Showing papers in "Canadian Journal of Soil Science in 1978"

Effects of soil acidity and liming on mineralization of soil nitrogen

Abstract: Forty acid surface soils of pH 4.0–5.6 were incubated with and without lime, and the amounts of N that were mineralized or nitrified were statistically compared with several soil acidity characteristics. In addition, three field experiments were used to find the effect of liming on N mineralization. There was no relation between the amounts of mineral N released per unit of organic N in 120 days of incubation and soil pH, base saturation or soluble Fe, Al or Mn. Despite this, liming the soils to about pH 6.7 approximately doubled the amounts of N mineralized during incubation. In the field experiments, lime increased uptake of soil N by 15–42 kg/ha in the 1st yr but only 7–10 kg/ha in the 3rd yr. Thus these laboratory and field experiments indicate that soil acidity does not restrict mineralization of organic N and although liming increases mineralization of N, it is generally a temporary effect. Nitrification in the 40 incubated soils occurred much more rapidly in cultivated soils than in virgin soils. F...

Relationships of specific surface area and clay content to shrink-swell potential of soils having different clay mineralogical compositions

Abstract: Data for 22 samples from 17 pedons were analyzed for relationships of specific surface area and amounts and kinds of clay to coefficient of linear extensibility, as determined by the paste method (COLErod), and to free swelling index (FSI). The soils were divided into three main groups according to their clay mineralogy. The clay of the first group was micaceous, that of the second group kaolinitic, and that of the third group montmorillonitic. Both clay contents and specific surface areas of the combined first and second groups of soils were closely related to COLErod (r2 = 0.81 and r2 = 0.91) with specific surface area giving the higher correlation. The correlation of clay content with COLErod decreased markedly, however, when the montmorillonitic soils were included (r2 = 0.56). In contrast, the correlation of specific surface area with COLErod remained high (r2 = 0.97), indicating that for the soils used in this study, specific surface area was more basic with respect to shrink–swell potential than wa...

Effects of fertilizer n and soil moisture on mineralization, n recovery and a-values, under spring wheat grown in small lysimeters

Abstract: The influence of rate of fertilizer N and soil moisture on N uptake by spring wheat, N mineralization, A-values and N recovery was determined in small lysimeters on stubble land by means of 15N-labelled KNO3. Net mineralization was enhanced by frequent irrigations but depressed by cropping. In contrast to most growth chamber results, N uptake was not linearly but logarithmically related to rate of application; uptake from fertilizer was positively related to rate, but only up to a point beyond which it levelled off; uptake from native soil N was generally negatively related to rate; A-values were not constant but negatively related to rate except at the highest rates (123–164 kg N/ha) when they were positively related especially under dry conditions. These differences in results were credited to the fact that the pot system does not adequately simulate the field situation. On dryland an average of 68, 20 and 12% of the plant N was located in the grain, straw and roots, respectively; under irrigation the c...

Nitrogen transformations in soil-plant systems in three years of field experiments using tracer and non-tracer methods on an ammonium-fixing soil

Abstract: Three years of field experiments showed the interplay of plant uptake of N, N movement, denitrification, fixation of fertilizer NH4+ and its release, and N mineralization in soil–plant systems. The N uptake by barley (Hordeum vulgare L.), averaged over the growing season, ranged between 0.97 and 2.02 kg N/ha/day and the rate depended on initial extractable inorganic N in the soil, and form and timing of N fertilization. The net mineralization rate of this soil, averaged over the growing season, ranged between 0.16 and 1.80 kg N/ha/day and varied with year and N fertilization practices. However, detailed monitoring of plant uptake showed that a maximum rate of uptake occurred early in its growth, decreasing to a negligible rate later in the season. The N mineralization rate was more uniform over the growing season. A pool of inorganic N in the soil at seeding or within the first half of the growing season overcame the seasonal deficit in N supply and resulted in increased crop growth and/or N uptake. Ferti...

