1,003 research outputs found
Yield and protein of wheat and durum in Brown Soil Zone as affected by long-term tillage system and crop rotation
Non-Peer ReviewedThree tillage-rotation experiments in the Brown soil zone showed that spring wheat and durum grain yield and protein were affected by tillage system, length of time in tillage system, crop sequence. During the initial 15 years of no-tillage (NT) monoculture wheat, grain yield and protein were equal or lower than minimum-till (MT) or conventional tillage (CT). These differences were attributed to reduced N availability with NT, likely from greater N immobilization (sequestration) in soil organic matter under NT. However, during the last several years, grain yield and protein with NT continuous wheat has been equal to higher than with MT practices. This may be due to improved management, specifically better control of foxtail barley and side banding of N at time of seeding, and/or simply a longer time in NT. When following non-cereal crop, spring wheat and durum had equal or higher yield and protein than wheat following wheat. In diversified rotations, the wheat or durum had highest yield under NT practices. Wheat on MT and NT fallow, with an extra 23 kg/ha fertilizer N applied, had higher grain protein than wheat on CT fallow but not higher grain yield. Durum grown on fallow after a pulse crop had higher yield and protein than that grown after fallow after durum
Mustard is better suited to the warmer and drier semiarid prairie than canola
Non-Peer ReviewedCanola is a risky crop in the warm and dry semiarid prairie. Mustard is reported to be less susceptible to stress, although very little evidence is available to support this view. Nitrogen is the second most important factor limiting potential yield on the semiarid prairie. Therefore, a three year field study over 14 site years was conducted to compare the adaptability of different canola and mustard cultivars, with special interest in canola quality mustard, under low, normal and high risk levels of N. Differences in Brassica spp. were noticed for growth duration, biomass production, seed yield and yield parameters. Seed yield of Cutlass was 15 and 32% higher than Quantum and Maverick cultivars, respectively. Canola quality mustard, J90-4316 produced seed yield similar to Quantum, but was lower than Cutlass, suggesting further breeding to improve agronomic quality of J90-4316 is needed. Mustards produced higher pods per plant and lower seeds per pod and seed weight compared to Quantum, while the lowest pods per plant, seeds per pod and seed weights were observed in Maverick. All Brassica spp. responded to N application by increasing growth duration, biomass and seed and yield component production. However, availability of water limits response of some of the parameters to higher levels N application. N application reduced oil content, but
overall oil yield increased with N application. Interaction between B. spp. and N application or environment was also observed. Thus, the results suggest that mustards, especially, cutlass is better adapted to semiarid prairie than canola cultivars
Specific heat study of the Na(0.3)CoO(2).1.3H(2)O superconductor: influence of the complex chemistry
We report results of specific heat measurements on polycrystalline samples of
the layered superconductor, Na(0.3)CoO(2).1.3H(2)O. The electronic contribution
to the specific heat, gamma, is found to be 12.2 mJ/mol-K2. The feature at the
superconducting transition is rather sharp, becoming broad and strongly
suppressed in an applied magnetic field. The data indicate a residual normal
state electronic specific heat at low temperatures, implying that there is a
sizable population of normal state electrons in the samples even below Tc.
