Showing papers in "Canadian Journal of Soil Science in 1977"

Effects of initial chemical composition on decomposition of roots of three grass species

Abstract: Grass root production is a major source of C entering Chernozemic soils. The influence of the initial chemical composition of the roots of three grass species on decomposition was studied in a laboratory incubation experiment. Roots of Stipa comata Trin. and Rupr., Stipa spartea Trin. var. curtiseta Hitchc., and Festuca scabrella Torr. were incubated at 28 C for 47 wk. Carbon dioxide production and percent loss of carbohydrate were inversely related to [(C:N) (% lignin)] (% carbohydrate−½). Percent loss of lignin, however, was directly proportional to this factor. This relationship was also found to fit data in the earlier literature. Decomposition rate appeared to be slower in the laboratory in the absence of soil than has been reported for decomposition rates in field soils. The data are discussed with reference to the dynamics of plant residues and organic matter in soil systems. It is postulated that the effect of soil in controlling decomposition may be as great as the effect of the substrate.

Effects of fertilizer n and soil moisture on growth, n content, and moisture use by spring wheat

Abstract: The accumulation of dry matter and N in wheat (T. aestivum L. cv. Manitou) grown on stubble land in lysimeters at two moisture levels and seven rates of N was measured and related to moisture use at five stages of development. In the irrigated lysimeters, leaf areas, plant dry matter and N content increased with fertilizer N. In the dry lysimeters, low rainfall between the shot blade and anthesis stages produced moisture stress; consequently, dry matter production and leaf area were depressed and plants lost significant amounts of N at rates of N > 61.5 kg/ha. Rain in the latter part of the growing season permitted the plants to recover and by maturity plant dry matter and N content increased with N. Approximately twice as much plant dry matter was produced in the wet treatment as in the dry for all levels of N. Total evapotranspiration (ET) increased with applied N in the wet treatment, and was much higher than in the dry treatment. It was not affected by applied N in the dry lysimeters. Root weight incr...

Effects of soil acidity on rhizobia numbers, nodulation and nitrogen fixation by alfalfa and red clover

Abstract: The effects of soil acidity on nitrogen fixation by alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were investigated in field experiments at 28 locations, and in greenhouse exp...

Effects of fertilizer n and soil moisture on yield, yield components, protein content and n accumulation in the aboveground parts of spring wheat

Abstract: The accumulation of aboveground dry matter (DM) and nitrogen (N) by spring wheat (T. aestivum L. cv. Manitou) grown on stubble land in lysimeters at two moisture levels (irrigation and natural rainfall) and seven rates of N was measured at five sampling dates. With irrigation, DM increased exponentially with time and N fertilization. This also occurred on dryland except between shot blade and anthesis when DM accumulated more slowly and plants lost 20% of their N at application rates > 61.5 kg N/ha. Rainfall after anthesis increased grain yields of dryland crops fertilized with > 61.5 kg N/ha more than those receiving less N because the former plants still had residual fertilizer N available to them. Grain yield response to N fertility followed the law of diminishing returns on irrigated land, but on dryland the relationship fitted a logarithmic growth curve. Grain yield when neither water nor N was added was 1,600 kg/ha; it increased by 71, 47 and 300% when water, 164 kg N/ha, and water plus 164 kg N/ha,...

Comparisons of four methods for determination of degree of peat humification (decomposition) with emphasis on the von post method

Abstract: The degree of decomposition (humification) of 10 peats, ranging from undecomposed to completely decomposed, was determined by the following methods: (1) von Post’s method using 10 classes of humification, (2) pyrophosphate-soluble organic matter determination using an index derived from Munsell color charts, (3) unrubbed fiber content in percent of total, (4) rubbed fiber content in percent of total. All four methods provided reliable and useful information. The von Post method requires no instrumentation and is therefore most suitable for field use. It is the least time-consuming and the cheapest of the four methods. The pyrophosphate method is best suited to use in a laboratory. It does not always readily differentiate grades of well humified and completely humified peats. Both methods of determining fiber content require instrumentation and a steady, running stream of water. The rubbed fiber content more accurately characterizes the amounts of undecomposed fiber in peat. In the range of humic peats the...

