The relative importance of oxalate and pyrophosphate extractable aluminum to the acidic leaching of aluminium in Podzol B horizons from the Precambrian Shield, Ontario, Canada

1995 ◽  
Vol 75 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Bruce D. LaZerte ◽  
Joe Findeis
Keyword(s):  
Key Words ◽  
Acid Deposition ◽  
Relative Importance ◽  
Precambrian Shield ◽  
Soil Aluminum ◽  
Extractable Fraction ◽  
Key Words Aluminum

Four Bf and one Bhf Podzol horizon samples from the Precambrian Shield, Ontario, Canada were leached with pH 3 solutions in three different experiments to determine which soil aluminum fraction was primarily responsible for the aluminum leached into solution. For the Bf horizons, it was primarily the oxalate-extractable aluminum fraction (corrected for pyrophosphate, Alo–Alp); for the Bhf horizon it was equally the pyrophosphate (Alp) and Alo–Alp. A comparison with other studies suggests that when the ratio (Alo–Alp)/Alp is above 0.3–0.7, the oxalate-extractable fraction will be most important, and at lower ratios the pyrophosphate fraction becomes most important. The pattern of fluoride leaching in these experiments suggests that F was concentrated primarily on the surface of the amorphous aluminum fraction. Key words: Aluminum, silica, fluoride, Podzol, acid deposition

scholarly journals Acidic leaching of a Podzol Bf horizon from the Precambrian Shield, Ontario, Canada

1994 ◽  
Vol 74 (3) ◽  
pp. 321-333 ◽  
Author(s):  
Bruce LaZerte ◽  
Joe Findeis
Keyword(s):  
Key Words ◽  
Acid Treatment ◽  
Base Cations ◽  
Distilled Water ◽  
Precambrian Shield ◽  
Primary Minerals ◽  
Extractable Al ◽  
Acid Weathering

Illuviated mineral horizons (Bf) from a Podzol on the Precambrian Shield, Ontario, Canada were collected, placed in columns and treated with distilled water, cation amended water, acidified water or cation and acid amended water over a 4-mo period. While the cation treatment had little effect relative to the control, the acid treatment removed large quantities of Al, Si and base cations. The source of the leached Al was primarily (~ 70%) dithionite–citrate–bicarbonate (DCB) extractable Al, apparently some form of amorphous gibbsite. Organic Al (pyrophosphate extractable) contributed only about 20%. However, even more pronounced was a major within-column migration of oxalate extractable Al–Si, perhaps allophane or imogolite, which was leached from the top of the acidified columns and precipitated below. The weathering of primary minerals and possibly interlayer Al in vermiculite contributed little to the leaching of Al from the acidified columns. Key words: Acid, weathering, Podzol, aluminum, silica

scholarly journals Relative importance of gene effects in bitter gourd (Momordica charantia L.)

1970 ◽  
Vol 36 (2) ◽  
pp. 189-191
Author(s):  
M Shafiullah ◽  
B Sikdar
Keyword(s):  
Key Words ◽  
Diallel Cross ◽  
Momordica Charantia ◽  
Bitter Gourd ◽  
Relative Importance ◽  
Inheritance Pattern ◽  
Gene Effects ◽  
Gene Effect ◽  
Made In

Full diallel set was made in bitter gourd (Momordica charantia L.) involving six genetically divergent parents, namely BGGB1, BGGB4, BGGB6, BGGB12, BGGB13 and BGGB14 and their inheritance pattern of yield and yield contributing traits were studied.   Key words: Diallel cross, Gene effect, Bitter gourd DOI = 10.3329/bjb.v36i2.1512 Bangladesh J. Bot. 36(2): 189-191, 2007 (December)

A STUDY OF SOME OF THE FACTORS INFLUENCING EASE OF CALVING IN RANGE BEEF HEIFERS

1983 ◽  
Vol 63 (2) ◽  
pp. 255-262 ◽  
Author(s):  
M. MAKARECHIAN ◽  
R. T. BERG
Keyword(s):  
Birth Weight ◽  
Key Words ◽  
Significant Influence ◽  
Threshold Effect ◽  
Phenotypic Correlation ◽  
Relative Importance ◽  
Beef Heifers ◽  
Factors Influencing ◽  
Condition Score ◽  
Calving Performance

This study was performed in two parts. In the first part, 349 calving records of 2-yr-old heifers in 1979, 1980 and 1981 were analyzed by least-squares to assess the effects of lowering sire birth weight on calf birth weight and ease of calving. The study demonstrated that using sires with lower birth weight in 1981 compared to 1979 and 1980 (31.12 vs. 40.12 and 40.17 kg, respectively), reduced the average calf birth weight (32.65 vs. 36.04 and 34.62 kg, respectively) which in turn improved calving performance of the heifers in 1981 compared to the previous years. In the second part, 128 calving records of 2-yr-old heifers in 1981 were analyzed to study the relative importance of hip height, area of pelvic opening, condition score and weight at calving on calving performance. The results indicated that heifer weight at calving had a significant influence of calving performance (P < 0.01). Calving performance improved with increases in heifer weight at calving. Height at hip was phenotypically correlated with weight at calving, area of pelvic opening and calf birth weight. Phenotypic correlation between weight at calving and area of pelvic opening was also highly significant. The area of pelvic opening might exert a threshold effect on calving performance in 2-yr-old heifers. Key words: Cattle, dystocia, range beef heifers

