence, weed control and crop sequence and weed control and N fertilizer.
Cause of Differential Susceptibility to Zinc Deficiency in Two Varieties of Navy Beans (Phaseolus vulgaris L.)1
Authors: Ambler J. E. , Brown J. C. 
Published: July 2010

AbstractTwo navy beans (Phaseolus vulgaris L.) varieties, ‘Sanilac’ and ‘Saginaw,’ were grown in soil, solution culture, and split medium. Plant growth and Fe, P, and Zn uptake were compared with differential Zn deficiency in each of the three media. In general, Fe and P aggravated Zn deficiency. Differential absorption of Fe and P by the two varieties appears to be the cause of differential susceptibility to Zn deficiency. Sanilac took up more Fe and P than Saginaw in a growth medium relatively low in Zn.
Potential Yield of Corn as Affected by Planting Date
Authors: Pendleton J. W. , Egli D. B. 
Published: July 2010

AbstractA field experiment was conducted at Urbana, I11., to determine the grain yield potential of corn plants developing during the period of maximum day length as compared to other plants developing later in the season. A high management level including high fertility and adequate soil moisture was maintained.Plants started in the greenhouse, transplanted to the field April 19 when approximately 15 cm tall, and pollinated June 15, yielded no more grain than plants started as seed in late April and pollinated July 8. Seedings made in the field May 14 and May 31 gave yield reductions of 103 kg/ha day as compared to the yield of the April 30 seeding. Stalk strength as measured by resistance to crushing was found to decrease with date of planting from April 19 to May 31.
Comparison of Indexes Relating Plant Response to Soil Moisture Status1
Authors: Rawitz E. , Hillel D. I. 
Published: July 2010

AbstractThe response of container‐grown sunflowers and snapbeans to soil moisture status was measured in a growth chamber and related to four soil moisture indexes. Drymatter yield was related to pre‐irrigation and to mean integrated soil moisture content and capillary suction. When related to moisture content indexes, yield appeared as a continuously rising function of moisture content, with a fairly constant slope. When related to moisture suction indexes, yield decreased very sharply with increasing capillary suction in the low‐suction range. When the maximum capillary suction index was used, most of the yield depression occurred at suctions lower than two bars, after which yield decreased at a much lower and constant rate to the 15‐bar suction. Among the four indexes examined, the maximum capillary suction index was found to be the most convenient for current control of soil moisture regimes. Application to results of fleld irrigation experiments indicates that it may be used under field conditions as well as with container‐grown plants. Since plant performance is a result of interaction between many factors in addition to soil moisture suction, an index based on a single factor cannot uniquely relate plant response to this factor. The maximum capillary suction index can, however, serve as a practical and simple tool when the effect of modifying factors is known or can be held constant.
Yield and Quality of Corn Silage as Influenced by Harvest Height1
Authors: Cummins D. G. , Burns R. E. 
Published: July 2010

AbstractYield and quality variations of corn silage associated with different harvest heights, and the yield and quality contributions of various plant segments below the ear were determined over a 3‐year period, 1966‐68, at Experiment. Ga. An increase in harvest height from 15 to 90 cm from the soil level decreased forage yields from 13.7 to 11.2 mt/ha, while in vitro dry matter digestibility (IVDMD) increased from 45.1 to 51.1%. The IVDMD for 15‐cm plant increments increased from 26.0% for the 15‐30 cm portion to 34.7% for the 75‐90 cm portion below ear. Harvested digestible dry matter (IVDMD ✕ forage yields) was 6.0, 6.0, and 5.9 mt/ha for the 15‐, 45‐, and 90‐cm heights, respectively. Although, total yields decreased with increased harvest height the increase in quality offset this loss in terms of harvested digestible dry matter.
A Linear Rule for Direct Nondestructive Leaf Area Measurements1
Authors: Grimes Donald W. , Carter Lyle M. 
Published: July 2010

AbstractA ruler was developed with graduations in area units of cm2 from the functional relationship Log10 Leaf Area (cm2) = a + b Log10 Leaf Length (cm). The functional relationship was established for cotton (Gossypium hirsutum L.) by sampling leaves twice during the growing season at different stages of morphologic development. Since the equations for the two sampling dates did not differ appreciably, the ruler was developed from the pooled data.
Soil Moisture Content, Tilth, and Soybean (Glycine max.) Response with Surface and Subsurface Drainage1
Authors: Fausey Norman R. , Schwab Glenn O. 
Published: July 2010

AbstractSoil properties and soybean response were compared for plots having different levels of drainage. The plots were established on a silty clay lakebed soil in northern Ohio. The soil and crop characteristics compared were: (1) average soil moisture content at four depths in the upper 30 cm during the seedbed preparation period (April and May); (2) soil tilth immediately preceding seedbed preparation as expressed by crust properties and resistance to surface penetration; and (3) stand establishment, root and top growth, and soybean yield. On plots with no drainage, crop stand was sparse and crop growth essentially nil. There were long periods with ponded water, and crusting and adverse structure of the surface soil were much in evidence. Among drained plots, there were no maesurable differences in crust bulk density and soybean stand. Plots having subsurface or combined surface‐subsurface drainage had lower moisture content, less resistance to surface penetration, smaller crust units, taller plants, better developed root systems, and greater yields than plots with surface drainage alone.
Evaporation and Condensation on Bare Soil under Irrigation in the East Central Great Plains1
Authors: Rosenberg Norman J. 
Published: July 2010

AbstractEvaporation from bare Sharpsburg s.c.l. was measured with precision weighing lysimeters at Mead, Nebr., during summer and fall, 1966. A number of drying cycles were included. Maximum daily evaporation was about 9 mm/day in August and about 3 mm/day in late October. The ratio E/Rn was frequently greater than unity especially when the lysimeters and a 1‐ha area surrounding them was visibly wet and the surface of the adjacent fields dry. A significant advectional contribution of energy in indicated. Nocturnal evaporation accounted for 10 to 50% of the total daily evaporation, the greater proportions occurring in fall. Dew was detected almost every morning. A maximum dew deposition of about 0.5 mm was measured. The Penman method yielded lower estimates of bare soil evaporation than did van Bavel's combination method. Both types of estimates varied from lysimetrically measured evaporation by from 3 to 50% on a daily basis.