Changes in decomposition rate, microbial population and carbohydrate content of an acid peat bog after liming and reclamation

Abstract: After 8 mo of decomposition, under laboratory conditions, the unlimed surface sample (0–15 cm, pH 3.8) of an acid peat bog contained about five times as many microbes as the unlimed subsurface material (15–41 cm, pH 4.1). As measured by CO2-C released and numbers of bacteria and actinomycetes, lime had greater effects on the microbial activity of the surface material. Nitrifying bacteria were present and needed lime to become active. Fungal numbers decreased with lime and only 12 genera were found. Temperature had little effect, whereas pH had a marked effect on the distribution of fungal genera. Fusarium oxysporum, Cephalosporium acremonium and a frequently isolated nematode-destroying fungus Harposporium lilliputianum were found only at pH 7.5 and thus appeared to be alien fungi that responded well to an environment of high pH and cultivation. Before incubation, the unlimed lower sample was higher in carbon, nitrogen and methoxyl but lower in hexose, pentose and uronic acid than the unlimed upper sample...

Fiber content, particle-size distribution and some related properties of four peat materials in eastern canada

Abstract: The effects of dispersion and sieving on the determination of fiber content was studied using four peat materials selected for their range of properties. In addition, a method of particle-size anal...

Heavy metals in cultivated soils and in cereal crops in alberta

Abstract: The content of cadmium, cobalt, copper, mercury, manganese, nickel, strontium, lead and zinc in several agricultural soils in Alberta was investigated. The abundances of these heavy metals were found to be low and represent levels naturally present in uncontaminated soils. Both pedogenesis and nature of parent material influenced the levels of heavy metals in surface soil horizons. On a local scale, drainage and groundwater effects contributed significantly to heavy metal redistribution in soil. Levels of heavy metals were also determined in seeds and straw of cereal grain crops grown on the soils of this study. Vegetative samples generally contained low amounts of heavy metals and for some of the physiologically essential elements (Cu, Mn, Zn), amounts in the plant material were at or near deficiency levels. Amounts of cadmium, mercury and lead were generally significantly higher in straw than in respective seed samples.

Mnii-fulvic acid complexing equilibrium measurements by electron spin resonance spectrometry

Abstract: Electron spin resonance (ESR) spectrometry was used to determine weighted average equilibrium functions for water-soluble complexes formed between fulvic acid and divalent manganese. values ranged from 0.2 × 10−2 (at pH 6.15) to 0.5 × 10−3 (at pH 6.45) and were in excellent agreement with values determined previously for Mn–fulvic acid complexes by an ion-exchange method. The ESR method was found to be more sensitive, convenient and faster than the ion exchange procedure. From the data presented in this and in earlier publications it appears that MnII is bound simultaneously electrostatically and by hydrogen-bonding as Mn(OH2)62+ to fulvic acid donor groups in outer sphere complexing sites. These complexes are likely to be unsymmetrical.

A comparison of lime requirement methods for acid canadian soils

Abstract: Several laboratory methods for estimating lime requirements of acid soils were compared using 24 soils from Alberta and northeastern British Columbia and 15 from elsewhere in Canada. The Peech, Schofield, Woodruff and SMP (Shoemaker et al. 1971) buffer methods were equally well correlated with lime requirements for raising soil pH to 5.5 or 6, which in turn were highly correlated with the amounts of soluble and exchangeable Al and organic matter in the soils. The SMP buffer method is recommended for use as the diagnostic index of lime requirement to achieve pH 5.5 or 6 because of its speed and simplicity. A refinement is suggested for Alberta and northeastern B.C. soils on the basis that lime need not be added to achieve pH 5.5 but should be added to reduce Al below the toxic level for sensitive crops. The lime requirements to reduce Al in those soils were highly correlated with the amounts of 0.02 M CaCl2-soluble Al they contained and it is recommended that the 0.02 M CaCl2-soluble AI be used as the diag...

