bluuebunny/crossref_metadata_2025_split huggingface dataset:
Subsoiling for Nitrogen Applications to Corn Grown in a Conservation Tillage System1
Authors: Reeves D. W. , Touchton J. T. 
Published: July 2010

AbstractSubsoiling not only improves root penetration and water infiltration but may also provide an efficient means of applying N fertilizer. Field studies were conducted 2 yr on a Norfolk sandy loam (fineloamy, siliceous, thermic Typic Paleudults) and 1 yr on a Dothan fine‐sandy loam (fine‐loamy, siliceous, thermic Plinthic Paleudults) to determine the effect of N source and application method, subsoiling placement, and time of subsoiling and N application on the efficiency of N applied to no‐till corn (Zea mays L.). Urea and NH4N03 (157 kg ha−1) were applied (i) surface‐banded at planting, (ii) in the in‐row subsoil track at planting, (iii) surface‐banded 5 weeks after planting, or (iv) interrow with subsoilers 5 weeks after planting. Nitrification inhibitors, dicyandiamide (cyanoguanidine) (DCD) and ethylene dibromide (1‐2‐dibromoethane) (EDB), were also used with urea applied in subsoil tracks. Neither inhibitor affected grain yields. Applying N in the subsoil track proved an effective application method. Generally, highest yields (8204 to 9486 kg ha−1) were obtained by applying N 5 weeks after planting with in‐row subsoiling. Results indicate no benefit to subsoiling interrow if in‐row subsoiling was done at planting; however, if corn was planted without in‐row subsoiling, subsoiling interrow 5 weeks later improved yields. Interrow subsoiling may be a practical alternate management tool, especially when used to apply sidedressed N, for growers in years when subsoiling at planting is not feasible.
Velvetleaf Control for Solid‐Seeded Soybean in Three Corn Residue Management Systems1
Authors: Freed B. E. , Oplinger E. S. , Buhler D. D. 
Published: July 2010

AbstractLack of adequate weed control is considered one of the most important factors limiting acceptance of solid‐seeded soybean [Glycine max (L.) Merr.] and reduced tillage systems. Recent interest in combining these two production practices further complicates weed control. Field research was conducted at Arlington and Janesville, WI, during 1982 and 1983 to evaluate the effectiveness of preemergence and postemergence herbicide treatments for velvetleaf (Abutilon theophrasti Medic.) control in solid‐seeded soybean in three corn (Zea mays L.) residue management systems. Soybean were planted in 0.20‐m‐wide rows following complete tillage (moldboard plow, cultipack), mulch tillage (chisel plow, field cultivate), and no tillage. Preemergence herbicide treatments included combinations of alachlor [2‐chloro‐N‐(2,6‐diethylphenyl)‐N‐(methoxymethyl)acetamide] or pendimethalin [N‐(l‐ethylpropyl)‐3,4‐dimethyl‐2,6‐dinitrobenzenamine] with chloramben (3‐amino‐2,5‐dichlorobenzoic acid) or metribuzin [4‐amino‐6‐(l,l‐dimethylethyl)‐3‐(methylthio)‐l,2,4‐triazin‐5(4H)‐one]. Postemergence herbicide treatments included tank‐mix and sequential applications of sethoxydim {2‐[l‐(ethoxyimino)butyl]‐5‐[2‐(ethylthio)propyl]‐3‐hydroxy‐2‐cyclohexen‐l‐one} or fluazifop‐butyl [butyl(±)‐2‐(4‐{[5‐(trifluoromethyl)‐2‐pyridinyl]oxy}phenoxy) propanoic acid] in combination with acifluorfen {5‐[2‐chloro‐4‐(trifluoromethyl)phenoxy]‐2‐nitrobenzoic acid} or bentazon [3‐(1‐methylethyl)‐(1H)‐2,1,3‐benzothiadiazin‐4(3H)‐one 2,2‐dioxide]or both. Preemergence treatments did not completely control velvetleaf and were influenced by residue management. All treatments containing bentazon afforded near complete velvetleaf control without soybean injury, regardless of residue management. Acifluorfen did not completely control velvetleaf and resulted in soybean injury. Soybean yields were not affected by residue management when velvetleaf was controlled. These data indicate that soybean can be successfully produced in a conservation tillage, solid‐seeded system.
Effect of Supplemental Irrigation on the Yield of Coastal Bermudagrass in the Southeastern United States1
Authors: Burton G. W. , Butler J. L. , Hellwig R. E. 
Published: July 2010

