bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐Term Wheat, Soybean, and Grain Sorghum Double‐Cropping under Rainfed Conditions
Authors: Crabtree R. J. , Prater J. D. , Mbolda P. 
Published: July 2010

AbstractInadequate amounts and distribution of rainfall are most often the major limiting factors to crop production in the southern Great Plains. This is especially true for summer crops, whether grown in mono‐ or double‐cropping situations. This study was conducted at the Oklahoma Vegetable Research Station, Bixby, OK from 1976 to 1987 on a Wynona silt loam soil (Cumulic Haplaquolls) with 0 to 1% slope. The objective was to determine the effects of long‐term double‐cropping on the potential for sustaining grain yields of wheat [Triticum aestivum (L.) em. Thell], soybean [Glycine max (L.) Merr.], and grain sorghum (Sorghum bicolor L. Moench) produced on the same land under rainfed conditions. Over a 12‐yr period monocropped wheat averaged 3050 compared with 2510 and 2450 kg ha−1 when double‐cropped with soybean and grain sorghum, respectively. Conventionally tilled monocropped soybean and grain sorghum and no‐till double‐cropping of both soybean and grain sorghum after wheat produced grain 11 out of 12 yr. Monocropped soybean averaged 2470 compared with 1930 kg ha−1 for no‐till double‐cropped soybean. Monocropped grain sorghum averaged 5130 compared with 4200 kg ha−1 for double‐cropped grain sorghum. During the years of near 30‐yr average rainfall amounts and distribution (5 out of 11), yields of double‐cropped soybean and grain sorghum were competitive with those of monocropped soybean and grain sorghum. These results indicate that yields of double‐cropped wheat, soybean, and grain sorghum can be sustained over long periods of time. In eastern Oklahoma double‐cropping on a deep medium textured soil produced more total grain that resulted in more efficient use of climatic, land, labor, and equipment resources when compared with monocropping.
Yield Dynamics of Canopy Components in Alfalfa‐Grass Mixtures
Authors: Mooso G. D. , Wedin W. F. 
Published: July 2010

AbstractRelationships between alfalfa (Medicago sativa L.) and associated grasses in a plant community are complex. A concern has developed whether alfalfa was, in fact, benefiting from grass association. A field study was conducted to describe the changes in canopy components of alfalfa‐reed canarygrass (Phalaris arundinacea L.) and alfalfa‐orchardgrass (Dactylis glomerata L.) mixtures. Alfalfa‐grass mixtures of one row of grass between two rows of alfalfa and one row of alfalfa between two rows of grass were planted in a repeating pattern. Monocultures of each species and four binary mixtures were sampled for total, alfalfa and grass component, and stratified alfalfa yields were measured at 10, 20, 30, 40, and 50 d of spring and summer regrowth for 2 yr. Planting pattern, grass species and season of growth affected botanical composition and yield of alfalfa‐grass mixtures. Alfalfa‐grass mixtures yielded more than alfalfa monocultures during only one spring growth cycle. During summer regrowth, alfalfa‐grass mixtures were less productive than alfalfa monocultures. In spring, reed canarygrass accounted for a greater proportion of the total yield than orchardgrass, whereas the two grasses were similar during summer. Grass yields of mixtures were not affected by alfalfa association. The results of this study suggest that alfalfa‐grass mixtures offer little yield advantage over alfalfa monocultures when harvested as hay.
Canopy Temperature and Stomatal Conductance of Water‐stressed Dormant and Nondormant Alfalfa Types
Authors: Hattendorf M. J. , Evans D. W. , Peaden R. N. 
Published: July 2010

