ALBERT

Description: The effects of different intensities of forest management on forest floor organic matter and nitrogen dynamics in northern hardwoods were simulated with a computer model built from the extensive data base of the Hubbard Brook Ecosystem Study. Three cutting intensities and three rotation lengths were tested. In all cases, both nitrogen availability and forest floor organic matter declined for 15–30 years following cutting and required 60–80 years to recover to precut levels. Rotation length had a much greater effect on the forest floor than harvesting intensity with short-rotation (30-year) complete forest harvesting causing the greatest reduction in both biomass and nitrogen availability. Average forest floor biomass under this treatment was reduced to roughly one-half of that under clear-cutting (90-year rotation).

Description: Soils on 53 burned sites in the upper peninsula of Michigan were examined for fire-induced water repellency. The development of water repellency was found to be fire related with over 40% of the burned soils showing at least some water-repellent properties. Most water-repellent layers occurred in the upper 5 cm of mineral soil and were related to burn intensity. Laboratory burning experiments with 10 hardwood and conifer litters showed that white pine, red pine, and quaking aspen litter produced water repellency in underlying mineral soil. Repellency was also found on unburned sites, particularly under aspen. Water-repellent soils were widely distributed, but their nonwettable properties generally decreased rapidly over time. Fire-induced water repellency does not appear to present a major long-term management problem on most soils in this region. However, on certain burned sites, water repellency may influence seedling survival and subsequent stand establishment.

Description: A review is presented of the shortcomings of most existing taper equations which predict diameter along the stem as a function of tree height and diameter at breast height. A new computerized system is developed that has many desirable features for tree profile prediction. This new system consists of two mathematical functions, one describing the upper bole and the other describing the lower bole. The two functions are linked together at the inflection point and are continuous at that point. Tests of this model on 32 species age and locality groupings of British Columbia species show that although there is still a slight bias near ground level, the prediction of diameter inside bark is almost perfect over most of the length of the trees.

Description: Seedlings of four coniferous species, Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), white spruce (Piceaglauca (Moench) Voss), and lodgepole pine (Pinuscontorta Dougl.), were grown for 4 months from germination and then exposed to soil drying. Rates of photosynthesis were measured for all species and rates of dark respiration and transpiration were measured for Douglas-fir and hemlock. In a study of survival, seedlings were exposed to various durations of soil drying and the plant water potential was determined before the plants were rewatered; seedling survival was subsequently recorded.Rates of photosynthesis declined for Douglas-fir, hemlock, spruce, and pine when the plant water potential decreased from −10.0, −10.7, −12.4, and −6.6 bars (1 bar = 100 kPa), respectively, and became zero with potentials of −53.9, −39.7, −28.6, and −22.4 bars. When grown together in the same pot and exposed to soil drought, hemlock had a consistently lower potential than Douglas-fir, and spruce had a lower potential than pine. Hemlock could survive potentials of −40 to −60 bars, whereas seedlings of the other species survived potentials to −110 bars.

Description: Temporal and spatial dynamics of organic matter and mineral elements were studied in an aspen woodland floor in southwestern Alberta, Canada. The average depths of the layers comprising the organic horizon were as follows: L, 0–2 cm; F, 2–4 cm; H, 4–7 cm; and Ah, 7–8 cm. The average annual amounts of organic matter in the soil layers were the following: L, 10.3 × 103 kg ha−1 (range 8.0–16.4); F, 18.2 × 103 kg ha−1 (13.2–24.5); H, 31.5 × 103 kg ha−1 (24.0–40.4); and Ah, 4.2 × 103 kg ha−1 (3.8–5.0); the total weight of soil organic matter was 64.2 × 103 kg ha−1 (49.0–86.3). The H layer accounted for 50% of the soil organic matter; total soil organic matter, to a depth of 8 cm, constituted about 0.30 of the total living above-ground plant biomass. There were no evident statistically significant seasonal fluctuations of organic matter in any of the organic layers; the turnover rate of the soil organic matter was 0.08 year−1 and the mean residence time was 12.5 years.The concentrations of Ca, Mg, P, and N generally decreased with profile depth, while K, Fe, Mn, and Na increased in concentration. Zinc concentrations showed no obvious trend but it did appear that Zn might be concentrated in the F and Ah layers. The orders of abundance of elements in the soil layers were as follows: L,  Ca 〉 N 〉 K 〉 Mg 〉 P 〉 Fe 〉 Zn 〉 Mn 〉 Na 〉 Cu; F, Ca 〉 N 〉 Mg 〉 K 〉 Fe 〉 P 〉 Zn 〉 Mn 〉 Na 〉 Cu; H, Ca 〉 N 〉 Fe 〉 K 〉 Mg 〉 P〉 Na 〉 Mn 〉 Zn 〉 Cu; Ah, Fe 〉 N 〉 K 〉 Ca 〉 Na 〉 Mg 〉 P 〉 Mn 〉 Zn 〉 Cu; total, Ca 〉 N 〉 Fe 〉 K 〉 Mg 〉 Na 〉 P 〉 Mn 〉 Zn 〉 Cu. Maximum weights of Ca, N, Mg, and P were found in the H layer, whereas K, Fe, Zn, Mn, Na, and Cu were most abundant in the Ah. There was some indication that the amounts of some elements fluctuated positively or negatively with rainfall and (or) soil moisture levels. Based on limited input data for the elements, turnover times were calculated and compared with literature values.

