bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF YEARLING WEIGHT SELECTION IN SHORTHORN BEEF CATTLE ON AGE-OF-DAM ADJUSTMENT FACTORS
Authors: OLTHOFF J. C. , CROW G. H. , RAHNEFELD G. W.
Published: March 2010

Lines within a breed which differ in their level of performance may require different age-of-dam adjustment factors in the same way that different breeds do. Age-of-dam adjustments calculated from a control and a yearling weight selection line indicated lower values in the selected line for calf birth weight, weaning weight and yearling weight for 2- and 4-yr-old dams. Trends for adjustment factors in each line over time were generally not significant but tended to diverge. Age-of-dam adjustment factors within a breed may need to be reevaluated at intervals as levels of performance change. Key words: Beef cattle, age of dam adjustment, selection, yearling weight
THE ACCUMULATIVE EFFECT OF FINNSHEEP BREEDING IN CROSSBREEDING SCHEMES: EWE PRODUCTIVITY UNDER AN ACCELERATED LAMBING SYSTEM
Authors: FAHMY MOHAMED H.
Published: March 2010

Ewes representing DLS, Finnsheep (F) and seven of their crosses were subjected to a system of lambing every 8 mo on a commercial farm. Ewes were mated in spring (Apr.), autumn (Aug.) and winter (Dec). For the three mating seasons, fertility was 80, 86 and 87% while number of lambs born alive was 1.85, 2.21 and 2.25 and those weaned were 1.84, 2.38 and 1.67 lambs, respectively. Fertility was highest in Finnsheep (98%) and 6/8F (97%). The largest (2.8) and smallest (1.2 lambs) litters were born to 7/8F and DLS ewes, respectively. The average interval between lambings was 264 d corresponding to 1.38 lambings producing 2.3 lambs ewe−1 yr−1. The 6/8F ewes had the highest productivity (3.27 lambs, 55.3 kg ewe−1 yr−1) followed by 5/8F and Finnsheep ewes. Key words: DLS, Finnsheep, accelerated lambing, crossbreeding
RESPONSES TO INDEX SELECTION FOR REDUCED BACKFAT THICKNESS AND INCREASED GROWTH RATE IN SWINE
Authors: McKAY R. M.
Published: March 2010

Selection resulted in a decrease in probed backfat thickness and a negligible change in postweaning average daily gain. Realized heritabilities in the Yorkshire and Hampshire select lines were 0.41 ± 0.04 and 0.34 ± 0.18, respectively, for probed backfat thickness and 0.38 ± 0.43 and 0.65 ± 0.19, respectively, for postweaning average daily gain. Key words: Swine, selection differential, selection response, backfat, growth rate
STUDIES ON THE SUITABILITY OF A COLORIMETRIC TEST FOR ANDROST-16-ENE STEROIDS IN THE SUBMAXILLARY GLAND AND FAT OF PIGS AS A SIMPLE CHEMICAL TEST FOR BOAR TAINT
Authors: SQUIRES E. JAMES
Published: March 2010

Analytical methods for measuring 5α-androst-16-en-3-one, the major boar taint steroid, that have been described to date are expensive, time consuming and generally not suitable for use in an abattoir. In this report the use of a qualitative colorimetric test for the determination of androst-16-ene steroids is described which is inexpensive, quick and simple to perform. The test is based on the established reaction of steroids with resorcylaldehyde and H2SO4 in glacial acetic acid. Androst-16-ene steroids give a purple color (λ max = 590 nm) while cholesterol produces a pink color (λ max = 543 nm) from the reaction. Assay conditions have been optimized to produce a maximum color with androst-16-ene steroids and to minimize color development with cholesterol. Since tissue extracts contain appreciable levels of cholesterol which would still produce a considerable amount of color in the assay, a method to remove cholesterol while concentrating the androst-16-ene steroids from tissue extracts was devised. This technique allows the specific determination of androst-16-ene steroids in tissue extracts using the resorcylaldehyde/H2SO2/acetic acid color reaction. The possible use of this test as a simple chemical method for estimating taint is illustrated by determining the levels of androst-16-ene steroids in salivary glands and backfat of a small number of boars, barrows and gilts and comparing these values to the levels of taint determined by the hot iron test. Key words: Boar taint, androst-16-ene steroids, quick test
EFFECTS OF DIETARY IRON CONCENTRATION ON THE PERFORMANCE AND MEAT COLOR OF GRAIN-FED CALVES
Authors: LAPIERRE H. , LACHANCE B. , ROLLAND J. R. , ST-LAURENT G. J.
Published: March 2010

Forty-two black and white male dairy calves were used to determine the effect of iron concentration in concentrate diets on growth performance and meat color. The experimental period began after weaning at 6 wk of age. Calves, averaging 67.2 kg, were randomly divided into three groups. Each group received, ad libitum, concentrates with different iron concentrations: low iron concentration, 100 mg kg−1 of dry matter (LI, n = 15), intermediate iron concentration, 150 mg kg−1 (II, n = 14) and a high iron concentration, 200 mg kg−1 (HI, n = 13). Calves were slaughtered at 190 kg body weight. Total iron intake averaged 30.0, 56.1 and 74.7 g for groups LI, II, HI, respectively. Iron concentration in the diet did not affect (P > 0.10) average daily gain or total dry matter intake, which averaged 1.23 kg d−1 and 334.5 kg, respectively. Blood samples were collected from the jugular vein on days 1, 29, 57 and on the day of slaughter. Hemoglobin concentration and hematocrit averaged, respectively, 11.9 g 100 mL−1 and 37% on slaughter day and were not affected (P > 0.10) by treatments. Carcass weight and classification, color of the pectoralis major, and composition of the liver and of the longissimus dorsi at the 12th rib level were not affected (P > 0.10) by treatments. Unexpectedly, color score of the longissimus dorsi was linearly (P < 0.05) related to iron concentration of the diet, likely due to random error as calves fed the HI diet had the lighter meat color. In conclusion, concentrates containing 100–200 mg g−1 of iron, exceed the iron concentration required to produce light meat color or affect hemoglobin concentration of grain-fed calves. Therefore, concentrates made using commercial ingredients would need the addition of an agent-chelating iron to produce light meat color. Key words: Iron, calves, growth, meat, liver, color, hemoglobin
EFFECTS OF CALCIUM LOSS AND HIGH DIETARY CALCIUM AND POTASSIUM ON CALCIUM KINETICS AND MAGNESIUM BALANCE IN SHEEP FED LOW MAGNESIUM DIETS
Authors: FREDEEN A. H.
Published: March 2010

