Showing papers in "Canadian Journal of Soil Science in 1976"

Metals in agricultural soils of ontario. ii.

Abstract: Farm fields (296) in all agricultural areas of Ontario were sampled to a depth of 15 cm and analyzed for 10 metals and one non-metal. Metal additions to soils in the form of pesticides, trace eleme...

CADMIUM IN DIFFERENT PLANT SPECIES AND ITS AVAILABILITY IN SOILS AS INFLUENCED BY ORGANIC MATTER AND ADDITIONS OF LIME, P, Cd AND Zn

Abstract: The Cd concentration in 10 plant species grown in a neutral surface soil (0.65 ppm Cd) varied from 0.18 ppm in potato tubers to 0.99 ppm in soybean roots on a dry matter basis. Addition of 5 ppm Cd...

Natural nitrogen-15 abundance of soil and plant samples

Abstract: Nitrogen isotope analysis of total soil N and soil-derived nitrate for nine selected Chernozemic and Luvisolic Ap horizons showed mean δa15N values based on atmospheric abundance of 8.8. Luvisolic soils were characterized by a relatively low level of the heavier isotope. Isotope enrichment of the total N reached a maximum in the lower B horizon. Subsoil nitrate (180-cm depth) had a δa15N value 1/3 that of the Ap horizon. The δa15N of subsurface soil horizons containing residual fertilizer N were low (−5.2) compared to the surface horizon (7.0). The δa15N of NH4-N in commercial fertilizers is close to that of atmospheric-N whereas the NO3-N has higher values. The data suggest that variations in δ15N abundance between horizons of the same soil, or between different soils, may be of real use in evaluating stresses which have been placed in the nitrogen cycle due to man's activities in the past. Similarly, differences in 15N abundance of soil, legume and air samples may provide an integrated estimation of sym...

Nitrogen transformations in an incubated soil as affected by combinations of moisture content and temperature and adsorption-fixation of ammonium

Abstract: An incubation experiment was conducted on a clay loam soil using a factorial design to study the effects of temperature, water content, and applied NH4+-N on the change of NO3−-N and NH4+-N concent

Effects of temperature and root on denitrification in a soil

Abstract: The effects of temperature on denitrification were studied in a soil system with a root in situ and one without a root. Soil samples of the Ap horizon of a Huron soil were used in the laboratory study. Germinated corn seedlings were planted and grown in cylinders for 84 h. At the end of this time the cylinders were cut horizontally so that the bottom 8.8-cm portion contained one root. Other cylinders were left unplanted. The soil in the cylinders was saturated with 5 ml of distilled water or 5 ml of a KNO3 solution. The rate of denitrification, both in terms of NO3− reduction and nitrogenous gas production, was more rapid in the system containing a root than in the fallowed system. Qualitatively, nitrogenous gases (N2, N2O and NO) were produced by both systems. At 30, 15 and 10 C there were no significant differences in the total quantity of gases produced by both systems. However, at all temperatures the crop system produced the larger quantities of NO, and also accumulated the larger quantities of NO2− ...

Effects of temperature and organic matter on denitrification in soil

Abstract: Aerobic incubation of soil from the Ap horizon of a Huron clay loam to which alfalfa as a carbon source was added resulted in rapid nitrification at 15 and 30 C and an apparent reduction in available carbon for denitrification. Use of the same soil in a subsequent study showed that aerobic incubation temperatures of 5, 10, 15 and 30 C did not influence its denitrification potential but that the level of available carbon probably did. Mean denitrification rates were 0.56, 1.23, 1.89 and at least 5.24 μg NO3−-N/g soil/h at 5, 10, 15 and 30 C, respectively, when carbon availability did not limit denitrification. At these rates, all NO3− applied or produced by nitrification, under normal soil fertility practices, could be denitrified within 1 or 2 days. Where readily available carbon was deficient, rates were 0.04, 0.18, 0.33 and 0.90 μg NO3−-N/g/h at 5, 10, 15 and 30 C, respectively. Reaction kinetics describing denitrification was of zero order when carbon was either available or seriously limiting; it was ...

