A Statistical Study of Several Methods Used in Determining the Botanical Composition of a Sward: II. A Study of Several Forage Mixtures 1

1957 ◽  
Vol 49 (11) ◽  
pp. 581-585 ◽  
Author(s):  
R. W. VanKeuren ◽  
H. L. Ahlgren
Keyword(s):  
Statistical Study ◽  
Botanical Composition ◽  
Forage Mixtures

scholarly journals Changes in botanical composition of alfalfa mixtures depending on the species and N fertilization

2007 ◽  
Vol 23 (5-6-2) ◽  
pp. 365-374 ◽  
Author(s):  
Z. Nesic ◽  
Z. Tomic ◽  
S. Vuckovic ◽  
V. Krnjaja ◽  
S. Josipovic ◽  
...  
Keyword(s):  
Plant Species ◽  
N Fertilization ◽  
Present Species ◽  
Botanical Composition ◽  
Forage Plant ◽  
Leguminous Species ◽  
Competitive Abilities ◽  
Positive Effect ◽  
Forage Mixtures

Alfalfa is the most important forage plant in our country. It is mainly grown as pure crop for livestock nutrition, although it gives very good results when grown in mixture with other plant species. By growing in mixtures many advantages are achieved, the most important are: possibility for alfalfa to be used in grazing and reduced need for fertilization of grassland. In two year trial (2003-2004), changes in botanical composition of alfalfa mixtures depending on the present species in the mixture, i.e. their competitive abilities and fertilization with N, were monitored. Investigations showed that by ageing of crops the share of grasses increases and share of legumes and weeds decreases. Fertilization showed positive effect on strengthening of competitive abilities of grass in relation to leguminous species and increased share of weeds in forage mixtures.

DETERMINATION OF BOTANICAL COMPOSITION OF TWO-COMPONENT FORAGE MIXTURES

1960 ◽  
Vol 40 (2) ◽  
pp. 225-234 ◽  
Author(s):  
J. W. Tanner ◽  
E. E. Gamble ◽  
W. E. Tossell
Keyword(s):  
Unit Cost ◽  
Estimation Method ◽  
Separation Method ◽  
Botanical Composition ◽  
Visual Estimation ◽  
Two Component ◽  
Late Maturity ◽  
The Difference ◽  
Forage Mixtures

A comparative study was made in 1958 of the visual estimation and hand separation methods of determining botanical composition of two-component forage mixtures. The results indicated that there were positive significant correlations between the per cent legume values obtained by the two methods. The visual estimation method was less variable than the hand separation method and the precision per unit cost was greater. The differences between per cent legume values obtained by the two methods were influenced by the stage of maturity (medium or late hay) of the components and the cut (hay or aftermath). In this study, the difference was significant only in the medium aftermath cut.Individually, three observers showed some inconsistencies between estimates on the medium and late maturity groups and between the hay and aftermath cut. However, by averaging the three estimates to obtain a mean sample, these inconsistencies were minimized.Both methods were more precise in the aftermath pasture cut than in the hay. An additional observer increased precision of the visual estimate more than an additional replicate or sample. The greater precision resulting from additional replicates, samples, or observers increased at a decreasing rate. The number of replicates, samples, and observers required for specific degrees of precision and a specific cost were calculated.The experiment showed that the visual estimation method can be superior to the hand separation method as a means of determining botanical composition.

Factors influencing the role of clover in grass-clover leys fertilized with nitrogen at different rates III. The effects of the variety of companion grass and of the variety of clover on the botanical composition of the sward

1961 ◽  
Vol 57 (2) ◽  
pp. 231-236 ◽  
Author(s):  
D. Reid
Keyword(s):  
Statistical Study ◽  
Slight Reduction ◽  
Botanical Composition ◽  
Nitrogen Response ◽  
Fertilizer Nitrogen ◽  
Factors Influencing ◽  
S 100 ◽  
Experimental Treatments ◽  
Optimum Balance

1. In an experiment designed to study some of the factors influencing the role of clover in grassclover swards fertilized with nitrogen at different rates, botanical studies of the sward were made each spring and autumn. The methods used, and the results obtained in the autumn studies, are described in this paper.2. Full details of the experimental treatments and design, and the yield results have been reported previously.3. The botanical composition of the sward depended to a far greater extent on the variety of grass than it did on the variety of clover included in the seeds mixture. This was true also of the yields from the different swards.4. Some relationships are suggested between the yield and nitrogen response results and the variations in the botanical composition of the sward attributable to the variety of grass included in the seeds mixture.5. Kersey white clover appeared to be more persistent than S. 184 and S. 100 where fertilizer nitrogen was applied to the sward, although no differences in persistency were noted in the absence of applied nitrogen.6. A statistical study of the botanical data obtained indicated that the intensity of sampling employed gave the optimum balance between variance and time expenditure, since only a slight reduction in variance would have been obtained if double the number of samples had been taken.

Statistical Study of the Rotation Effect of Am Stars

1976 ◽  
Vol 32 ◽  
pp. 675-683
Author(s):  
Keiichi Kodaira
Keyword(s):  
Statistical Study ◽  
Rotation Velocity ◽  
General View ◽  
Slow Rotation ◽  
Rotation Effect

SummaryExcess of [m1] index of Am stars, relative to normal stars, is statistically found to be correlated with rotation velocity; the coefficient is estimated at ∆׀m1׀ /∆V(km/sec) ˜ - 0.0007 among Am stars. This result supports the general view that slow rotation is essential for Am phenomena.

Identification of Venous Variants in the Pineal Region with 3D Preoperative Navigation. A Statistical Study on the Venous Anatomy in the Living

Skull Base ◽  
2009 ◽  
Vol 19 (01) ◽  
Author(s):  
Mario Giordano ◽  
Wolf Luedemann ◽  
Lennart Stieglitz ◽  
Karsten Wrede ◽  
Laura Columbano ◽  
...  
Keyword(s):  
Statistical Study ◽  
Pineal Region ◽  
Venous Anatomy

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

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