Effects of low dietary Mg with low or high Ca and K and sudden Ca loss, on Ca kinetics and Mg balance in sheep were studied. Six sheep were randomly assigned to one of two dietary treatments to provide (g d−1) either low levels of Ca (3.9), K (8.4) and Mg (2.3) or high levels of Ca (6.4) and K (30.6), and low levels of Mg (2.1). Lactational Ca loss was simulated via continuous iv infusion of ethylene glycol-bis (β-amino ethyl ether) N, N, N1, N1-tetraacetic acid (EGTA). In a control period sheep were not infused. Kinetics of Ca absorption and metabolism were determined using a radio-dilution technique and the Simulation, Analysis and Modeling program. Diets containing high Ca and K and low Mg reduced apparent Mg absorption and Mg balance compared to diets containing low Ca, K, and Mg. Confronted with a simulated lactational Ca loss, bone Ca resorption failed to increase when diets contained high Ca and K levels, whereas Ca absorption failed to increase when diets contained low Ca and K levels. Calcium balance was negative, and size of the exchangeable Ca pool was smaller in EGTA-infused sheep fed a low Ca, K, and Mg diet compared to a high Ca, K and low Mg diet. Key words: Calcium, magnesium, potassium, metabolism, kinetics, sheep, SAAM
THE INFLUENCE OF FEEDING LEVEL DURING LACTATION AND GESTATION ON THE ENDOCRINE STATUS AND REPRODUCTIVE PERFORMANCE OF SECOND PARITY SOWS
Authors: KIRKWOOD R. N. , BAIDOO S. K. , AHERNE F. X.
Published: March 2010

During their second lactation, 123 second-parity Yorkshire × Landrace sows were fed either 6 kg or 3 kg d−1 of a barley-soybean meal diet formulated to provide 12.5 MJ DE kg−1 and 16% crude protein (approximately 90 and 45% of National Research Council (NRC 1988) requirements). From 48 h after the onset of the post-weaning estrus, sows from each lactation feed treatment were allocated equally to receive the same diet at 3.6 kg or 1.8 kg d−1 (approximately 160 and 80% of NRC (1988) requirements), until slaughtered at 25 d of gestation. On days 4, 8, 12 and 16 of gestation, eight sows from each of the four feed level combinations were blood sampled at 15-min intervals for 4 h. Additionally, a further eight sows were sampled once on each of the above days. The lower plane of feeding during lactation resulted in a greater body weight and backfat loss (26.6 vs. 13.8 kg and 6.5 vs. 3.6 mm, respectively; P < 0.01 for both), an increased incidence of anestrus (21 vs. 8%; P < 0.05) and a longer and more variable interval to estrus (8.9 ± 0.4 vs. 6.0 ± 0.2 d; P < 0.01) than higher level feeding. There was no effect of lactation feeding level on ovulation rate (17.6 ± 0.3 vs. 17.7 ± 0.4 for sows having the higher and lower feed intakes, respectively). There was a main effect of lactation (P < 0.01), but not gestation, feeding level and an interaction between lactation and gestation feeding level (P < 0.02), on number of embryos and percent embryo survival. Embryo numbers and survival were reduced following lower plane feeding during lactation but were lowest following lower plane feeding during both lactation and gestation. There was no effect of sampling day on plasma LH concentrations but plasma LH was lower (P < 0.01) in sows on lower plane feeding during both lactation and gestation. The present data confirm an adverse effect of low plane feeding during lactation on subsequent sow reproductive performance and suggest that a reduction in plasma LH concentrations may be involved. These data fail to confirm any adverse effect on embryo survival of high plane feeding during the first 25 d of gestation. Key words: Sow, feed intake, LH, progesterone, reproduction
TECHNIQUE FOR THE DETERMINATION OF BONE VOLUME AND SPECIFIC GRAVITY
Authors: OGUNBAMERU B. O. , EVANS J. L. , KORNEGAY E. T.
Published: March 2010

The distal halves of third metacarpals from 93 crossbred pigs were used to determine the effect of hydration time (0, 30, 60 or 120 min) for frozen or thawed (2 h) bones on volume and specific gravity. Based on the findings of this study, a procedure for the determination of volume and specific gravity is suggested. Key words: Specific gravity, hydration, bone, pigs
RELATIONSHIPS BETWEEN CARCASS WEIGHTS, BACKFAT AND LOIN MUSCLE DEPTH IN CULL SOWS
Authors: AZIZ N. N. , RAE W. A. , BALL R. O. , ALLAN J. W.
Published: March 2010

The carcass weight distribution of the cull sow population was evaluated from 104 456 sows slaughtered in Ontario in 1988. Carcass weight, backfat depth and loin muscle depth were evaluated for 797 additional sows, randomly selected at a commercial abattoir. Approximately 85% of sows were between 100 and 200 kg with 4.5% less than 100 kg and 10.5% more than 200 kg carcass weight. The frequency distribution showed backfat depth was most frequently between 15 and 19.9 mm (26.73%) and 20 and 24.9 mm (29.99%). Sow carcasses are extremely diverse, varying 3- to 9-fold in backfat depth and 2- to 3-fold in loin muscle depth within any 25-kg weight class. Key words: Sows, carcass composition, backfat
INFUSION OF ESTRADIOL DURING THE LUTEAL PHASE OF THE ESTROUS CYCLE IN THE EWE COMPLETELY ELIMINATES LH PULSES
Authors: JOSEPH I. B. J. K. , RAWLINGS N. C.
Published: March 2010