Soil bacterial changes as affected by growing season weather conditions: a field and laboratory study

Abstract: During the 1972 and 1974 growing season, soil bacteria, actinomycetes, moisture and temperature in the top 15 cm of a Wood Mountain loam were monitored regularly under sheltered and unsheltered summer-fallow and cropped conditions. The 1972 temperatures and rainfall were later simulated in the laboratory and their effects on the bacterial population in the Wood Mountain loam, a Sceptre heavy clay, and a Melfort silty clay loam determined. Multiple regression was used to quantify the relationships between the different microbial populations and several selected environmental variables. Microbial change was generally directly proportional to moisture change, the latter being the main factor influencing response. The effect of moisture change was usually dependent on the temperature and/or the initial moisture content prior to the change. Soil microbial populations increased in response to both increases and decreases in temperature. The inverse relationship with temperature appeared to be the result of the ...

Persistent organic and inorganic pesticide residues in orchard soils and vineyards of southern ontario

Abstract: Soils from apple, cherry and peach orchards and vineyards were collected between 1972 and 1975 for analyses of major metals found in inorganic pesticides and for organochlorine and organophosphorus pesticides. The pattern of pesticide use for fruit production in Ontario between 1892 and 1975 was reviewed for those compounds included in this chemical survey. The use of lead arsenates on apple orchards over the past 70 yr elevated arsenic and lead from background levels (7.4 ppm As and 6.4 ppm Pb) to 121 ppm As and 774 ppm Pb. Accumulations in cherry orchard soils, where a lesser volume was used annually, were considerably lower. Levels in both peach and vineyard soils were only slightly above background contents. Twenty years of recommended use of phenyl mercuric acetate, a scab eradicant, elevated the mercury content in apple orchard soils from 0.08 ppm to 0.29 ppm. Copper salts used as fungicides over the past 80 yr have produced only small elevations in copper content of some orchard soils. In apples th...

Field measurement of hydraulic conductivity with a modified air-entry permeameter

Abstract: The air-entry permeameter procedure for measuring hydraulic conductivity (Bouwer 1966) was modified so that the position of the wetting front was detected during measurement by a fine tensiometer probe. Data obtained by the modified permeameter showed similar magnitude of scatter at each of seven sites on five different soils. Comparisons with data from laboratory determinations on cores (assumed to be representative of the corresponding soil) showed that the permeameter gave reliable values with more consistant precision. The values from the double tube permeameter and the crust method were comparable to air-entry permeameter values. Although further evaluations are desirable, the speed, accuracy, and low water requirement of this permeameter tended to recommend it over other procedures available for measuring the hydraulic conductivity of soils above the water table.

Fractionation of soil and 15n nitrogen to separate the organic and clay interactions of immobilized n

Abstract: Labelled 15N was added to two soils in cylinders in the field, and allowed to equilibrate for two summers of crop growth. The labelled soils were fractionated to provide information on the effect of organic and inorganic colloids on the stabilization of immobilized, 15N. Organic materials removed by 0.5 N NaOH without pretreatment contained more 15N than those extracted by the same reagent following decalcification and removal of sesquioxides with dithionite and HCl. Both extracts had similar amino acid (contents) and similar degrees of hydrolability. A fractionation system using an initial 0.1 M NaOH–0.1 M Na4P2O7 extraction followed by sonication and peptization in H2O yielded a humic acid fraction and a sedimentation fraction (< 0.04 μm) which differed markedly in degree of hydrolyzability, 15N content and amino acid-N content. The N associated with inorganic colloids < 0.04 μm, and that remaining in solution after the removal of larger particles accounted for 50% of the amino acid-N in a clay soil, an...

Some effects of alfalfa, fertilizer and lime on corn yield in rotations on clay soil during a range of seasonal moisture conditions

Abstract: The yields of corn (Zea mays L.) grown in rotation with alfalfa (Medicago sativa L.) and oats (Avena sativa L.) were compared with continuous corn on Brookston clay soil. Yields were measured in the presence and absence of fertilizer, alone or combined with lime, and covered a period of 13 yr, commencing in 1961. The 2-yr alfalfa sod system produced a significant yield increase over continuous corn and, also, over the 1-yr alfalfa sod system. Yields of corn varied widely from season to season, according to moisture conditions, but always responded to alfalfa in the rotation, particularly where no fertilizer had been applied. The effect of 2 yr of alfalfa sod every 4 yr in the cropping system was equivalent to 110 kg N/ha/yr on continuous corn in producing corn yield. Lime application was most beneficial on rotations where fertilizer was not applied and was associated with alfalfa and/or oat rotations.

The nature of mercury in chernozemic and luvisolic soils in alberta

Abstract: Contents of mercury in surface soil horizons of Chernozemic soils from Alberta were considerably lower than contents in respective C horizons. For eluviated soils, highest contents of mercury were found in B horizons, with lowest levels in A horizons. Results for content of mercury in particle-size separates together with profile distribution patterns for the element suggested that a significant portion of the mercury in surface mineral horizons was mobilized to the atmosphere. Pyrolysis studies indicated that the dominant form of mercury in the soils consisted of organically bound compounds.