AbstractThe objective of this study was to determine the effect of supplemental irrigation on the yield of Coastal bermudagrass [Cynodon dactylon (L.) Pers.] when fertilized annually with 700 kg/ha of N plus adequate P and K, and usually cut at 24‐day intervals. Paired plots, one irrigated to keep soil moisture above 25 MPa, the other not irrigated and replicated six times, received 100 kg/ha of N in mid‐March and after the first six cuts in 1966, 1967, and 1968 when respective annual rainfall was 97, 81, and 82% of the 44‐yr average, and rainfall for the 210‐day test period was 92, 87, and 77% of the 44‐yr average. Irrigation significantly increased the yield on only two of the 23 cuts made during the 3‐yr test period and failed to increase the total yield in 1966, 1967, or 1968. Three‐year respective average annual yields were 13 750 and 13 860 kg/ha for the irrigated and nonirrigated treatments. Irrigation had no effect on protein content or the pelleting properties of the forage produced.
Photoperiod Influence on Development in Sunflower Genotypes1
Authors: Goyne Philip J. , Schneiter A. A. 
Published: July 2010

AbstractSynchronization of anthesis of male and female inbred sunflower (Helianthus annuus L.) lines to be crossed in either breeding nurseries or seed production fields is important. Research was conducted to determine the influence of photoperiod on phenological development in a diverse group of sunflower genotypes. An understanding of this response would allow the development of a model to predict sunflower anthesis. Sixteen sunflower genotypes, including hybrid and inbred lines, were classified for photoperiod response in greenhouse plantings carried out over a 2‐yr period at Fargo, ND (latitude 46°54′N, elevation 183 m). Plantings were made so that emergence occurred each time natural photoperiod changed by about 1 h. Although some genotypes displayed long‐day, short‐day, or insensitive photoperiodic reactions for the period from emergence to floral bud development, many of the genotypes appeared to be ambiphotoperiodic, with 11 through 13 h at emergence being the photoperiods delaying time to flower bud development. This delay could be of consequence to breeding programs in those latitudes where planting dates may result in emergence and early growth of the sunflower coinciding with these intermediate photoperiods.
Planting Date and Tillage Effects on Corn Following Corn1
Authors: Imholte A. A. , Carter P.R. 
Published: July 2010

AbstractCrop residue remaining on the soil surface for erosion control under no‐tillage (NT) corn (Zea mays L.) production depresses early season soil temperatures compared to conventional tillage (CT). This has resulted in questions concerning planting date recommendations for NT in the northern United States. The objective of this study was to determine the influence of planting date on crop development and grain yield when corn produced under CT and NT follows corn. Conventional and no‐till systems were compared during 1983 to 1985 at Arlington, WI, on a Plano silt loam (fine‐silty, mixed, mesic Typic Argiudoll). Planting dates were 26 April to 6 May (early), 14 to 19 May (medium), and 27 May to 6 June (late). Plots were overplanted and stands were thinned to constant densities following complete emergence. Daily seed‐zone soil temperature and seedling emergence were measured. Colder soil temperatures under NT were associated with reduced corn emergence, delayed emergence and silking, and increased harvest grain moisture compared to CT, for early planting. With medium and late planting dates, differences between tillage systems for emergence and silk date were less pronounced or inconsistent between years, or both. For both tillage systems, highest grain yields were generally obtained when planting was completed by early May, with yield declining as planting was delayed. Decreased grain yields with NT or delayed planting, or both, were related to reduced cumulative air growing degree days between silk and the first 0°C frost. These results suggest that for corn following corn in northern U.S. regions, current recommendations for early planting under CT are applicable to NT. However, increased seeding rates may be required to overcome reduced emergence with NT systems.
Contributions of Ground Cover, Dry Matter, and Nitrogen from Intercrops and Cover Crops in a Corn Polyculture System1
Authors: Scott T. W. , Mt. Pleasant J. , Burt R. F. , Otis D. J. 
Published: July 2010

AbstractContinuous corn (Zea mays L.) grown on sloping land and harvested for silage, returns few residues to the soil and leaves the soil unprotected against erosion for most of the year. Three field experiments were conducted on a Lima loam (a fine‐loamy, mixed, mesic Glossoboric Hapludalf) to determine the contributions from various intercrops and cover crops towards ground cover, dry matter, and N. In Exp. 1 and Exp. 2, the effects of intercrops and cover crops were measured by determining corn grain yields following the plow down of the various crops. Corn grain yields following the incorporation of various crops were compared to yields of corn where no cover crops had been incorporated but N rates of 0, 56 or 112 kg ha−1 had been applied. In Exp. 3, the effects of intercrops and cover crops on corn yields were measured over a 5‐yr period. First‐year corn grain yields were neither increased nor decreased as a result of seeding intercrops when the corn was 0.15 to 0.30 m high. All intercrop and cover crop treatments in Exp. 3 provided significantly more ground cover than the control treatment. Annual ryegrass (Lolium multiflorum Lam.), medium red clover (Trifolium pratense L.), and a combination of the two were the most effective in terms of ground cover and dry matter production.
Aerial Parts of Hard Red Spring Wheat. I. Dry Matter Distribution by Plant Development Stage1
Authors: Bauer Armand , Frank A. B. , Black A. L. 
Published: July 2010

