bluuebunny/crossref_metadata_2025_split huggingface dataset:
Corn Response to Rye Cover Crop, Tillage Methods, and Planter Options
Authors: Raimbult B. A. , Vyn T. J. , Tollenaar M. 
Published: July 2010

AbstractStudies in Ontario have shown that corn (Zea mays L.) yields are reduced when corn is seeded immediately after rye (Secale cereale L.) harvest or chemical kill of winter rye. A study was conducted in 1983 and 1984 on a Maryhill (Typic Hapludalf) loam soil to determine the effect of spring tillage systems and timing of rye chemical kill on the subsequent corn crop. The rye was seeded in early October after corn silage harvest. The tillage treatments consisted of (i) moldboard plow plus secondary tillage, (ii) strip tillage, (iii) notillage with ripple coulters (iv) no‐tillage with disc furrowers plus plow coulters, and (v) no‐tillage with ripple coulters plus plow coulters. The rye kill treatments were early (2 wk before planting) or late dust prior to corn planting). Corn whole‐plant yields averaged 13.6 and 12.4 Mg ha−1 for early and late rye kill, respectively. Corn yield in the moldboard plow treatment was higher than in strip tillage and the average of no‐till treatments; however, using disc furrowers produced yields equal to those with the moldboard plow treatment. Moving the residue out of the row with disc furrowers no‐till treatments with ripple coulters. The improvement in plant growth due to an early rye kill (as opposed to a late rye kill) was often greater with the conservation tillage systems relative to the moldboard plow treatment. A crop production system is proposed involving chemical control of a winter rye cover crop 2 wk before corn planting and planting the corn with a modified no‐till system that removes rye residue from the row area.
Water Use Efficiency of Double‐Cropped Wheat and Soybean
Authors: Daniels M. B. , Scott H. D. 
Published: July 2010

AbstractMany studies have demonstrated that double cropping wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] allows for greater utilization of natural resources by intensifying cropping practices. A 3‐yr study was conducted on a Captina silt loam (finesilty, mixed, mesic, typic Fragiudult) to determine the water use efficiency (WUE) of winter wheat and to determine the effects of selected management practices on WUE of double‐cropped soybeans. The 3‐yr mean grain yield of wheat was 3170 kg ha−1 and the mean cumulative evapotranspiration (ET) after 1 April was 32.8 cm. This translated into an average WUE of 96.6 kg ha−1 cm−1 of water. Shortly after wheat harvest, the effect of irrigation, planting date, and stubble management on soybean water use and yield were determined. Irrigation significantly increased soybean grain yield in 2 of 3 yr. The 3‐yr yield mean was 2406 and 1704 kg ha−1 for irrigated and non‐irrigated soybean, respectively. When irrigation significantly increased grain yield, irrigated soybean had a highet WUE than non‐irrigated soybean. Planting date had a significant effect on soybean yield and WUE in only 1 of 3 yr and only when planting date was confounded with row‐spacing. Burning of wheat stubble produced significantly higher soybean yields only when herbicide interference by standing wheat stubble was observed. Stubble management had no effect on soybean ET or WUE. The 3‐yr mean WUE for the double cropped wheat and soybean system was 79.3 kg ha−1 cm−1 of water.
Suitability of Corn Growth Models for Incorporation of Weed and Insect Stresses
Authors: Retta A. , Vanderlip R. L. , Higgins R. A. , Moshier L. J. , Feyerherm A. M. 
Published: July 2010