Sesquioxide-cemented soil horizons in northern quebec: their distribution, properties and genesis

Abstract: Cemented subsoil horizons are observed in soils along the St. Lawrence North Shore, as far north as Esker. Cementation is mostly strongly developed at depths of 30–90 cm in freely drained soils of sand texture containing large amounts of amphibole minerals. The cemented horizons contain generally small quantities of extractable iron, aluminum and organic matter, though larger than their non-cemented counterparts. A slaking experiment indicates that amorphous iron and aluminum are the main cementing agents. Three hypotheses for the genesis of these cemented horizons are examined; it is proposed that iron and aluminum are released in the Ae horizon, translocated in a basically inorganic form, and precipitated in the B horizons as cementing agents. Study of a chronosequence of soils suggests that 5,000–6,000 yr are required for the formation of strong cementation. The new chemical criteria established for the Podzolic Order of the Canadian Classification System work well in these soils.

Digestion procedures for simultaneous automated determination of nh4, p, k, ca and mg in plant material

Abstract: The efficacy of several digestion procedures for mineralizing organic matter from plant tissue was compared, and a rapid and precise method suitable for automated determination of NH4, P, K, Ca and Mg in a single digest was selected. A wet-digestion technique using hydrogen peroxide and perchloric acid as oxidative agents in a sulphuric acid medium was deemed the most advantageous among the tested procedures. Appropriate manifolds were designed to determine the sought plant constituents, present in the digests, by automated instruments. Although, recovered ammonium seemed more accurate and precise with the conventional Kjeldahl procedures, mean recovered ammonium was not significantly higher than the suggested method, when the latter was corrected for oxidized ammonium. Further, significantly larger quantities of K, Ca and Mg were recovered compared to the dry-ashing method, though the differences were small. The suggested procedure was verified with a plant-tissue standard and fortified samples. Further,...

Chemical and plant extractability of metals and plant growth on soils amended with sludge

Abstract: The addition of sludge to a Fox sandy loam (sl), Granby sl and Rideau clay (c) soil increased soil pH, total C, NaHCO3-extractable P, cation exchange capacity and exchangeable Ca. Sludge application increased DTPA-extractable Cd 2 to 5 times, Pb 2 to 3 times, Cu 3 to 7 times and Zn 7 to 31 times. Metal extractability in Granby and Fox sl soils was not greatly changed after 11 mo incubation but extractable Zn, Cu, Pb and Cd were reduced in the clay soil following incubation. Cropping to lettuce reduced the quantity of metal extracted from Fox sl soil and to a lesser extent from Rideau c soil but not from Granby sl soil. Lettuce (Lactuca sativa L.) yields were significantly reduced for the first crop grown on sludge + fertilizer-treated Rideau c and Granby sl soils and for all three harvests from similarly treated Fox sl soil compared to harvests from soils treated with fertilizer only. Yield reduction for the first crop was attributed to a salt effect, as subsequent yields on Rideau c and Granby sl soils w...

Modelling nitrogen processes in soil: mathematical development and relationships

Abstract: A small subsystem model was developed to simulate the major nitrogen flow pathways in an unsaturated soil treated with ammonium sulphate. A nonlinear Freundlich equilibrium model and a Langmuir kinetic model were used to describe mathematically the adsorption–desorption of soluble NH4+ to the exchangeable and clay-fixed phases, respectively. Time dependent, microbial mediated first-order kinetic models were used to quantify the ammonification and nitrification processes. The subsystem model was then used as a research tool to derive ammonification and nitrification rate coefficients for a preceding incubation experiment conducted using different soil moisture contents and temperatures. The model yields reasonably good fits to the observed data. A subsequent regression analysis relating the coefficients to temperature and moisture pointed out the importance of the temperature–water content interaction term in quantifying microbial mediated processes.