AbstractAlfalfa (Medicago sativa L.) from diverse origins may respond differently to water stress. Objectives were to assess dormant and nondormant‐type alfalfa response to water stress as inferred from canopy temperature and stomatal conductance. The effects of continuous deficit irrigation produced by a line‐source sprinkler system on ‘Vernal’ (dormant type), ‘Vernema’ (intermediate dormancy type), and ‘CUF 101’ (nondormant type) were investigated at Prosser, WA, on a Warden loam (coarse‐silty, mixed, mesic Xerollic Camborthids). Water stress was expressed as the Crop Water Stress Index (CWSI), a canopy‐temperature (Tc) based indicator of water stress. The Y‐intercepts of Vernal and CUF 101 canopy‐air temperature/vapor pressure deficit (Tc–TaVPD) curves were significantly different (P = 0.05) with CUF 101 0.6 °C (28.5%) higher than Vernal. Mean canopy resistance to vapor transport (rcp) was 33% greater for CUF 101 than for Vernal. Slopes of stomatal conductance/CWSI curves were similar, but stomatal conductance at zero CWSI of CUF 101 was 60% of Vernal. Total water use and yields of Vernal, Vernema, and CUF 101 were not significantly different (P = 0.05) among cultivars, although CUF 101 mean daily water use was 2.1 mm greater than Vernal water use early in the growth cycle. Higher Tc for CUF 101 was consistent with lower CUF 101 stomatal conductance. The differences in Tc and stomatal conductance were related to dormancy type. Lower transpiration of CUF 101 at full canopy cover has implications for development of more water‐use efficient alfalfa.
Irrigation of Turfgrass with Secondary Sewage Effluent: II. Turf Quality
Authors: Hayes A. R. , Mancino C. F. , Forden W. Y. , Kopec D. M. , Pepper I. L. 
Published: July 2010

AbstractDue to limited water resources, golf course irrigation with municipal sewage effluent is a common practice, and, in some areas of the USA Desert Southwest mandatory. However, effluent irrigation changes soil properties and therefore different management practices are needed for good quality turfgrass. This field experiment evaluated the continuous use of secondary treated municipal sewage effluent on turfgrass quality over a 64‐wk period. In April 1987, common bermudagrass (Cynodon dactylon L. Pers.) was seeded to a Sonoita gravelly sandy loam (coarse‐loamy, mixed, thermic Typic Haplargid) and maintained under fairway conditions. In October of that year, perennial ryegrass (Lolium perenne L.) was overseeded to maintain an actively growing turf. Plots were irrigated identically with either effluent or potable water. Effluent irrigation led to significantly lower seed emergence but improved seed establishment. Turf quality was assessed under each irrigation with four N fertilization rates of 0, 16.1, 32.3 and 48.4 kg N ha−1 (4 wk)−1. Established effluent irrigated turf did not show signs of osmotic stress with the leaching fraction employed. Effluent provided significant amounts of nutrients at high application rates. No single fertilization rate or irrigation regime consistently produced a superior turf quality over the course of the whole study. Effluent irrigated turf showed signs of overfertilization, greater heat stress and chlorosis of overseeded ryegrass stands during the summer months on plots receiving N fertilizer amendments. Municipal effluent did produce a high quality turf, but, the greater soluble salt and nutrient content of the water necessitate special management strategies.
Soybean Growth and Yield as Affected by Surface and Suboil Compaction
Authors: Johnson J. F. , Voorhees W. B. , Nelson W. W. , Randall G. W. 
Published: July 2010

AbstractAxle loads from wheel traffic on farmland ranges from less than 4.5 Mg axle−1 to over 20 Mg axle−1. Loads of <4.5 Mg axle−1 generally cause compaction only in the upper 0.3 m of the soil (surface compaction), while higher loads have caused soil compaction below this surface layer (subsoil compaction). A replicated field study was conducted on a Webster clay loam (fine‐loamy, mixed, mesic Typic Haplaquoll) in southern Minnesota and on two Ves clay loams (fine‐loamy, mixed, mesic Udic Haplustoll) in southwestern Minnesota to assess the effect of surface and subsoil compaction on the growth and yield of soybean (Glycine max L. Merr.). Surface compaction treatments consisted of no interrow traffic on either side of the row at any time during the experiment and annually applied interrow wheel traffic on both sides of the row from an axle load <4.5 Mg. Subsoil compaction treatments consisted of control (no subsoil compaction), 9 and 18 Mg axle−1 loads applied once at the beginning of the experiment. Surface compaction, when averaged over years on both Ves sites, decreased yield by 15% overall and up to 27% in a single year. Yield response to surface compaction on the Webster site was climate dependent, in general, decreasing yield during a wet year but increasing yield during a dry year. Subsoil compaction from the 18 Mg axle−1 treatment reduced plant height and integrated leaf area index on the Webster site each year of the experiment, and tended to decrease yield. The response to the 18 Mg axle−1 load on the Ves was inconsistent. Yield was increased significantly in 5 out of 14 location‐years by the 9 Mg axle−1 treatment when compared with the control treatment. Soybean growth parameters and yield were affected more by annual surface compaction than by a one‐time application of subsoil compaction. A decrease in vegetative growth did not necessarily result in a comparable decrease in seed yield.
Increasing Soybean Productivity through Selection for Nitrogen Fixation
Authors: Burias N. , Planchon C. 
Published: July 2010