Etude de la perturbation des horizons du sol par un arbre qui se renverse et de son impact sur la pedogenese

Abstract: In a work on soil variability within a given site, a detailed study was undertaken to determine the perturbation on soil horizons by a windfall. A representative windfall of the most frequent type was studied. The arrangement of soil horizons was described for this type of windfall qualified as normal. The mechanisms of this new arrangement of soil horizons are also described. Other types of windfall are briefly described and compared with the normal one. The importance of this phenomenon is discussed in view of the variations in soil properties between (bordering) profiles and its effect to soil development in a given ecosystem.

Uptake of radioisotopes by vegetation growing on uranium tailings

Abstract: An investigation was carried out on the uptake of several long-lived radioisotopes by grasses growing on uranium tailings. Field plots of creeping red fescue (Festuca rubra L.), reed canary grass (Phalaris arundinacea L.), redtop (Agrostis alba L.) and climax timothy (Phleum pratensis L.) which have been growing for 4 yr were sampled in this study. The tailings and the plant tissue were analyzed for uranium, thorium, radium-226, lead-210 and polonium-210. Sedimentation within the tailings area gave two zones: one of sands and one of slimes. The slimes contained significantly more radium-226, lead-210 and polonium-210 than the sands. There was no difference in uptake behavior by grasses growing in the sands and those growing in the slimes. Creeping red fescue (Festuca rubra L.) showed an anomalous uptake of lead-210, but other than this, all four grass species showed similar uptake behavior. Only uranium and radium-226 were significantly higher in the grasses from the tailings than the control.

An assessment of the soil acidity problem in alberta and northeastern british columbia

Abstract: The amount of cultivated acid soil in Alberta and northeastern British Columbia was estimated from pH values of farm samples analyzed by the Alberta Soil Testing Laboratory, and the effect of soil acidity on crops was assessed from field experiments on 28 typical acid soils. The field experiments consisted of two cultivars of barley (Hordeum vulgare L.) and one cultivar each of rapeseed (Brassica campestris L.), red clover (Trifolium pratense L.) and alfalfa (Medicago sativa L.) grown with and without lime for 2 yr. There are about 30,000 ha of soils with a pH of 5.0 or less where soil acidity seriously restricts yields of all four crop species. There are approximately 300,000 ha with a soil pH of 5.1–5.5 where liming will on the average increase yields of alfalfa by 100%, yields of barley by 10–15%, and yields of rapeseed and red clover by 5–10%. There are a further 1,600,000 ha where soil pH ranges from 5.6 to 6.0 and liming will increase yields of alfalfa by approximately 50% and yields of barley, rape...

SOIL pH MEASUREMENT AND ITS APPLICATION TO ORGANIC SOILS

Abstract: The average soil pH of 10 organic soils was significantly influenced by drying and the salt concentration of the suspending media. Accordingly, mean soil pH of field-moist and oven-dried soils was pH 5.0 and 4.5, 4.1 and 3.9, and 3.8 and 3.6 for soils suspended in water, 0.015 M CaCl2 and 1 M KCl. A significant treatment–soil interaction indicated that the soils responded differently to the treatments. No junction potentials were found when the ionic strength of the solution was 0.01 M CaCl2 equivalent or greater. Milli-equivalents exchangeable hydrogen (−0.984**), percent hydrogen saturation (−0.966**) milli-equivalents extractable bases (0.937**) and percent base saturation (0.957**) were more closely correlated with 1 M KCl pH values than with values in the other media. Liming influenced soil pH significantly on all field sites and within 8 h after application on two field sites. The influence of liming on soil pH tended to diminish the year after applications were made. Measured soil pH variability am...

Effects of different seeding machines on spring wheat production under various conditions of stubble residue and soil compaction in no-till rotations

Abstract: The effectiveness of several commercial seeders and an experimental triple-disc press drill was assessed on a silt loam soil at Lethbridge over a 7-yr period on fields receiving chemical weed control instead of tillage between crops. The double- and triple-disc press drills generally failed to penetrate untilled surfaces adequately when soil bulk density in the upper 5 cm exceeded about 1.2 g/cm3 or when the quantity of surface residue exceeded about 3,700 kg/ha. Hoe openers penetrated the soil but failed to clear heavy residues when stubble and straw lengths were excessive (> 25 cm). In 2 of the 7 yr, yields of spring wheat (Triticum aestivum L.) on small plots seeded with the double- and triple-disc drills were superior to those seeded with the wide-spaced hoe drill (1,159 vs. 721 kg/ha in 1969, and 667 vs. 573 kg/ha in 1973). Yield differences were primarily due to wild oats (Avena fatua L.), which germinated because of the tillage action of hoe openers, in ridge areas between rows and which, despite t...

