ALBERT

Description: Progenies belonging to 49 open-pollinated families of paper birch (Betulapapyrifera Marsh.) representing 13 provenances were evaluated sequentially for rate of root elongation in solutions containing only calcium nitrate and solutions containing calcium nitrate + 120 ppm aluminum. Provenances, but not families within provenances, differed significantly in both rate of root elongation and apparent response to Al. Provenance mean tolerance indices (root growth in Al solutions/root growth in non-Al solutions) varied from 0.10 to 0.37. Exposure to 120 ppm Al caused decreased concentrations of Ca and Cu in the foliage, decreased or nearly unchanged concentrations of P and Mg, and increased concentrations of Al, B, and Mn. Compared with the more tolerant provenances, intolerant provenances exhibited generally greater increases in foliar Al concentration after exposure to Al. Differential tolerance to Al will be useful in improving the performance of planted trees on Al-toxic sites.

Description: Seasonal patterns of change in lipids, sugars, starch, labile (ethanol soluble) constituents, holocellulose, and lignin were studied in six forest-grown white oak (Quercusalba L.) trees. Contents of metabolically active constituents in leaves, twigs, branches, boles (upper and lower), and roots (support and small lateral) were used to construct whole-tree budgets of energy allocation. [14C]Sucrose was also concurrently supplied to the study trees to follow the fate and efficiency of utilization of food reserves. Results showed that white oak rapidly mobilized and replaced food reserves during the critical period of canopy generation in the spring. Starch was more important as a reserve food than lipids or sugar. Large fluctuations in starch in roots in spring and fall suggested a bimodal belowground growth pattern. Labile constituents showed the most pronounced seasonal changes and dominated the calculated whole-tree energy flux patterns. Rapid decline in labile compounds in early spring and a parallel increase in holocellulose suggested a possible pattern of mobilization and resupply of stored reserves associated with in cell wells. This possibility was supported by a concurrent shift of labile 14C to nonlabile 14C in tissues. Canopy generation was calculated to have cost ≤17.7 kg of glucose (1.6 g glucose/g of canopy) of which 13 kg appeared to have come from within the canopy.

Description: Growth of diameter of individual trees can be expressed as diameter increment or basal area increment. Little work has been done to determine which of these parameters is preferable for use in growth studies. This paper examines growth of trees in pure and mixed stands of even-aged, regrowth forest of Eucalyptusregnans, E. obliqua, and E. globulus, aged 6-80 years, thinned and unthinned, in southeastern Tasmania. Weighted least squares regression equations are developed to relate diameter and basal area increments, over 1- to 6-year increment periods, to initial tree diameter in 29 growth plots. The correlation between basal area increment and initial diameter was always greater than that between diameter increment and initial diameter in these relationships. Despite this, the precision of estimates of future diameter in each plot is shown to be the same whether diameter or basal area increment equations are used. Data from a thinning experiment in 38- to 85-year-old, even-aged Acersaccharum, Fraxinusamericana, and Prunusserotina stands in southern Ontario are also examined and similar results obtained. It is concluded that no apriori reason exists for expressing growth as diameter increment or basal area increment in studies of these types.

Description: Using data on CO2 exchange, growth, and biochemical composition, an approach was developed to calculate the seasonal production, consumption, and surplus of photosynthate in shoots of loblolly pine (Pinustaeda L.). The amounts of CO2 released and of glucose substrate required in biosynthesis of shoot biomass over the growing season were also calculated. Individual growth flushes of different age-classes, as well as of an entire 1-year-old branch unit, ofPinustaeda were used as bases for calculations.Substrate requirements and CO2 production were relatively constant throughout the growing season. Within the whole 1-year-old branch unit, 63% of the photosynthate production was supplied by the two growth flushes of the previous year. Growth of the current year's shoot represented the major consumption of photosynthate, and this made up 66% of the total photosynthate consumed in the branch unit. Surplus of photosynthate, which would be available for translocation from the branch, was about 38% of the total photosynthate produced. Most of the photosynthate surplus was derived from the growth flushes of the previous year. Source and sink relationships, with regard to photosynthate partitioning in the 1-year-old branch unit over the growing season, were clarified and described.

Description: White oak (Quercusalba L.) seedlings grown in a silt loam soil inoculated with Pisolithustinctorius (Pers.) Coker and Couch exhibited 80% ectomycorrhizal development after a 6-month establishment period whereas the noninoculated controls exhibited less than 5%.When water was withheld and soil water potential decreased as the soil dried, xylem pressure potential and leaf conductance of both the inoculated and noninoculated seedlings declined gradually. At the peak of the drying cycle, the inoculated seedlings exhibited mean prelight and midlight xylem pressure potential values which were 0.2 MPa and 0.15 MPa, respectively, more negative than the noninoculated seedlings. Although the inoculated seedlings had a mean leaf surface area 1.5 times larger than that of the noninoculated seedlings, there were no significant differences in leaf conductance at the peak of the dehydration cycle. Mean rates of root elongation were greater among the inoculated seedlings during the drying cycle. Following reirrigation of the soil, the inoculated seedlings yielded significantly less negative values of prelight and midlight xylem pressure potential and greater leaf conductance when compared to the noninoculated seedlings.