AbstractShattercane [Sorghum bicolor (L.) Moench] and second generation European corn borer (ECB) [Ostrinia nubililis (Hubner)] are pests that singly or in combination reduce corn (Zea maize L.) production in the northcentral regions of the USA. Shattercane reduces corn growth and yield because it competes effectively with corn for light and water. Second generation ECB larvae, in tunneling through the vascular system, apparently affect yield by disrupting water and photosynthate movements. Pest models may be linked to physiological models for assessing the effects of pest stresses on corn growth and yield. CERES‐Maize and CORNF corn growth models were chosen to test accuracy and consistency in predicting corn growth and yield parameters. The objectives were to evaluate corn growth models to which pest models could be attached and to test the sensitivity of the selected model to variations in light and water. Simulated leaf area index; vegetative, grain, and total biomass; and yield components were compared to measured data. CERES‐Maize modified for leaf growth and phenology computations (VO/SAT) gave more accurate predictions of date of silking (bias = 1 d) than CORNF (bias = 6 d) or original version CERES‐Maize (bias = −5 d). Accurate estimation of phenology is important because the severity of yield reduction from ECB infestation is dependent on the stage of growth. Sensitivity of VO/SAT to reductions in light and water inputs was tested by simulating combinations of light and water levels ranging from 50 to 100% of actual. A 50% reduction in light resulted in average reductions of 26% in yield, 16% in kernel weight, 16% in kernel number, and 20% in leaf area index. Similarly, a 50% reduction in precipitation resulted in average reductions of 47% in yield, 51% in kernel weight, 1% in kernel number, and 1% in leaf area index. The combination model showed adequate sensitivity to light and water, and thus could be modified to mimic weed competition.
Water Use by No‐Till Winter Wheat Influence of Seed Rate and Row Spacing
Authors: Tompkins D. K. , Fowler D. B. , Wright A.T. 
Published: July 2010

AbstractManagement practices are required in rainfed agriculture of western Canada to reduce early season water evaporation from soil relative to loss by transpiraition. The objective of this study was to measure the effect of two seed rates and two row spacings on the pattern of water use and writer use efficiency (WUE) of no‐till winter wheat (Triticum aestivum L.). Nine field trials were conducted on Udic Haploboroll and Molllic Cryoboralf soils in Saskatchewan from 1987 to 1989. Higher dry matter production and more rapid early season plant ground cover associated with the 9 cm row spacing and 140 kg ha−1 seeding rate, compared to other row spacing‐seeding rate combinations reduced water loss from evaporation and increased the partitioning of evapotranspiration to transpiration during the pre‐anthesis growth period. Pre‐anthesis water use was 11% higher, post‐anthesis wateir use 6% lower, and growing season water use 4% higher for the 140 compared to the 35 kg ha−1 seeding rate, The 140 kg ha−1 seeding rate produced 40% more preanthesis dry matter than the 35 kg ha−1 rate, thus establishing a higher yield potential for the crop. A row spacing of 9 compared to the 36 cm resulted in water use that was 6% higher during the pre‐anthesis, growth period and 3% higher during the entire growing season. The combination of 140 kg ha−1 seeding rate and 9 cm row spacing ultimately produced a 21% higher grain yield and a 9 kg cm‐−1 higher WUE than the combination of 35 kg ha−1 seeding rate and 36 cm row spacing. Grain protein concentration increased from 13.1% with the 35 kg ha−1 seeding rate to 13.9% with the 140 kg ha−1 seeding rate. Grain protein yield increased from 198 to 227 kg ha−1 for the 35 compared to the 140 kg ha−1 seeding rate. The increase in grain protein concentration and yield associated with 140 kg ha−1 seeding rate was related to the pattern of water use by the crop. Even under conditions of high dronght stress, a larger number of more uniformly distributed plants associated with seeding rates higher than 35 kg ha−1 and row spacings narrower than 36 cm resulted in a higher WUE and a water use pattern that produced larger yields and higher grain protein concentration.
Steer Performance in Fescue‐Clover Pastures with Different Levels of Endophyte Infestation
Authors: Fribourg H. A. , Chestnut A. B. , Thompson R. W. , McLaren J. B. , Carlisle R. J. , Gwinn K. D. , Dixon M. C. , Smith M. C. 
Published: July 2010