Elevation of serum estradiol (E2) levels to ≈ 23 pg mL−1 on day 12 of the estrous cycle of the ewe eliminated LH pulses, but did not induce luteolysis and a preovulatory surge release of gonadotropins. The E2 treatment appeared to exert a functional luteotropic effect. The results indicate a strong synergism between E2 and progesterone (P4) in the control of tonic LH secretion during the luteal phase and that P4 blocks the preovulatory LH surge mechanism at high, but physiological levels of E2. Key words: Estradiol, LH pulses, luteal phase, ewe, luteotropic
COMPARATIVE POTASSIUM LEVELS REMOVED FROM SOILS BY ELECTRO-ULTRAFILTRATION AND SOME CHEMICAL EXTRACTANTS
Authors: LIEROP W. VAN , TRAN T. SEN
Published: March 2010

The objective of this study was to compare extractable potassium levels removed from soils by electro-ultrafiltration (EUF) and by conventional chemical soil tests. Accordingly, concentrations of potassium removed from soils by three EUF and six chemical extraction procedures were compared, on a group of 50 soils which contained less than 20% clay and on a second group of 52 soils which contained from 20 to 50% clay, by means of regression and correlation techniques. The following three EUF extraction procedures were tested: (i) 50 V at 5-min; (ii) 50 V at 5-min plus 200 V at 25-min; and (iii) 300 V at 15-min. Results indicated that the concentrations of soil K found in the combined anolyte and catholyte of the EUF or removed by the chemical procedures were very closely related (r-values generally greater than 0.90). However, EUF was less efficient in removing K from soils containing higher proportions of clay than NH4OAc, the new Mehlich solution, or the double acid mixture used at 1:30 wt/vol soil-solution ratio. As soil K fractions extracted by different EUF procedures were closely related among themselves as well as between the chemical methods tested, EUF would not provide soil fertility information that could not be obtained by less laborious and expensive chemical procedures. Key words: Soil testing, NH4OAc, double acid, new Mehlich extractant, electro-ultrafiltration
VALEUR FERTILISANTE DES ENGRAIS AZOTÉS ET PHOSPHATÉS ET TAUX DE FERTILISATION POUR LA PRODUCTION DU TABAC À CIGARETTE
Authors: LAMARRE MICHEL
Published: March 2010

During a period of 5 yr, the influence of different forms of N, P, combinations of K and levels of fertilizers on cigarette tobacco production were studied. Potassium nitrate was found to be significantly inferior compared with the other sources of nitrogen. No significant difference was detected between the different sources of phosphorus. The greatest yield but the poorest quality of tobacco was obtained with the highest level of fertilization. Key words: Flue-cured tobacco, nitrogen, phosphorus, potassium
SPATIAL VARIATION OF EXTRACTABLE MICRONUTRIENTS IN A CULTIVATED AND A NATIVE PRAIRIE SOIL
Authors: SINGH J. P. , KARAMANOS R. E. , KACHANOSKI R. G.
Published: March 2010

The variability in DTPA-extractable micronutrients was studied for the A and B horizons of a cultivated site and its native prairie counterpart. The results showed that there was a high degree of variability in samples taken every meter on a 46-m long transect. There were large differences among the cultivated and native prairie soils, the two soil horizons and the four micronutrients studied. In cultivated fields, larger numbers of samples were required for Cu and Mn than for Zn and Fe to obtain a precise estimate of the mean. The number of samples becomes critical as deficiency levels are approached. Key words: Soil sampling, sample size, soil variability
GENERAL AND SPATIAL VARIABILITY OF SOLONETZIC SOILS IN NORTH CENTRAL ALBERTA
Authors: CARTER M. R. , PEAREN J. R.
Published: March 2010

The general and spatial variation of several soil profile chracteristics, and properties of agronomic and ameliorative importance, were determined on a regional and local area of Solonetzic soil in north central Alberta. Differences in general variation as characterized by the mean, median, coefficient of variation (CV), and range allowed grouping of soil properties according to high (e.g. EC in the Ap horizon), medium and low (e.g. pH of the Ap horizon) variation. Such grouping, along with specific differences in soil variation between the regional and local area was associated with the saline-sodic characteristics of these Solonetzic soils. Spatial variability was studied using a geostatistical method (variograms) on soil samples obtained from a 5-m grid. The variograms for most of the various soil properties did not reveal strong spatial dependence. Large nugget variances accounted for 60–90% of the total variance. The semivariance approximated the overall variance usually within 10 m. Variograms suggested periodic variation for the pH and EC of the Ap horizon. Extractable Ca in the Bnt horizon and the depth of the Ap and Bnt horizons were anisotropic showing significant spatial dependence with direction of sampling. The implication of soil variability in regard to soil sampling is discussed. Key words: Spatial variability, Solonetzic soil, saline-sodic soil, soil sampling, variogram
PREPARATION OF ALUNDUM/CERAMIC PLATE TENSION LYSIMETERS FOR SOIL WATER COLLECTION
Authors: NEARY A. J. , TOMASSINI F.
Published: March 2010