Nitrogen transformations and transport over 17 months in field fallow microplots using 15n

Abstract: A field experiment with an Ottawa area clay loam soil utilizing open-ended microplots and 15N-labelled fertilizer showed the relative importance of seasons on transformation and transport of nitrog...

Nitrogen isotope fractionation during ammonium exchange reactions with soil clay

Abstract: Nitrogen isotopic fractionation during ammonium adsorption by clay colloids was shown to occur in two time-dependent stages. A rapid 15N enrichment of the NH4+ in solution was followed by a gradual depletion until, after an 8- to 10-h equilibrium period, the δa15N of the NH4+ in solution was approximately 1; this value was significantly lower than the initial value of 2.3 for the NH4Cl used in these experiments. The isotopic equilibrium constant (ke) for the ammonium adsorption reaction was greater than unity, and higher for the Ca2+- than K+-saturated clay colloids.

The effects of soil and fertilizer nitrogen and moisture stress on yield, oil and protein content of rape

Abstract: Rape yields were increased nearly fourfold by the combination of irrigation and fertilizer N for eight site-years in which average soil NO3-N to 60 cm was 34 kg/ha. The increase due to irrigation and fertilizer N in combination was more than double the increase due to the two factors applied separately. Irrigation increased the oil and reduced the protein content of rape. In irrigation experiments, soil NO3-N plus fertilizer N was positively correlated with yield and protein content and highly negatively correlated with oil content. The separation of irrigation experiments into three soil NO3-N categories showed significant differences in yield, oil and protein response to N for some of the categories. However, these data showed that soil test categories based on increments of less than 30 kg/ha of NO3-N to 60 cm are of doubtful practical significance.

Mass spectrometric investigation on denitrification

Abstract: A quantitative mass spectrometric technique utilizing Ar of air as an internal standard was applied to investigate the denitrification process under air atmosphere in closed containers. The disappe...

Microorganisms and ochre deposits in field drains of ontario

Abstract: The effluents and ochreous deposits in several partly blocked field drains in Ontario were microbiologically and chemically assayed. The effluents contained several million per milliliter of the iron-oxidizing bacterium Gallionella. Sphaerotilus, a sheath-forming bacterium, was also numerous. Both microorganisms were generally encrusted with amorphous ferric iron oxides. They were also found in the ochreous deposits inside the tiles and also in the deposits adjacent to plugged filters surrounding the tiles. The iron-oxidizing bacterium Thiobacillus ferrooxidans was not found. Filamentous structures resembling the iron-oxidizing bacterium Metallogenium were frequently observed but the experimental evidence indicated them to be aggregates of colloidal Fe(OH)3. Calcite, dolomite, quartz and feldspar were common constituents of the effluents and the ochreous deposits. In some cases, one or more of gypsum, plagioclase, chlorite and illite were present. The ochreous deposits were generally high in iron and cont...

TRANSFORMATIONS IN THE Feo/Fed RATIO OF PEDOGENIC IRON OXIDES AFFECTED BY IRON-REDUCING BACTERIA

Abstract: In model experiments under controlled conditions of pH, particle size and amount of glucose, changes in the free Fe oxides (Fed) and acid oxalate soluble Fe (Feo) of six soils were studied after inoculation with iron-reducing, nitrogen-fixing Clostridia. In all soils, the total amount of Fed as well as crystalline Fe (Fed-Feo) decreased immediately and significantly, while Fe(II) in solution increased sigmoidally and was inversely proportional to changes in pH. Feo remained relatively constant throughout the incubation period. As a consequence, the Feo/Fed ratio increased in all samples. At the end of the reduction process, total dissolved Fe(II) correlated with the original Feo content and showed a negative correlation to Fed-Feo. These results are explained by a mechanism in which active non-crystalline iron oxides are reduced in preference to the crystalline forms. The latter are probably transformed and reduced to non-crystalline forms but not until all available active non-crystalline oxides have bee...