AbstractInformation is lacking on the proportionate mass distribution of dry matter among aerial components of spring wheat (Triticum aestivum L.) over its life cycle at recognized plant development stages. Benefits of such an assessment would accrue to segments of the agricultural industry and modelers/forecasters of crop development and yield. Measurements of aerial components were made weekly from the three‐leaf to kernel‐hard stage of three spring wheat cultivars grown on Williams loam (fine‐loamy, mixed Typic Argiborolls) with three fertilizer N and three water levels in 1981 and 1982. Relations were determined of total aerial dry mass percent in leaves, stems, and spikes, of tillers per plant, fresh and dry leaf mass, and leaf area index (LAI) to the Haun scale expanded to include grain filling, and, as well, fresh and dry leaf mass to LAI. Development stage accounted for 92,96,85, and 79% of the change in total aerial dry mass and in percent of aerial dry mass in leaves, stems, and spikes, respectively, and 52, 85, 59, and 59% of tillers per plant, LAI, dry leaf mass, and fresh leaf mass, respectively. About 50% of aerial dry mass at flag leaf was distributed in each of leaves and stems, while maximum tiller number occurred one Haun stage earlier, and maximum LAI at boot stage. Water and N variables altered the magnitude of mass change, but did not cause a shift in development stage when maximums occurred. Through flag‐leaf‐extension stage, LAI changed one unit for each increase of 37 and 237 g m−2 of dry and fresh leaf mass, respectively.
Nitrogen from Soybean for Dryland Sorghum1
Authors: Gakale L. P. , Clegg M. D. 
Published: July 2010

AbstractCrop and soil data were collected for 2 yr (1984–1985) from a soybean [Glycine max (L.) Merr.]‐grain sorghum [Sorghum bicolor (L.) Moench] rotation experiment established in 1974, to evaluate the residual effects of soybean on N uptake, some agronomic characters, and yield of the sorghum crop and residual soil N accumulation. The soil at the experimental site was a Sharpsburg silt clay loam (fine, montmorillonitic, mesic Typic Argiudoll). Fertilizer rates of 0, 56, 112, and 168 kg N ha−1 were applied to the sorghum crop in both the continuous sorghum and rotation cropping sequences. Total N uptake by sorghum was significantly increased by rotation cropping (P<0.05) when the N fertilizer rate was 112 kg ha−1 or less. Sorghum grown in rotation or with the application of 56 kg N ha−1 or more flowered 6.1 days earlier than continuously grown sorghum without N. At the zero level of fertilizer N, sorghum after soybean yielded 85% more grain than did continuous sorghum. Rotation with soybean increased subsequent sorghum grain 14% compared to continuous sorghum when averaged over 2 yr. At or above the 112 kg N ha−1 level, differences between the cropping systems were not different. Estimates of residual soil N as NO−3−N in 1985 showed that after soybean there was 50 to 60 kg N ha−1 more than after continuous sorghum when 56 kg N ha−1 or less had been applied.
Forage Yield, Nonstructural Carbohydrate Levels, and Quality Trends of Caucasian Bluestem
Authors: Forwood J. R. , Matches A. G. , Nelson C. J. 
Published: July 2010

