ALBERT

Beschreibung: The use of commercially available porous cup soil water samplers for soil solution extraction was evaluated. Ortho-P, (NO3 + NO2)-N and potassium (K) were adsorbed by the porous cup during extraction of soil water samples, but the retention of (NO3 + NO2)-N was minimal. The screening of NO3− by the cup was not obvious. The retention of ortho-P and K was a function of solution concentration and the time of contact between soil solution and the cup. A rest period between extractions, during which samplers remained in contact with solution at zero tension, appeared to enhance phosphorus sorption capacity of the ceramic cup. Furthermore, phosphorus sorption was reversible in nature. The porous cup subjected to high solution concentration initially, released phosphorus when flushed with soilsolution of low concentration. It is recommended that several consecutive soil water extractions be carried out at high (0.6 bar) tension, using high flow rate porous cups. The sample collected in the last extraction should be used to determine true soil water quality.

Beschreibung: The distribution of lipid S (sulpholipids) in 27 soils was examined in relation to factors which influence its abundance in different soil environments. Lipid S was found in all soils examined, but at levels varying from 1.6 to 291 ppm S. Lipid S content was higher in organic horizons than in mineral horizons, and poorly drained soils had higher lipid S than freely drained soils. Highest levels were observed in poorly drained organic soils. Lipid S accounted for a small proportion of total S (0.5–3.5%) and of total lipid (0.03–1.7%). Lipid S levels were on average three times higher than lipid P. Lipid S was significantly correlated with total S, HI-reducible S and organic C. In a regression analysis, 89% of the variation in soil content of lipid S was accounted for by total lipid and total S contents. The distribution of total lipids confirmed previous reports that higher levels were associated with soils having restricted biological activity.

Beschreibung: A study designed to assess gaseous losses of N as N2O and N2 from soils of conventional till fields seeded to wheat in the Chernozemic soil region of Saskatchewan, together with limited supporting laboratory investigations, has confirmed that for the May-November period losses were in the vicinity of 3 kg N∙ha−1 or less. In contrast, total losses from a summer-fallowed field were approximately 300% higher. Comparisons at one site were made of N losses from a conventionally tilled and zero-tilled Dark Brown Chernozemic soil seeded to wheat; the total losses of N were twice as high for the zero till as the conventional till treatments. The N2O fluxes were shown to be the result of both reductive (denitrification) and oxidative (nitrification) processes and generally, under the conditions of these field experiments, both occurred simultaneously. This experiment also confirmed that C2H2 inhibited nitrification in a manner very similar to N-serve, a well-known nitrification inhibitor.

Beschreibung: The morphological expression of podzolization in four Humo-Ferric Podzols increased in a northerly direction over a distance of approximately 74 km from the north shore of Lake Huron. The transect coincided with changes in both geology and vegetation. All the soils were developed in coarse-textured acid tills whose composition was not significantly different to explain the observed variations in soil morphology. Using quartz as an internal standard, the order of mobility from surface horizons was found to be Mg 〉 Fe = Ca 〉 Na = Al 〉 K 〉 Ti. Pyroxenes, amphiboles, chlorite and albite were the most easily weathered minerals. Protocatechuic, p-coumaric, gentisic and gallic acids were found to be the major phenolic acids in water extracts of soil surface horizons. The content of both phenolic acids and carbohydrates in surface horizons increased as the morphological expression of podzolization increased.

Beschreibung: Two separate field experiments were conducted on several crops to determine the effect of selenium (Se) applied to soils with pH levels between 5.7 and 6.6. Tissue Se levels after a single application of Se and lime, were monitored for up to six cropping years or until the tissue Se fell below 0.1 ppm, the level considered to be necessary for animal nutrition. For applications of 1.12 and 2.24 kg Se/ha, the minimal tissue Se concentration (〉 0.1 ppm) was maintained in barley (Hordeum vulgare L.) for two cropping years, but with a very sharp decrease for the first 3 yr. In the case of timothy (Phleum pratense L.), tissue levels greater than 0.1 ppm were maintained for 3 yr at the higher rate of Se without lime and up to 5 yr at high soil pH levels. At the applied rates of 0.28 and 0.56 kg Se/ha, the tissue Se levels above 0.1 ppm in timothy, red clover (Trifolium pratense L.), and alfalfa (Medicago sativa L.) were maintained for one and two cropping years, respectively. In spite of the sharp decrease in plant tissue Se levels, little decrease in total soil Se was noted at rates of 1.12 and 2.24 kg Se/ha after successive croppings of barley and timothy. Although not always significant, liming, in general, increased the plant Se concentration. The Se concentration (log ppm) for tissues (or depletion of Se availability) in the Se-applied plots decreased linearly for at least the first three cropping seasons.

Beschreibung: Soils cultivated for 60 yr were compared with uncultivated forested soils at 10 sites in Appalachian Quebec. All soils belonged to the Humo-Ferric Podzol Great Group, five sets of comparisons being located on the Ascot soil series and five on the Greensboro. Comparisons were made between corresponding soil horizons, analytical data being derived from the bulking and analysis of six sample cores per horizon. Cultivation increased weight of soil in the solum and in the whole profile of both the Greensboro and the two soil series combined; bulk density was slightly affected. Field capacity, permanent wilting point and available water of the surface and sub-surface layers, in the solum and in the whole profile, were significantly increased by cultivation. The increase of available water was accompanied by a corresponding decrease in gravitational water. The content fine clay was significantly decreased in the surface layer and in the solum, while it was increased significantly in the C horizon by cultivation which also decreased the acidity of the surface and sub-surface in both series. There was a marked increase in organic matter content, but the level of fulvic acid was relatively unaffected by cultivation, indicating that the increased H/F ratio was primarily due to an increase in humic acid. Generally, Al content was not significantly changed, while significant increases in Fe and Mn were observed in the surface and solum of cultivated profiles. A deduction is made that cultivation has regraded podzol profiles into Dystric Brunisol ones which have started to evolve already toward kinds of Luvisolic profiles.

Beschreibung: The variability of forest floor properties over short distances and the number of samples required to achieve desired levels of precision for estimation of property means have received little attention. The importance of the forest floor for forest management is well known and increasingly forest floor characteristics are being used to classify forest sites. Highly variable forest floor properties require more intensive sampling and often have less predictive value for characterization and classification purposes. A study site at Port Hardy was used to characterize forest floors for selected physical and chemical properties. The three sites chosen represented xeric, mesic and hygric positions along a hygrotopic gradient. A stratified random sampling procedure was used to obtain 15 samples at each site. Fifteen samples were adequate to characterize the means at 10% allowable error with a 95% confidence level for total nitrogen, organic carbon, pH and cation exchange capacity. Greater than 15 samples were required for exchangeable bases and forest floor thickness for the same level of accuracy and confidence. Even at 25% allowable error and 90% confidence, 40 samples and 16 samples, respectively, were required for exchangeable Ca and Mg.