Distilled water leaching of new alundum/ceramic plate lysimeters removed considerable amounts of Ca, Mg, Na, K, SO4, Cl and Zn. After washing with 3 L of distilled water, levels were still of sufficient magnitude to interfere with the analysis of solutions with low solute concentration. Washing the plates with 2 L of 1 N HCl extracted considerable amounts of Ca, Mg, Na and K, and higher amounts of Fe, Zn, Al and Mn, but further distilled water washing resulted in rapid equilibration with a spike solution. Rinsing new lysimeters with progressively more acidic solutions indicated residual zinc contamination when the solution pH was below 6.0. There was virtually no iron or manganese contamination from the lysimeters at a solution pH between 3.0 and 5.0. Aluminum was leached from the plates at solution pH of between 3.5 and 4.0; however, the high Al concentration in the soil solution at these pHs may mask this interference. Although Al poses a considerable contamination problem at solution pHs of 3.0, soil solutions at this pH level are unlikely except in unusual situations (e.g. soils developed on acid mine tailings). The pumping of 2 L of 1 N HCl followed by large volumes of distilled water through the lysimeters is recommended for most field studies. Prior testing of the plates is required if low solute concentrations are expected or if elements other than those mentioned here are of interest. Key words: Lysimeters, ceramic samplers, soil water collection, alundum lysimeters, soil solution
SOIL SALINITY STATUS AND ITS RELATION TO SOME OF THE SOIL AND LAND PROPERTIES OF THREE IRRIGATION DISTRICTS IN SOUTHERN ALBERTA
Authors: CHANG C. , KOZUB G. C. , MACKAY D. C.
Published: March 2010

A detailed soil salinity survey was carried out in three of the 13 irrigation districts in southern Alberta. About 30 quarter-sections in each district were randomly selected for soil sampling. The location, distance from water supply ditches, slope of the land, and depth to till and water table at each site were recorded. Soil texture and electrical conductivity of extracts of soil samples were determined in the laboratory. The extent of the area with a soil salinity level of 4 dS/m or more is 5% of the total surveyed land in the Western Block of the St. Mary River Irrigation District (WSMRID), 6% in the Lethbridge Northern Irrigation District (LNID) and 9% in the Taber Irrigation District (TID). These values are not as high as others have previously estimated. The salinity level of the soil at each site was found to vary with its location and distance from water supply ditches in the WSMRID and LNID, clay content in the 0- to 120-cm depth in the WSMRID and TID, and water table level in the TID. Key words: Soil texture, EC, SAR, pH
COMPARISON OF MODELLED SOIL WATER RESERVES ON CANADIAN PRAIRIE SOILS WITH WATER-HOLDING CAPACITIES OF 280 AND 250 mm
Authors: JONG R. de , SLY W. K.
Published: March 2010

Based on soil water modelling results of 19 stations, averaged long-term soil water reserves on the Canadian Prairies were compared for two soils having available water-holding capacities of 280 and 250 mm. The soil water reserves of the 250-mm capacity soil were 6.5%, 8.7% and 6.2% less than those of the 280-mm capacity soil on 1 May after a fallow year, 30 June heading time and 1 May after a crop year, respectively. The aridity indices for wheat at the soft dough stage for the 250-mm capacity soil ranged from 4% less in the drier part of the Prairies to 7–9% more in the wetter regions as compared to the 280-mm capacity soil. Water deficits for a perennial crop grown on a 280-mm capacity soil could not be used to infer the deficits on a 250-mm capacity soil because of the model’s sensitivity to rainfall distribution with time. Key words: Soil water, modelling, available water-holding capacity
APPLICATION OF GLYCEROL/ETHANOL SOLUTIONS FOR SOLVATION OF SMECTITES DRIED ON GLASS SLIDES
Authors: MILES N. , KIMPE C. R. DE
Published: March 2010

Glycerol/ethanol solutions with various glycerol concentrations were used for the solvation of smectite on glass slides. The effects of concentration and standing time before X-ray analysis were considered. A 14% glycerol solution in ethanol applied to the clay with a glycerol/clay weight ratio of 31% produced after 10 min standing time high intensity and maximum expansion of the basal spacing of smectite from 1.4 to 1.78 nm. The procedure described may be especially useful for the identification of smectite when present in small percentages. Key words: Glycerol solvation, basal spacing expansion, smectite characterization
WIND EFFECT ON DISCER INCORPORATION OF HERBICIDE GRANULES INTO SOIL
Authors: KUSHWAHA R. L. , REED W. B.
Published: March 2010

Soil surface distribution patterns of herbicide granules from a Gandy dribble type applicator were determined under different wind velocities in the laboratory and verified in the field. Results indicted that a combined operation of application and incorporation during seeding with a discer would not provide satisfactory placement of granules assuming wind velocities that occur normally in Saskatchewan during the seeding period. Key words: Wind, discer, herbicide granules, incorporation
A PNEUMATIC SYSTEM FOR HERBICIDE GRANULE INCORPORATION INTO SOIL WITH A DISCER
Authors: KUSHWAHA R. L. , REED W. B.
Published: March 2010

In an effort to minimize the effect of wind on the placement of herbicide granules during simultaneous application-incorporation while seeding with a discer, a pneumatic conveying and dispersion system was designed, fabricated and tested. Nozzles designed for the system produced a uniform granule distribution pattern over a width of 300 mm. The system was mounted on a 2.8-m-wide discer for field evaluation. Field tests were conducted to determine the uniformity of incorporation at different soil depths under windy conditions. Bio-assay field trials were conducted over a period of 2 yr to evaluate crop injury and weed control with the pneumatic system. It was compared with other currently used methods of granular and liquid triallate application. The pneumatic system provided good weed control, no apparent crop injury and no reduction in crop yield. Key words: Pneumatic application, discer, herbicide granules
DENITRIFICATION BY INTACT SOYBEAN NODULES IN RELATION TO NATURAL 15N ENRICHMENT OF NODULES
Authors: BRYAN BARBARA A. , SHEARER GEORGIA , SKEETERS JERRI L. , KOHL DANIEL H.
Published: March 2010