Description: Decomposition rates and changes in the nutrient content of needle and leaf litter were examined in Douglas-fir (Pseudotsugamenziesii Mirb. Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), Pacific silver fir (Abiesamabilis (Dougl.) Forbes), and red alder (Alnusrubra Bong.) ecosystems in western Washington, U.S.A. Nylon litterbags (1-mm mesh) were placed in the stands in November and December 1974. Bags were collected after 3, 6, 12, and 24 months and weighed, except in the Pacific silver fir stand when bags were collected after 6, 9, 14, and 24 months. Litter was analyzed for C, N, P, K, Ca, Mg, Mn, lignin, and cellulose. Decomposition constants (k values) were determined. Fastest decomposition after 2 years occurred in red alder leaves, followed by Douglas-fir, western hemlock, and Pacific silver fir needles. There were significant differences in weight loss among species after 1 year, but no significant differences were evident after 2 years. Red alder leaves showed rapid weight loss in the 1st year but decomposed little in the 2nd year. Decomposition constants were highly positively correlated with minimum air temperatures and negatively correlated with C:N ratios. Low litter moisture tended to reduce decomposition in summer, particularly in the Pacific silver fir stand. Decomposition proceeded under snow in this ecosystem. The pattern of loss of elements from litterbags after 2 years varied from ecosystem to ecosystem, particularly for N. The following element mobility series resulted for the four ecosystems: red alder (K 〉 Mg 〉 Ca 〉 P 〉 N 〉 Mn), Douglas-fir (K 〉 P 〉 Ca 〉 Mg 〉 Mn 〉 N), western hemlock (K 〉 Ca 〉 Mg 〉 N 〉 Mn 〉 P), and Pacific silver fir (K 〉 Mg 〉 Ca 〉 Mn 〉 P 〉 N).

Description: Research was conducted to study (1) seasonal changes in tissue composition and (2) dynamic allocation of photosynthate to different biochemical fractions in growing shoots of the current and previous years of 15-year-old loblolly pine (Pinustaeda L.). As the growing season progressed, the shoots increased rapidly in total biomass; however, old needles formed in the previous year lost dry weight. The most striking biochemical change was a rapid decrease in starch content of old needles early in the growing season. Soluble sugars and organic acids in old needles also decreased slightly. Contents of biochemical constituents generally increased in current axes and needles as the organs grew and increased in weight, although there were decreases in organic acid contents of current axes early in the growing season. Formation of nonlabile major constituents (cellulose, hemicelluloses, lignin, and protein) in current-year shoots proceeded at different rates. These rates were interpreted in terms of aspects of shoot growth and development. Seasonal allocation of photosynthates into biochemical constituent fractions in current year growth flushes was calculated. Results suggested that photosynthates were allocated to constituents of different functional categories (metabolism, storage, structure, and protection) at different times of the growing season in such a way that structural growth was of first priority. Thus, allocation of photosynthates to structural growth early in the season enables branches to compete for favorable growing conditions.

Description: The author describes a stochastic model of forest stand rotation which can be used to determine the optimal planned rotation interval for flammable forest stands. The model can also be used to estimate the value of fire management activities in terms of the potential enhanced value of timber production. The use of the model is illustrated by applying it to a simplified case of jack pine (Pinusbanksiana, Lamb.) management.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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 (

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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).

Description: 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.

Description: 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.

Description: 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.

Description: 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%).

Description: 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.

Description: 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.

Description: 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.

Description: 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 (

Description: 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.

Description: 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.

Description: 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.

Description: 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).

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: 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.

Description: Colorimetric soil pH measurements made systematically across Belcarra Mountain in the rain-forest of British Columbia over the 4-yr period 1975 to 1978 showed summer (June or July) values to increase somewhat with total cumulative precipitation (previous November to July). After dry winters, lower pH values in both A and B horizons were recorded, the increase in acidification being so marked on the sandy Podzols as compared to the less light-textured Brunisols that the normal increase in pH down the profile was reversed. The causes of such variations are discussed along with their significance when characterizing Orthic Humo-Ferric Podzols of the region.

Description: Conditions were investigated for using a Biosonic BP-III ultrasonic probe for reproducible soil dispersion. The importance of probe-tip conditions and an instrument rest period between successive dispersions is emphasized. A procedure for bulk isolation of particle size separates is described, based on ultrasonic dispersion and continuous flow centrifugation. For 500-g soil samples, average recovery of soil solids was 98%. The procedure is relatively rapid and should be useful where high yield of size separates is needed for characterization or mineralization studies on organo-mineral complexes.

Description: The Folin-Ciocalteau reagent was used to determine the total content of soluble peat phenolic compounds by a colorimetric method. The response of known phenolic compounds to the reagent was measured and it indicated its usefulness for studying peat humus. The results showed that the absorbance at 550 nm of the Na4P2O7 extracts of peat materials from two peat soil profiles was correlated with the total phenolic content but anomalous results were encountered in some horizons. Additionally, the total phenolic content per microgram of dissolved organic matter and the behavior of known phenolic compounds revealed that one peat profile had the most reactive phenolics in the bottom horizon.

Description: Soil-temperature studies were conducted under forage and zero tillage conditions at the Whiteshell Nuclear Research Establishment (WNRE), Pinawa, Manitoba, as part of the plant radiation ecology research program. The objective was to develop estimation equations for monthly mean and daily mean soil surface temperatures from atmospheric meteorological measurements. Subsoil temperatures were estimated from predicted soil surface temperatures by applying an appropriate damping factor. Monthly mean soil surface temperatures were estimated for summer and winter months from regression equations with meteorological predictors. Daily mean soil surface temperatures were predicted from regression equations with meteorological predictors combined with best-fit Fournier-series seasonal curves. Daily mean subsoil temperatures at 10 cm were estimated from predicted soil surface temperatures by applying an appropriate damping factor. The standard deviation of the difference between predicted and observed temperatures was generally less than 1 °C for daily and monthly estimates. A good estimate of the seasonal subsoil temperature at 10, 50, 100 and 200 cm was found from a periodic function with damping and phase paramaters. The explained variance was 95% or more. With appropriate assumptions regarding soil thermal properties and mean annual soil temperature, accurate results were obtained quickly and economically.