AbstractA 3‐yr study was conducted at Ames Plantation, Grand Junction, TN to determine the effects of fungal endophyte (Acremonium conenophialum Morgan‐Jones & Gams) infestation (E+) levels in ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.) pastures on steer (Bos taurus L.) performance. Two replications were used of 1.2‐ha pastures overseeded yearly with ladino white clover (Trifolium repens L.) on a fine‐silty, mixed, thermic Typic Hapludalf soil. Yearling tester steers (three per pasture) and additional steers of similar size maintained available forage at heights of 2.5 to 7.5 an. Botanical composition, available forage, average daily gain (ADG), grazing days, and gain per hectare were determined every 21 d; serum prolactin, haircoat roughness, rectal temperatures, and E+ levels were measured at longer intervals. Results were computed using a generalized linear mixed models procedure. Generalized least squares means and standard errors for the broad inference space were estimated (BLUE) and differences for specific linear contrasts were predicted (BLUP). Steer ADG was depressed from over 800 to about 450 g in spring and from about 700 to 400 g during the entire grazing season as A. coenophialum increased from 3 to 81%. Animal grazing days were not different among treatments. Gain was about 65 kg ha−1 more with 22% E+ (379 kg ha−1) than at higher endophyte levels, but it was almost 500 kg ha−1 at 3% E+. Serum prolactin (125 ng mL−1 in steers grazing 3% E+) was halved with 22% E+ and was depressed further at higher E+ levels (41 to 18 ng mL−1). Results suggested that the effect of the endophyte on animal performance in tall fescue‐clover pastures is not linear, with greater depression per unit infestation at lower levels than at higher levels.
Soybean Cultivar Yield Response to Benomyl, Nitrogen, Phosphorus, and Irrigation Levels
Authors: Slater G. P. , Elmore R. W. , Doupnik B. L. , Ferguson R. B. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.] production for greatest yield involves intensive management of resource inputs. Proper cultivar selection, irrigation, and P application on P‐deficient soils have all been shown to increase yields. Nitrogen applications have resulted in variable yield effects. Under sprinkler irrigation, several diseases caused by species of Diaporthe [D. phaseolorum var. sojae (Lehman) Wehm., and D. phaseolorum var. caulivora Athow. G Caldwell.] and Phomopsis longicolla Hobbs, the Diaporthe/Phomopsis complex may also be yield limiting. This disease complex includes pod and stem blight (PSB), Phomopsis seed decay (PSD), and stem canker. In order to determine the combined influence of cultivar, irrigation level, fertility level, and disease control, field experiments were conducted in 1986, 1987, and 1988 at the South Central Research and Extension Center near Clay Center, NE to evaluate these possible soybean yield limiting factors. All combinations of two levels of benomyl [methyl‐l‐(butylcarlbamoyl)‐2‐benzimidazole carbamate] fungicide (0 and 1.12 kg ha−1 applied at R3 and R5), two levels of N (0 and 134.4 kg ha−1) and P (0 and 67.2 kg ha−1), and two cultivars (determinate Hoyt and indeterminate Zane) were tested at two nonreplicated levels of irrigation. Nitrogen and P application seldom increased seed yield. A yield increase (517 kg ha−1, 1986; 396 kg ha−1, 1987; 215 kg ba−1, 1988) occurred when benomyl was applied to Hoyt soybean under a high level of irrigation. Less of a yield response to benomyl was obtained with later‐maturing Zane, for both cultivars at the lower irrigation level, and during a year of below normal rainfall. Benomyl application decreased the incidence of PSB and increased seed size, but did not consistently affect PSD based on seed appearance. Stem canker was never observed during the course of this study. Yield increases were primarily the result of increased seed size associated with delayed maturity doe to PSB control and increased number of seeds per pod due to benomyl's possible growth regulatory properties. This research indicates that, contrary to previous reports in the northern USA, pod and stem blight can be a yield‐limiting factor with or without the development of Phomopsis seed decay under high‐yield environments.
Multi‐Year Response of Sugarcane to Calcium Silicate Slag on Everglades Histosols
Authors: Anderson D. L. , Snyder G. H. , Martin F. G. 
Published: July 2010

AbstractPlant crops of sugarcane (Saccharum spp.) grown in the Eveiglades respond to calcium silicate slag. Substantial cost is associated with application of slag. Thus, it is important to know whether yields of successive ratoon crops of sugarcane respond to residual soil Si applied as slag. Our objective was to determine the long‐term response of sugarcane grown on a Terra Ceia muck (euic, hyperthermic Typic Medisaprist) at two locations in the Everglades Agricultural Area to slag applied (0, 2.5, 5, 10, 20 Mg ha−3.1) before either a rice (Oryza sativa L.)/sugarcane rotation or immediately before sugarcane. Slag increased cane and sugar yields as well as tissue Si concentrations. Application of 20 Mg slag ha−1 increased cumulative cane yields as much as 39% and sugar yields as much as 50% over the three crop years. Yield response to slag was generally greater from application immediately prior to sugarcane planting than to the preceding rice rotation crop. Without slag, ratoon yield production decreased as much as 45% in cane and 50% in sugar, whereas with slag, yields decreased only 28% in cane and 29% in sugar. Our data indicate that the critical level for leaf Si may be greater than the previously reported value of 10 g kg−1, and that reduced yields in ratoon crops vs. plant crops were associated with lower Si levels. Consequently, more extensive Si deficiencies may exist in the Everglades than were previously considered. Other yield‐limiting factors such as low soil Mg concentrations were also shown to contribute to the decline of sugarcane ratoon yields.
Yield Potential of Soybean Grown under a Subirrigation/Drainage Water Management System
Authors: Cooper R. L. , Fausey N. R. , Streeter J. G. 
Published: July 2010