Relief and microclimate as related to soil properties

Abstract: This study was undertaken to determine the influence of relief and microclimate on soil properties. Seven sites were chosen at different positions on the north- and south-facing slopes of a moderately rolling till knob. Physical, chemical and mineralogical analyses were conducted to characterize the soils at each of the sites. The vegetation of the area was described and soil temperatures and moisture were monitored at four depths. Redox potential and pH were measured to detect seasonal variations. Data for oxalate and dithionite-extractable iron and aluminum, cation exchange capacity, and X-ray diffraction showed only minor differences among the seven pedons along the slope faces. Soil temperature was higher on the south-facing slope than on the north-facing slope and air temperature was usually higher than soil temperature at the 10-cm depth. Soil moisture regime varied with position in the landscape. The soil on the north-facing slope was generally more moist than the soil on the south-facing slope. Re...

Relationships between copper contents, rates of soil respiration and phosphatase activities of some histosols in an area of southwestern quebec in the summer and the fall

Abstract: Samples from 17 fields of organic soils (Histosols) were collected on the same day between rows of crops in the summer of 1976 from the environs of Ste. Clothilde, Quebec. Thirty-three properties of the soils were examined for possible correlations. The copper contents of the samples were found to have statistically significant negative correlations with their rates of respiration which were measured as carbon lost as CO2 upon incubation at 21 ± 2 °C. The acid phosphatase enzyme contents in these Histosol samples at each of three different levels of soil biochemical activity were also similarly negatively correlated with their copper concentrations. The above results were confirmed almost without exception by the data obtained by similar analysis of seven samples collected from the same area in the fall of 1976 when the fields were bare. The results supported an earlier suggestion of Mathur and Rayment (1977) that copper application (at a few quintals/ha) be investigated as a means of mitigating the miner...

Availability of zinc, copper and nickel to plants grown in sewage-treated soils

Abstract: In a pot experiment with additions of Zn, Cu and Ni to a loam soil (pH, 6.3) at rates up to 480 ppm, sewage sludge eliminated the toxic effect of Cu and reduced the toxic effect of Ni on corn, reduced the concentrations of Zn and Ni in the plants, and reduced the amounts of DTPA-extractable metals and of 0.01 M CaCl2-soluble Zn and Ni in the soil. Lettuce grown with the metals and sludges was more susceptible than corn to the toxic effects of the three metals in the loam soil and to Zn in a clay soil (pH 5.9). In the latter soil, Ni was less toxic to lettuce than to corn. The concentrations of metals were considerably higher in lettuce than in corn. Liming of the clay soil to a pH of 6.5 eliminated the toxic effect of Ni on corn and of Zn and Ni on lettuce and reduced the concentrations of the metals in the plants and the amounts of DTPA-extractable and CaCl2-soluble metals in the soil. The order of magnitude of the DTPA-extractable metals was Cu > Zn > Ni whereas the order for CaCl2-soluble metals was Ni...

Native clay-fixed ammonium content, and the fixation of added ammonium of some soils of eastern canada

Abstract: A study was made of the native clay-fixed NH4+ of some typical soils of Eastern Canada. Usually the amount of fixed NH4+ was related to the clay contents and increased down the profile but there were frequent exceptions to both of these generalizations. The amounts found ranged from 12 to 450 μg fixed NH4+–N/g soil. In general, with some cultivated soils, the cropped areas had lower native fixed NH4+ contents than areas that were in sod. The capacity to fix added NH4+ was usually low in the sandy soils and in general the B and C horizons fixed more NH4+ than the A horizons. For the soils that did fix NH4+, a larger amount but lower percentage was fixed as the amount of added NH4+ was increased. The amount of water in which the NH4+ was added had a slight effect on the percentage fixed, being a little lower as the amount of water was increased. The cultivated New Brunswick surface soils had low NH4+ fixing capacities. Analysis of the clay mineralogy of some soils showed a fairly close relationship between ...