Beschreibung: The objectives of this study were to evaluate if zero tillage had significantly altered the distribution of certain soil properties formally developed under the shallow cultivation (conventional tillage) soil management systems used on the Canadian prairies. To this end, concentration gradients of available plant nutrients, microbial biomass and mineralizable C and N, were determined in the Ap soil horizon from four locations representing zero and conventional (shallow) tillage systems of 2-, 4-, 12- and 16-yr duration. No significant change coud be detected in total soil organic C and N between tillages systems. Concentrations of plant-available P and K were slightly increased in the surface 0- to 2-cm depth after 16 yr of zero tillage. Except for the 2-yr tillage site, concentration gradients of potential microbial biomass C and N, and potential net mineralizable C and N were significantly greater in the surface soil under zero tillage in comparison to conventional tillage. The reverse situation was observed at the lower depth. The percentage of soil organic C and N that was in the microbial biomass also reflected the above trends. Accumulation of mineral N and calculated N mineralization potentials were closely correlated to both the initial microbial biomass N and the decrease in size of the latter during mineralization. The possible relationships of tillage induced change and redistribution in potential biological activity to N availability were discussed.

Beschreibung: Experiments were done to characterize the hydrolyzed solutions of aluminum nitrate, aluminum chloride and aluminum sulfate. The hydrolysis of the dilute solutions (10−3M) was accomplished under reflux process at 92 °C. The results showed that anions associated with Al have an effect on hydrolysis of aluminum and the order of ease of hydrolysis for similar concentrations of Al was NO3 〉 Cl 〉 SO4. The average composition of the hydroxyaluminum cation (Aln(OH)m) was calculated as [Formula: see text] and [Formula: see text] for hydrolyzed solutions of Al(NO3)3, AlCl3, and Al2(SO4)3, respectively. The infrared spectra of the hydrolyzed species of aluminum were obtained by a subtraction technique and infrared peaks at 1410 cm−1 and 1085 cm−1 in the AlCl3 system and at 1435 cm−1 and 1070 cm−1 in the Al2(SO4)3 system were assigned to polynuclear hydroxyaluminum species having been formed due to reflux process.

Beschreibung: Organic matter with high C:N ratios accumulated on mineral soil retards cycling of nutrients in semi-mature jack pine (Pinus banksiana Lamb.) ecosystems. To test whether N as ammonium sulfate or as urea stimulates organic matter decomposition, 200 kg N∙ha−1 were applied to mixed L and F horizon material in Warburg respirometer flasks. Soils were incubated at 13 °C and constant 0.3 bar (340%) moisture; O2 consumption was measured as an index of microbial activity. In urea-treated soil, O2 uptake was much higher than with unamended soil over a 7-wk incubation period, and this indicated a marked effect of urea on microbial activity. The fact that ammonium sulfate depressed respiration rates was evidence that stimulation of microbial respiration by urea was not initially related to added N, but rather to an increase in soil-soluble C resulting from soil pH changes during hydrolysis. In the presence of a C source (ethanol), a 5-fold increase in respiration was noted, whereas C and urea together produced a 15-fold increase in activity. These results suggest that readily available energy for microbial growth, rather than N, limits the initial decomposition of L and F materials in this pine stand. Once microbial demand for C is satisfied, a further increase in microbial activity is produced by N addition.

Beschreibung: From the solubility equilibrium data of basic aluminite at three temperatures, the standard free energy change (ΔG°), enthalpy change (ΔH°), and entropy change (ΔS°) were determined as 160.02 kcal∙mole−1, 65.48 kcal∙mole−1 and 317.1 cal∙deg−1]mole−1, respectively. From these values the free energy of formation (ΔGf°) and the heat of formation (ΔHf°) of basic aluminite was also computed and was 1465.25 kcal∙mole−1 and 1682.08 kcal∙mole−1, respectively.

Beschreibung: Current irrigation water criteria for boron (B) are based upon the B concentration of either the irrigation water or the soil saturation extract. The effects of the leaching fraction (LF) and the boron adsorption capacity (BAC) of the soil upon the soil solution concentration have not been considered. The objectives of this paper were (i) to develop a predictive model relating soil solution B concentration at equilibrium to the B concentration in irrigation water and the LF, and (ii) to show how the relationship between the B concentration of the soil solution under field conditions and the B concentration of the soil saturation extract can be modelled. The predictive model, derived from the mass balance concept, indicated that at equilibrium the value of the soil solution B in well-drained soil would be close to that of irrigation water, at the soil surface and will increase with depth with the highest value being near the bottom of the root zone where its magnitude is determined primarily on the degree of leaching. For irrigation water concentrations between 0.5 and 10 mg B/L, the weighted average B concentration of the soil solution in the profile of an alfalfa field would be about 1.9–2.7 times the irrigation water concentration at a LF of 0.1; it would be 1.4–1.9 times for a LF of 0.25; and 1.3–1.5 times for a LF of 0.4. The model of the relationship between soil solution B at field capacity and saturation extract B indicates the importance of the BAC of the soil. Without considering BAC, the ratio between the two would be 2. However, the model indicates that the ratio ranges from 1.0 to 1.8 depending upon the B concentration in the solution and the BAC of the soil. This suggests that the B concentration of the soil saturation extract does not provide a true representation of the soil solution B. In assessing B toxicity, the saturation extract concentration should be converted to the soil solution concentration at the actual water content of the soil.

Beschreibung: Regression and covariance analysis of a 13-yr rotation experiment of corn on Brookston clay soil showed that grain yield of corn could be related to each of nine other plant and soil measurements. Soil compaction as measured by bulk density was negatively associated with the level of leaf K in the plants, as well as available soil moisture. The major part of the yield difference between fertilized continuous corn and fertilized corn following alfalfa could be accounted for by multiple regression of grain yield on leaf N and K nutrient levels, soil compaction and soil moisture. Soil compaction was not affected or modified by fertilizer treatment. Response of corn grain yield to soil conditions, moisture and plant nutrient level appears to vary with rotation and fertilizer input.

Beschreibung: The dynamics of fixation and release of NH4+ in soils were studied using tracer N under field and laboratory conditions. Field data showed that release of fixed NH4+ was relatively slow after an initial moderately fast release. Forty months of field weathering of Bainsville soil left 3.48 kg 15N/ha in the 75-cm profile of the 13.5 kg 15N/ha applied and most (76%) of this recovered 15N was fixed NH4+–N. The relative quantitative importance of recently fixed NH4+ in the various particle size fractions was not in the same order as the native fixed NH4+. The fine silt fraction (2–5 μm) fixed a larger amount (whole soil basis) than the fine clay fraction (

Beschreibung: Cutans that coat and link sand grains in cemented podzolic B horizons (ortstein) of well and poorly drained podzolic soils from Nova Scotia and New Brunswick were described in thin sections and analyzed by energy dispersive spectrometry (EDS). The principal type of cutan was brown and weakly to moderately anisotropic; it included numerous silt and fine sand grains. X-ray spectra showed this type to be composed dominantly of Al and Si with lesser amounts of K and Fe, and minor amounts of P, S, and other elements. The silt and clay particles of these cutans were apparently impregnated with Al, Fe-organic complexes. Another common type of cutan was dark reddish brown, monomorphic and isotropic; it consisted mainly of Al and organic matter as indicated by dominant Al and weak P and S peaks. In a few samples such cutans were composed mainly of Fe and organic matter. Rarer black cutans contained Mn in various proportions. The dominant cementing material of these ortstein horizons was shown to be organic complexes of Al and, less commonly, of Fe. The genesis of soils with ortstein is discussed.