AbstractNitrogen fixation and accumulation are major factors of soybean [Glycine max (L.) Merr.] production. Investigations were carried out to determine whether higher N2 fixation could be considered as a criterion for the improvement of productivity. A selection for N2 fixation, which was based on acetylene reduction estimates, was carried out at Growth Stage R5. A set of 210 F2 plants issued from three crosses and developed in nutrient solutions was studied in phytotronic chambers, under temperature and mineral N nutrition conditions that were favorable for the maximum expression of the symbiosis. The seed yield of the F4‐derived lines was evaluated under normal population density on a Typic Udifluvent loamy‐sand soil (pH 6.0, organic matter 1.5%, and total N 1 g kg−1). Seed yield and N2 fixation were expressed with respect to the mean value of the genotypes with the same date of maturity. Seed yields of the F4‐ derived lines were significantly correlated with the N2 fixation of the F2 parent plants. This correlation was observed for all of the plants investigated including all crosses (r = 0.294**, significant at P = 0.01) and for each of the three crosses: Weber × Maple Arrow (r = 0.433**), Weber × Jiling 14 (r = 0.394*, significant at P = 0.05), Weber × Kingsoy (r = 0.597**). The seed yield of the F4 lines was also significantly correlated with nodule volume and nodule dry weight, particularly at each cross level. High nodulation ability and high N2 fixation rates appear to increase soybean seed yield. Early breeding for these traits may therefore be expected to result in a genetic gain in seed yield in the progeny.
Nitrogen Fertilization of Wheat Double‐Cropped Following Grain Sorghum in a No‐Tillage System
Authors: Howard Donald D. , Lessman Gary 
Published: July 2010

AbstractUtilization of wheat (Triticum aestivum L. em Thell.) as a cash crop or cover crop in a double‐cropping system is desirable to prevent excessive soil erosion on loess‐derived soils in the southern USA. Fall and spring N application to winter wheat double‐cropped following grain sorghum (Sorghum bicolor L.) was evaluated on a Grenada silt loam (fine‐silty, mixed, thermic Glossic Fragiudalf). The experimental design was a randomized complete block with a split‐plot arrangement of treatments. Rates of N applied at planting; (0, 34, and 67 kg ha−1) were the main plots, with N rates applied in the spring (0, 34, 67, 101 and 134 kg ha−1) the sub‐plots. Fall N (Nf) increased both yield and plant height. Spring N (Ns) had a. greater effect on yield and plant height than Nf. Yields increased from 0.83 to 2.61 Mg ha−1) by increasing Ns from 0 to 134 kg ha−1) without Ns. Yields increased from 1.50 to 2.67 Mg ha−1) by increasing Na from 0 to 67 kg ha−1 with 67 kg ha −1>/ Nf. Yield variation was expressed by Y = 0.822 + 0.0098 Nf + 0.0248 Ns − 8.5 × 10−5) N2s + 1.45 × 10−5 NfNs − 7.41 × 10−7 NfN2s. Plant height increased from 56 to 85 cm by increasing Ns from 0 to 134 kg ha−1 without Nf, but increased from 67 to 80 cm by increasing Ns from 0 to 67 kg ha−1 with 67 kg ha−1 Nf One‐hundred‐kernel weight decreased from 2.35 to 2.11 g by increasing Ns from 34 to 134 kg ha‐1. Grain N increased from 19.9 to 23.2 g kg‐1 by increasing Ns from 34 to 134 kg ha−1.
Temperature Effect on Growth and Development of Cotton During the Fruiting Period
Authors: Reddy V. R. , Reddy K. R. , Baker D. N. 
Published: July 2010