Soil respiration in a mixed grassland ecosystem

Abstract: Soil respiration was measured in a mixed grassland ecosystem in southwestern Saskatchewan during 1970–72, using an infrared gas-analysis system. The site, on heavy-clay soil, was dominated by Agropyron dasystachyum and A. smithii. Soil respiration reached peak values (about 200 mg m−2h−1) during late June or early July. Rates earlier and later were limited primarily by low temperatures and soil water stress. A multiple regression analysis revealed that up to 74% of the variation in soil respiration could be explained by the variables: soil temperature, soil moisture and precipitation. The strong influence of precipitation suggests that wetting of the litter layer and dead vegetation might exert an important control over decomposition in this grassland.

Organic nitrogen distribution in selected peats and peat fractions

Abstract: The nitrogenous products formed by 6 N HCl hydrolysis of a variety of peats including a cultivated mesic profile, a virgin humic profile, a sedge, a woody and a sphagnum fibric peat were studied. Peat fractions separated according to particle size, woody and herbaceous materials isolated from a peat sample, and Typha and Carex plants growing on peat soils were also analyzed. Of the two profiles examined, the cultivated mesic peat showed significant quantitative changes in the content of individual amino acids throughout the profile. Also the amino sugar and amino acid N increased to a maximum, then decreased. On the other hand, the virgin humic peat profile exhibited random variations in the content of the individual amino acids and in the amount of amino acid N. Of the other peats examined, the fibric sphagnum had the highest percentage of amino acid N. Among the separates, the 100- to 200-mesh material had the highest proportion of amino acid N. The amino acid composition of the plant remains from the p...

Effects of manures, ammonium nitrate and s-coated urea on yield and uptake of n by corn and on subsequent inorganic n levels in soils in southern quebec

Abstract: Effects of added N in the form of ammonium nitrate, S-coated urea, solid cow manure, liquid hog manure, and liquid hog manure plus straw on yield and N uptake of corn (Zea mays L.) were determined in 1971. Residual effects of the fertilizers were measured in 1972. Levels of added N were 150 kg/ha, on three soils varying in texture. In 1971, highest yield and N uptake was found using ammonium nitrate, followed by S-coated urea. The manures were not different than the control, and the average values with liquid manure plus straw were generally lowest. Ammonium nitrate treatments had the lowest mineral N levels in the soil profile in September. Thus, ammonium nitrate was considered to have the lowest pollution potential, assuming that fall-accumulated inorganic soil N was a hazard for pollution of groundwater.

MICROMORPHOLOGICAL EVIDENCE OF ILLUVIAL CLAY IN HORIZONS DESIGNATED Bt IN THE FIELD

Abstract: Semi-quantitative counts of areas of oriented, apparently illuvial clay in thin sections of B horizons showed that less than half of the 44 horizons designated Bt in the field had at least 1% apparently illuvial clay, and the counts for more than 1/3 was 0.2% or less. Many of the horizons that did not meet the micromorphological criteria of a Bt (at least 1% illuvial clay) contained much more clay than the associated Ae horizon and a higher proportion of fine clay than the associated C. Most of the soils having Bt horizons with more than 1% apparently illuvial clay were soils of humid to sub-humid regions, Luvisolic soils and Black or Dark Gray subgroups of Chernozemic or Solonetzic soils; none were Brown or Dark Brown Chernozemic or Solonetzic soils. Comparisons of counts of apparently illuvial clay in thin sections by four operators showed that compatibility of results varied among samples and that prior consultation resulted in an increased degree of agreement. Problems of distinguishing illuvial clay ...

Barley response to phosphorus from phospholipids and nucleic acids

Abstract: Barley responses in a phosphate-deficient soil to 50 μg P/g soil showed DNA and KH2PO4 similarly efficient at increasing dry matter and P content per unit biomass. Phosphatidylcholine increased P c...