AbstractInformation is limited on growth pattern and the effects of management on regrowth yield, quality, and total nonstructural carbohydrate (TNC) levels of Caucasian bluestem [Bothriochloa caucasica (Trin.) C.E. Hubb.] grown in the southern Corn Belt. Field studies on a Creldon silt loam soil (fine, mixed, mesic Mollic Fraguidalf) were conducted to determine trends of the above parameters under various primary growth harvests (one‐time harvests at 0, 14, 28, 42, and 56 d after 4 June) and summer and late‐season regrowth harvests (initial harvest on 18 June and 16 July, respectively, with regrowth harvests 14, 28, 42, 56, 70, and 84 d later). Yield increased linearly (104 and 55 kg ha−1 d−1, respectively) for primary growth and summer regrowth, while late‐season regrowth yield had a cubic trend (y = 201 − 11x + 2.3x2 − 0.02x3; x = days after initial harvest). In vitro dry matter digestibility declined linearly with time (2.9 g kg−1 d−1) in primary growth, but the rate of decline varied depending on length of delay for summer and late‐season regrowth (y = 548 − 4.0x + 0.26x2; y = 436 + 0.9x − 0.19x2, respectively). Crude protein declined quadratically under all treatments (y = 125 − 1.0x − 0.005x2; y = 137 − 3x + 0.001x2;y = 71.2 + 1x − 0.001x2, respectively, for primary growth and summer and late‐season regrowth). Neutral detergent fiber levels increased linearly for primary growth and late‐season regrowth (y = 668 + 1.9x;y = 662 + 1.1x, respectively), while summer regrowth response was quadratic (y = 637 + 2.7x − 0.002x2). Digestible dry matter yield increased throughout the season until it declined in late September. Total nonstructural carbohydrate levels were lower than previously found in native C4 grasses and may not be as important for survival in Caucasian bluestem. Our data indicate that a mid‐June defoliation, with further defoliation up to late summer, may optimize Caucasian bluestem's potential in livestock grazing systems.
Photoperiod Requirements for Flowering and Flower Production in Soybean
Authors: Board J. E. , Settimi J. R. 
Published: July 2010

AbstractPhotoperiod has been recognized as playing a major role in soybean [Glycine max (L.) Merr.] growth and development. The objective of these studies was to determine the number of short days (13.5 h) representative of early spring daylengths in the southeastern United States necessary to cause anthesis and adequate flower production in soybean. Growth chamber studies were conducted at the Phytotron at North Carolina State University, during the first 26 wk of 1985. The soybean cultivar Tracy‐M and the delayed flowering genotype D77‐12480 were subjected to treatments in which they were transferred either from short‐day (13.5‐h) to long‐day (16‐h) or long‐day to short‐day treatments at different times of their development. The number of days to first flower and the rate of flower production were taken. Results indicated that Tracy‐M and D77‐12480 appeared to become responsive to short‐day induction at 8 to 12 and 8 to 16 d after emergence, respectively. While flowering occurred in Tracy‐M with as few as eight short days, optimal flower production required short‐day treatment up to and past first flowering. In D77‐ 12480, application of long days before first flowering inhibited any flower production. As in Tracy‐M, short days were required throughout the flowering period for maximum flower production. Results indicate that under field conditions, diminished flower production can be expected if long days occur before or during the flowering period, or both. Short‐day treatment sufficient to cause anthesis was not necessarily adequate for ample flower production.
Variation among Soybean Breeding Lines in Relation to Yield and Seed‐Fill Duration
Authors: Smith James R. , Nelson Randall L. , Vasilas Bruce L. 
Published: July 2010

AbstractThere are exceptions to the positive relationship between seedfilling period (SFP) and seed yield in soybean [Glycine max (L.) Merr.]. Studying genotypes that do not show a positive relationship between SFP and yield may aid in identifying factors that influence seed yield or SFP, or both. The objective of this research was to analyze groups of soybean genotypes that differed in their SFP‐yield relationship, and determine which factors affected seed yield. Eight experimental lines were selected from a ‘Williams’ ✕ ‘Kanrich’ cross to represent the four SFP‐yield combinations of long or short SFP and high or low yield. Replicated field plots were grown in 1984 and 1985 at Urbana, IL, on a Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudoll). Data taken in each year included: SFP, seed yield, harvest indices for dry matter and N, total flowers, total pods at three stages (5 mm long, pod containing a seed 3 mm long, and mature pod), and total N and dry matter at the beginning and end of SFP. Early flowering was related to SFP, but not to yield. Rate as well as duration of seed fill can influence seed yield. Total N in the plant at the end of SFP was related to yield, but not to SFP. Total N and dry matter assimilated during SFP, harvest indices for N and dry matter, and final seed yield were all related.
Seasonal Carbon and Nitrogen Accumulation in Relation to Net Carbon Dioxide Exchange in a Carbon Dioxide‐Enriched Soybean Canopy
Authors: Reddy V. R. , Acock B. , Acock M. C. 
Published: July 2010