Beschreibung: This study evaluated the relative responses of alfalfa (Medicago sativa L.), peanuts (Arachis hypogaea L.), and soybeans [Glycine max (Merr.)] on two calcareous Ontario soils. The B-horizon of a Pontypool sand (Typic Psammentic Hapludalf) and the Ap-horizon of a Plainfield Fine Sand (Typic Udipsamment) were each cropped to all three species in the greenhouse. Thirty-six treatments comprised factorial combinations of three rates (0, 0.25 and 1.00 μg/g) of B, two rates (0 and 25 μg/g) of Mn, the two soils, and the three crops with three replications. Plants were clipped at soil level at flowering stage, oven-dried to constant weight, and analyzed for nutrient content. Boron and Mn additions significantly increased concentrations of these elements in plant tissue. Boron uptake was significantly higher on the coarser-textured Pontypool soil and toxicity significantly reduced soybean yields on this soil, but alfalfa and peanut yields were unaffected. Peanuts appeared least sensitive to B toxicity and Mn deficiency. Soybeans were most sensitive to B toxicity and alfalfa most sensitive to Mn deficiency. The differences in tolerance to B seem attributable to the relative abilities of the three species to withstand high B concentrations in plant tissue rather than to differences in uptake. Differential susceptibility to Mn deficiency on the other hand seems attributable to relative efficiencies of the crops to extract Mn from Mn-deficient soils. Soil organic matter may have had some ameliorative effect on B toxicity. Yield and nutrient uptake were not significantly affected by B × Mn interactions.

Beschreibung: Soil samples contaminated in the laboratory with a NaCl solution were leached with water after various amendments had been added. With no amendments added, percolation rates were reduced more on a light-textured Dark Brown Chernozemic A than on a medium-textured Black Chernozemic A. Undisturbed B horizon cores showed a smaller decrease in percolation rate than the A horizons, but natural gypsum or carbonates were of no benefit in maintaining percolation through the unamended contaminated subsoils. Percolation generally increased as more Ca-amendment was added to the contaminated A horizons, but rate of (surface-applied) amendment had no effect on the percolation through the B horizon cores. Gypsum mixed into the contaminated soil was much more effective than gypsum applied on the surface; adding NH4NO3 to the gypsum had no effect. The efficiency of incorporated amendments decreased in the order: gypsum 〉 MgSO4 〉 Ca(NO3)2. Surface-applied Ca(NO3)2 was a better amendment than mixed-in Ca(NO3)2. Caching losses decreased in the order: Cl 〉 Na 〉 Mg 〉 Ca 〉 K. Initial losses of Cl, Na, Mg and Ca were faster than expected from the rule of thumb that one pore volume of water reduces the salt content by about one-half. Subsequently, losses were much slower than in the rule of thumb as most of the remaining cations are in exchangeable form.

Beschreibung: Twelve soil profiles, developed on gravelly parent material, have been sampled in the region of Quebec City and analyzed. Six profiles are developed on sandstones and shales whilst the six other profiles are formed on shales and mudstones. The shales, and to a lesser extent the sandstones, weathered readily to produce a large percentage of clay. Because of this, many B horizons with significant pyrophosphate-extractable Fe and Al do not meet the criteria for a Podzol B. The coarser than 2 mm material, which ranges in individual horizons from 14 to 82% in the first group of soils and from 0 to 84% in the second group, cannot be ignored as it contributes up to 69% of the total exchange capacity of the soil and therefore is important for the natural fertility of the soils. The differences between the stability of the gravel in air and in water also explain some of the problems in classifying these soils.

Beschreibung: The salinity tolerance of six annual crop species, wheat, oats, barley, rye, flax and rapeseed, were determined on saline soils that occur north of the Quill Lakes in the northeastern corner of the agricultural area of Saskatchewan. The relative merits of a salt-tolerant grass-legume mixture were also given consideration. The effects of salt stress on spring-sown cultivars became most apparent following exposure to hot, dry summer weather. In contrast, maximum salt tolerance for both winter wheat and winter rye was a function of winterkill. The winterhardiness of both winter annuals was reduced by saline conditions, but winter rye was more adversely affected than winter wheat. Large decreases in seed yield, plant dry weight and height occurred before the effects of increased soil conductivity were expressed for hectoliter weight, 1000-kernel weight, date of maturity, protein content and oil content. Among the spring and winter annual cultivars considered, Bonanza barley and Garry oats demonstrated the greatest salt tolerance. However, where severely saline conditions occurred, mixtures of salt-tolerant perennial grasses and alfalfa proved to be more productive than either barley or oats. The salinity tolerance of all cultivars was greater for years with more favorable growing conditions. It was apparent that stress factors, such as soil salinity, cold, heat, drought, etc., have a cumulative effect in reducing crop performance. This observation emphasizes the importance of minimizing all stress factors when attempting to crop saline soils. Detailed soil analyses indicated that where salts were a problem, the level of salinity was extremely variable, often changing dramatically over short distances. This extreme variability made it difficult to assess the magnitude of the salinity problem. In this regard, crop performance, especially plant height, provided a good indicator for identifying saline areas for purposes of soil testing.

Beschreibung: The Podzolic B horizon of the Calder series sampled in Quebec was incubated at field capacity for 2 yr in the presence of various amounts of P (0–1500 ppm). Total and available P measured after incubation ranged from 179 to 1627 ppm and from 26 to 489 ppm, respectively, following the different P additions. Charge properties were determined using 1 N NH4OAc at pH 4.8 and 7.0, potentiometric titration and ion adsorption techniques. The CEC of the sample measured at pH 4.8 varied from 7.2 to 11.4 meq/100 g, while at pH 7.0 it ranged from 9.1 to 16.3 meq/100 g following the 0- to 1500-ppm P additions. This increase in negative charges was attributed to the progressive lowering of the pHzpc (from 4.30 to 3.35 in NaCl) determined by potentiometric titrations of the P-treated samples and as a result of specific P adsorption. Ion adsorption in 0.01 N NaCl showed a gradual increase in Na+ adsorbed as a function of pH and amount of P added while an opposite trend was observed for Cl− as a function of pH. P added did not seem to change the amount of Cl− adsorbed or compete for adsorption sites; this would rather demonstrate the specificity of these sites for anion adsorption.

Beschreibung: The effects of different tillage methods (normal, chiselling and deep plowing) on chemical characteristics and reclamation of a Duagh, Black Solonetz, soil were evaluated separately and in combination with chemical amendments of lime and gypsum. It was found that within the tillage treatments, deep plowing was the most effective in reducing exchangeable sodium percentage, sodium adsorption ratios and alkalinity potential in most soil layers. Also, deep plowing changed the chemistry of the soil solution thereby improving plant nutrition conditions in the root zone. There was only one significant difference in exchangeable sodium percentage values within the chemical amendments under tillage treatments, namely for the Ap and Bnt horizons of the chiselling treatment where lime and gypsum lowered the ESP. This indicates that chiselling hastened the penetration of the amendments. However, the amended values were not markedly lower than the ESP for the normal tillage treatment without chemical amendments.