MICROBIAL PARTICIPATION IN IODIDE REMOVAL FROM SOLUTION BY ORGANIC SOILS

1989 ◽  
Vol 69 (1) ◽  
pp. 127-135 ◽  
Author(s):  
J. T. KOCH ◽  
D. B. RACHAR ◽  
B. D. KAY
Keyword(s):  
Gamma Irradiation ◽  
Key Words ◽  
Microbial Activity ◽  
Nuclear Fuel ◽  
Organic Soil ◽  
Organic Soils ◽  
Γ Radiation ◽  
Precambrian Shield ◽  
Biological Removal ◽  
Nuclear Fuel Waste

The migration of the long-lived nuclide 129I in the biosphere may be changed if the nuclide passes through an organic soil (organic soils often occur in topographical depressions where groundwater generally enters the biosphere). The reactivity of I and, hence, its transportability may be altered in organic soils by processes in which microorganisms participate. The aim of this study, therefore, was to test for microbial participation in these processes. Twelve samples of nine organic soils, varying widely in degree of humification and in parent vegetation, were used in this study and were collected mainly on the Precambrian Shield of Ontario. Experiments were conducted using glucose, thymol, and γ radiation (60Co) to stimulate or suppress microbial activity in the soils. The presence of glucose generally increased I− removal from solution whereas thymol depressed removal. Gamma irradiation of the soils decreased I− removal from solution in all samples, but 100 kGy terminated I− removal in only one sample. If the removal of I− from solution after exposing the soils to 100 kGy of γ radiation is termed nonbiological, the biological removal of I− from solution exceeded the non-biological in all samples but one. The natural I content of the soils was directly related to both the biologically and the nonbiologically mediated processes of I− removal from solution. We conclude that microorganisms play an important role in the processes of I− removal from solution in organic soils of the Precambrian Shield of Ontario. Key words: Nuclear fuel waste, 129I, groundwater, microorganisms, enzymes, mobility

scholarly journals INFLUENCE OF PHOSPHATE IONS ON THE EXTRACTION OF ALUMINUM BY 8-HYDROXYQUINOLINE FROM OH-AL SUSPENSIONS

1986 ◽  
Vol 66 (4) ◽  
pp. 573-579 ◽  
Author(s):  
G. DI PASCALE ◽  
A. VIOLANTE
Keyword(s):  
Key Words ◽  
Molar Ratio ◽  
Aging Period ◽  
Phosphate Ions ◽  
Key Words Aluminum ◽  
Extractable Al

Aluminum was extracted from OH-Al-suspensions ([Al3+] = 6.4 × 10−4 mol L−1; OH/Al molar ratio = 1.0, 1.5, 2.2) aged 5 and 18 mo by 8-hydroxyquinoline into four different species: readily extractable (Alre), moderately ex tractable (Alme), slowly extractable (ALse) and nonextractable (Alne) aluminum. In all the systems, the percentages of Alre were the highest of the ultrafiltered hydrolytic products of Al, ranging from 68.1 to 21.1%, whereas the percentages of Alme and Alse were [Formula: see text]. The higher the OH/Al molar ratio and the longer the aging period of OH-Al-suspensions, the lower the percentages of Alre, Alme and Alse, and the higher the percentages of Alne (ranging from 13.3 to 71.1%). With addition of phosphate ions, increasing the P/Al molar ratio from 0.05 to 0.5 decreased Alre and increased Alne. Finally, it was ascertained that the ultrafiltered aluminum was not completely extracted by 8-hydroxyquinoline after 3 h. More aluminum was extracted from 3 to 48 h from the suspensions containing phosphate ions than from those without phosphate. Key words: Aluminum hydrolytic products, phosphate, aluminum extraction, 8-hydroxyquinoline

MEASUREMENT AND SIGNIFICANCE OF CELLULOSE IN PEAT SOILS

1988 ◽  
Vol 68 (4) ◽  
pp. 681-685 ◽  
Author(s):  
ANN BROWN ◽  
TIIU KAURI ◽  
D. J. KUSHNER ◽  
S. P. MATHUR
Keyword(s):  
Carbon Dioxide ◽  
Key Words ◽  
Respiration Rate ◽  
Aerobic Respiration ◽  
Organic Soils ◽  
Peat Soils ◽  
Precambrian Shield ◽  
Acid Hydrolysate ◽  
Operator Error ◽  
Cellulose Component

