The comparative response of tropical and temperate grasses to varying levels of nitrogen and phosphorus nutrition

1971 ◽  
Vol 22 (4) ◽  
pp. 573 ◽  
Author(s):  
JR Wilson ◽  
KP Haydock
Keyword(s):  
Phosphorus Nutrition ◽  
Nitrogen And Phosphorus ◽  
Nitrogen Response ◽  
Tropical Grasses ◽  
Nitrogen Levels ◽  
Species Response ◽  
Wide Range ◽  
Comparative Response ◽  
Low Nitrogen ◽  
Better Than

Ten temperate and nine tropical grasses were compared in glasshouse trials in their response to a wide range of nitrogen and phosphorus nutrition. For all attributes there was a gradation in species response within the temperate and tropical groups; the means for the two groups were different although the spread of values showed some degree of overlap between the groups. In general, the temperate grasses had more tillers per plant and a lower top/root ratio than the tropical grasses. The tropical grasses grew better than the temperate grasses at low nutrient combinations but the reverse was true for the high nutrient combinations. The linear response to nitrogen of the tropical group of species was lower than that of the temperate group but was probably a consequence of the ability of the tropical grasses to grow at low nitrogen levels since the curvature in nitrogen response was similar for all species. Within both groups of grasses, the proportional response to nitrogen increased with increase in the species potential for yield. The temperate grasses accumulated nitrogen and phosphorus to higher concentrations in the plant tops, and were higher in digestibility, than the tropical grasses. Nevertheless, the tropical grasses would appear to have the potential for higher quality forage than is generally produced in field situations.

Yield, oil and protein content of oilseed rape as affected by soil and fertilizer nitrogen and phosphorus

1978 ◽  
Vol 18 (90) ◽  
pp. 107 ◽  
Author(s):  
GJ Osborne ◽  
GD Batten
Keyword(s):  
Oilseed Rape ◽  
Soil Nitrogen ◽  
Available Phosphorus ◽  
Wagga Wagga ◽  
High Nitrogen ◽  
Nitrogen And Phosphorus ◽  
Matter Production ◽  
Wide Range ◽  
High Level ◽  
Low Nitrogen

The Zephyr cultivar of oilseed rape (Brassica napus) was grown on two sites at Wagga Wagga. Both sites had a wide range in levels of available phosphorus; one had a low and the other a high level of soil nitrogen. On both sites superphosphate applied prior to, and during, the current cropping phase caused significant increases in dry matter production, seed yield, oil and protein yields. Pod numbers increased significantly only on the high nitrogen site. On the high nitrogen site, seed, protein and oil yields (kg ha-1) were higher than on the low nitrogen site, even when the latter site was cropped using nitrogen fertilizer. Oil yields ranged from 237 to 1273 kg ha-1 on the high nitrogen site and from 229 to 91 6 kg ha-1 on the low nitrogen site. The rape crop responded to drilled superphosphate on sites with low to medium levels of 'available' phosphorus. Soil tests developed for wheat indicated sites with adequate soil nitrogen and phosphorus.

Response to nitrogen of three annual grasses

1974 ◽  
Vol 14 (67) ◽  
pp. 167 ◽  
Author(s):  
PS Cocks
Keyword(s):  
Nitrogen Uptake ◽  
Dry Weight ◽  
Low Density ◽  
Lolium Rigidum ◽  
Nitrogen Response ◽  
Harvest Dates ◽  
Wide Range ◽  
Annual Grasses ◽  
Hordeum Leporinum ◽  
Better Than

The responses of three annual grasses (Lolium rigidum, Vulpia myuros, and Hordeum leporinum) to nitrogen fertilizer were studied at three densities. Total herbage and nitrogen uptake were measured at four harvest dates. The response of the three grasses to nitrogen depended on their density. At low density both Lolium and Hordeum had greater dry weight increase than Vulpia, but at high density Vulpia responded as well as Lolium and better than Hordeum. By comparing the nitrogen responses at similar amounts of available herbage it was seen that, over a wide range of availability, both Lolium and Vulpia had greater absolute response than Hordeum. It was concluded that nitrogen response would probably be greatest on swards of Lolium or Vulpia that have a particular amount of available herbage.