The natural 15N abundance of nodules of soybeans (Glycine max (L.) Merrill) which are actively fixing N2 is considerably higher than other tissues. To investigate the question of whether isotopic fractionation associated with denitrification by bacteroids causes this 15N enrichment, we inoculated soybeans with two strains of Rhizobium japonicum. Free-living cultures of one of these (strain USDA 33) were unable to denitrify or respire NO−3, while free-living cultures of the second (strain USDA 138) were capable of denitrification. USDA 138 formed nodules which fixed N2 very efficiently. The N of these nodules was enriched in 15N and the nodules reduced a substantial amount of NO−3 to NO−2 and N2O. Nodules infected with USDA 33 fixed about half as much N2 as those infected with USDA 138. The former nodules were enriched in 15N (although less so than nodules infected with USDA 138), despite the fact that the nodules formed by USDA 33 did not reduce NO−3. Clearly denitrification could not have been the cause of 15N enrichment of nodules infected with strain USDA 33. Alternative causes of 15N enrichment of soybean nodules and their possible metabolic significance are discussed. Key words: δ15N, nitrogen fixation
COMPARISON OF CANADIAN AND AMERICAN CLASSIFICATION SYSTEMS FOR SOME ARCTIC SOILS OF THE UNGAVA-LABRADOR PENINSULA
Authors: HENDERSHOT W. H.
Published: March 2010

Thirteen pedons in an arctic environment were classified according to the Canadian and American systems of soil classification. Major differences in groupings result from the contrasting approaches. Although the definition used in Canada to define Cryosols is sometimes difficult to apply in the field, the underlying concept is valid, since soils with permafrost at a shallow depth should be separated at the highest level of classification. The American system virtually ignores the influence of permafrost on pedogenesis. Its reliance on soil temperature regimes at both the great group and subgroup levels is redundant. It is suggested that the definition of Cryosols, in the Canadian system, be changed to include strongly cryoturbated soils with very cold or colder soil temperature regimes. The American system should be altered to provide for pergelic great groups; in addition permafrost and strong cryoturbation should be used to create new subgroups. The requirement that a cambic horizon have a texture finer than loamy fine sand should be waived in soils having cryic or pergelic soil temperature regimes. Key words: Cryosols, cryoturbated soils, permafrost, pergelic soils
EFFECT OF ORCHARD SOIL MANAGEMENT ON THE GROWTH AND LEAF NUTRIENT CONCENTRATION OF YOUNG DWARF RED DELICIOUS APPLE TREES
Authors: NEILSEN G. H. , HOGUE E. J.
Published: March 2010

Bisbee Delicious apple trees (Malus domestica Borkh.) on Mailing 26 rootstock, planted in 1979 on an Osoyoos loamy sand were subjected, commencing in 1981, to five different orchard soil management treatments including full ground cover, early season vegetation control, total vegetation control, black plastic mulching and shallow tillage. All ground cover suppression treatments decreased leaf K and increased leaf Mg, leaf N and yield. With the exception of early season vegetation control, all ground cover suppression treatments decreased leaf P although P was adequate for initial growth. Declines in soil solution Ca, Mg, and K concentration, 1980–1983, were observed regardless of soil management method. Key words: Apples, M.26 rootstock, leaf N, P, K, Ca, Mg, fruit yield
SURFICIAL REARRANGEMENT AND CRACKING IN SWELLING CLAY SOILS OF THE GLACIAL LAKE REGINA BASIN IN SASKATCHEWAN
Authors: MERMUT A. R. , ACTON D. F.
Published: March 2010

A pipeline trench across the Glacial Lake Regina basin provided an opportunity to examine the nature of soil development in heavy textured swelling clays in Saskatchewan. Radiocarbon dates showed a steep age versus depth gradient within the upper 1 m of these soils, and an abrupt change of gradient at this depth. Granular surface structure, deep and wide cracking, slickensides, weak horizon development, and gradual changes in organic matter content were the major characteristics of these soils. The dark-colored subsurface layer in the depressional position appeared to represent a former surface which was buried by accretion of materials from upper slopes. The characteristic morphological features signify the need to re-examine the classification of these soils in the Canadian System of Soil Classification. Key words: Organic 14C dates, soil age, paleosols, swelling clay soils, Holocene soils
SOIL CHEMICAL AND MINERALOGICAL CHANGES DUE TO ACIDIFICATION IN OKANAGAN APPLE ORCHARDS
Authors: ROSS G. J. , HOYT P. B. , NEILSEN G. H.
Published: March 2010

Five Okanagan Valley soil series that had been in orchard for from 12 to 40 yr were studied to determine the effect of orchard practices on chemical and mineralogical soil properties. The soils were coarse-textured with relatively low organic C contents. Acidification produced by fertilization, irrigation and herbicide use had lowered soil pH values from between 5.0 and 6.0 in the alleys between the trees to about 3.0–3.5 near the trees and had greatly decreased permanent-charge cation exchange capacities, base saturation percentages, and ratios of exchangeable Ca/Mg, Ca/K, Mg/K. The pH-dependent or variable charge increased with organic C content and thus originated mainly from the organic matter of these coarse-textured soils. The proportional losses of exchangeable bases during acidification followed the order Ca > Mg > > K. Acidification had also released large quantities of plant-available Al and Mn. The soil clays from both the higher and lower pH sites were relatively poorly crystalline with X-ray amorphous constituents and mica as major components. Acidification appeared to have decreased mineral crystallinity as well, as indicated by consistently higher levels of extractable oxides of Si, Al and Fe in the clays from the acidified soils. These effects of orchard practices on chemical and mineralogical properties developed rapidly and were evident in one soil within 12 yr. Practical implications of these results for improving the management and fertility of orchard soils are discussed. Key words: Acidification, chemical and mineralogical changes, Okanagan soils, apple orchards
CHEMICAL PROPERTIES OF SOIL AS AFFECTED BY A SINGLE BURN OF ALFALFA STUBBLE TO CONTROL INSECTS
Authors: DORMAAR J. F. , SCHABER B. D.
Published: March 2010