AbstractCotton (Gossypium hirsutum L.) requires warm days and relatively warm nights for optimum growth and development. However, in many areas of the cotton belt, sub‐ and super‐optimal temperatures frequently occur, both early and late in the season, resulting in altered growth and development. The purpose of this research was to quantify plant responses to temperature, so that these responses could be incorporated into plant growth models used to manage cotton crops. Plants, initially grown out of doors in pots, were moved into sunlit, temperature‐controlled growth chambers 5 d prior to initial bloom. Growth and development were studied in 20/10,25/ 15,30/20,35/25, and 40/30 °C day/night temperature regimes from initial bloom. Temperature significantly affected phenology, leaf expansion, internode elongation, biomass production and the partitioning of assimilates to different plant parts. Optimum temperature for biomass production was 30/20 °C, with 40 and 50% less biomass at 20/10 and 40/30 °C, respectively. By 49 d after initial bloom, 13, 15 and 43% of the biomass had been partitioned to bolls and squares at 20/10,25/15 and 30/20 °C, respectively, reflecting to some extent slower development at the temperatures lower than 30/20 °C. Above 30/20 °C, most of the squares and bolls were aborted. The growth of the main‐stem and its successive leaves at 30/20 °C was rapid initially, but was restricted later due to competition with bolls for available carbohydrates. The quantification of growth and developmental rates over a wider range of temperatures will enable us to predict crop performance if temperature increases as a result of global climate change.
No‐Till Warm‐Season Grass Establishment as Affected by Atrazine and Carbofuran
Authors: McKenna J. R. , Wolf D. D. , Lentner M. 
Published: July 2010

AbstractTall growing, perennial, warm‐season grasses that produce 65 to 75% of their yield in mid‐summer may provide needed summer grazing; however, establishment is often slow and inconsistent when compared to cool‐season grasses. Improved establishment would make these warm‐season grasses less vulnerable to annual weed competition. No‐till plantings of switchgrass (Panicum virgatum L.) and Caucasian bluestem (Bothriochloa caucasica (Trin.) C. E. Hubbard] were made at Blacksburg, VA (37° 11' N° 80° 25' W, 610‐m elevation) on a Groseclose loam soil (clayey, mixed, mesic Typic Hapludult). Eight experiments included carbofuran (2,3‐Dihydro‐ 2,2‐dimethyl‐7‐benzofuranol methylcarbamate) at 0 and 1.1 kg a.i. ha−1 and atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) at 0, 1.1, and 2.2 kg a.i. ha−1 in all possible combinations. Seedling growth, leaf appearance rates, seedling weights, density, leaf elongation rates, and heights were measured. Yields of weedfree perennial warm‐season grasses were determined in the year of planting and the year after planting. Carbofuran at 1.1 kg a.i. ha−1 placed in the row with the seed at planting enabled seedlings to develop faster, elongate more rapidly, and provided more and heavier seedlings than without carbofuran. In the year after seeding, yields of warm season grass were higher where carbofuran was applied at seeding in seven of eight experiments. Atrazine reduced herbage yields as well as population, weight, development, and leaf elongation rate of seedlings in the seeding year. Atrazine at 1.1 kg a.i. ha−1 was not detrimental to either grass in the second year of the study. Atrazine at 2.2 kg a.i. ha−1 appeared to injure switchgrass more than Caucasian bluestem. Yields in the year after planting further confirmed these observations. Atrazine at 1.1 kg a.i. ha−1 increased yields over untreated controls. However, in one of four switchgrass experiments, yields of grass treated with atrazine at 2.2 kg ai. ha−1 were lower than controls the year after planting. A yield reduction was observed in two of four caucasian bluestem experiments. All stands were nearly pure with planted species the year after planting. Carbofuran and atrazine at 1.1 kg a.i. ha1 was considered the best recommendation for establishment of switchgrass and Caucasian bluestem under the conditions of the experiment.
Water Status Effect on Dinitrogen Fixation and Photosynthesis in Soybean
Authors: Djekoun A. , Planchon C. 
Published: July 2010

AbstractWater deficiency brings about a marked limitation in soybean (Glycine max. L. Merr.) yield by impairing photosynthesis and symbiotic N2 fixation. The objective of this study was to determine the photosynthetic and N2‐fixation response to short‐ and long‐duration water status variations in leaves and nodules. Plants were grown in pots in a greenhouse. Carbon dioxide exchange rate was measured by gas analysis and N2 fixation by the acetylene reduction method. Leaf water status was determined with a pressure bomb and nodule water potential with a psychrometer. Dinitrogen fixation decreased steadily throughout the water deficiency period whereas photosynthesis first decreased only slightly, and then dropped dramatically. After a severe water stress, partial recovery was slower for N2 fixation than for photosynthesis. The N2‐fixation response appeared to be directly related to a reduction in nodule mass, which affected nodule structural constituents after a severe stress. During the water deficiency period, the water status of the nodules responded only partially to water status variations within the plant during the day. Dinitrogen fixation depended more on the water status of the nodules than on the changes in nodule mass. There was a higher dependence of N2 fixation on nodule water content than on nodule water potential, particularly for values <‐1.2 MPa. The N2‐fixation activity maintained during the severe phase of water stress, when photosynthesis was zero, resulted from the relative independence of the nodules on the daily water variations within the plant and from the strong binding of the nodule water.
Separation of Mesophyll from Non‐Mesophyll Cell Wall Tissue in Indiangrass Leaf Blades
Authors: Piwonka Edward J. , MacAdam Jennifer W. , Kerley Monty S. , Paterson John A. 
Published: July 2010