Description: Three southwestern Ontario soils differing in texture were studied for penetration of the nematicide ethylene dibromide. A 3 × 2 × 2 factorial experiment was used that permitted evaluation of the effects of temperature, bulk density and moisture level in all combinations on response to the fumigant. The coursest soil (Fox loamy sand) showed the most rapid penetration, with moisture level, temperature and their interactions having the greatest effect on fumigant movement. On a medium-textured soil (Vineland silt loam) the degree of penetration was dependent on moisture, temperature and bulk density, with relatively small interaction effects, suggesting that effective fumigation depends upon careful soil management and timeliness of application. On the fine-textured soil (Lincoln clay) the fumigant did not move in the soil, regardless of edaphic factors, thereby explaining the difficulty of using fumigation to control nematodes on clay. The development of factorial methods and statistical techniques to study several variables concurrently should lead to more specific and effective methods of soil fumigation.

Description: The distribution of eight neutral monosaccharides in the 19 horizons of three organic soil profiles from the Riverton Peatland, Manitoba has been studied. The amounts of the monosaccharides have been found to be related to several characteristic physical, chemical and morphological properties of the horizons. Some horizons afforded appreciable amounts of deoxy-sugars relative to glucose, the predominant monosaccharide. This finding suggested that monosaccharides other than glucose may be useful chemical markers with which to differentiate peats.

Description: Research on cultivated and uncultivated Gray Luvisols at the Breton Plots was conducted to determine the effects of management practices on soil fabric arrangements. Soil fabrics were readily classified into two dominant groupings: the granic sequence for cultivated layers and upper solum of uncultivated soil and the fragmic sequence for Bt horizons. Mullgranic and humigranic sequences were also characteristic of pedotubules in all horizons examined. The investigations showed that tillage practices play a much larger role in determining fabric arrangements than do fertilizer treatments, within and among f-members best classified as crumbs and clods. However, clods, crumbs and crusts of cultivated layers were frequently found to comprise basic granic units (approximately 150–200 μm) which expressed a variable degree of granularity. The granules were most discrete and strongly developed in plots receiving organic fertilizer and where grasses and cereals were grown in rotation; their plasma fabric also showed a weak mull component. While the exact genetic origin of the granules is unknown, it appeared that soil fauna were at least in part responsible for their formation.

Description: Soil temperatures were measured at six depths within 1 m of the surface on 10 Cryosolic soils in the north-central Keewatin area during the summer of 1976. The mean soil temperatures during the study period varied between 1.7 °C and 8.2 °C at a depth of 20 cm and −0.2 °C and 6.0 °C at a depth of 50 cm. The maximum and minimum soil temperatures at a depth of 20 cm ranged from 4.4 °C to 13.9 °C and from −0.6°C to 3.9 °C, respectively, while those at a depth of 50 cm ranged from −0.2 °C to 6.7 °C and from −1.1 °C to 2.2 °C, respectively. During the study period a freeze-back of 30 cm or more occurred from the permafrost on several sites. Soil temperatures were markedly higher where the soil material and vegetation were disturbed. The effects of drainage, soil materials, aspect, slope position, vegetation and peat cover on the soil temperature are discussed.

Description: The δa15N for the total and nitrate soil N from surface samples taken from recharge and discharge areas associated with a saline seep differ significantly. Suggested reasons for these differences are included. These data suggest that the nitrate moving towards the surface with the soluble salts is depleted in the heavier isotope; the very high δa15N for total and nitrate N of surface samples suggests that denitrification has been a dominant process operating in the saline seep area. Incubation studies carried out on Ap samples taken from the recharge and discharge areas have verified that the δa15N (and perhaps also the nature of the mineralizable organic nitrogen) from a "mature" and "recent" saline profile are different from each other, and distinctly different from that of the recharge area.

Description: In a field plot study to examine the residual effects of heavy rates of coarse limestone (0, 11, 22 and 44 t/ha) in combination with P (560 kg/ha), K (1120 kg/ha), Mg (560 kg/ha) and PKMg (560 + 1120 + 560 kg/ha) applied five growing seasons previously, dry matter production of oats (grain and straw) decreased with increasing rate of limestone application. The decrease was attributed to lime-induced Mn and Zn deficiency. Both Mn and Zn uptake decreased significantly with increased limestone applications. Plant Mn and Zn concentrations were below critical levels in the heavily limed treatments. Neutral normal ammonium acetate soil extractable Mn was significantly related to oats Mn uptake and yield. This same extractant for Zn was not related to uptake of Zn or yield of oats. After the fifth season of cropping, residual limestone (Ca), P and K effects were evident as increased plant uptake and soil extractable Ca, P and K. Residual Mg was shown only by soil extractable Mg.

Description: Background levels of As, Cd, Co, Cu, Pb, and Zn in Chernozemic and Luvisolic soils from Alberta were established and are similar to the average terrestrial abundances in shale and granite. Redistribution of As, Cd, Co, Cu, and Zn within the solum was more pronounced in Luvisolic soils than in Chernozems. Partitioning of the six trace elements, determined by analysis of particle size separates, was unique for each element. Copper and zinc were more uniformly enriched in clay separates than were the other four trace elements. Differences in the content of trace elements within and among soils arise not only from textural variation, but also from large variations in the quantity of trace elements within a specific particle size fraction.