Beschreibung: Fluorescence excitation spectra of fulvic acid (FA) and humic acid (HA) were recorded at different pH as well as at different netural salt concentrations. Spectra of both FA and HA exhibited distinct bands at 465 nm, while spectra of FA showed additional bands at 360 nm. Fluorescence intensities decreased with decreasing pH and increasing ionic strength. This is due to decreasing ionization, increasing particle association, and to coiling of macromolecular structures. The fluorescence characteristics of FA and HA were observed to be related to the free radical content, color, and phenolic structures. Our data show that fluorescence excitation spectra can be utilized for differentiating between soil FA and HA.

Beschreibung: The distribution, composition and nature of concretions occurring in some moderately well-drained to poorly drained soils of Saskatchewan were investigated. The soils selected were: Gleyed Humo-Ferric Podzol, Orthic Luvic Gleysol, Orthic Gray Luvisol and Gleyed Gray Luvisol. The concretions range from  15 mm in diameter and are distributed throughout the sola with maximum concentrations of about 8% in Aeg and Bf horizons. The data indicate that the concretions from Gleysolic and Gray Luvisolic soils are markedly higher in Fe, Mn and P than the surrounding soil matrix; concretions from the Podzol are high in Fe but very low in Mn and P. Mn is directly related to the size of concretions whereas Fe and P contents generally increase with decreasing size of concretions. The formation of concretions and their significance in soil genesis are discussed.

Beschreibung: Many measurements of oxygen flux in mineral soils have been reported; however, few such measurements have been made in organic soil. Almost all reported measurements of oxygen flux are at constant applied voltage, despite criticism of this technique, possibly due to the complexity of existing techniques for measuring oxygen flux at effective voltage. Equipment suitable for measuring oxygen flux at applied and effective voltage in organic soil was designed, and simplified techniques were developed and tested. As reported for mineral soils, soil resistance is relatively constant spatially and with depth in individual soils. Limited poisoning of the platinum electrode surface occurred after long periods of time and, contrary to previous assumptions, cannot be detected by erratic readings. Unlike mineral soil, the amperage-voltage slopes are constant over a wide range of organic soils, simplifying the technique for estimating oxygen flux at constant effective volatage. Comparison of simultaneous measurements of oxygen flux at constant and effective voltage indicates that oxygen flux measurements at effective voltage were twice those at applied voltage and strongly correlated (r2 = 0.96, n = 22).

Beschreibung: Twenty-one topsoils, with texture varying from sandy loam to clay and organic matter content ranging from 1.6 to 11.9%, were submitted to compaction and settling at different moisture contents where dry bulk density was determined. Under compaction, the density curve went through a maximum while a minimum was observed in the case of settling. Optimum moisture contents corresponding to these two characteristic densities were almost the same. The most important physical properties affecting soil behavior under compaction and settling were found to be water retention properties at low matric potential which themselves depended primarily on organic matter content. Samples submitted to compaction had saturated hydraulic conductivities less than 1 cm/h, while after settling, Ksat measurements ranged from 0.8 to 234 cm/h. Organic matter played an important role in reducing the effects of compaction, and moisture content alone was not sufficient to predict the best conditions for workability in the fields.

Beschreibung: An improved procedure for measuring water retention curves at low suction (0–300 mbar) by the hanging-water-column method is described. The proposed method produces curves obtained on the same sample over the whole range of measurements. Good agreement was found between data measured by the proposed technique and those obtained by a conventional pressure plate technique.

Beschreibung: An increase in wheat yield in 1977 on an Elstow silt loam to levels slightly greater than those of the checks was obtained on dolomite-treated (11.2 and 22.4 t/ha) plots that had formerly received 17.9 and 33.6 t/ha KCl dust, and had subsequent wheat yield reductions of 21 and 53% in 1973, and rapeseed yield reductions of 19 and 25% in 1975. Water-soluble and NH4 Ac-extractable K in the surface horizons were increased by high application of KCl, and the Ca and Mg were reduced; K was not increased below the 55-cm depth. An application of 33.6 t/ha KCl had made this soil, below 45 cm, slightly saline due to Ca and Mg from the upper horizon’s exchange complex, and Cl from the added KCl. Eighteen months after the application of dolomite, K was slightly reduced, Ca mainly restored, and Mg partly restored in the surface 15 cm of this soil. Forty percent of the Cl applied with 33.6 t/ha KCl had leached beyond 213 cm by 1976. An upward movement of Ca and MgCl occurred during 1977.

Beschreibung: Yield of corn on Brookston clay increased 0.45 t∙ha−1∙yr−1 as distance from subsurface drain was reduced by 2 m (2.5 vs. 0.5 m). Yield increases associated with this drain-spacing interval were significant [Formula: see text] in eight of the individual years 1971–1980. While drain spacing affected yield and plant height, it had little effect on plant leaf percent NPK, soil porosity and compaction. Variation in soil measurements appeared to be primarily due to climate and rotation. Analysis of the yield data suggests that the effects of soil drainage, crop rotation and use of fertilizer are primarily additive, and that each of these practices is essential to achieving high yields of corn on southwestern Ontario clay soils. The response of rotation corn to applied fertilizer was lower than that of continuous corn, indicating that adjustment of N application in accordance with cropping history of soil may be cost effective.

Beschreibung: The NH4+-N concentration at the point of anhydrous ammonia injection of 19 Saskatchewan soils ranged from 200 to 800 μg/g. More than 90% of the NH4+-N was retained in a zone 5 cm in diameter from the injection point. Increasing the application rate generally increased the NH4+-N concentration in the retention zone.

Beschreibung: Humus fraction distribution in a wide range of horizon samples was examined by measuring carbon content in humic acid (Ch), in fulvic acid (Cf) and in the strongly colored polyphenolic component of the fulvic acid fraction (Ca). Fraction distribution was described by the ratios Ch/Cf and Ca/Cf. It was concluded that humus fraction ratios were related to horizon types as used in the Canadian System of Soil Classification, and were effective in discriminating between certain horizon types, particularly between Luvisolic Bt and Podzolic Bf. The results also suggested that humus fraction ratios may be effective in separating distinct sub-populations within Ah horizons and Bf horizons in general, based on qualitative differences in organic matter present. Aspects of the role of humus fractions in soil genesis are discussed.

Beschreibung: Acidification of two soils was measured in an experiment in which fertilizer and CaCO3 treatments were applied in various combinations. The highest rate of fertilizer used, which included N at 139 kg/ha, decreased the pH in 4–5 yr in unlimed Donnelly (Gray Luvisol) and Josephine (Eluviated Gleysol) soils by 0.43 and 0.18 units, respectively. The fertilizer increased the soluble Al content in both soils. Yields of barley (Hordeum vulgare L.) were greatly increased by the fertilizer and lime treatments. However, by the fourth crop on the Josephine soil, fertilizer failed to give a yield increase in the absence of lime; this was apparently due to declining soil pH and increasing soluble Al. In another experiment, loss of lime was measured over an 8-yr period in six soils that had been limed with Ca(OH)2 to pH 6.5–7.0. The average loss of lime from the soils was equivalent to 495 kg of CaCO3/ha annually. This was accompanied by a decline in pH of 0.48 unit in the 8 yr. Liming caused substantial increases to subsoil pH for three of the soils. Despite the decline in surface soil pH, increases in yields of barley from liming were sustained over the 8-yr period. The implication of these findings to soil fertility practices in the Peace River region are discussed.