AbstractCombination subsurface irrigation/drainage systems to manage water (add or remove) on poorly drained soils is a relatively new concept in the humid Midwest. The objective of this research was to evaluate the yield potential of a subirrigation/drainage system, when used in combination with a soybean [Glycine max (L.) Merr.] production system with known high yield potential, on a poorly drained soil at Wooster, OH. The water table was maintained on a Ravenna silt loam soil (fine‐loamy, mixed, mesic Aeric Fragiuqualfs) by subirrigation at an average depth of 39 cm. Water table depth ranged from 25 cm over the drain line to 53 cm at the midpoint between drain lines which were spaced 6 m apart. Five cultivars (Sprite, Sprite 87, Hobbit 87, Asgrow 3127, Williams 82) and two row spacings (18 and 76 cm) were compared in 1985 and 1986. In 1987, the five cultivars were all planted in 18‐cm rows and compared at two water table levels (the 1985 and 1986 level and a non‐irrigated naturally varying depth). Averaged over the five cultivars, the constant water table produced a 3‐yr average yield of 5392 kg/ha. In 1987 there was a 2051 kg ha−1 or 58% yield advantage for the subirrigation/drainage system over non‐irrigation (5563 vs 3512 kg ha−1). The 1985, 1986 mean yield advantage for 18cm rows compared to 76‐m rows was 1010 kg ha−1 or 23%. These results indicate that with a properly managed subirrigation/drainage system, combined with a soybean production system with high yield potential, long‐term average soybean yields of 5300 kg ha−1 should be possible in the humid Midwest.
Phosphate Interaction with Uptake and Leaf Concentration of Magnesium, Calcium, and Potassium in Winter Wheat Seedlings
Authors: Reinbott T. M. , Blevins D. G. 
Published: July 2010

AbstractLow concentrations of Mg and Ca in cool‐season grasses in late fall and early spring are a primary cause of grass tetany and wheat pasture poisoning in grazing cattle. Our objective was to investigate phosphate interaction with the uptake and leaf concentration of Mg, Ca, and K in winter wheat (Triticum aestivum L., cv. Larned) seedlings. Seedlings were grown hydroponically or in pots containing perlite with a solution containing nutrient element concentrations that mimicked the soil solution of a typical midwestern alfisol. Phosphate concentration of this solution was low so that wheat seedlings depleted solution P within a few hours. At low solution P concentrations, Mg and Ca were effluxed from roots. As solution P was increased from 25 to over 100 μM, net uptake of both Mg and Ca was observed over a 48 h period. In 41‐d greenhouse experiments, Mg and Ca concentrations increased and K concentration decreased in the leaf as P treatments were increased. Tetany is likely to occur in ruminants consuming grass with equivalent ratios of K/(Ca + Mg) > 2.2. Increasing P from 50 to 400 μM lowered this ratio from 1.8 to 1.0 and from 1.7 to 1.2 in separate greenhouse experiments. Concentrations of P above 100 μM stimulated net uptake, increased leaf Mg and Ca concentration, and produced leaf tissues with a very low K/(Ca + Mg) ratio.
Subsurface Compaction Reduces the Root and Shoot Growth and Grain Yield of Wheat
Authors: Oussible M. , Crookston R. K. , Larson W. E. 
Published: July 2010