Inhomogeneity in the Na content, to which the superconducting state is
exquisitely sensitive, appears to be the most likely explanation for these
results. These results further indicate that special sample handling is
required for an accurate characterization of the superconducting state in this
material.Comment: publication information adde
Optimum plant population density for chickpea in a semiarid environment
Non-Peer ReviewedChickpea (Cicer arietinum L.), an annual grain legume, is being rapidly included in cereal-based cropping systems throughout the semiarid Canadian prairies, but information on optimum plant population density (PPD) has not been developed for this region. This study was conducted from 1998 to 2000 in southwestern Saskatchewan to determine the impact of PPD on field emergence, seed yield and quality, and harvestability of kabuli and desi chickpea compared with dry pea (Pisum sativum L.). Seed yields of all legumes increased with increasing PPD when the crops were grown on conventional summerfallow. The PPD that produced the highest seed yields ranged from 40 to 45 plants m-2 for kabuli chickpea, 45 to 50 plants m-2 for desi chickpea, and 75 to 80 plants m-2 for dry pea. When the legumes were grown on wheat stubble, the PPD that gain optimum seed yield ranged from 35 to 40 plants m-2 for kabuli, 40 to 45 plants m-2 for desi chickpea, and 65 to 70 plants m-2 for dry pea. The proportion of large-sized (>9-mm diameter)
seed in the harvested seed was >70% when the kabuli chickpea was grown on summerfallow regardless of PPD, whereas the large-seed proportion decreased with increasing PPD when the crop was grown on wheat stubble. Increases in PPD advanced plant maturity by 1.5 to 3.0 days, and also increased the height of lowest pods from the soil surface by 1.4 to 2.0 cm (or 5 to 10%), with desi type receiving the greatest benefits from increased PPD
Chickpea in semiarid cropping systems
Non-Peer ReviewedRelative to other pulse crops such as dry-pea (Pisum sativum L.) and lentil (Lens culinaris L.), chickpea (Cicer arietinum L.) is still new in western Canada. In 1999, there were 350,000 acres of chickpea seeded in Saskatchewan with more than 75% of the seeded area being located in the districts of Swift Current, Shaunavon, Moose Jaw, Rosetown, and Assiniboia (Noble 2000). Approximately 93% of the seeded chickpea area was harvested in Saskatchewan in 1999 (Statistics Canada, 1999). Due to abundant rainfall and generally cooler than normal growing conditions in 1999, some late-seeded chickpea fields did not reach full maturity. The best production success came in the southwest corner of Saskatchewan where the growing season (May to August) precipitation usually is less than 8 inches. The deeper rooting habit and the tolerance to water stress makes chickpea a winner under these adverse drought conditions. The objective of this study was to develop agronomic information for the inclusion of chickpea in cropping systems for the semiarid prairie region. The focus has been on aspects pertaining chickpea water use characteristics, stubble effect, re-cropping constraints, and other rotational considerations
Water use and water use efficiency of field pea and chickpea under the semiarid Canadian prairie conditions
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The development of coal-based technologies for Department of Defense facilities: Phase 1 final report. Volume 1: Technical report
The first phase of a three-phase project investigating the development of coal-based technologies for Department of Defense facilities has been completed. The objectives of the project are to: decrease DOD`s dependence on foreign oil and increase its use of coal; promote public and private sector deployment of technologies for utilizing coal-based fuels in oil-designed combustion equipment; and provide a continuing environment for research and development of coal-based fuel technologies for small-scale applications at a time when market conditions in the US are not favorable for the introduction of coal-fired equipment in the commercial and industrial capacity ranges. The Phase 1 activities were focused on developing clean, coal-based combustion technologies for the utilization of both micronized coal-water mixtures (MCWMs) and dry, micronized coal (DMC) in fuel oil-designed industrial boilers. The specific objective in Phase 1 was to deliver fully engineered retrofit options for a fuel oil-designed watertube boiler located on a DOD installation to fire either MCWM or DMC. This was achieved through a project consisting of fundamental, pilot-sale, and demonstration-scale activities investigating coal beneficiation and preparation, and MCWM and DMC combustion performance. In addition, detailed engineering designs and an economic analysis were conducted for a boiler located at the Naval Surface Warfare Center, near Crane, Indiana. Results are reported on MCWM and DMC combustion performance evaluation; engineering design; and cost/economic analysis