Southern Alberta growers often burn fields of seed alfalfa (Medicago sp.) prior to initiation of growth in the spring as apart of an Integrated Pest Management Program. The present study examined the effect of a single burn of the standing dead growth and debris of a 4-yr-old alfalfa crop in early spring, late spring, or autumn on various chemical properties of the upper 50 mm of soil. Burning led to small but significant increases in organic matter, NO3-N, NH4-N, available P, extractable K, EC, and pH levels immediately after the fire. The only measurable impact 1 year later was slightly higher (P < 0.05) organic matter, but after 2 years there were no differences in these levels. Even though this study portrayed a single burn event, thereby precluding predictions of the long-term effects of different fire regimes, the changes observed were only measurable for less than 1 year. If the burning of the alfalfa stubble is done every third year it is unlikely that this practice would be detrimental to the soil characteristics examined. Key words: Fire, pest management, organic matter, prescribed burning
VERTICAL AND LATERAL VARIABILITY OF VANE SHEAR TEST DATA FOR A CLAYEY SOIL
Authors: WIRES K. C.
Published: March 2010

Vane shear (VS) strength in the upper 2 m of a relatively uniform clay soil varied both vertically and laterally. Obtaining VS values which are reliable at the 80% confidence level for the transect tested required measurements at three sites for a depth increment within the upper meter, but a single site would be adequate for depth increments between 1 and 2 m. A preferred procedure to that of characterizing a modal pedon is outlined for estimating VS strength in soil survey. Key words: Vane shear, variability
MASS LOSS IN A FORESTED BOG: RELATION TO HUMMOCK AND HOLLOW MICRORELIEF
Authors: FARRISH K. W. , GRIGAL D. F.
Published: March 2010

The importance of microrelief in relation to mass loss was studied in a Minnesota ombrotrophic forested peatland. Litter and paper strips placed in hummocks for 1 yr lost significantly more mass (two and three times, respectively) than similar material placed in hollows. Less favorable environmental conditions for decomposition, especially lower temperature, reduced decomposition in the hollows. Key words: Peatlands, ombrotrophic, decomposition, Histosols
EVALUATION OF THE COLOR VALUE CRITERION OF HUMIC GLEYSOL
Authors: WANG C.
Published: March 2010

Organic carbon content and color value of A horizons are used as differentiating characteristics in separating Humic Gleysols from other Gleysolic soils in the Canadian System of Soil Classification. Many Gleysolic soils meet the organic carbon criterion but fail to meet the color value criterion of Humic Gleysol. It is concluded that the color value criterion is not an effective differentiating characteristic even though color is a useful indicator of organic carbon when laboratory data are not available. Key words: Principles of soil classification, differentiating characteristics
BORON TOXICITY AND DEFICIENCY: A REVIEW
Authors: GUPTA UMESH C. , JAME Y. W. , CAMPBELL C. A. , LEYSHON A. J. , NICHOLAICHUK W.
Published: March 2010

In this review the soil and environmental factors influencing B toxicity and deficiency in plants are discussed with the main emphasis being given to B toxicity. Some of the topics covered are sources of B, importance of B to plants, deficiency and toxicity criteria, factors affecting B sorption, quantification of B sorption, difficulties encountered in appraising B deficiency and toxicity limits and confusion in the specification of available B units, Eaton’s sand culture work — its assets and weaknesses, B fertilization of crops, B toxicity due to irrigation, and B equilibrium in soils. Suggested areas requiring further research are delineated. Key words: Plant boron, soil boron, boron adsorption characteristics of soil, irrigation management
COMPUTER ASSISTED MAPPING OF SOIL EROSION POTENTIAL
Authors: VOLD T. , SONDHEIM M. W. , NAGPAL N. K.
Published: March 2010

Soil erosion potential maps and summary statistics can be produced from existing information with relative ease with the aid of computers. Soil maps are digitized and survey information is stored as attributes for each soil. Algorithms are then prepared which evaluate the appropriate data base attributes (e.g. texture, slope) for each interpretation. Forty surface soil erosion potential maps were produced for the Lower Fraser Valley which identify the most erosion-prone areas and indicate average potential soil losses to be expected under assumed conditions. The algorithm developed follows the universal soil loss equation. Differences across the landscape in the R, K, and S factors are taken into account whereas the L factor is considered as a constant equal to 1.0. Worst conditions of bare soil (no crop cover, i.e. C = 1.0) and no erosion control practices (i.e. P = 1.0) are assumed. The five surface soil erosion potential classes are determined by a weighted average annual soil loss value based both on the upper 20 cm of mineral soil and on the proportion of the various soils in the polygon. A unique polygon number shown on the erosion potential map provides a link to computer tables which give additional information for each individual soil within that polygon. Key words: Erosion, computer mapping, USLE
SORPTION OF CARBON AND PHOSPHORUS FROM LIQUID POULTRY MANURE BY SOIL AGGREGATES OF DIFFERING SIZE
Authors: BHATNAGAR V. K. , MILLER M. H.
Published: March 2010

A series of laboratory experiments was conducted to determine the mechanism(s) responsible for a previously reported observation that addition of liquid manure to soil increased the NaHCO3-extractable P (Ext-P) of large aggregates (> 2 mm) more than that of smaller aggregates whereas addition of an inorganic P solution did not. Application of liquid poultry manure increased the total P, Ext-P and total C concentrations in large aggregates (> 2 mm) much more (> 2.5 ×) than that in small aggregates (< 1 mm). Addition of inorganic P solution or of supernatant liquid from a centrifuged manure slurry increased the P content of the large aggregates only slightly (1.2 ×). A greater increase in Ext-P in large aggregates was observed even when the smaller aggregates were purposely layered on top of the larger ones prior to addition of the liquid manure. A similar but less pronounced effect of aggregate size on increase in P or C concentration was observed when different sized aggregates were left in contact with an effectively infinite source of liquid manure for 24 h. It is concluded that the larger aggregates absorbed more of the bulk manure slurry than smaller aggregates. A partial sealing of small aggregates by particulates is suggested as a possible mechanism. Key words: Carbon, phosphorus, liquid manure, soil aggregates
RATE OF PYROPHOSPHATE HYDROLYSIS IN ORGANIC SOILS
Authors: PARENT L. E. , MacKENZIE A. F.
Published: March 2010