AbstractThe recent use of heavy machinery combined with frequent disk tillage has created a subsurface compacted horizon in many of the irrigated soils of Morocco. The objective of this study was to evaluate the effect of subsurface compaction on the mot and shoot growth, grain yield, and grain yield components of wheat (Triticum aestivum L.). Field experiments were conducted in 1982 and 1983 on a Moroccan clay loam soil (typic Calcixerolls). Soil compaction was artificially created. The 0.10‐m surface layer was removed from all plots with a road scraper. The exposed subsurface layer was then packed by making four passes over the plots with a 7.5‐ton tractor. The removed soil was then replaced and leveled. Control plots were tilled with a disk plow followed by two passes of a disk harrow. Both compacted and control plots were then roto‐tilled for final seedbed preparation. The result of this compaction was a 12 to 23% decrease in grain yield and 9 to 20% decrease in straw yield. The decrease in yield was accompanied by a consistent reduction in the number of shoots per unit area. Number of kernels per spike and kernel weight were unaffected. Both root growth and distribution were markedly changed as a result of subsurface compaction. Wheat plants in compacted plots had a denser, finer, and shallower root system than wheat plants in control plots. Plant height, and leaf area and dry matter per shoot were also unaffected. The decrease in shoot number might be attributed to a limitation in the amount of available soil N to the roots.
Measuring Plant and Soil Water Potentials with Thermocouple Psychrometers: Some Concerns
Authors: Brown R.W. , Oosterhuis D.M. 
Published: July 2010

AbstractThermocouple psychrometers are commonly used to measure soil and plant water status. Users often assume that these instruments can be used routinely with little regard for understanding how they operate, or for the precautions required for accurate measurements of water potential. Poor procedures and inadequate attention to both practical and theoretical requirements can jeopardize the successful performance of these highly sensitive instruments. For example, in addition to understanding the theory of operation of thermocouple psychrometers, calibration and proper cleaning of these instruments are among the most important steps in successfully using them. Important sampling precautions include consistency of technique, prevention of evaporative loss during collection and sealing, and careful sample selection. Major concerns during measurements of water potential include achieving complete vapor pressure equilibrium, interpreting data, and detecting and preventing temperature gradients. Although many precautions for in situ measurements are similar to those for measuring soil and plant samples, each use has specific requirements. Thermocouple psychrometers are useful for accurate and reliable measurements of water potential if proper techniques and precautions are used.
Portable and Desktop Computer Integrated Field Book and Data Collection System for Agronomists
Authors: Berke T.G. , Baenziger P.S. 
Published: July 2010

AbstractAn integrated, computerized system has been developed to facilitate data collection and storage. It utilizes hardware, commercial software, and menu‐driven software and has two parts. The first part utilizes a portable microcomputer to collect data in the field or lab. This microcomputer can be interfaced with an electronic balance to facilitate data entry by weighing. Off‐line data storage is available when remote field situations prevent immediate data transfer. The second part utilizes a desktop microcomputer with a hard disk to generate randomized complete block design treatment arrangements with one to six replications, create and manipulate data storage files, print fieldbooks, and print adhesive labels. Data files from the portable microcomputer can be imported into a spreadsheet for simple statistical analyses (means, variances, ranks, etc.) or transferred as an ASCII file to a more sophisticated statistical analysis program. This system allows control of data collected from an experiment on one integrated computer system. Transcription errors are avoided and data are immediately available for analysis. The software developed for the system is available upon request.
Mycorrhizae: Possible Explanation for Yield Decline with Continuous Corn and Soybean
Authors: Johnson Nancy Collins , Copeland Philip J. , Crookston R. Kent , Pfleger F. L. 
Published: July 2010

AbstractEarlier studies showed that mycorrhizal fungi selectively proliferate in soils cropped in monoculture to corn (Zea mays L.) or soybean [Glycine max (L.) Merr.]. This study evaluated whether the dominant mycorrhizal fungi, based on spore numbers present in soil, affected growth and nutrient uptake of the following crop. Plots at two locations in Minnesota with a continuous corn or continuous soybean history were planted to both corn and soybean. The relationship between spore numbers of proliferating species of mycorrhizal fungi and crop yield and nutrient concentrations were assessed using simple correlation analysis. Spore populations of mycorrhizal fungi which proliferated in corn were generally negatively correlated with the yield and tissue mineral concentrations of corn, but were positively correlated with the yield and tissue mineral concentrations of soybean. Spore populations of soybean proliferators exhibited the reciprocal relationship, although less clearly. We suggest that, compared to other fungi, proliferating VAM fungal species may be less beneficial (or perhaps detrimental) to the crop in which they proliferate. We propose a mechanism to explain how vesicular‐arbuscular mycorrhizal (VAM) fungi could cause yield depressions associated with monoculture, and outline research needed to test this hypothesis.