Description: Diurnal measurements of leaf conductance, xylem water potential, temperature, humidity, and radiation were taken on six sites throughout Oregon. Xylem water potential was hypothesized to influence leaf conductance in two ways. First, predawn xylem water potential controlled the early-morning maximum leaf conductance of Pseudotsugamenziesii (Mirb.) Franco. Second, irrespective of predawn water potential, a threshold diurnal water potential was found. Whenever water potential of Pseudotsugamenziesii dropped below −20 bars (−20 × 105 Pa) during the day, a significant decrease in leaf conductance resulted. If the water potential threshold was not reached during the day, leaf conductance stayed at the morning maximum or decreased slightly in response to decreasing humidity.

Description: Damage caused by the white-spotted sawyer, Monochamusscutellatus (Say), to felled white spruce, Piceaglauca (Moench) Voss, in northern Alberta was studied to provide data for improving a damage assessment technique. Numbers, density, and size of larval entrance holes, length of larval galleries, and diameter of adult exit holes were examined on three 122-cm-long log sections cut near the butt, middle, and top of each of 30 trees. Information on larval development and survival and adult emergence was also obtained.Size of larval entrance and adult exit holes and gallery length decreased from the butt to top of the tree, numbers of entrance holes were similar at the three stem positions, and density of entrance holes increased from butt to top on both south and north aspects. The density of entrance holes around the logs showed two maxima, while the mean density was approximated slightly above midlevel on south and north aspects. Larval galleries extended to an average maximum depth of 7.5 cm into the wood. About 25% of adults emerged 1 year after oviposition, the rest emerged after 2 years. Mortality of M. scutellatus within the logs averaged 71%. The results are discussed in relation to sampling problems for damage assessment in felled and standing fire-killed trees.

Description: Decay caused by some common wood-destroying fungi in several associated tree hosts of the Intermountain forests of western Montana was evaluated as a potential environment for the fixation of dinitrogen. Differences in the rates of fixation were demonstrated between various decay stages, tree species, decay fungi, and brown and white rots. Advanced brown-rotted wood was a more favorable system for nitrogen fixation than wood partially brown rotted. Also, brown-rotted substrates proved to be more favorable than did white rotted, particularly Pseudotsugamenziesii (Mirb.) Franco wood decayed by Fomitopsispinicola (Swartz ex Fr.) Karst. Data demonstrate that a nitrogenase function coexists naturally with decay fungi in woody substrates and that appreciable and significant amounts of nitrogen are fixed in these substrates.

Description: Lateral buds were formed on Piceasitchensis (Bong.) Carr. leaders in April–May before the leaders emerged from the winter buds. At that time, the lateral buds seemed to be evenly (not randomly) dispersed over the cone-shaped surfaces of the parent leader buds. This observation was confirmed and extended by defining the positions of lateral buds on fully extended leaders of P. sitchensis, P. abies (L.) Karst., P. omorika (Pancic) Purkyne, and Larixdecidua Mill. and 'theoretically' telescoping the leaders to their probable shapes in April–May by using computer simulations. It was concluded that the centres of cell division which preceded lateral bud formation were positioned by inhibition–competition mechanisms. This explained why (a) the numbers of lateral buds were related to the sizes of the parent shoots, (b) lateral branches were dispersed with equal expectation in all compass directions, with minimal mutual shading, and (c) a variety of staggered and whorled branch arrangements could occur on leaders of different trees, as long as each whorl was associated with a branchless zone.

Description: Armillariamellea isolations from the roots of dead and dying conifer saplings increased by 40% when o-phenylphenol (OPP) was added to malt agar compared with isolations on malt agar alone; they were similar on the two media from the roots of larger, healthy trees. This is attributed largely to the inhibiting effect of the additive on fast-growing Hyphomycetes and other fungi which are far more abundant in the roots of dead or dying saplings than in the roots of healthy older trees. Decay-causing Basidiomycetes other than A. mellea were isolated less frequently, whereas bacteria and yeasts were isolated more frequently, when OPP was added to the malt agar medium. This suggests that the additive must be used with discretion.