Les effets de la mise en culture et de la prairie prolongee sur le carbone, l'azote et la structure de quelques sols du quebec

Abstract: The effects of cultivation (cultivated vs. non-cultivated soils) and the age of cultivated meadows (from 5 to 25 yr) on the evolution of carbon, nitrogen and soil structure were studied on some Quebec soils. The soil series used were Beaurivage, Charlevoix, Greensboro and Kamouraska which are important agricultural soils for Eastern Quebec. The air- and water-stability of soil aggregates were used to characterize the soil structure. As a result of cultivation, the Kamouraska soil lost 33% of the carbon and 8% of the nitrogen originally present in the virgin soil, while the decrease in the water-stable aggregates was 84%. Charlevoix and Greensboro soils showed losses varying from 30 to 35% for carbon and from 21 to 31% for nitrogen while the water-stable aggregates decreased by 50%. Under continuous meadow for 25 yr, the Kamouraska soil showed an increase of up to 36% for carbon and 64% for nitrogen whereas the Beaurivage soil did not show much variation. Such a cultural practice improved the soil structur...

Transformations of nitrogen added as ammonium and manure to soil with a high ammonium-fixing capacity under laboratory conditions

Abstract: Ammonium sulfate, dairy cattle liquid manure and the “liquid" and “solid" fractions from the manure were separately added to 300-g samples of a loam soil at the rate of 250 μg N/g of soil and incubated in the laboratory at 22 C and 60% water-holding capacity. The Brunisolic soil sample used contained 20% clay which was largely vermiculite. Subsamples were removed at intervals for analysis of nitrate, exchangeable and fixed ammonium, Warburg studies of respiration rate and the distribution of organic N. One series of duplicate samples was leached with water three times during the course of the experiment which was over a year. About half of the nitrogen of the manure was in the NH4+ form and the exchangeable N from this as well as that from (NH4)2SO4 was rapidly nitrified (in about 3 wk) in both the leached and unleached series. About 40% of the NH4+-N of the manure and fertilizer was fixed by the clay and this was nitrified more slowly. With the fertilizer-NH4+, the fixed-N was reduced after about a year ...

Effect on microorganisms and persistence of field-applied carbofuran and dyfonate in a humic mesisol

Abstract: Banded and broadcast applications of carbofuran at 4.48 kg a.i. (active ingredient)/ha, and a banded application of Dyfonate at 2.24 kg. a.i./ha were made to field plots on an organic soil on which...

Development of a barley yield equation for central alberta. 1. effects of soil and fertilizer n and p

Abstract: Equations were derived relating yields of barley, grown on previously cropped land, to inputs of fertilizer nitrogen (NA) and phosphorus (PA) and to soil test values for nitrate nitrogen (NS) and extractable phosphorus (PS). The first model, Y = f (NA, PA), fitted to pooled data of 17 site-years, explained about 23% of yield variations. The second model, Y = f (NA, PA, NS, PS), fitted to the same data, explained 36–38%, depending on depth of sampling. When the optimal nitrogen applications obtained from the latter model were compared to the optimal nitrogen applications obtained from the first model applied to the individual site-years, the 30-cm sampling depth was found to be superior to the 15-cm depth; there was no further improvement by sampling to 61 cm. Our results indicated several ways in which the Alberta Soil Testing Laboratory could improve its fertilizer recommendations, namely: basing nitrogen recommendations on samples taken to 30 cm rather than 15 cm, adjusting recommended nitrogen applicat...

Linuron adsorption and the degree of decomposition of peats as measured by rubbed fibre content and pyrophosphate index

Abstract: Determination of the Freundlich adsorption isotherms for linuron with some peats showed that the adsorption coefficient, K, is closely related to the degree of decomposition as measured by the rubbed fibre content and the pyrophosphate index. The K values indicate that adsorption increases with decomposition. The analyses required for the determination of K were facilitated by the use of a column extraction technique.

The uptake of native and applied lead by alfalfa and bromegrass from soil

Abstract: The uptake of native and applied fractions of lead (20 and 100 μg Pb/g soil) by alfalfa and bromegrass was studied in a growth chamber experiment using three soils. The applied soil lead treatments did not affect dry matter (DM) yield but the concentration of lead in the plant tops was found to increase twofold when the amount of lead added to soil was increased fivefold (mean values for both crops 3.8 and 8.7 ppm in the 20 and 100 ppm Pb treatments, respectively). Added sulphur gave significant DM yield response in both crops on all soils but did not significantly alter the lead concentration in the aboveground DM. Lowering the temperatures and reducing the photoperiod to simulate autumn conditions resulted in a significant increase of lead concentration in plants grown on the 100 ppm Pb treatment, which was attributed to the corresponding reduction in the DM yields of the plants. High concentrations of lead (mean 132 ppm) were found in the fine roots of both crops in comparison with lead levels in main ...