The degree of decomposition of 30 organic soils from southern Superior Province of the Precambrian Shield was investigated by comparing the cellulose component, measured as glucose in the acid hydrolysate, with the aerobic respiration rate and with the rubbed fiber content of the soils. Bivarient analyses of these parameters show reasonable correlation. It is suggested, therefore, that cellulose determination is suitable for assessing the biodegradation potential of organic soils. The method is quantitative and less subject to operator error and variability than the fiber determinations, and more rapid and reproducible than measurement of carbon dioxide produced by respiration. Key words: Cellulose, peatlands, organic soils, respiration rate, degree of decomposition

Reasons for disposal of cows in a purebred Hereford and two multibreed synthetic groups under range conditions

1992 ◽  
Vol 72 (4) ◽  
pp. 751-758 ◽  
Author(s):  
P. F. Arthur ◽  
M. Makarechian ◽  
R. T. Berg ◽  
R. Weingardt
Keyword(s):  
Beef Cattle ◽  
Key Words ◽  
Reproductive Failure ◽  
The Other ◽  
Relative Importance ◽  
Calf Survival ◽  
The Mean

Reasons for disposal were determined for 983 cows from a purepred Hereford and two multibreed synthetic groups; all were born in the 1966–1975 period. One synthetic group (Beef Synthetic #1) was composed mainly of beef breeds, while the other synthetic group (Dairy Synthetic) had 64% dairy breeding. The cows were managed under a stringent culling policy under which any cow failing to wean a calf each year was culled. Cows were also culled for unsoundness and other defects. The mean longevity was 4.2 yr, with 16 yr being the maximum age attained by any cow. The highest percentage of cows was disposed as 2-yr olds (first calvers). Death losses accounted for 8.8%, while culling for reproductive failure, calf survival problems, calving problems and udder problems accounted for 51.3, 12.1, 10.9 and 7.7% of all disposals, respectively. Culling for reproductive failure was the major reason for disposal at all ages, although its relative importance diminished with advancing age. Culling for udder problems was of greatest significance in 6-yr-old and older cows. Culling for calf survival problems was higher (P < 0.05) in the Hereford than in the two synthetic groups. While mortality in the Dairy Synthetic group was higher (P < 0.05) than in the other two groups, the reverse was the case with respect to culling for severe calving problems, with Dairy Synthetic cows being culled the least (P < 0.05). Key words: Beef cattle, longevity, mortality, culling, breed

Effect of acid deposition on trichome morphology and dogwood anthracnose biology

1992 ◽  
Vol 50 (1) ◽  
pp. 840-841
Author(s):  
Kyle T. Thornham ◽  
R. Jay Stipes ◽  
Randolph L. Grayson
Keyword(s):  
Acid Deposition ◽  
Disease Incidence ◽  
Natural Populations ◽  
Tree Disease ◽  
Flowering Dogwood ◽  
Discula Destructiva ◽  
Disease Induction ◽  
Dogwood Anthracnose ◽  
Trichome Morphology ◽  
Precipitation Events

Dogwood anthracnose, caused by Discula destructiva (1), is another new catastrophic tree disease that has ravaged natural populations of the flowering dogwood (Cornus florida) in the Appalachians over the past 15 years, and the epidemic is prognosticated to continue (2). An estimated 9.5 million acres have been affected, primarily in the Appalachian Mountains, from VA southwards, alone, and an estimated 50% of all dogwoods in PA have been killed. Since acid deposition has been linked experimentally with disease induction, and since the disease incidence and severity are more pronounced at higher elevations where lower pH precipitation events occur, we investigated the effect of acidic foliar sprays on moiphologic changes in the foliar cuticle and trichomes (3), the initial sites of infection and foci of Discula sporulation.

Identifying Sources of Sulfate Aerosols Reaching Whiteface Mountain, NY

1985 ◽  
Vol 43 ◽  
pp. 98-101
Author(s):  
James S. Webber
Keyword(s):  
Trace Metals ◽  
Acid Deposition ◽  
Surface Waters ◽  
Dry Deposition ◽  
Coal Combustion ◽  
Public Awareness ◽  
Sulfate Aerosols ◽  
Wet And Dry Deposition ◽  
Whiteface Mountain ◽  
Toxic Trace Metals

INTRODUCTION“Acid rain” and “acid deposition” are terms no longer confined to the lexicon of atmospheric scientists and 1imnologists. Public awareness of and concern over this phenomenon, particularly as it affects acid-sensitive regions of North America, have increased dramatically in the last five years. Temperate ecosystems are suffering from decreased pH caused by acid deposition. Human health may be directly affected by respirable sulfates and by the increased solubility of toxic trace metals in acidified waters. Even man's monuments are deteriorating as airborne acids etch metal and stone features.Sulfates account for about two thirds of airborne acids with wet and dry deposition contributing equally to acids reaching surface waters or ground. The industrial Midwest is widely assumed to be the source of most sulfates reaching the acid-sensitive Northeast since S02 emitted as a byproduct of coal combustion in the Midwest dwarfs S02 emitted from all sources in the Northeast.

Sign in / Sign up

Export Citation Format

Share Document