Performance of Improved Rice Varieties in the Tropics with Special Reference to Tillering Capacity

1972 ◽  
Vol 8 (3) ◽  
pp. 203-212 ◽  
Author(s):  
Shouichi Yoshida ◽  
F. T. Parao
Keyword(s):  
Special Reference ◽  
Grain Production ◽  
Experimental Conditions ◽  
Rice Varieties ◽  
Area Index ◽  
Nitrogen Levels ◽  
Wide Range ◽  
The Tropics ◽  
Better Than ◽  
High Tillering

SUMMARYThe growth of improved short varieties of rice with low and high tillering capacities was compared under a wide range of nitrogen levels and spacings. A high tillering variety performed better than a low tillering one under the experimental conditions tested. Leaf area index values as high as 10 to 12 were not detrimental to grain production unless the crop lodged.

The development of cuttings of the Washington navel orange to the stage of fruit set. IV. The effect of different nitrogen and phosphorus levels on fruiting cuttings

1961 ◽  
Vol 12 (6) ◽  
pp. 1089 ◽  
Author(s):  
D Bouma
Keyword(s):  
Fruit Quality ◽  
Dominant Role ◽  
Sugar Content ◽  
Navel Orange ◽  
Nitrogen And Phosphorus ◽  
Nitrogen Levels ◽  
Washington Navel ◽  
Low Nitrogen ◽  
Phosphorus Levels

Washington Navel orange cuttings, which had flowered 6 months after striking and had set fruit, were subjected to three nitrogen and three phosphorus levels in factorial combination. Increasing nitrogen and phosphorus supply caused a relatively greater increase in the fresh weight of the peel and rag of the fruit than in that of the juice, and this was reflected in a greater diameter of the fruit, a thicker peel, and a decrease in the percentage juice content. The acidity and sugar content of the juice differed little between nitrogen levels, but a marked decrease in both was apparent with increasing phosphorus supply. The results are compared with those of a field experiment. The adverse effects of increasing nitrogen supply on fruit quality were similar in the two experiments. In the glass-house experiment, some improvement in fruit quality with increasing phosphorus levels was only apparent at the low nitrogen level. The dominant role of fruit development with respect to vegetative growth observed in the previous paper of this series was confirmed. Leaves on fruiting shoots showed considerably lower nitrogen and phosphorus contents than the remainder of the leaves, particularly at the higher levels of nutrition.

Research of the activity and viability of spermatozoa at different concentrations and proportions of diluents after incubation

2020 ◽  
pp. 88-95
Author(s):  
Svitlana Lobchenko ◽  
Tetiana Husar ◽  
Viktor Lobchenko
Keyword(s):  
Plasma Concentration ◽  
Incubation Time ◽  
Coefficient Of Variation ◽  
Incubation Medium ◽  
Wide Range ◽  
Series Of Experiments ◽  
The Subject ◽  
Boar Spermatozoa ◽  
Native Plasma ◽  
Better Than

The results of studies of the viability of spermatozoa with different incubation time at different concentrations and using different diluents are highlighted in the article. (Un) concentrated spermatozoa were diluented: 1) with their native plasma; 2) medium 199; 3) a mixture of equal volumes of plasma and medium 199. The experiment was designed to generate experimental samples with spermatozoa concentrations prepared according to the method, namely: 0.2; 0.1; 0.05; 0.025 billion / ml. The sperm was evaluated after 2, 4, 6 and 8 hours. The perspective of such a study is significant and makes it possible to research various aspects of the subject in a wide range. In this regard, a series of experiments were conducted in this area. The data obtained are statistically processed and allow us to highlight the results that relate to each stage of the study. In particular, in this article it was found out some regularities between the viability of sperm, the type of diluent and the rate of rarefaction, as evidenced by the data presented in the tables. As a result of sperm incubation, the viability of spermatozoa remains at least the highest trend when sperm are diluted to a concentration of 0.1 billion / ml, regardless of the type of diluent used. To maintain the viability of sperm using this concentration of medium 199 is not better than its native plasma, and its mixture with an equal volume of plasma through any length of time incubation of such sperm. Most often it is at this concentration of sperm that their viability is characterized by the lowest coefficient of variation, regardless of the type of diluent used, which may indicate the greatest stability of the result under these conditions. The viability of spermatozoa with a concentration of 0.1 billion / ml is statistically significantly reduced only after 6 or even 8 hours of incubation. If the sperm are incubated for only 2 hours, regardless of the type of diluent used, the sperm concentrations tested do not affect the viability of the sperm. Key words: boar, spermatozoa, sperm plasma, concentration, incubation, medium 199, activity, viability, rarefaction.