Description: The NH4OAc pH 7 method has been used traditionally to assess the availability of cations in soils for tree growth in coastal British Columbia but there have been no attempts to assess the validity of the method for this purpose. This objective was accomplished by determining the quantities of extractable cations (K, Mg, and Ca) in 42 forest soils in the Coastal Western Hemlock Biogeoclimatic Zone of British Columbia using four different extraction methods. The methods used were the NH4OAc pH 7, NH4OAc pH 4.8, 10% HCl, and 1% citric acid methods. A stepwise elimination multiple-regression technique was used to test the relationship of extracted cations to forest productivity. The amounts of cations extracted by the NH4OAc method were well-correlated with those extracted by each of the other three methods. Of the cation quantities extracted, those of Ca were best, although still poorly correlated with productivity. Of the extraction methods, the NaOAc method yielded quantities most closely correlated with productivity and is recommended for use in assessing the cation status of forest soils in the Coastal Western Hemlock biogeoclimatic zone.

Description: In the southeastern portion of Vancouver Island are found soils that are dark-colored in their surface horizons. These dark-colored surface horizons are mainly the result of the climate and vegetation. The surface horizons can be classified as either Ah(f) or Bhf horizons using the criteria of the System of Soil Classification for Canada. The B horizons were designated podzolic (Bf or Bhf) even though not all criteria were met for all horizons. The soils were classified as Sombric Humo Ferric Podzols, as this subgroup appeared the most suitable.

Description: The dispersive efficiency of ultrasonic vibration of Gleysolic samples in water or in electrolytes was comparable to that obtained by the peroxide-calgon method, with insonation in electrolytes yielding generally higher recoveries of clay than insonation in water. Ultrasonic dispersion in water was accompanied by considerable dissolution of Fe, Al, Si and organic-C. B horizon samples released on average about five times as much Fe, Al and Si as A horizons. The converse was found for organic-C release. Dissolution resulting from ultrasonic treatment averaged 49.6, 48.4 and 228 ppm (soil basis) Fe, Al and Si, respectively, for A horizons, and 286, 275 and 1492 ppm, respectively, for B horizons. The ratios of released Fe, Al and Si were consistently in the neighborhood of 1:1:5. Fe and Al dissolution were inversely related to organic-C release. Ultrasonic disperson in 0.01 M CaCl2 0.01 M BaCl2 or 0.1 M NaCl resulted in substantial suppression of these dissolution effects, with CaCl2 being the most effective. For Gleysolic soils, ultrasonic vibration is likely to give higher yield of less-altered organo-clay complexes than ultrasonic dispersion in water.

Description: A terrace section in the Peace River Valley of British Columbia contained seven buried paleosols developed in eolian material. Chemical, physical and micromorpholgical data showed the soils to be Chernozemic. The main soil-forming processes have been the leaching and reprecipitation of carbonates, the formation of mull aggregates, the weathering of primary minerals and the weak physical translocation of soil fabric. Five cultural components or levels had been identified in nearby archaeological excavations and these were correlated with the Ah horizons of five of the paleosols. However, none of these Ah horizons contained large amounts of organic P as have been found in cultural layers of other archaeological sections. The cultural components contained tools, flakes, shell beads, bones and projectile points. Radiocarbon dates from charcoal ranged from 5830 ± 80 yr B.P. in the second lowest paleosol to 1530 ± 70 yr B.P. in the second highest paleosol. They showed that most of the eolian material had been deposited on the terrace by about 4500 yr B.P.; that is, by the end of the Hypsithermal. The chronology of soil development and eolian deposition are discussed by applying a previously published system of horizon designations that combines and describes the gradational and pedomorphic features in soils.

Description: This study examines the effects of rural land uses on soil moisture and soil water use, the latter expressed in terms of vertical latent heat flux (LE). The field program took place during the 1976 growing season, utilizing a site at the University of Alberta Farm at Ellerslic, Alberta. The site contained several different rural surface plots, identically exposed to prevailing weather, thereby permitting direct comparisons of differences in soil moisture and LE between these plots. Thus, the effects of the surface cover were isolated from those of location. It was found that significant differences in soil moisture content had developed, despite the small sizes of the plots. Some generalizations appearing in the literature were evaluated, and several qualifications were found to be necessary, particularly in reference to the influence of stand density and plant activity on water use.

Description: A gas-stripping flow system is described whereby an inert gas, He, is used to remove nitrogenous product gases from a soil column undergoing anaerobic denitrification under steady state conditions. Net rates of nitrous oxide N2O, production are measured, for Brookston clay over a temperature range of 4–25 °C. The calculated Arrhenius activation energy for net N2O production remained approximately constant at 79.9 kJ∙mol−1 over a 37-day period. The emission rates declined slowly over the period by roughly a factor of 2. The significance of these results is discussed with comparisons to results obtained by others on the effect of temperature on denitrification rates in a variety of soils.

Description: The surface horizons of some Sombric Brunisols and Podzols were fractionated to determine the distribution of the organo-mineral complexes. The soils were dispersed in water using ultrasonics and fractionated by wet sieving and the continuous flow supercentrifuge. The amounts of organic matter and the surface area of each fraction were determined. The weight of organic matter per unit of surface area increased with increasing size of soil separates. A considerable amount of organic matter is associated with the coarser fractions, with 5, 12 and 49% of the total organic matter being associated with the sand, coarse silt and fine silt fractions, respectively.