Effects of high rates of chemical fertilizer and barnyard manure on yield and moisture use of six successive barley crops grown on three gray luvisolic soils

Abstract: High rates of chemical fertilizer and barnyard manure were applied separately and together to barley (Hordeum vulgare L.) grown on three Gray Luvisolic soils for 6 successive yr. The fertilizers were applied annually with the N–P–K rates greater than 110–50–40 kg/ha. The manure was applied initially at 134 tonnes/ha and at 150 tonnes/ha before the fifth crop. Moisture use by the barley was measured for the last five crops. Average yields of barley were 1,530, 3,270 and 3,950 kg/ha for the nil, manure and fertilizer treatments, respectively. The manure + fertilizer treatment gave little or no further increase in yield over the fertilizer treatment. Efficiency of moisture use was generally more than doubled by the fertilizer and fertilizer + manure treatments. These treatments also greatly increased the use of soil moisture reserves, the greatest increase being for Beryl fine sandy loam, followed by Hazelmere loam and the least for Nampa clay loam. Soil moisture reserves at harvest time were depleted more u...

Influence of trace element fertilization on the decomposition rate and phosphatase activity of a mesic fibrisol

Abstract: Determinations were made of the relative decomposition rates of samples taken from pasture plots on a blanket bog which had been drained, limed and variously fertilized for 8 yr. Under all three temperature regimes of incubations employed in the laboratory, samples of plots receiving fritted trace elements (FTE) and NPK fertilizers lost significantly less (22–29%) carbon than those of plots treated annually only with NPK. Subsequent measurements of bulk densities of the field plots confirmed the mitigating effect of FTE applications on biological degradation and humification of this organic soil. Chemical analyses and preliminary trials indicated that the increased Cu levels in the FTE-treated soils, although obviously not biocidal, may have inactivated some extracellular degradative enzymes in the soil at an accelerated rate, thus slowing degradation. Acid phosphatase activity was studied as an example. Indeed, this activity, both before and after laboratory incubation, was significantly lower in the FTE...

Atrazine residues in tile-drain-water from corn plots as affected by cropping practices and fertility levels

Abstract: The herbicide atrazine was applied pre-emergence to corn plots which were drained by separate drains (average depth 70 cm). Water samples were collected from the tile outlets, extracted with chloroform, and the atrazine content determined by gas chromatography. The discharge of atrazine residues monitored over a 4-yr period ranged from 2.75 to 8.69 g/ha annually. The concentration varied between 0.5 and 3.50 μg/liter of water. Losses of atrazine were greater from plots under a continuous corn crop and a high fertility level than from plots under rotation corn and low fertility.

Pedogenesis in a subarctic iron-rich environment: schefferville, quebec

Abstract: More than 50 soil profiles have been examined and analyzed in the Schefferville area, and 5 are studied in detail. Leaching, sesquioxide translocation and surficial organic matter accumulation are the main pedogenic processes. The soils are acid, and leaching is generally confined to a depth of 60 cm. Morphological evidence of podzolization occurs in well drained soils, and analytical data reveal the translocation of Fe, Al and organic matter in the profile. Organic soils develop at sites which are permanently waterlogged and morphological and chemical evidence of gleying occurs in soils that are waterlogged for most of the summer. In soils that are waterlogged for only part of the summer, there is morphological and chemical evidence of podzolization and gleying, as shown by translocation of Fe, Al, Mn and organic matter and by mottling. Because of the reddish-brown parent materials, morphological evidence of soil development is weaker than in soils developed from deposits on the Canadian Shield. Clay min...