Beschreibung: Growth chamber studies were conducted on the relative effects of various placements of NH4H232PO4 applied at 20 kg P ha−1 in a single band away from the seed on growth, and on uptake of soil and fertilizer P by flax (Linum usitatissimum L. ’Linott’) grown on two P-deficient Chernozemic soils; one calcareous, the other non-calcareous. Crop response was very sensitive to location of the placed P. Placement of the P away from, and up to 3.0 cm to the side and from 0–4.5 cm below the seed on average increased aboveground dry matter yield and P uptake of flax 8 wk after seeding by 2.3- and 2.1-fold, respectively, compared with the non-P fertilized soils. Maximum yields and P uptake, which were approximately four and three and a half times greater, respectively, than the non-P fertilized values, were achieved by placing the P no more than 1.5 cm to the side and 1.5–3.0 cm below the seed. Flax root development studies indicated that this was due largely to root development during the first few weeks being limited to a small cylinder of soil immediately surrounding the single vertical tap root. Distance of placement of P away from the seed was more critical for the calcareous soil, with crop use of the applied P being noticeably less for this soil (4.8–17.3%) than for the non-calcareous soil (18.3–40.2%).

Beschreibung: Three non-replicated, non-fertilized, dryland grain rotations — continuous wheat, wheat-fallow, and wheat-wheat-fallow — were established in 1912 on a Dark Brown Chernozemic soil. In 1967, the rotations were altered to include an annual application of 45 kg N/ha to a portion of each field. Above- and below-ground organic residue and soil were sampled in September 1975, April and August 1976, and April 1977 from both the fertilized and non-fertilized treatments of each rotation to measure the effects of the rotations on a number of chemical characteristics. The soil samples were analyzed for pH and contents of C, N, ethanol/benzene- and resin-extractable C, polysaccharides, and waterstable aggregates. The organic residues were analyzed for contents of C, N, ethanol/benzene-extractable C, lignin, and methoxyl groups, and for caloric content. The soils of the continuous wheat rotation contained the most C, total N, and polysaccharides, whereas the soils of the wheat-fallow rotation were about 12 percentage points higher in resin-extractable C than those of the continuous wheat or wheat-wheat-fallow rotations. The cultivated soils contained 47% less C, 46% less N, 53% less polysaccharides, 100% more solvent-extractable C, 49% more resin extractable C, and a slightly higher pH than the soils from the proximate native grassland. Individual rotations had little effect on the chemical composition of organic residues on the soil surface but did affect the decomposition and nature of subsurface plant residues.

Beschreibung: In this review, the fate of herbicides in Canadian field soils and their effects on soil fertility are discussed. Pertinent data are summarized for field persistence studies involving single and repeated annual applications, for the movement of herbicides in and from the soil, for the incorporation of metabolites into soil colloids, and for their effects on soil microflora and fauna.

Beschreibung: A method for calculating the fractions of water leached through the profile (leaching factor) in irrigated soils high in gypsum was developed. The method requires data on long-term changes in the salinity status of the soil profile, and is based on the principle that water moving through gypsum-rich soils becomes saturated with gypsum. The average total soluble salt content of two soils to a depth of 180 cm has decreased logarithmically since 1917. The average Ca content has decreased linearly at rates of 0.091 and 0.097 meq∙100 g−1∙yr−1 in a clay and clay loam soil, respectively. A leaching fraction 0.16, as obtained by our method, is similar to that calculated from a water balance procedure. However, the latter method required accurate information on the annual rate of irrigation and precipitation and consumptive water use by the crops grown. The results indicate that irrigation management at the two sites has provided sufficient leaching water to reduce the total soluble salts and to actually improve the suitability of the sites for crop production.

Beschreibung: Dynamics of woody material degradation were studied in the soils of six forest ecosystems of meridional Quebec. This comparative study was performed measuring weight losses of wood samples, buried for long periods of time in the different horizons of each soil studied. In all cases, degradation was much faster close to the soil surface; thus a more or less marked decreasing vertical gradient was observed in the activity for most of the soils studied. The lengths of time necessary for half decomposition (50%) were calculated for the samples buried in each station. For the hardwood forests, values of about 1.7, 2.8 and 2.3 yr were obtained for half decomposition in the Melanic Brunisol, the Sombric Brunisol and the Dystric Brunisol, respectively. A value of 4.6 yr was calculated for the Minimal Humo-Ferric Podzol of the mixed forest to reach half decomposition. Similarly about 35 and more than 40 yr would be necessary for half decomposition of the samples in the Orthic Ferro-Humic Podzol and the Ortstein Ferro-Humic Podzol of the two coniferous forests, respectively. The influence of major environmental factors, such as climate, soil and vegetation on the dynamics of microbial and faunal soil communities is discussed.

Beschreibung: The extent to which horizons can be differentiated from one another on the basis of chemical properties was examined. The horizons studied included F, H, Ah, Ae, Bhf and Bf and were taken from Podzolic soils developed on granodiorite-derived sediments in southwestern British Columbia. The determination of the degree to which the horizons form distinct groups in a multivariate context was performed using a grouping procedure based on the multivariate density equation. It was found that 63% of the observations were nearer to their own horizon centroid than to any of the other centroids. When horizon membership was altered in an attempt to form optimal groupings, the membership of 54% of the observations was unchanged. Considerable overlap was shown to exist between the F and H horizons and between the Ah and Bhf horizons. Otherwise the picture that emerges is one in which the horizons do not form distinct clusters, but do tend to fall into definite regions of the multivariate space.

Beschreibung: Humo-Ferric Podzols (Typic Cryorthods) developed on glacial till or glaciolacustrine deposits were sampled in the Chapleau-Foleyet area of northeastern Ontario. pHs of Ae horizons ranged from 3.30 to 4.20 and of C horizons from 4.40 to 4.85. Cation exchange capacities (CEC) of mineral soil horizons averaged 1.7 meq/100 g, whilst those of the forest humus (fibrimors) averaged 166 meq/100 g. The CECs of the Bf and BC horizons were highly pH-dependent, averaging 3.2 meq/100 g at pH 4 and 16.8 meq/100 g at pH 8. The pH-dependency of CEC in these horizons was believed to be due to Al-complexes with organic matter. Calculated elemental loss using Zr as an internal standard showed significant losses of Mg, Fe, Ca and Al from Ae (albic) horizons and gains of Fe and, to a lesser extent, gains of Al in Bf (spodic) horizons. The clay mineralogy of Ae horizons was dominated by a high-charge smectite and that of Bf and BC horizons by chlorite.