Description: Forest floor samples were obtained from three mature, even-aged, naturally regenerated conifer stands which varied with respect to drainage and indigenous soil fertility. Field moist subsamples were stored for 200 days in a refrigerator maintained at 4 °C and in a freezer maintained at − 10 °C; in addition, forest floor samples, dried at 60 °C for 48 h, were stored at room temperature. Subsamples were extracted initially and at predetermined time intervals with 2 N KCl (to determine mineral NH4+-N and NO3−-N), with neutral 1 N ammonium acetate (to determine water-soluble + exchangeable K, Ca, and Mg), and with distilled water (to determine soluble P). At 4 °C, extractable NH4+-N changed little during the first week of storage but increased steadily thereafter at rates which appeared to increase with increasing total N. Nitrification, present only in the sample taken from the most fertile site, commenced after 40 days of refrigerated storage. Concentrations of soluble P decreased initially, but rose thereafter at low, moderate, and high rates depending on total P. Freezing changed mineral NH4+-N to a minor extent, whereas NO3−-N was not affected. Concentrations of soluble P increased steadily during the first 2 mo of storage at − 10 °C. Levels of extractable K, Ca, and Mg were not affected by refrigeration and by length of storage time, but freezing increased extractable K considerably. Drying at 60 °C for 48 h produced abrupt increases in exchangeable + water-soluble nutrient levels. Further changes, however, were not observed during subsequent storage at room temperature.

Description: Rather marked variations in δa15N values were obtained in a study carried out on samples taken from four soils belonging to the Weyburn soil association. The δa15N of the total N of well-drained depressional profiles dropped sharply with depth and, in contrast, for upper slope positions was relatively constant to a depth of approximately 5 m. This characteristic enrichment in the heavier isotope of total nitrogen of surface horizons may represent long-term immobilization of partially oxidized ammonium N into the organic N fraction; δa15N of the total N more closely represents past soil-forming processes while that of the nitrate N appears to reflect, in addition, recent N cycle stresses.

Description: Following deep plowing and subsoiling treatment in 1971, alfalfa and corn silage were grown continuously during a 5-yr period on Chaloupe soils which have an indurated layer at 40 cm or deeper. These soils were formed from laminated particles of very fine sand and loam of recent sedimentary origin. Measurements taken in 1972 and 1975 included bulk density, resistance to penetration, permeability, organic matter content and soil texture. Subsoiling did not significantly change soil physical properties; only a slice of soilless than 10 cm wide at depth 50 cm and deeper on each side of and in the furrow made by the ripper showed modifications, without affecting crop yields. Deep plowing, however, in turning the soil by 120° to 150° resulted in redistribution of the organic matter and the soil texture down the profile, a diminution in resistance to penetration in the subsoil. But it did not change the porosity or the permeability of the lower layers. Physical modifications brought by deep plowing were still persistent after more than a 3-yr period. Improvement in physical and hydrodynamic soil properties following deep plowing did not have any beneficial effect on corn and alfalfa yields.

Description: The yields of monosaccharides from peat fractions in five organic soils segregated by particle size revealed that as a general trend, the total monosaccharide content decreased as particle size decreased. However, in some peats, the 100-mesh fraction yielded more monosaccharides than the 40-mesh fraction. Likewise, the 200-mesh fraction yielded more monosaccharides than the 100-mesh fraction. The

Description: Two serpentine soils from western Newfoundland have been described and their chemical and physical properties documented. The Blomidon soil series is a moderately well to imperfectly drained Gleyed Regosol, cryoturbic phase, and the Round Hill series a well to moderately well drained Orthic Regosol, cryoturbic phase. Both soils developed from base-rich very stony, sandy-loam colluvium and till, derived mainly from serpentinized rocks. Horizon development is restricted by cryoturbation and this factor, combined with high Mg content (12–16%, total) (6.8–16.64 meq/100 g, available) and low essential macronutrient content, create adverse conditions for plant growth. In addition, there are present possibly toxic quantities of Ni (0.308–0.389% total) (0.008–0.031 meq/100 g available). The Ca/Mg ratios are 0.008–0.190, total and 0.030–0.361, available; soil textures are loam to sandy loam. Comparison is made to serpentine soils in Poland, Sweden, Great Britain, Rhodesia and the U.S.A., similarities and differences being noted.

Description: Seven placements ranging from natural sequence to complete mixing of the genetic soil horizons in soil columns were applied to six Dark Brown Chernozemic and Solonetzic soils. Two cultivars of barley (Hordeum vulgare L.) and one of wheat (Triticum aestivum L.) were grown in the greenhouse on the columns without watering after initial moistening to field capacity. Soil horizon mixing enhanced crop growth on the three Solonetzic soils but not on the Solodic or the two Chernozemic soils. With horizon placement in the natural sequence, almost half of the roots were contained in the upper 12.5 cm of the column. With complete horizon mixing, root distribution with depth was almost uniform. Maturity and senescence of the plants were delayed on the saline soils compared to the normal stils. The results agree with the known beneficial effects of soil horizon-mixing by deep plowing on some dryland Solonetzic soils and indicate that after such drastic landscape disturbance as occurs in strip mining, the solum should be stockpiled and replaced on the spoil but may be mixed without serious depression of crop productivity. The glacial till subsoils, which were of relatively low salinity in this study, were found to be superior to B and C horizon materials when placed beneath A horizon soil and within the rooting zone of the crop.