Twenty-four organic soil materials were selected in order to study pyrophosphatase activity and pyrophosphate retention and hydrolysis. The activation energy of pyrophosphate hydrolysis was 22 kJ∙mol−1 for virgin fibric soil materials and 33 kJ∙mol−1 for cultivated humic soil materials. Phosphatase and pyrophosphatase activities were highly correlated (r = 0.947**) and were promoted apparently by non-specific enzymes. Enzymatic activities varied from 11.6 to 148.1 mmol∙kg−1∙(2 h)−1, and were higher in virgin than in cultivated soil materials. Soil retention increased with an increase in ash content (r = 0.876**) and was apparently weak, as noted by complete pyrophosphate hydrolysis after 4–8 days of incubation. Half-life values of pyrophosphate incubated at room temperture varied from 0.1 to 3.7 days, and were highly correlated with enzymatic activities and levels of nonretained pyrophosphate. A regression model, involving an interaction between pyrophosphatase activity and level of nonretained pyrophosphate, accounted for 77% of the variation in log of half-life values of pyrophosphate in organic soil materials. Key words: Pyrophosphatase, phosphatase, pyrophosphate, half-life values, pyrophosphate retention
MOLYBDENUM, COBALT AND BORON UPTAKE FROM SEWAGE-SLUDGE-AMENDED SOILS
Authors: SOON Y. K. , BATES T. E.
Published: March 2010

Molybdenum, Co and B concentrations in, and uptake by, corn and bromegrass were measured over a period of several years from three field experiments in which sewage sludge was applied and compared with ammonium nitrate as a source of N. There was little effect of sludge on B and Co concentrations in the crops grown. Slight increases in uptake were apparently due to yield increases due to sludge. A lime-treated sludge increased Mo concentration in plant tissues after several years of sludge application. The increase in plant Mo concentration was highest in the eighth and last year of the experiments, although lime-sludge application had ceased 1–3 yr previously. The soil-sludge interactions contributing to increased Mo uptake are discussed. Key words: Molybdenum, cobalt, boron, sewage sludge, corn (Zea mays L.), bromegrass (Bromus inermiss Leyss).
CHANGES IN THE THERMAL STABILITY AND ACIDIC CHARACTERISTICS OF HYDROXY-Al-MONTMORILLONITE COMPLEXES FORMED IN THE PRESENCE OF CITRIC ACID
Authors: GOH TEE BOON , HUANG P. M.
Published: March 2010

The thermal stability and acidic characteristics of Al interlayered montmorillonite were affected by citric acid which was present during its formation. Perturbation to the formation of Al interlayers by citric acid resulted in more gradual loss of their structural water in the 430 °C to 520 °C region at initial citric acid/Al molar ratios of 0.1 and 0.5. The data clearly reveal that, besides hydroxy-Al polymers, hydroxy-Al-citrate complexes adsorbed on the surfaces of montmorillonite very substantially contribute to the total and third buffer range titratable acidity of the clay. Key words: Hydroxy-Al-citrate interlayers, smectite, organic acid, DTA, third buffer range, organic carbon
PERSISTENCE AND AVAILABILITY OF PARAQUAT IN A LETHBRIDGE CLAY LOAM SOIL
Authors: MOYER J. R. , LINDWALL C. W.
Published: March 2010

To determine the capacity of the Lethbridge soil to inactivate paraquat, applications equivalent to a maximum of 3000 kg/ha of paraquat were made in growth chamber and field experiments. In the growth chamber and field, more than 600 and 1000 kg/ha, respectively, of paraquat in one application were required to reduce wheat growth by 10%. Paraquat residue levels in the field soil did not decrease after the first summer. Paraquat residue was not found in wheat grain growing in soil with 1650 kg/ha of paraquat in the 0–15 cm layer, but it was detected in plant leaves. The paraquat associated with plant leaves could have resulted from contamination of the leaves by soil rather than from translocation from roots to leaves. The 500 kg/ha rate of paraquat reduced the cation exchange capacity by 5%; however, further paraquat additions did not cause additional reductions. Paraquat could likely be applied for several hundred years at currently recommended rates for weed control on chemical fallow and not exceed the ability of Canadian Prairie soils to inactivate it. Key words: Paraquat, persistence, availability, inactivation, wheat, soil
DISTRIBUTION OF SULPHUR FORMS IN SIX FACIES OF PEATS OF THE FRASER RIVER DELTA
Authors: LOWE L. E. , BUSTIN R. M.
Published: March 2010

The distribution of organic and inorganic S forms was examined in peats formed under the influence of fresh and brackish water on the Fraser River Delta. Six peat facies classified as sphagnum, ericaceous sphagnum, freshwater sedge, brackish sedge, freshwater clay or brackish clay were found to contain variable levels of sulphur. Brackish systems contained much more S than freshwater-derived materials. Highest S contents (mean 3.0%) were found in brackish sedge peat samples, and the lowest in sphagnum-derived peat (mean 0.19%). For all facies examined, organic S was dominant and accounted for 90–97% of Total S. Carbon-bonded S was the dominant organic form and was much more abundant than organic sulphate S. Inorganic sulphate, elemental S, pyritic S and H2S made minor contributions to the total S. Increasing degree of decomposition of peat is associated with increasing S content. Key words: Sulphur forms, organic sulphur, peat sulphur, degree of decomposition
SPECIFICATIONS FOR SOIL SURVEY INTENSITY (SURVEY ORDER) IN CANADA
Authors: VALENTINE K. W. G. , LIDSTONE A.
Published: March 2010