Beschreibung: The effect of fertilizer N on yield, protein content and symbiotic N2 fixation in faba beans (Vicia faba L.) was studied with nine field trials during 3 yr. Forage and seed yields of nodulated faba beans were infrequently and unpredictably affected by rate of application at seeding (up to 300 kg N/ha), type of application (34 and 67 kg N/ha surface-broadcast or placed with the seed), and time of application (at full bloom or at mid pod-fill). Protein content of faba bean forage material was variably affected by applied N; in one-half of the harvests conducted, at least one of the N application treatments resulted in significantly higher forage protein contents. No logical pattern or reason for the forage protein response was found. Seed protein content was unaffected by applied N up to 150 kg N/ha, but was significantly increased by 300 kg N/ha in two out of three trials. Maximum rate of dry matter accumulation and N uptake commenced at blooming and continued up to the mid pod-fill growth stage. In seven trials monitored, the proportion of faba bean shoot N derived by symbiotic N2 fixation was 54%, with values of five out of the seven trials ranging from 63 to 71%. This amounted to 54–111 kg N/ha. Applied N decreased faba bean symbiotic fixation at all trials but one where available soil N was very high and symbiotic N2 was not occurring.

Beschreibung: A study of plant uptake, incubation-extraction and acid hydrolysis was carried out on soil samples from a field study using 15N. The samples had varying proportions of residual fertilizer 15N (15Nex) as clay-fixed ammonium and organic N. Availability of 15Nex to plants was positively correlated with percent of 15Nex as clay-fixed ammonium, and negatively correlated with percent of 15Nex as organic N. A similar relationship was noted for recovery of 15Nex in acid hydrolysates. The relationship was reversed for recovery of 15Nex in aqueous extracts following incubation, although this may have been due to lack of removal of N by plant uptake or leaching, and limitation of microbial activity by lack of readily available carbon. This direct comparison of availability of residual fertilizer N as clay-fixed ammonium N and organic N demonstrates that fertilizer N, once incorporated into organic forms, is much less available to plants than fertilizer N in the form of clay-fixed ammonium.

Beschreibung: Experiments were conducted to determine the effect of Sea Crop (SC 16) and Ergostim on the yield and nutrient composition of a few crops. Studies conducted under greenhouse and field conditions showed that the yields of wheat (Triticum aestivum L.) and peas (Pisum sativum L.) were not affected by the addition of SC16. The nitrogen (N) and sulfur (S) concentrations of the two crops were not affected by SC 16, except in the control and SC 16 treatment only where the increases were likely due to a concentration effect, since these two treatments had lower yields. Boron (B) and molybdenum (Mo) concentrations in the plants were significantly affected by B and Mo applications, but not by SC 16. A greenhouse study showed that the yields of alfalfa (Medicago sativa L.) and wheat were not affected by the addition of Ergostim. The addition of Ergostim did not affect the N or S concentration of wheat or three cuts of alfalfa.

Beschreibung: The refractive index change caused by KCl diffusing from a cylinder into agar gel was found to distort a grid projected through it by laser light. By ray tracing and Fermat’s Principle it was shown that values of concentration of KCl at various times and distances were within experimental error of those calculated from the transient diffusion equation for diffusion from a cylindrical source. The diffusion equation was derived for the first time using Eyres’ method. Since the model and mechanism were confirmed as correct by experiment it was then possible to design a computer program to predict transient concentration gradients and hence concentration at any distance and time. The program has built into it flexibility to deal with such expected variables in soil as tortuosity, water content, etc., as well as different diffusion coefficients for different nutrients and also multiple sources. Such a program should be very valuable to fertilizer suppliers in designing timed release capsules and to those using them to obtain optimum nutrient concentrations in a volume of concern of soil.

Beschreibung: The formation and coexistence of four aluminum compounds, namely, gibbsite (Al(OH)3), boehmite (AlOOH), alumina (Al2O3) and alunite (NaAl3(OH)6(SO4)2) is reported under laboratory conditions. These solid phases were formed as hydrolytic products of aluminum sulphate solutions at room temperature. These results provide evidence that thermal conditions are not essential and not the only conditions under which boehmite and alumina are formed.

Beschreibung: The objectives of this work were to determine the effects of N-fertilizer sources, rates and fractionation on potato (Solanum tuberosum L.) yields, petiole-N content, defoliation and tuber specific gravity. To achieve these ends, urea and ammonium nitrate were side-dressed at 0, 70, 140 and 210 kg N/ha, by applying either all at planting or by fractionating the applications into half at planting and the other half a month later. The field experiments were carried out on eight sites consisting of six soil series. Nitrogen fertilization increased yields on all sites; the rate required for attaining maximum yields varied for 130 to 210 kg N/ha, according to the experimental site, with an average of 180 kg N/ha. Generally, both N-sources and fertilization methods had similar effects on yields defoliation, petiole N-content and tuber specific gravity. A 210-kg urea-N application at planting on the Lapointe loamy sand, however, decreased yields significantly. The importance of soil type, available water and total soil-N are discussed in relation to the quantities of fertilizer-N required to achieve maximum yields.

Beschreibung: Fertilizer tests using hard red spring wheat (Triticum aestivum L.) were conducted in the field from 1967 to 1979 on stubble and fallow land on the major soil types throughout southwestern Saskatchewan. The yield, percent nitrogen and phosphorus in the grain, kernel and volume weights of the grain were measured, and the responses of each of these characteristics to N and P fertilizer were determined. These responses were related to soil measurements of available H2O, NO3-N, NH4-N and sodium-bicarbonate-extractable P, which were taken at seeding time, at depths to 120 cm, and to the monthly rainfall during the growing season. On fallow, nitrogen rates higher than 15 kg N/ha gave little significant increase. The yield increase per kilogram of P applied decreased as the rate of application increased. On stubble, the yield increase per kilogram of N applied decreased for each additional increment of N added, down to 3.1 kg/ha yield increase per kilogram of nitrogen per hectare when the rate of application was increased from 45 to 60 kg N/ha. Regression analysis showed that the soil and the weather variables used accounted for only 20% of the variability in yield on fallow crops and for 40% on stubble crops. Nitrogen content of the grain was only increased by rates of 45 kg N/ha or greater. The P content of grain was decreased by both N and P fertilizer.

Beschreibung: Concentrations of oxygen and carbon dioxide in the soil were measured periodically in disturbed and undisturbed Eriophorum vaginatum tussock tundra from 16 July to 21 Aug. 1979. The disturbed sites were in vehicle tracks, on plots cleared of vegetation, and on plots treated with urea, cornstarch, and artificially altered drainage. Vehicle tracks made in 1979 and the artificial impoundments did not significantly affect soil oxygen and carbon dioxide concentrations. The lowest soil oxygen concentration occurred in a 15-yr-old vehicle track and on the cleared plots. Urea and cornstarch temporarily reduced soil oxygen concentration and increased soil carbon dioxide levels. Tussocks were more poorly aerated than intertussock areas except in the old vehicle track. Soil oxygen concentration did not usually vary significantly between 5 and 15 cm, but dropped sharply at 25 cm. Oxygen diffusion coefficients calculated from an earlier study on soil oxygen flux and the current data on oxygen concentrations suggest that despite generally well-aerated conditions, anaerobic zones may occur frequently in tussock tundra soils.