Site characteristics, morphology and physical properties of selected ortstein soils from the maritime provinces

Abstract: Ortstein horizons at two sites in the Maritime Provinces were found to be strongly developed and continuous in poorly drained locations in the observation trenches, and intermittent at well drained locations. Roots did not penetrate the ortstein horizons but most ortstein clods were permeable to water, with saturated hydraulic conductivities ranging from about 0.1 to 31 cm/h. The unconfined compression strength of dry or moist ortstein clods usually exceeded 5 kg/cm2 and this is suggested as a limit to aid in separating weakly cemented materials from ortstein. The general environment of ortstein and its significance as related to land use are discussed.

Effects of nitrogen source, method of placement and soil type on seedling emergence and barley crop yields

Abstract: An inverse correlation between seedling damage caused by urea drilled with the seed and soil cation exchange capacity was determined in eight field trials conducted on soils with a wide range in cation exchange capacity and pH. Seedling damage increased with increasing rates of urea nitrogen and seriously affected potential grain yields of Conquest barley (Hordeum vulgare L.). Drilled NH4NO3 caused greater grain yield increases than drilled urea in a manner inversely related to the seedling damage caused by urea. Drilled NH4NO3 caused greater yield increases than broadcast and incorporated NH4NO3 at 22.4 and 44.8 kg/ha over the 2-yr period. The NH4NO3 broadcast and incorporated in the soil caused greater yield increases than urea similarly applied. The magnitude of the difference was related to soil cation exchange capacity and pH which jointly influenced the quantity of NH3 volatilized.

Reorganization of soil materials in the genesis of an acid luvisolic soil of the peace river region, alberta

Abstract: The Boundary soil is described as a "podzolic complex" developed from acidic parent material derived from shale of Cretaceous age. The soil has low pH and base saturation values that result from the formation of sulfates, primarily natrojarosite, and its subsequent alteration in the soil solum to various forms of hydrated iron oxides. The iron oxides impart to the B horizon reddish hues of high chroma. The acidic condition has resulted in weathering of clay-sized mica to vermiculite, especially in the upper part of the solum. Results from micromorphological and analytical studies also show that considerable clay and, to a much lesser extent, organically combined iron and aluminum have been leached from the upper solum and deposited throughout the lower solum and C horizon. Reorganization of clay through illuviation appears to extend well into the C horizon. Microscopic investigations show strong reorganization of materials in the upper solum to a granic–granoidic fabric by biological processes and in the ...

Surface application of gypsum and ammonium nitrate for amelioration of a black solonetz soil

Abstract: Heavy rates of gypsum surface applied alone and in combination with ammonium nitrate to a Black Solonetz under dryland conditions favorably affected the chemical properties of the Ap and Bnt horizons and increased water penetration into the Bnt. Gypsum alone was equally as effective in ameliorating the soil as the combined treatment.

Nitrogen and chloride distribution and balance in a clay loam soil

Abstract: In field experiments conducted on a poorly drained clay loam soil from 1974 to 1976, inclusive, 21–44% of added chloride was lost from the 0- to 75-cm layer by the end of September, whereas NO3−-N increased in this layer in both the control and fertilized plots. Mineralization during the summer masked any N losses by leaching or denitrification. N losses were highest between late fall and early spring. NO3−-N and chloride tended to show similar distribution patterns in the profile but not necessarily similar leaching losses, since simultaneous denitrification occurred in an adjacent experimental site. Chloride distribution in the profile and leaching losses did not appear to coincide with expectations of typical transport theory, since losses were associated with diffuse bulges near the surface instead of distinct peaks or slugs of chloride moving steadily downward.