Description: Gnathotrichusretusus (LeConte) of both sexes were significantly more responsive to traps baited with S-(+)-sulcatol whenever ethanol was also present as a bait. Ethanol and α-pinene together acted as synergists for male G. sulcatus (LeConte) response to (±)-sulcatol. There was no synergistic effect on female response and no interaction between trap form and synergistic for G. sulcatus. Use of ethanol and α-pineneas synergists for (±)-sulcatol in a pest management program for G. sulcatus would enhance the male catch and thus reduce the possibility of uncaptured males creating competing pheromone sources.

Description: not available

Description: It has already been shown that a relation exists between the daily rate of spring sap flow and the twig temperature of sugar maple. The authors first develop a method to calculate this temperature from radiation, wind speed, and air temperature. For each sap flow cycle, the values of four factors controlling the phenomenon are determined: the number of hours and degree-hours below 0 °C and above 0 °C. Each factor is then converted into an efficiency function. The combination of the four functions gives the global efficiency of the climatic conditions for each sap flow cycle. The flows calculated from the global efficiency are strongly correlated (r = 0.94) with the measured ones.

Description: Foliage litterfall, Ol litter mass, and its Mg, P, and K content were estimated for six forest types in the Southern Appalachian region using 252 forest survey plots of the USDA Forest Service. General allometric equations were used to compute foliage litterfall, and average species foliage elemental concentrations were used for litterfall elemental content. Exponential decay rate constants (k) of foliage mass and elements were estimated from foliage lignin concentrations. The procedure was tested with measured litterfall and Ol litter at Coweeta Hydrologic Laboratory and selected Forest Service plots in Macon County, North Carolina. Litterfall and Ol litter mass were accurately computed. Elemental content of litterfall and Mg and K mineralization rates were overestimated; P mineralization rate was underestimated. First-year immobilization of Ca may render the exponential decay model invalid for Ca.

Description: A number of untransformed regression models were compared to the log-log form of the allometric function for estimating biomass. Models were evaluated using two tree species, Betulapapyrifera Marsh, and Pinusresinosa Ait., and one tall shrub, Ilexverticillata (L.) Gray, with total aboveground biomass as the dependent variable. Using goodness of fit as the criterion, both weighted linear and weighted nonlinear models proved to be acceptable alternatives to the transformed allometric equation. Weighted models retain the advantage of the log-log form, i.e., compatibility with the homogeneity of variance assumption, but avoid the transformational bias.

Description: Volume, dry weight, density, and kraft pulping data were obtained from control and fertilized, mature balsam fir (Abiesbalsamea (L.) Mill.) from Nova Scotia. Fertilization treatments consisted of 450 kg N/ha; 450 kg N and 112 kg P/ha; and 450 kg N, 112 kg P, and 112 kg K/ha, plus the untreated control. Samples were taken at three height positions in trees: stump, breast height, and mid-stem. Wood laid down for 5 years after treatment was separated from wood laid down for 5 years before treatment, and its density determined before being pulped by the kraft process.Fertilization significantly increased volume and dry weight increment and reversed patterns of growth decline during the response period. Any effect specifically due to phosphorous or potassium fertilization over that of nitrogen could not be detected with certainty. Wood density was reduced by N and NP applications; however, pulp yield was unaffected by the fertilization treatments. The need for tree equivalence prior to treatment is stressed for more precise testing of differences.

Description: Sensitive and tolerant eastern white pine (Pinusstrobus L.) clones were exposed to 5.0 ± 0.5 pphm SO2 for 2 h. At the end of the fumigation, the average apparent photosynthetic rate was depressed by 27% in sensitive clones and by 10% in tolerant clones. Regression analysis of rate of reduction in photosynthesis over the 2 h was significant (0.05 level) for both classes, as was the difference (0.01 level) between the levels of the two regressions. Differences in final needle lengths of fumigated tolerant and sensitive clones were not significant.

Description: The impact of the current budworm outbreak on deer (Odocoileusvirginianusborealis Miller) was studied from 1972 to 1979 in a wintering area located at the northern extremity of Témiscouata Lake, Québec. This area encompassed 20 km2 and consisted mostly of balsam fir (Abiesbalsamea (L.) Mill.) and spruce (Piceaglauca (Moench) Voss) stands which suffered high mortality in 1975. The proportion of coniferous cover dropped from 66 to 29% as a result of the outbreak. Nevertheless, the area occupied by deer and the deer population itself remained quite stable. Deer progressively deserted balsam fir - spruce stands and sought shelter in cedar (Thujaoccidentalis L.) stands that are well distributed throughout the study area. Elimination of balsam fir from the shrub layer of the more severely affected stands resulted in a loss of two-thirds of the browse biomass and invasion by raspberry (Rubusidaeus L.). Conversely, tree lichens on dead trees have become an important new food source. The impact of large-scale tree mortality by the budworm in wintering areas sharing the same ecological conditions may depend on the presence or absence of cedar stands as an alternative coniferous cover type.

Description: Cambial electrical resistance (CER) of more than 10 000 trees, predominantly balsam fir (Abiesbalsamea) and red spruce (Picearubens) was measured in 90 stands in northern Maine, New Hampshire, and Vermont, U.S.A. CER index values (mean CER, kiloohms per stand) ranged from 9 to 13 for fir in nonoutbreak situations, and 9 to 18 in outbreak situations with moderate to heavy budworm infestation, whereas values for red spruce remained essentially constant at 7 to 13 in both situations. Balsam fir trees in stands with an index value of 9 grew almost three times faster (diameter growth) than in stands with an index value of 13. An increase of index values from 13 to 18 in outbreak situations indicated no further reduction in growth, but may indicate impending mortality of trees with lower vitality. Such index values may be useful in developing a hazard rating system for fir stands infected with spruce budworm.