Beschreibung: Three years after disturbance of soil, by digging sample pits to a depth of 1 m, soil at a depth of 85–95 cm had greater air porosity and greater total porosity than previously and soil strength of disturbed soil was much less than strength of the undisturbed side wall. At a depth of 25–35 cm, air porosity was increased and soil strength was decreased. Disturbance of wet soil tended to have less beneficial or detrimental effects. These data suggest than Berwick and Kentville sandy loams would be amenable to improvement by deep tillage provided moisture conditions were favorable.

Beschreibung: Atomic absorption analyses of pyrophosphate extractions of B horizons from some Luvisolic, Gleysolic and Solods had higher Fe and Al contents when using 0.1% Superfloc and low speed centrifugation than those obtained when using 0.2% or 0.5% Superfloc or when using high speed centrifugation. Laboratories not equipped with a high speed centrifuge should use a method other than Superfloc to clarify the solution or use the recommended colorimetric method.

Beschreibung: The inorganic clay constituents of the B horizons of three Podzolic soils from British Columbia were analyzed by X-ray diffraction, infrared, electron-optical and chemical methods. The amorphous inorganic constituents comprised from 51 to 82% of the clay in these Podzol B horizons. Quartz, feldspar, chlorite, and vermiculite were the dominant minerals in the crystalline portion of the clay. Infrared spectra suggested the presence of appreciable amounts of imogolite in the fine clays of the three soils. Electron optical evidence confirmed its presence in small amounts (

Beschreibung: The internal drainage of a saline-sodic soil having till at 51 cm from the surface was studied in the field and laboratory. Average water intake (infiltration) for the profile was 3.76 cm/day. The Btj could be a limiting factor for vertical flow. The horizontal hydraulic conductivity indicated that lateral flow of water in the C horizon (36 cm/day) and surface of the till (22 cm/day) could be as much as five times greater than that of the Ah (5 cm/day) and Btj (8 cm/day) horizons. Salts were leached from the profile by the 22 cm of water that had been applied. It was concluded that the internal drainage of the soil was sufficient to accommodate infiltrated water under normal conditions, and that the buildup of a water table and salinization of the soil were probably due to lateral flow of water from canal seepage and irrigation mismanagement.

Beschreibung: These calcareous brown soils are low in organic matter. The clay and carbonate content increase with depth. Carbonate percentage ranges from 1.7 to 27.5% and the accumulation is found between 45 and 105 cm from the soil surface. Sulfate exceeds chloride ions in the soil extract. The exchange capacity, varying from 8.2 to 27.9 meq/100 g of soil, increases with depth. The major clay mineral is vermiculite and the maximum percentage is found in the lower horizons, while illite, which is the second clay mineral in these soils, decreases with depth. There was a relationship between K+ fixation and the content in clay and vermiculite. K+ fixation, which represents 7–11% of the cation exchange, is also enhanced by the drying of the soil.

Beschreibung: Four series of agricultural soils of Quebec were sampled in the Lowlands on drained and undrained sites in order to investigate the effect of long-term internal drainage on the physical and chemical properties of the profiles. Change in structure was observed in the Ste-Rosalie soils. A massive layer found below 18 cm in the undrained profile was replaced by a more structured layer at greater depth in the drained profiles. Occurrence of mottles down to the Cg horizon reflected the better aeration conditions in the drained sites. Saturated hydraulic conductivity values were sometimes higher and sometimes lower than those measured in the undrained profiles. Below the plow layer, the two profiles drained for more than 50 yr had a cation exchange capacity 12–15% higher than the undrained profiles. Oxalate-extractable iron represented a high percentage of the dithionite-extractable iron and indicated a low rate of formation of crystalline pedogenic oxides. Mn accumulations were found in the more compact layers. The improvement of internal drainage requires a soil management that will enhance soil structure.

Beschreibung: Forty-nine sandy soils developed in till, outwash, alluvium and marine sands were studied to determine the effect of mode of deposition on soil development and to classify the soils according to the Canadian and U.S. classification systems. Forty-three of the soils met the morphological and chemical criteria of Humo-Ferric Podzols but none of these was a Spodosol because the ratio of pyrophosphate-extractable Fe + Al to clay in the B horizon was below 0.2. Mode of deposition had only a minor effect on soil evolution. However, B horizon development was strongest in the till soils, perhaps because of their somewhat finer texture and greater age. A pronounced maximum of clay occurred in the B horizons of the Podzolic soils; commonly, clay in the B exceeded that in the A and C by a factor of 2–5. A higher pyrophosphate Al/Fe ratio was found associated with soils low in total pyrophosphate Al + Fe and vice versa. It was also found that pyrophosphate Al + Fe was positively correlated with total organic C (r = 0.891).

Beschreibung: Analysis by energy dispersive X-ray spectrometry (EDS) of cutans linking grains in coarse-textured duric horizons with plectic fabrics indicated that Al-organic material was a component of the cement. (Al, Fe)-organic material occurred in voids near the upper surface of duric horizons with porphyroskelic fabrics but EDS was not useful in detecting the cement of such horizons. Ground (2 mm) sandy loam C horizon material from a soil with a dense duric horizon was cemented strongly by as little as 0.1% (Al + Fe) precipitated with Na2 SiO3. Results of this and previous studies suggest that various combinations oa Al, Fe and Si hydrous oxides and humified organic matter act as cementing agents of duric horizons and that very little cement is required to indurate closely packed materials.

Beschreibung: The effect of degree of decomposition and depth of sampling on gamma probe wet bulk density measurements was investigated for two organic soils. Sampling depth did not significantly affect the probe calibration. In situ calibration must be done rather than in laboratory.

Beschreibung: The neutral monosaccharides released by the acid hydrolysis of five peat profiles were analyzed by ion exchange chromatography and gas-liquid chromatography in order to ascertain whether monosaccharide composition can be used to differentiate peats. Glucose, mannose and galactose were the predominant monosaccharides found. Changes observed with depth in the relative abundances of the monosaccharides were not always correlated with the degree of decomposition as measured by fibre content or pyrophosphate index. The arabinose to xylose ratio was a diagnostic chemical feature which reflected the degree of decomposition of the peats.

Beschreibung: Sand-soil mixtures are commonly used in drained turf sites such as golf greens and athletic fields to ensure adequate soil strength, minimum compaction, and corresponding suitable water retention and infiltrability. The physical properties of the components vary significantly from site to site and mixture proportions must be adjusted to compensate for this. This adjustment usually involves empirical testing of various mixtures of the components to determine the correct proportions to use. One objective of this project is to develop a simple, applied method useful in the prediction of mixture porosity and water retention, which might eliminate or at least significantly reduce empirical testing. A graphical method based on component bulk volume proportions and which requires knowledge of the component porosities was developed and demonstrated to accurately predict water retention porosity, aeration porosity, and total porosity in sand-soil mixtures. This method, described herein, should prove of practical use in determining correct mixtures of sand and soil for drained turf sites.