Degradation of hydrocarbon sludges in the soil

Abstract: Hydrocarbon residues from crude oil storage tanks were incorporated into field plots of a Red River Clay soil. The oil content immediately after application was 1.45% based on the weight of air-dried soil. The plots were sampled after application and after 106, 476 and 833 days. Hydrocarbons were extracted from samples with tetrahydrofuran at room temperature and fractionated by a combination of solvent extraction and column chromatography into the following fractions: (1) saturates, (2) monoaromatics, (3) diaromatics, (4) polyaromatics and polar compounds and (5) high molecular weight material such as asphaltenes. Fractions (1) to (4) were examined by gas–liquid chromatography. The results showed that 50.4% of the total applied residues were degraded within 833 days. The individual fractions were degraded to varying extents: (1) 54.6%, (2) 50.0%, (3) 57.1%, (4) 44.4% and (5) 11.1%. The alkanes in fraction (1) degraded to low levels during the first 106 day s.

Metals in soils of some agricultural watersheds in ontario

Abstract: The total concentrations of seven metals (Cr, Zn, Cu, Ni, Pb, Cd and Hg) and two non-metals (As and Se) in the Ap horizons of 26 soils from six agricultural watersheds in Southwestern Ontario were consistent with normal background levels of agricultural soils. The concentrations of Se, Hg, Pb and Zn were higher in the Ap than in the C horizon. In the Ap horizon, the metals but not the non-metals were usually correlated significantly with the amounts of organic matter, clay, Al and Fe but the magnitude of the coefficients (r) was not high. There was an enrichment of Cu and Ni along with clay, Al and Fe in the B horizons of the soils. The concentrations of DTPA-extractable Zn, Cu, Ni, Pb and Cd were considerably higher in the Ap than in the C horizon of the soils. Furthermore, of the total concentrations of these five metals present, DTPA removed a larger proportion from the Ap than from the lower horizons.

Analyse par dilution isotopique de la fertilite et de la fertilisation phosphorique de quelques sols du quebec

Abstract: Analysis of available soil phosphate by isotopic dilution method, observed as kinetics between 1 and 100 min after the injection of 32PO43− in the soil–solution system, allows the measure of three kinetics parameters: r1/R, r1 is the radioactivity remaining in the solution after 1 min of isotopic exchange and R the total radioactivity injected in the system, n the slope of the straight line which, in logarithmic coordinates, gives the decrease of the radioactivity remaining in the solution versus time, and p the phosphate-ions concentration in the solution. Analysis performed in this manner on some Canadian typical agricultural soils shows that localization of phosphatic fertilizers is absolutely necessary in some cases, the soil fixation capacity for phosphate ions being too large. In these soils a homogeneous increase of available soil phosphate is economically impossible.

Seasonal patterns of denitrification and leaf nitrate reductase activity in a corn field

Abstract: Denitrification in soil around the bases of corn stalks, determined by the "acetylene blockage technique," exhibited a general trend of decline from June to September. Leaf nitrate reductase activity, determined by an in vivo assay procedure, was low in June and July, and then exhibited a pronounced maximum at the time of tasselling.

Effects of soil erosion on yield of corn.

Abstract: Historically, special or intensive soil conservation methods have been recommended to control soil and water losses and maintain crop yields. However, farmers have not adopted these recommendations due to the high-energy input and the resulting reduction in high-value crop acreage. Crop yields do not appear to justify the cost of erosion control. Over a 10-yr period at Guelph, corn grown one year in a 4-yr rotation of corn, oats, hay and hay on runoff plots yielded 200–400 kg/ha above the average annual yield of corn grown continuously. Soil erosion losses averaged < 0.01 cm/yr from corn in rotation compared with 0.125 cm/yr from continuous corn. Under uniform cropping at the end of the period, corn grain yields did not reflect differences in soil erosion. In a subsequent 6-yr period, continuous corn with stover left on the soil surface and no tillage controlled soil erosion to < 0.01 cm/yr. The greatest soil and nutrient losses (0.36 cm soil, 87 kg N/ha and 59 kg P/ha/yr) occurred when stover was removed...

A portable sampler for perennially frozen stone-free soils

Abstract: A simple, hand-operated tool was developed, using seamless steel tubing. The sampler has been used to core and sample perennially frozen stone-free, fine-grained soils, peat, and ice.