AbstractCrop modelers routinely equate net CO2 exchange (CE) in crop canopies with biomass to simulate crop growth and productivity. This study was initiated to validate this relationship experimentally by monitoring CE during a whole‐season C02‐enrichment study on soybean [Glycine max (L.) Merr. cv. Forrest]. Dry weights of soybhean grown in sunlit plant growth chambers in C02 concentrations ([CO2]) of 330,450,600, or 800 μL L−1 were sampled at 25 d after emergence (DAE) and after physiological maturity. Photosynthetic nates (P) and respiration rates were calculated from CE rates measured at 0.25‐h intervals, day and night, throughout an entire season. The accuracy of CE measurements was tested by plotting gross P against [CO2] at 28,54, and 80 DAE (days when light flux density was at least 1300 μmol photons m−2 s−1). Gross P had the expected hyperbolic dependence on [CO2] with all estimated coefficients of determination >0.93. The net CO2 required for producing various plant parts was calculated from measurements of dry weight and N content and from assumptions about carbohydrate, oil, mineral, and lignin content. The amount of C required to fix 1.0 g of N symbiotically has been reported to be anywhere from 2.5 to 19.4 g. In this sludy the relationship between CO2 fixation and biomass was closest when calculations were based on the theoretical value of 2.0 g of C for each gram of N reduced for all [CO2] treatments except 800 μL L−1, where a value of 4.0 g of C per gram of N fitted the data better.
Sunflower Genotype Response to Photoperiod and Temperature in Field Environments
Authors: Goyne P. J. , Schneiter A. A. , Cleary K. C. , Creelman R. A. , Stegmeier W. D. , Wooding F. J. 
Published: July 2010

AbstractSunflower (Helianthus annuus L.) is cultivated over a wide range of photoperiod and temperature conditions. The objective of this research was to determine the response of 16 diverse sunflower genotypes to varying photoperiod and temperature. Field research sites were at five locations including Argentina, Alaska, and Hawaii. The photoperiod (daylength + twilight hours) at vegetative emergence (VE) for most sites, except Hawaii and Alaska, ranged from 14.5 to 16.2 h. Within this range there was no evidence that photoperiod affected the time from VE to bud visible stage (R1). Instead, differences in temperature at various sites were responsible for differing rates of development. However, the short photoperiods at VE at Hawaii (11.2 h) decreased development rate and long photoperiods at Alaska (24 h) increased development rate dramatically. A nonparametric method was applied to rank the genotypes into temperature response groups. Four distinct groups resulted for the VE to R1 growth stage intervals, which were classed as very quick, quick, medium, and slow with respect to the time taken to reach R1 from VE. Four groups also resulted for the R1 to anthesis (R5.1) time period. The groups for R1 to R5.1 differed from those for VE to R1. Genotypes within these groups were dissimilar to those for VE to R1. It was concluded that models used to predict phenological development in sunflower could be based on temperature alone provided photoperiod was within the 14.5 to 16.2 h range, To predict development outside this photoperiod range would require photoperiod be included in the model.
Crop Response to Lime and Phosphorus on New Bench Terraces in the Tropics
Authors: Schmidt D. R. , Casler M. D. , Saefuddin A. 
Published: July 2010

AbstractPopulation growth in many tropical areas has led to the cultivation of steeply sloped hillsides. Soil disturbance from construction of conservation terraces to reduce land degradation in humid tropical areas often intensifies P deficiency and problems related to acidity. This trial measured the response of food crops to lime and P application for 2.5 yr following construction of bench terraces. Factorial combinations of 0, 2, and 4 Mg ha−1 lime and 0, 10, 20 and 40 kg P ha−1 were applied on a deep, well‐drained clay of volcanic origin (Typic Haplumbrept) at Andapraja, West Java, Indonesia. A pretrial soil test indicated pH of 5.0, available P (Bray 1) of 5.9 mg kg−1 and exchangeable Al saturation of 17%. Upland rice (Oryza sativa L.) responded strongly to P application. Three crops averaged 0.35, 2.45, 2.89 and 3.46 Mg ha− of unmilled grain from respective applications of 0, 10, 20 and 40 kg P ha−1. Lime had no effect on rice yield. Soybean [Glycine max (L.) Merr.] and cowpea [Vigna unguiculata (L.) Walp.] responded to both lime and P but yields were low because of disease. Mean lime and no‐lime yields were 0.48 and 0.62 Mg ha−1 for soybean. Cowpea yields were maximum (0.15 Mg ha−1) at the 2 Mg ha−1 lime rate. Mean P and no‐P yields were 0.13 and 0.64 Mg ha−1 for soybean and 0.01 and 0.13 Mg ha−1 for cowpea. Cassava (Manihot esculenta Crantz) root yield response to P was less pronounced than the response by rice and the legumes, and was the only crop to show a lime ✕ P interaction. This was attributed to limited response to P when lime was applied, significant response to P with zero lime and marked response to lime with zero P. The efficiency of return from applied P indicated that the 10 kg P ha−1 rate applied to rice, soybean or cassava had the highest efficiency, producing yields 70 to 80% of the 40 kg P ha−1 rate.