This study was an evaluation of soil survey methods, particularly soil survey intensity (survey order), based on information from 53 recent surveys in Canada. The data were gathered by questionnaire and indicate that revisions to the specifications outlined by the Expert Committee on Soil Survey are required.(1) An index calculated from the density (number of inspections per unit area) and distribution (percent of delineations with at least one inspection) of soil inspections allocates a survey unambiguously to one survey intensity level (SIL).(2) For each SIL, ranging from 1 (very detailed) to 5 (exploratory), the proportion of delineations with at least one inspection is reduced, and a smaller proportion of the total length of soil boundaries is checked in the field. A closer spacing of traverses at each SIL is recommended.Other information shows that SIL 5 surveys are more appropriately published at a scale of 1:250 000 than the usual 1:100 000; a smaller proportion of time is spent in the field in surveys of lower intensity; soil surveyors concentrate more on describing areas than verifying boundaries; and rates of progress at a given intensity level vary among different physiographic regions, with slowest progress in the Canadian Shield. Key words: Soil survey, intensity, order, index, Canada
SENSITIVITY AND ADAPTATION OF SELECTED RHIZOBIA AND AGROBACTERIA TO PARAQUAT
Authors: ROSLYCKY E. B.
Published: March 2010

Sensitivity to paraquat as function of growth varied considerably among 15 rhizobia from seven cross-inoculation groups and 13 agrobacteria from five different species. No relationship was evident between the sensitivity and the "fast-growing" or the "slow-growing" characteristics among the rhizobia. The agrobacteria were uniformly less sensitive. Maximum stabilized paraquat resistance induced by the adptations ranged from 200 μg paraquat∙mL−1 in Rhizobium lupini 112, to 20 000 μg paraquat∙mL−1 in Agrobacterium radiobacter R-590 and A. tumefaciens A6-K1. No relationship was found between the sensitivity and the adaptability. Identical lytic patterns with six bacteriophages confirmed the relationship between the adapted and parent cultures suggesting no genetic effect of paraquat on susceptibility to lysis. The bacteria-plant symbiont interaction, including nodulation, plant weight, vigor and color, was unaffected by the adaptations to paraquat resistance. Similarly, the adaptations exerted no effect on tumorigenicity of A. tumefaciens A6-K1. Key words: Rhizobia, agrobacteria, adaptation, herbicides, paraquat, N2-fixation
A COMPARISON OF THREE FIELD METHODS FOR MEASURING SATURATED HYDRAULIC CONDUCTIVITY
Authors: LEE D. M. , ELRICK D. E. , REYNOLDS W. D. , CLOTHIER B. E.
Published: March 2010

The saturated hydraulic conductivity, Ks, was measured on a loamy sand, a fine sandy loam, a silt loam and a clay at four 100-m2-area sites in southern Ontario. Twenty measurements of Ks were obtained by each of three different measurement techniques at each of the four sites. The techniques included: (1) the air-entry permeameter method; (2) the constant head well permeameter method using the Guelph Permeameter; and (3) the falling-head permeameter method applied to small soil cores. The Ks data were found to be better described by the log-normal frequency distribution than by the normal frequency distribution. Statistical comparison of the mean Ks values [Formula: see text] indicated significant differences between some or all of the methods within each site. This site-method interaction was interpreted in terms of the influence of macropores and air entrapment on each of the measurement techniques. The measured Ks values ranged over an order of magnitude on the sand, one to two orders of magnitude on the loams, and three orders of magnitude on the clay. The [Formula: see text] estimates averaged over the three methods were: 3 × 10−5 m∙s−1 for the sand; 2 × 10−6 m∙s−1 for the loams and 1 × 10−7 m∙s−1 for the clay. Although all techniques were able to discriminate between the three soil types, the best choice of method for any particular situation appears dependent on the required type and accuracy of the Ks measurement, soil type, and the various practical constraints on the investigation. Key words: Air-entry permeameter, Guelph Permeameter, falling-head permeameter, spatial variability, macropores, entrapped air
DINITROANILINE HERBICIDE PERSISTENCE IN SOIL IN SOUTHWESTERN ONTARIO
Authors: GAYNOR J. D.
Published: March 2010

Under southwestern Ontario climatic conditions ethalfluralin (1.0 kg/ha) (N-ethyl-N-(2-methyl-2-propenyl)-2,6-dinitro-4-trifluoromethylbenzenamine) and dinitramine (0.55 kg/ha) (N4,N4-diethyl-a,a,a-trifluoro-3,5-dinitro-toluene-2,4 diamine) applied preplant incorporated to Brookston clay loam dissipated to less than 20% of the original rate within 70 days after application. Trifluralin (1.0 kg/ha, preplant incorporated) (a,a,a-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) was more presistent with about 40% remaining in an extractable form after 110 days. In Fox sandy loam trifluralin (2.0 kg/ha, preplant incorporated) and oryzalin (2.0 kg/ha, preemergence) (3,5-dinitro-N4,N4-dipropylsulfanilamide) appeared to have similar persistence with about 30% residue remaining after 80 days. Key words: Trifluralin, dinitramine, ethalfluralin, oryzalin, field persistence
EFFECT OF SOIL ORGANIC MATTER OXIDATION ON THE COLLAPSE OF VERMICULITE
Authors: MILES N. M. , SCHNITZER M. , KIMPE C. R. DE
Published: March 2010

Oxidation of organic matter with H2O2 produced substantial amounts of NH3 which was then fixed by vermiculite, causing partial or complete collapse and converting the mineral to a mica-like product. The collapse of the mineral was indicated by shifts in the 001 spacing from 1.476 to 1.030 nm and the appearance of a well-defined band at 1430 cm−1 in the IR spectrum, indicative of the presence of NH4+ in the interlayer positions of the clay. Our data suggest that: (a) the transformation of vermiculite to mica during H2O2 oxidation may result in underestimation of the vermiculite content of soils by XRD, and (b) the wide occurrence of mixed-layer minerals in soils may in part have resulted from the fixation of NH3 liberated from the microbial mineralization of organically bound N. Key words: Ammonia, X-ray diffraction, IR spectrophotometry, mixed-layer minerals, H2O2 pretreatment