Organic compounds formed by the hydrogen peroxide xidation of soils

Abstract: Two samples taken from tropical volcanic surface soils and one sample from a Canadian Podzol subsurface soil were oxidized with H2O2 under conditions usually employed for the removal of organic matter from soils prior to mineralogical analyses. Between 65 and 82% of the C but only between 23 and 36% of the N in the initial organic matter in the three soils was oxidized to volatile and water-soluble products. Among the latter, small amounts of about 40 different aliphatic and aromatic compounds were identified, most of which were phenolic. Extraction with organic solvents removed n-alkanes and n-fatty acids from H2O2-resistant organic matter, but most of the latter consisted of humic substances strongly bonded to or absorbed on inorganic soil constituents. H2O2-resistant fractions accounted in the case of two soils, initially rich in organic matter, for 12.0 and 7.5% of the air-dry weights of peroxidized soils. The presence of such substantial amounts of H2O2-resistant organic matter may interfere with the...

Residual effects of phosphorus fertilizer. i. for wheat grown on four chernozemic soil types in saskatchewan and manitoba

Abstract: The effects of single applications of 100, 200, and 400 kg/ha of P were measured under field conditions on Chernozemic soils in Manitoba and Saskatchewan for 8 yr. All applications of P increased the yield of wheat and increased the amount of available P in the soil. The addition of P with the seed did not increase the yield on plots that had received 100 kg/ha of P or more, except in 2 yr at one of the four test locations. On extremely P-deficient soils in Manitoba, 21% of the broadcast P (applied at 100 kg P/ha) was recovered by grain in 8 yr; the percent recovered was lower from the 200 and 400 kg P/ha at all sites (15 and 9%, respectively) but the amount of available P remaining in the soil was greater. Single large applications of 100 kg/ha of P were shown to be effective over the 8-yr period. Higher rates of application showed little advantage over 100 kg P/ha in the 8 yr but would probably remain effective for longer periods.

Acidification of a luvisolic soil caused by low-rate, long-term applications of fertilizers and its effects on growth of alfalfa

Abstract: Soil samples collected from the Breton plots, which had received various treatments and had been cropped to a 5-yr rotation of cereals and forages over a 40-yr period, were analyzed to determine the effects of the treatments on soil acidity. Treatments included applications of fertilizers at low rates, infrequent applications of lime, applications of manure and applications of various combinations of these. Those receiving NS, NPS and NPKS were more acidic than the check plots and those receiving lime, lime + NPKS and P as 0–45–0 were less acidic. Plots treated with manure or manure + NPKS were not acidified. Since 1967, a brome–alfalfa mixture has been seeded and on the more acidic plots the established stand contained less than 30% alfalfa as compared to greater than 70% in the lime or P (0–45–0) treatments. Liming one half of each plot in each series in 1972 significantly increased the stand and reduced the aluminum content of alfalfa, especially in the more acidic plots. Alfalfa grown on these more ac...

Residual effects of phosphorus fertilizer. ii. for wheat and flax grown on chernozemic soils in manitoba

Abstract: Broadcast applications of 0, 100, 200 and 400 kg P/ha were made on two Chernozemic soils in 1965. The soils were cropped for 8 yr in a continuous wheat-flax rotation. In each year, crops grown on the phosphorus treatments yielded more and had higher phosphorus content than crops grown without added phosphorus. Over 8 yr of cropping, 100 kg P/ha was the most efficient treatment in increasing yield. Yield increases beyond 100 kg P/ha were either not significant or only marginally significant. Wheat used twice as much phosphorus as did flax. Together the two crops used approximately 30, 22 and 14% of the 100, 200 and 400 kg P/ha applied. The NaHCO3-extractable phosphorus level of the 100 kg P/ha treatment after 8 yr of cropping was reduced to about 8 kg P/ha which is considered to be inadequate for crop production. Soils treated with 200 and 400 kg P/ha contained high levels of NaHCO3-extractable P (20–54 kg P/ha) and little response in yield to additional P would be expected in the near future. Annual varia...