Description: Northern red oak (Quercusrubra L.) 1-0 seedlings were planted in plastic tubes with a rubber moisture barrier placed around taproots at midpoint so that upper and lower sections of the root system could be independently watered with polyethylene glycol solutions to induce various soil moisture stress conditions. Trees were also grown at two relative humidity (RH) levels.In the first of two studies, soil moisture stress levels were −1/3, −3, −6 bars (1 bar = 105 Pa), and RH's were 75 and 45%. Root regeneration (largely confined to cut end of lower taproot) and top growth decreased, and dieback of planted stems increased, as soil moisture stress of either upper or lower root sections increased. When both sections were −6 bars, root regeneration was nil.In the second study, upper root soil moisture stress levels included a −12-bar treatment which reduced dry weight of leaves and roots to about one-half that of unstressed plants. However, a unit increase in stress to lower root sections was 1.5 to 4 times more inhibitory to growth than a similar stress to upper root sections. Low RH decreased several measures of seedling growth, increased stem dieback, and prolonged time to budbreak from 6 to 12 days for most soil moisture treatments.These studies demonstrate that root regeneration is very sensitive to soil moisture stress on lower roots, where most of the new roots originate, and moderately sensitive to stress on upper roots and to atmospheric stress on shoots.

Description: The monoterpene composition of the cortical oleoresin was studied in young trees of Piceasitchensis (Bong.) Carr., chosen to provide a wide range of chemical types. The cortical oleoresin systems of main stem and branch shoot apex differed from each other in composition, but for each system the variation within trees generally became significantly large only in basal and apical regions of the trees, with 3-carene showing the greatest variation. Blister oleoresin monoterpene composition was similar to that of the main stem. Seasonal changes in the composition of the main stem cortical oleoresin were insignificant. Young shoots immediately after flushing showed monoterpene compositions different from those of the previous year's mature shoots, and gradually reached the mature compositions during summer and early autumn. The nature of some of the differences, notably that of α-pinene, varied between trees. In most trees the new shoots contained relatively high concentrations of β-pinene and limonene; terpinolene was at very low concentration but had returned to normal levels after a month, while 3-carene gradually accumulated over a longer period sometimes extending into autumn.

Description: Soil and air temperatures, and soil water tension were measured at two sites from June 1972 to August 1973 in order to determine the effect of scarification. This study is part of a project concerning yellow birch regeneration. The minimum air temperature at 30 cm height and at the soil surface were, respectively, 0.5 and 1.0 °C higher at the scarified site; on the other hand, the maximum temperature at 30 cm was lower. The soil temperatures during the summer were 2 to 4 °C higher at the scarified site according to the level considered. Soil water tension was much lower in the scarified station between 0 and 15 cm depth, but the effect decreased during the second summer of the study.

Description: The effects of 13 growth retardants and inhibitors on the growth of container-grown seedlings of Pinuscontorta var. latifolia Engelm. and Piceaglauca (Moench) Voss were examined. Shoot and root growth was reduced to different extents by the various compounds, thus causing alterations in shoot/root ratios. The results are discussed with regard to the potential use of these chemicals for enhancing survival after outplanting or for use in held-over material. Ancymidol, Ethrel, Phosphon and Maintain caused decreases in the shoot/root ratio and may have potential for use in material to be planted out. CCC, RH531, Ethrel, and Mefluidide appear to have potential for use in held-over material.

Description: Eighty black spruce (Piceamariana (Mill.) B.S.P.) trees from four pulpwood stands in north central Ontario were sampled to determine crown fuel weights. Crown fuel components, both living and dead, were separated into size classes precise enough for use in forest fire behavior research. Regression equations expressing various crown fuel components as a function of tree diameters at breast height (DBH) were derived, and the resulting.R2 values were between 0.75 and 0.84.Total crown biomass figures are presented herein for the four stands sampled. Approximately 80% of the total crown weight per hectare is made up of fuel particles ≤0.64 cm in diameter (including needle foliage). Live fuels make up approximately 74% of total crown weight per hectare.

Description: Correlations among measurements of electrical resistance of cambial zone tissue, phloem thickness, and tree diameter, reported earlier for other species, were also found for lodgepole pine (Pinusconforta Dougl.). Using these relationships, a model was developed for estimating phloem thickness in lodgepole pine, an important factor in assessing stand susceptibility to mountain pine beetle (Dendroctonusponderosae Hopk.) epidemics. The predictive model and procedures for scaling estimates to specific time and location were tested with data from a lodgepole pine stand nearly 100 miles (161 km) away from the sample trees used in fitting the model. Results for stand data grouped into 3-in. (7.6 cm) diameter classes showed that class means of scaled model estimates were within ±4% of class means of phloem thickness for all diameter classes of the test stand. Model development and application procedures should be applicable to other species where estimates of phloem thickness and its distribution in stands is of interest.

Description: Dimension analysis techniques were used in the harvest of 31 largetooth aspen (Populusgrandidentata Michx.) from three mature stands (55 ± 7 years) representing a wide range of soil quality and clonal variation among aspen in northern lower Michigan, U.S.A. Regression equations were derived to predict component biomass and net annual production from tree dbh. Evaluation by analysis of covariance indicated significant differences (P 

Description: Results with Pinuspalustris Mill, seedlings grown in pine bark with and without Pisolithustinctorius ((Pers.) Coker and Couch) inoculum and drenched with seven fungicides showed that ectomycorrhizal development by P. tinctorius was completely inhibited by Terraclor, reduced by Captan and Dexon, not affected by Mertect and Truban, and stimulated by Benlate and Banrot. In the noninfested medium, ectomycorrhizal formation by airborne fungi (mostly by Thelephoraterrestris Ehr.) was greater on seedlings drenched with Benlate, Mertect, and Dexon than on the control. Terraclor and Truban reduced T. terrestris ectomycorrhizal development. Generally, fresh top and root weights were not affected by fungicide treatment. Stem diameters of seedlings treated with Captan, Dexon, Mertect, and Truban, and the control were larger in the noninfested medium than in the medium with P. tinctorius.