The pyritization of basic ferric sulfates in acid sulfate soils: a microbiological interpretation

Abstract: The aim of this investigation was to suggest a mechanism whereby the basic ferric sulfates, which occur in acid sulfate soils as a result of the microbial oxidation of pyrite in the original sedimentary parent material, can be microbiologically transformed back to pyrite when the soils are flooded. Three basic ferric sulfates were tested and it was found that in the presence of lactate and Desulfovibrio desulfuricans, 10 g of each mineral were reduced within 12 wk to mackinawite (FeS). Additional incubation, to a total of 33 wk, resulted in no further sulfidation. However, in the presence of elemental sulfur, the sulfidation process resumed and mackinawite was soon transformed into greigite (Fe3S4) and then, following an aging process of increased temperature and pressure, pyrite (FeS2) was produced. Under simulated flooding conditions of sea water and decomposing seaweed, the sulfates were converted to a black X-ray amorphous sulfide which is known to change to mackinawite and/or greigite. The ability of...

Extractability of added lead in soils using lead-210

Abstract: Four soils of different physical and chemical characteristics were treated with 10 ppm lead in the form of PbCl2 labelled with lead-210 (2.5 mCi/g 207Pb) and subjected to a 7-wk incubation period. The extractability of the added lead was assessed using 12 extractants. Almost complete recovery (93–98%) of the applied lead was obtained with 6 N HNO3. Large amounts of the applied lead could be extracted by chelating agents (DTPA and EDTA). Relatively small amounts were exchangeable with 0.5 M BaCl2 (0.1–4%) and N NH4OAc (1–11%). Proportionally slightly higher amounts were extracted with 2.5% AcOH and 0.5 M NaHCO3. Only traces could be found in the 0.05 M CaCl2 extract.

Effects of agricultural land use on potential sheet erosion losses in southern ontario

Abstract: Potential sheet erosion losses from 13 agricultural watersheds were investigated to assess the effects of agricultural land use on soil erosion levels. The agricultural watersheds, ranging in size from 19 to 54 km2, were representative of the predominant livestock and cropping management systems in the major physiographic and climatic regions of Southern Ontario. Average annual sheet erosion losses were estimated on a field basis using the universal soil loss equation. Rainfall intensity and soil and topographic variability were considered in deriving mean annual soil losses for a range of field crops. Crops yielding the highest annual sheet erosion loss estimates were row crops, such as horticultural cash crops (9.1 ton/ha/yr), beans (7.6 ton/ha/yr), and continuous corn (6.7 ton/ha/yr). Erosion losses from crops in rotations with grasses or legumes (corn, small grains, meadow) and from tobacco were determined to be approximately one half of values obtained for continuous row cropping systems. Lowest shee...

Residues of paraquat and linuron in an organic soil and their uptake by onions, lettuce and carrots

Abstract: Paraquat (1,1′-dimethyl-4,4′-bipyridinium dichloride) and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea] were applied to an organic soil, as spray treatments, at rates of 1.12 and 2.24 kg/ha, and 2.24 and 4.48 kg/ha, respectively. The persistence of the herbicides and their residues in lettuce (foliage), onions (root), and carrots (foliage and root) at harvest time were studied under field conditions. Proportionately more residues persisted in the soil from the higher rates of application of paraquat (2.24 kg/ha) and linuron (4.48 kg/ha). About 83–86% of the initial amounts of paraquat and 59–74% of the linuron remained in the soil 4 mo after application. Furthermore, about 50% of the paraquat was recovered from the treated soil 15 mo after application, whereas only about 20% of the linuron was recovered at the end of the same period. Carrots grown in this soil did not absorb detectable (>0.005 ppm) amounts of linuron, while onions and lettuce grown 12 mo after application absorbed the herbicide ...

Development of a barley yield equation for central alberta. 2. effects of soil moisture stress

Abstract: An equation was derived relating barley yield to inputs of fertilizer nitrogen (NA) and phosphorus (PA), soil test values for nitrate nitrogen (NS) and extractable phosphorus (PS) and moisture stress (W). This model, fitted to pooled data of 17 site-years, explained about 57% of yield variation in an investigation conducted on Chernozemic and Luvisolic soils in central Alberta. To identify days of moisture stress, a daily soil moisture budget was calculated for each site. A moisture stress equation derived from data external to this study was used to estimate a site moisture stress index. The moisture stress equation indicated that barley yield was decreased significantly by stress occurring within three stages of crop development: planting–emergence, emergence–onset of tillering, and jointing–heading. Such an equation should be useful for estimating, at intervals from seeding to heading, what the final yield of barley is likely to be in central Alberta at the end of the season. A yield equation was deriv...