AbstractA method to isolate large quantities of non‐mesophyll cell wall material for studying factors that limit the susceptibility of these cell wall polysaccharides to microbial degradation was evaluated. Mesophyll cells were separated from non‐mesophyll cells in indiangrass (Sorghastrum nutans [L.] Nash) leaf blades by ball milling to separate cells and then sieving to isolate non‐mesophyll cells. The mesophyll fraction was comprised of non‐lignified mesophyll cells contaminated with some fiber (sclerenchyma, xylem, and bundle sheath) particles. The non‐mesophyll fraction was virtually free of mesophyll cells and consisted primarily of lignified cell wall material. The weight ratio of mesophyll to non‐mesophyll cell wall material was 1.2:1. Non‐mesophyll cell walls were similar to mesophyll cell walls in their concentrations of arabinose, mannose, and galactose, and higher in their concentrations of xylose, glucose, p‐coumark acid, and ferulic acid. The ratio of xylose to arabinose was significantly greater for the non‐mesophyll fraction. Compositional differences between non‐mesophyll and mesophyll cell walls may in part explain the lower susceptibility of non‐mesophyll cell wall material to microbial degradation compared to mesophyll cell wall material.
Growth Rate and Water Use by Legume Species at Three Soil Temperatures
Authors: Zachariassen J. A. , Power J. F. 
Published: July 2010

AbstractLegumes may be used to reduce fertilizer inputs, provide ground cover for soil erosion protection, and reduce residual soil nitrates. Little data are available to guide a producer in selecting a legume that matches water and temperature conditions and produces acceptable growth and N2‐fixation rates. The purpose of the experiment reported here was to provide such information. After a 14‐d germination period at 20 °C, we grew eight legume species at soil temperatures of 10, 20, and 30 °C (± 2 °) for 105 d in a greenhouse. Daily water use was recorded, and plant dry weights were measured every 21 d. Initially annual species such as soybean [Glycine max (L.) Merr.] and fababean (Vicia faba L.) grew fastest at all temperatures. For the first 42 d at 10 °C, white clover (Trifolium repens L.), crimson clover (Trifolium incarnatum L.), and hairy vetch (Vicia villosa L.) also exhibited rapid growth. With warmer temperatures and longer growth periods, lespedeza (Lespedeza stipula L.) as well as soybean grew rapidly. At 20 and 30 °C, soybean growth was often more than double that of most other species. Growth was maximal at 10 °C for fieldpea (Pisum arvense L.), hairy vetch, and crimson clover; at 20 °C for fababean and white clover; and at 30 °C for soybean, sweetclover (Melilotus alba L.), and lespedeza. Average water‐use rates and water‐use efficiency generally paralleled growth, except water use increased and water‐use efficiency decreased as soil temperature increased. These results indicate that growth and water use differed greatly among legume species, that each legume species has its own characteristic optimum growth temperature, and that this optimum temperature for a given species may change as growth progresses.
HERB: Decision Model for Postemergence Weed Control in Soybean
Authors: Wilkerson G. G. , Modena S. A. , Coble H. D. 
Published: July 2010

AbstractTo efficiently use postemergence herbicides, decision makers must determine when weed populations exceed economic treatment thresholds. An interactive microcomputer program named HERB has been developed to help evaluate potential crop damage from multi‐species weed complexes in soybean [Glycine max (L.) Merr.] and determine the appropriate course of action. Seventy‐six weed species were rated on a scale of zero to 10 according to their competitiveness with soybean. Potential yield loss is estimated from these rankings, the number of weeds of each species present in the field, and expected weed‐free yield. The recommendation whether to apply a herbicide and, if so, which one, is based on herbicide cost and efficacies under different conditions and expected soybean selling price. Alternative herbicide choices are ranked according to expected net return. HERB is intended to provide the latest research information in an organized and easily usable format. The approach should be applicable to other crops and pests.