Deinking sludge influences biomass, nitrogen and phosphorus status of several grass and legume species

1997 ◽  
Vol 77 (4) ◽  
pp. 693-702 ◽  
Author(s):  
A. Fierro ◽  
J. Norrie ◽  
A. Gosselin ◽  
C. J. Beauchamp
Keyword(s):  
Soil Amendment ◽  
Mineral Soil ◽  
Nitrogen And Phosphorus ◽  
Agropyron Elongatum ◽  
Festuca Ovina ◽  
Melilotus Officinalis ◽  
Medicago Lupulina ◽  
Wide Range ◽  
Galega Orientalis ◽  
Four Levels

In a greenhouse study, deinking sludge was evaluated as a soil amendment supplemented with four nitrogen (N) fertilization levels for the growth of the grasses Agropyron elongatum (Host.) Beauv. (tall wheatgrass), Alopecurus pratensis L. (meadow foxtail), Festuca ovina var. duriuscula (L). Koch (hard fescue), and four levels of phosphorus (P) for the growth of the legumes Galega orientalis Lam. (galega), Medicago lupulina L. (black medic), Melilotus officinalis (L.) Lam (yellow sweet clover). Fertilizers were applied on the basis of sludge level to maintain uniform carbon (C)/N or C/P ratios across sludge treatments. In one experiment, sand was mixed with 0, 10, 20 or 30% sludge while, in a second experiment, mineral soil was mixed with 0, 27, 53 or 80% sludge (vol/vol). In sand mixtures of 30 and 20% sludge, grasses had similar or greater growth than in unamended mineral soil when N was added at about 6.5 and 8.4 g kg−1 deinking sludge, respectively. For all legumes but Medicago lupulina, P at about 0.8 g kg−1 sludge was required for these sand mixtures. In soil mixtures of 53 and 27% sludge, grasses grew well when supplemental N was about 5.3 and 6.9 g kg−1 sludge, respectively. Legumes required P at 0.5 and 1.2 g kg−1 sludge, respectively. In general, growth was closely related to total amount of added N or P in spite of the wide range of C/N or C/P ratios. When growing in media amended with sludge, grasses needed higher tissue N concentration for an equivalent growth than in control soil; legumes had similar tissue P concentration. The grasses Agropyron elongatum and Alopecurus pratensis as well as the legumes Melilotus officinalis and Galega orientalis are promising species for field testing, based on dry matter production. Deinking sludge can be used as soil amendment when adequate N and P supplements are provided. Key words: Soil amendment, papermill sludge, Agropyron elongatum, Alopecurus pratensis, Festuca ovina, Medicago lupulina, Galega orientalis, Melilotus officinalis

Effect of Contact Ratio on Spur Gear Dynamic Load With No Tooth Profile Modifications

1996 ◽  
Vol 118 (3) ◽  
pp. 439-443 ◽  
Author(s):  
Chuen-Huei Liou ◽  
Hsiang Hsi Lin ◽  
F. B. Oswald ◽  
D. P. Townsend
Keyword(s):  
Dynamic Load ◽  
Spur Gear ◽  
Tooth Size ◽  
Contact Ratio ◽  
Gear Dynamics ◽  
Wide Range ◽  
Gear Contact ◽  
Center Distance ◽  
Selection Of ◽  
Better Than