Distribution of nitrogen in representative canadian soils

Abstract: Forms of nitrogen in 92 samples were measured in a study designed to determine the similarities and differences in the nitrogen distribution in various horizons of a wide range of Canadian soils. The samples, representing all of the nine soil orders, were chosen from different climate and vegetation zones. Some peat soils were analyzed also. The data were first grouped according to the nitrogen content of the samples, but the amino acid composition of the soil "protein" did not appear to be related to this. The data were then grouped according to LFH, A, B and C horizons and also according to the Ah, Ap, Ae, Bhf, Bh, Bm and Bt layers. Again, few significant differences in the amino acid composition could be found. Data for the average amino acid composition and standard deviations for 92 mineral soils, 6 LFH and 2 ’O’ horizons of these and 18 peat soils were calculated. Since the analytical and sampling errors appear to be relatively small and would not account for all the variation between samples, there...

Field performance of the dew-point hygrometer in studies of soil–root water relations

Abstract: In situ measurements of soil water matric potential and root xylem water potential in a Douglas fir forest using a Wescor HR-33T dew-point microvoltmeter and PT51-10 hygrometers are described. Root xylem water potential measurement required tangential insertion of the hygrometer into the root xylem and sensor protection from plant resins using gypsum powder. Soil water matric potential measurements were compared with matric potentials computed using gravimetric and neutron meter measurements of soil water content and laboratory soil water retention data, while root water potential measurements were compared with measurements made using the pressure chamber method. The comparisons showed agreement to within ± 0.3 bar over an 8-bar range. There was good agreement between soil water matric potentials determined using the dew-point and psychrometric modes of operation of the instrument. The root xylem water potential showed a marked diurnal response to atmospheric demand.

EFFECTS OF ORGANIC MATTER CONTENT ON EXCHANGEABLE Al AND pH-DEPENDENT ACIDITY OF VERY ACID SOILS

Abstract: Twenty-nine soil samples were selected within a field for similar pH (4.60–4.72) but with widely varying organic matter contents (3.5–20.5%). Exchangeable Al decreased while pH-dependent acidity increased with increasing organic matter content. The implication of these relationships for liming practices is discussed.

Amelioration of a brown solodized solonetz soil by a surface application of gypsum plus ammonium nitrate

Abstract: Combined applications of ammonium nitrate (449 kg/ha) and gypsum (4.48 tonnes/ha) were added annually to a bromegrass sod for 4 yr. The soil was a Brown Solodized Solonetz with an exchangeable sodium percentage (ESP) of 17 and 33 in the Ap and Bnt horizons, respectively. The significant effects of the combined applications were to reduce exchangeable Na, increase water infiltration and depth of Ca penetration, and provide small increased yields over that of ammonium nitrate alone. Analysis of columnar peds from the Bnt horizon showed that inped penetration of Ca had occurred at the expense of Na. These studies indicate a synergistic effect, whereby the solubility and penetration of gypsum are enhanced by ammonium nitrate.

Adsorption of dyfonate (o-ethyl-s-phenyl ethylphosphonodithioate) on humic acid

Abstract: The adsorption of Dyfonate (O-ethyl-S-phenyl ethylphosphonodithioate) was studied on humic acid (HA) saturated with various cations (Fe3+, Al3+, Cu2+, Zn2+, Co2+, Mn2+, Ni2+, Ca2+, Mg2+, and H+). The amount of Dyfonate adsorbed was affected by the cation with which the HA was saturated. The adsorption process could be described empirically by a Freundlich-type isotherm. The K and constants of the Freundlich equation decreased and increased, respectively, with increase in temperature. The data suggest a physical type of adsorption.

Radiocarbon dating of organic matter from a cultivated topsoil in eastern canada

Abstract: Radiocarbon dating was used to determine the mean residence time of the organic matter from a Gleysolic Ap horizon of eastern Canada. The total soil organic matter and the fulvic acids dated modern, the humic acids as 1,220 ± 150 yr B.P. and the humin as 180 ± 100 yr B.P. Acid hydrolysis of the total soil organic matter yielded a soluble fraction dating modern and an unhydrolyzed material dating 1,530 ± 110 yr B.P. Acid hydrolysis of this topsoil appears practical to separate the soil organic matter into two fractions of different stability. Fractionation into fulvic, humic acids and humin may help to give information on the dynamics of the soil organic matter by separating the soil into at least three fractions of varying stability.