Response of cereals to fertilizer N on pulse and other stubbles
Non-Peer ReviewedTo optimize cropping systems requires knowledge of effects of the preceding crop on the grain yield and protein and the response to N of a following cereal crop. To gain this knowledge, we grew hard red spring (HRS) wheat, durum wheat, Canadian Prairie Spring (CPS)-class wheat, Canadian Western Extra Strong (CWES)-class wheat, and barley on barley, bean, coriander, fenugreek, kabuli chickpea, lentil, mustard, and pea stubble at different N fertilizer rates over 9 site-yr: Swift Current (1998-2002), Redvers (2001-02), and Canora (1999 and 2002). N rates were medium (recommended rate based on fall soil nitrate in cereal stubble), low (15-30 kg ha-1 less than medium) and high (15-30 kg ha-1). There was a significant effect of stubble on subsequent cereal grain yield. Cereal on cereal stubble was consistently lowest or second lowest yielding (typically 100 – 800 kg ha-1 lower than other stubbles) with the exception of 2001 at Swift Current when it was the highest yielding. This latter effect was attributed to the superior moisture conserving benefits of cereal stubble during this year with extreme early drought. No single cereal crop was consistently highest or lowest yielding. The trend was for greatest grain protein on pulse stubbles although stubble effects on protein were not as great as on yield owing to confounding yield dilution effects. Within this narrow range of fertilizer N rates, yield or protein response to N was weak. Generally, there were no significant interactions between stubble and cereal crop or stubble and fertilizer indicating the effect of stubble was consistent across cereal type and N rates. The cereal yield and protein response to N on the non-cereal stubbles was not significantly different than that on cereal stubble with the exception that barley protein responded more positively to N on lentil stubble than on cereal stubble. Cereals grown on pulse stubbles tended to have higher yields and protein than on other stubbles. For HRS wheat and durum, the chance of achieving high protein grain was greatest with high fertilizer N on pea stubble (>75% of years). Applying a high fertilizer N rate on cereal stubbles did not markedly increase the chance of attaining high protein wheat or durum. For barley, where low protein is desired for malting, the best chance for low protein barley was on cereal and mustard stubble although barley protein appeared less affected by stubble and fertilizer N than wheat or durum
Einstein's "Zur Elektrodynamik..." (1905) Revisited, with Some Consequences
Einstein, in his "Zur Elektrodynamik bewegter Korper", gave a physical
(operational) meaning to "time" of a remote event in describing "motion" by
introducing the concept of "synchronous stationary clocks located at different
places". But with regard to "place" in describing motion, he assumed without
analysis the concept of a system of co-ordinates. In the present paper, we
propose a way of giving physical (operational) meaning to the concepts of
"place" and "co-ordinate system", and show how the observer can define both the
place and time of a remote event. Following Einstein, we consider another
system "in uniform motion of translation relatively to the former". Without
assuming "the properties of homogeneity which we attribute to space and time",
we show that the definitions of space and time in the two systems are linearly
related. We deduce some novel consequences of our approach regarding
faster-than-light observers and particles, "one-way" and "two-way" velocities
of light, symmetry, the "group property" of inertial reference frames, length
contraction and time dilatation, and the "twin paradox". Finally, we point out
a flaw in Einstein's argument in the "Electrodynamical Part" of his paper and
show that the Lorentz force formula and Einstein's formula for transformation
of field quantities are mutually consistent. We show that for faster-than-light
bodies, a simple modification of Planck's formula for mass suffices. (Except
for the reference to Planck's formula, we restrict ourselves to Physics of
1905.)Comment: 55 pages, 4 figures, accepted for publication in "Foundations of
Physics
Breakdown of correspondence in chaotic systems: Ehrenfest versus localization times
Breakdown of quantum-classical correspondence is studied on an experimentally
realizable example of one-dimensional periodically driven system. Two relevant
time scales are identified in this system: the short Ehrenfest time t_h and the
typically much longer localization time scale T_L. It is shown that
surprisingly weak modification of the Hamiltonian may eliminate the more
dramatic symptoms of localization without effecting the more subtle but
ubiquitous and rapid loss of correspondence at t_h.Comment: 4 pages, 5 figures, replaced with a version submitted to PR
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