This paper presents a computer simulation showing how the gear contact ratio affects the dynamic load on a spur gear transmission. The contact ratio can be affected by the tooth addendum, the pressure angle, the tooth size (diametral pitch), and the center distance. The analysis presented in this paper was performed by using the NASA gear dynamics code DANST. In the analysis, the contact ratio was varied over the range 1.20 to 2.40 by changing the length of the tooth addendum. In order to simplify the analysis, other parameters related to contact ratio were held constant. The contact ratio was found to have a significant influence on gear dynamics. Over a wide range of operating speeds, a contact ratio close to 2.0 minimized dynamic load. For low-contact-ratio gears (contact ratio less than two), increasing the contact ratio reduced gear dynamic load. For high-contact-ratio gears (contact ratio equal to or greater than 2.0), the selection of contact ratio should take into consideration the intended operating speeds. In general, high-contact-ratio gears minimized dynamic load better than low-contact-ratio gears.

scholarly journals Cache-efficient sweeping-based interval joins for extended Allen relation predicates

2021 ◽  
Author(s):  
Danila Piatov ◽  
Sven Helmer ◽  
Anton Dignös ◽  
Fabio Persia
Keyword(s):  
Data Structure ◽  
Experimental Evaluation ◽  
State Of The Art ◽  
Temporal Databases ◽  
Access Method ◽  
Wide Range ◽  
Interval Relation ◽  
Cache Efficient ◽  
Join Algorithms ◽  
Better Than

AbstractWe develop a family of efficient plane-sweeping interval join algorithms for evaluating a wide range of interval predicates such as Allen’s relationships and parameterized relationships. Our technique is based on a framework, components of which can be flexibly combined in different manners to support the required interval relation. In temporal databases, our algorithms can exploit a well-known and flexible access method, the Timeline Index, thus expanding the set of operations it supports even further. Additionally, employing a compact data structure, the gapless hash map, we utilize the CPU cache efficiently. In an experimental evaluation, we show that our approach is several times faster and scales better than state-of-the-art techniques, while being much better suited for real-time event processing.

Triazole, Benzotriazole, and Naphthotriazole as Corrosion Inhibitors for Brass

CORROSION ◽  
1976 ◽  
Vol 32 (10) ◽  
pp. 414-417 ◽  
Author(s):  
R. WALKER
Keyword(s):  
Corrosion Inhibitors ◽  
Lower Cost ◽  
Solution Ph ◽  
Inhibitor Efficiency ◽  
Wide Range ◽  
Better Than

Abstract The use of triazole, benzotriazole, and naphthotriazole as corrosion inhibitors for brass is briefly reviewed. The corrosion of 70/30 brass immersed in a wide range of solutions is reported both with and without the inhibitors. The inhibitor efficiency of benzotriazole is given as a function of the solution pH and the concentration used. Triazole was only effective in mildly corrosive solutions and benzotriazole and naphthotriazole were much better. Generally naphthotriazole was better than benzotriazole but is much more expensive and a higher concentration of benzotriazole can give the same protection as naphthotriazole at a much lower cost.

Poisson mixtures

1995 ◽  
Vol 1 (2) ◽  
pp. 163-190 ◽  
Author(s):  
Kenneth W. Church ◽  
William A. Gale
Keyword(s):  
Negative Binomial ◽  
Probability Distributions ◽  
Hidden Variables ◽  
Heterogeneous Structure ◽  
Text Compression ◽  
Inverse Document Frequency ◽  
Poisson Mixtures ◽  
Document Frequency ◽  
Wide Range ◽  
Better Than

AbstractShannon (1948) showed that a wide range of practical problems can be reduced to the problem of estimating probability distributions of words and ngrams in text. It has become standard practice in text compression, speech recognition, information retrieval and many other applications of Shannon's theory to introduce a “bag-of-words” assumption. But obviously, word rates vary from genre to genre, author to author, topic to topic, document to document, section to section, and paragraph to paragraph. The proposed Poisson mixture captures much of this heterogeneous structure by allowing the Poisson parameter θ to vary over documents subject to a density function φ. φ is intended to capture dependencies on hidden variables such genre, author, topic, etc. (The Negative Binomial is a well-known special case where φ is a Г distribution.) Poisson mixtures fit the data better than standard Poissons, producing more accurate estimates of the variance over documents (σ2), entropy (H), inverse document frequency (IDF), and adaptation (Pr(x ≥ 2/x ≥ 1)).

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