Description: Recent growth and harvest trends in commercial timberlands of the temperate zone suggest that these forests have been serving as a net sink for about 1.0 × 109 to 1.2 × 109 t of carbon annually over the past 3 decades. This is 20 to 60% of the annual carbon release from combustion of fossil fuels over the period, indicating that recovery transients in temperate zone forests apparently have been partially dampening the increase in atmospheric CO2 caused by fossil fuel combustion and tropical forest reduction. Net forest growth is occurring throughout the temperate zone with principal carbon sinks found in North America and in Siberia. Timber inventories for North America show an excess of growth over harvest equivalent to over 5 × 1015 g of C since the 1950. Limited data suggest that in Siberia there is a large stock of slowly growing conifers that are underexploited, forming a sink equivalent to that of North America. Reafforestation in western Europe has expanded forest area by 5% since World War II. Similar recovery may now be occurring in temperate Asia. Problems of data reliability, particularly for the U.S.S.R., and the limited basis for estimating carbon balance in entire forests, suggest a severalfold uncertainty in the carbon sink estimates.

Description: The following relationships were quantified in a mathematical computer model to predict spread and intensification of dwarf mistletoe (Arceuthobiumtsugense (Rosendahl) G. N. Jones) infection, originating from residual trees, in regeneration of western hemlock (Tsugaheterophylla (Raf.) Sarg.): distribution of dwarf mistletoe infections in residual source trees, dwarf mistletoe seed production, escape from crown and dispersal, interception of seeds by neighboring trees, distribution of seeds within crowns, development of dwarf mistletoe infections, mortality of plants, and tree crown growth. The model included options for thinning or sanitation by removal of infected residual or regeneration trees. Predictions by the model for a 10-year period did not differ significantly (p = 0.05) from results of a field plot with respect to average number of infections per tree, percentage of infections at 1-m distances from the residual tree, and percentage of infections in each quadrant centered on residual source tree. Predictions of the effects of stocking density and sanitation or thinning on infection agreed with results obtained from experiments with other tree species.

Description: Classical growth analysis was used to examine the basis of major variation in seedling growth characteristics among and within six deciduous tree species in nursery beds. A combination of high investment in leaf area and substantial net assimilation rate accounted for the high relative growth rate of Liriodendrontulipifera L. and Prunusserotina Ehrh.; these species also produced the largest seedlings in the test. Final weight of four Quercus species was closely associated with initial leaf area established at germination; Q. rubra L. and Q. prinus L. had the largest seedlings despite having net assimilation rates lower than Q. alba L. and Q. ilicifolia Wangenh., the smallest seedlings in the test. Within species, relative growth rate was significantly correlated with both net assimilation rate and relative growth rate of leaf area. Leaf area partition coefficient was positively correlated with relative growth rate in L. tulipifera, P. serotina, and Q. rubra but not in Q. alba, Q. prinus, and Q. ilicifolia.

Description: Pressure–volume curves for western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings showed roots to have lower osmotic potentials, at both full turgor and incipient plasmolysis, and lower relative water contents at incipient plasmolysis than shoots. Roots remained turgid under mild water deficit, whereas shoots lost turgor exponentially with water content. Shoots of seedlings given a 2-week drought stress had lower osmotic potentials at full turgor and incipient plasmolysis than shoots of unstressed seedlings; roots showed a similar trend.

Description: Variation in duff depth and weight was studied on two adjacent different aged subalpine stands in eastern Washington, U.S.A. In a 105-year-old Pinuscontorta Dougl. stand, the duff depth averaged 5.46 cm as compared with 4.57 cm for a 305-year-old stand of the same habitat type. The difference between the means was not significant. The greatest duff depth (46 cm) in the younger stand was almost twice that of the older stand (26 cm), due principally to the time since last disturbance by fire. A correlation of duff depth (D; centimetres) to weight (W; tonnes per hectare) produced the equation W = 7.26 + 13.27 D which had r2 = 0.849 and SE = 7.06.

Description: Potted grafts of old spruces (Piceaabies (L.) Karst.) were continuously fumigated with SO2 (contro1, 0.05, 0.1, and 0.2 ppm) in outdoor fumigation chambers. SO2 concentrations were maintained for 10 weeks from late in April till early in July 1976. CO2 uptake was measured periodically under standardized laboratory conditions with an infrared gas analyzer. After fumigation, the plants remained in the nursery till November 1977. Afterwards, stem slices were taken for X-ray measurements of both ring width and wood density. An arbitrary density of 0.5 g cm−3 was chosen to distinguish early wood from late wood. CO2 uptake was depressed significantly before visible symptoms of injury appeared. The relative CO2 uptake in the 7th to 10th week of fumigation and the number of cells in a radial file of the annual ring were well correlated. With increasing SO2 concentration, the width of the annual ring decreased. The amount and density of late wood was reduced by a springtime fumigation. A distinct decline of wood production with increasing SO2 concentration was also found in cases where no visible injury occurred.