Beschreibung: The influence of soil moisture on urea hydrolysis and microbial respiration in mixed L and F horizons of a Brunisolic soil under a boreal forest jack pine (Pinus banksiana Lamb.) stand was determined in an incubation study at 13 °C. Respiration rates in untreated soil were similar over a wide range of moisture contents below 300% (45% water-holding capacity). Significant decreases in respiration rates occurred only below 60% moisture content. Initial microbial response to urea increased as soil moisture rose from 20 to 300%. There was sufficient urease in pine humus to hydrolyze rapidly the equivalent of 200 kg urea-N∙ha−1, when moisture was not limiting. During the drying of initially moist soil (340% H2O) to 240% H2O or lower, urea hydrolysis was retarded significantly and microbial respiration reduced by an average of 25% over that observed in a constantly moist soil.

Beschreibung: Recommended concentrations of Vorlex and linuron exerted little initial effect on bacterial and actinomycete populations in a muck, whereas Vorlex caused drastic reduction in that of the fungi. This resulted in linuron accumulation in the soil which was deleterious to growth of Lactuca sativa L. New fungal population produced by the survivors was resistant to subsequent Vorlex treatments, but was linuron passive. Proliferation of the surviving fungi was accompanied by appreciable and lasting increases in the bacterial and actinomycete populations. Absence of pathogenic symptoms on lettuce plants due to any of these organisms precluded selection or enrichment of pathogens potentially present in the soil. The findings demonstrated the consequence of this pesticide combination on non-target microbiota, the accumulation of linuron, and plant growth.

Beschreibung: N and P fertilizers were applied at increasing rates in alternating directions crossed over (IRADCO) at right angles upon each other. One fertilizer was applied so that, in the contiguous strips, the rates increased in alternate directions. The second fertilizer was applied similarly but at right angles to and on top of the first fertilizer. This arrangement with the increasing-rate spreader available allowed 162 combinations of the two fertilizer elements in duplicate in each block. Two such blocks set at right angles to each other were considered to offer reasonable control of possible fertility gradients in the field. The main value of the design is that many fertilizer levels for the establishment of yield response surface functions can be acquired with less effort and in a fraction of the area required with plots of conventional size. The form of the yield response to fertilizer was adequately represented by regression models fitted to the data. The IRADCO design, involving both the field technique and regression modelling, can be used to determine the response to fertilizer levels by various crops at several locations.

Beschreibung: The map index linkages (from CanSIS cartographic file) of seven soil maps were analyzed to find out how many map delineations represented each map unit and what proportion of the map they covered. Many map units were represented by only one or two delineations. This was more true for uncontrolled than controlled legends (51–85% of map units in uncontrolled legends versus 27–37% of map units in controlled legends). In both types of map the map units that had only one or two delineations covered only a small proportion of the land area. On the other hand, only a small proportion of the map units (between 14 and 31%) was needed to cover 75% of the land area in both types of maps. It proved possible to reduce the number of map units in one map with an uncontrolled legend from 193 to 91. This was done, firstly, by combining map units that represented only very small areas (or were represented by only one delineation) with larger map units that were very similar for the purpose of the survey. Secondly, map units were combined when more than 85% of the soils within them were the same. Controlled legends need not be very long and need not omit significant information.

Beschreibung: Cryosolic soils have been identified on forested, upper subalpine, north facing slopes in eastern Banff and Jasper National Parks. Soil morphology and soil and air temperatures all confirm the presence of permafrost.

Beschreibung: Poultry numbers, density and potential environmental quality problems have increased greatly in the Lower Fraser Valley. A field experiment was carried out in 1975 and 1976 to determine the effect of manure from a deep-pit laying house on the growth, yield and chemical composition of orchardgrass-ladino clover forage. The manure had N:P:K, ratios of 5.1:2.5:2.0 and 3.5:1.6:1.4 in 1975 and 1976, indicating that its K content relative to N and P was relatively low for forages. Manure rates were 1.25, 2.5, 5.0, 10, 20 and 40 t/ha. In 1976, these rates were applied as a single application in the early spring or split into three equal increments applied in the early spring and following the first and second cuts. The grass component of the sward responded positively to increased manure rates. However, at rates in excess of 2.5 t/ha, the clover was almost totally eliminated from the stand. The maximum 1975 dry matter yield of 7.00 t/ha occurred with 40 t/ha of manure although the rate of yield increase was greatest at rates of 10 t/ha or less. The maximum forage yield of 16.1 t/ha occurred in 1976 at the 20 t/ha split-application rate of manure. At the 5, 10 and 20 t/ha manure rates the split application produced yields about 1.2 t/ha higher than the single application method. Except for the last cuts in both years, manure significantly increased percent total Kjeldahl nitrogen, especially at rates of 20 t/ha or less. Forage NO3-N concentrations exceeded 0.20%, the level cited as being toxic to ruminants, at rates of 20 and 40 t/ha. Forage P concentrations were not significantly affected by manure addition, probably because the available P level in the soil was high. Forage K concentrations were increased at all cuts by increasing manure rates although K was not a factor in the crop response to manure because initial soil K was high. Manure applied at rates in excess of 20t/ha to supply adequate K for forage production would make inefficient use of the N and P in the manure. Good forage yields without damage to the sward and with little problem with high forage NO3 concentrations were obtained at the 10 t/ha rate; however, for manure disposal, rates as high as 20 t/ha could be used.

Beschreibung: Application of Ca(NO3)2 to a Black Solonetz soil at Vegreville, Alberta provided the known beneficial effects of NH4NO3 in increasing yields and improving the chemical and physical properties of the Ap and Bnt horizons without the harmful increase in soil acidity associated with the use of NH4NO3.

Beschreibung: A simple and inexpensive instrument for measuring soil water table levels that can be used with metal or plastic wells was designed and constructed. The accuracy of the measurements is within ± 1 mm. The instrument has been thoroughly tested both in the field and in the greenhouse and proved to be very reliable.

Beschreibung: Nitrous oxide emission from agricultural soil has been measured in two relatively long-term studies over two different soil types, Brookston clay and Fox sandy loam, located at Woodslee and Harrow Ontario, respectively. The clay plots treated with various amounts (0–366 kg N∙ha−1) of ammonium nitrate, potassium nitrate, or urea were routinely monitored for periods up to 1 yr. Extreme variability in rates within the range 109–1013 molecules∙cm−2∙s−1 was observed (1 × 109 molecules∙cm−2∙s−1 = 4.02 = 10−4 kg N∙ha−1∙day−1 = 1.68 μg N∙m−2∙h−1). Over sandy loam, rates which were lower and more uniform (108–1011 molecules∙cm−2∙s−1) showed a strong correlation with amount of NH4NO3 applied. About 0.25% of applied fertilizer was released as N2O within 80 days following treatment.

Beschreibung: Agricultural land use and cropping statistics were examined to determine yield trends of wheat and barley since the early 1900’s. A general decline in yields of these crops occurred until the return of favorable weather and introduction of disease-resistant varieties in the mid-1930’s. Since about the mid-1950’s, yields of wheat and barley have been greater than at any previous period, and have generally been increasing rapidly during the period 1958–1978. An estimate of the contribution of modern technology to the increased yields was calculated, using 5-yr moving averages for the periods ending 1962 and 1978. Increased fertilizer use had the greatest effect on yield increases achieved. New disease-resistant varieties with improved yielding potential had a lesser effect. The impact of herbicides and improved machinery was examined but could not be effectively evaluated from available data.