Description: Sporulation by the Indian paint fungus was maximal during cool, wet periods in the fall. Basidiospores were viable throughout the year, but maximum germination occurred only after temperatures had fallen below 0 °C. It is postulated that infection of western hemlock (Tsugaheterophylla) occurs in spring when a single basidiospore comes in contact with the stub which remains after shade-killed branchlets, about 1 mm in diameter, are broken off at their base. Anatomical studies of branch stub formation showed that this stage is reached around age 40 and that residual stubs must be exposed almost 2 years before they can serve as infection courts. After stub closure, the fungus becomes dormant and can survive in the medullary tissues for up to 50 years or more without causing decay. The possibility is discussed that conditions associated with large branch stubs and other deep-seated injuries, such as logging scars, broken tops, or frost cracks, are responsible for reactivating dormant infections and initiating the decay process. Clarification of the infection mechanism explains observed variations in severity of decay caused by E. tinctorium in different forest associations and provides a simple method, based on host age and stem-ring patterns, for estimating the decay threat in individual trees and stands, without extensive, destructive sampling.

Description: Dry matter production by Sitka spruce seedlings (Piceasitchensis (Bong.) Carr) outside the period of shoot extension was determined in southern Scotland by harvesting plants from a nursery on 13 occasions between late September and mid-May. Air and soil temperature and incoming radiation were measured in an attempt to relate weight changes to climatic variables. Dry weight of the plants apparently doubled between late September and mid-April but subsequently changed little. Most dry weight increase occurred during October, late March, and April but there was also a slight increase in weight in midwinter. The relative increase in weight was similar in roots and shoots until mid-January but thereafter was proportionally much greater in shoots than in roots and was associated with a marked increase in needle weight. Lack of weight increase in late spring was attributed to the respiratory demands of bud expansion. Dry matter changes in the 12 harvest intervals was not related to mean daily temperature, incoming radiation, or photoperiod, but when averaged over periods of 1 month a much closer relationship was evident.

Description: Descriptive records of wildfires since the earliest writings and quantitative provincial fire records since 1915 have been used to produce a synthesis of fire history for the Province of Nova Scotia, Canada. Large annual burns were common up to the mid-1930's. Annual burns totalling over 15 000 ha occurred in each of the years 1918, 1920, 1921, 1930, 1934, 1944, and 1947, and annual burns totalling over 30 000 ha occurred in each of the years 1920 and 1921. Lightning has accounted for 1% of the number of fires (three per year). Thirty percent of the fires have occurred in the month of May; however, fires have been recorded for all months. Fire rotation periods for the province as a whole were 1000 or 2500 years, using the mean annual burn or median annual burn, respectively, for all burns in the years 1915 to 1975. In contrast, calculations of burned areas on maps produced at the turn of the century gave presuppression fire rotation periods of just over 200 years. Vegetation types have had widely varying fire rotation periods. The vegetation of Cape Breton Island has been subjected to almost no fires over 20 ha, whereas the vegetation type with the shortest fire rotation period (in the interior of western Nova Scotia) has been subjected to fire rotation periods as low as 65 years at the turn of the century, to about 2000 years for the years 1958 to 1975. A summary of fire rotation periods for the Boreal, Great Lakes – St. Lawrence, and Acadian Forest Regions found in the literature is presented for comparison with the Nova Scotia data, and more detailed comparisons are made between the fire rotation periods of the similar vegetation types in New Brunswick and Nova Scotia.

Description: A rooted-tree computer data structure is used as an analogue of coniferous tree crowns in building a simulation model of a single tree. Submodels of branch death and the allocation of stored reserves are used to illustrate the model. The programming language used is PL/1.

Description: Some theory and observations are presented on the factors governing the start and spread of crown fire in conifer forests. Crown fires are classified in three ways according to the degree of dependence of the crown phase of the fire on the ground surface phase. The crown fuel is pictured as a layer of uniform bulk density and height above ground. Simple criteria are presented for the initiation of crown combustion and for the minimum rates of spread and heat transfer into the crown combustion zone at which the crown fire will spread. The theory is partially supported by some observations in four kinds of conifer forest.

Description: Oleoresin viscosity, flow (rate, duration, and total amount), and rate of crystallization were determined for Pinuselliottii Engelm., Pinuspalustris Mill., Pinustaeda L., and Pinusechinata Mill, in central Louisiana, U.S.A. Physical properties of the oleoresin and tree morphological characteristics (diameter at breast height, growth rate, height, crown ratio, and age) were not strongly related in either of the four species. Pinuselliottii oleoresin was extremenly viscous, crystallized very slowly, and flowed at a slow rate over a long period, and total yield was moderate. Pinuspalustris oleoresin was of moderately high viscosity and very high yield and had a high rate of flow. Pinustaeda and Pinusechinata oleoresin had, on the average, low viscosity, a moderate to low total yield, a short duration of flow, and rapid rate of crystallization. A discriminant function analysis revealed that 19% of the Pinustaeda and 6% of the Pinusechinata trees had oleoresin properties more similar to Pinuspalustris and Pinuselliottii than to the means for their own species. This information is being used to assess tree susceptibility to attack by Dendroctonusfrontalis Zimm.

Description: This paper describes the variation in the drying rate of jack pine (Pinusbanksiana Lamb.) litter with external conditions. Temperature, relative humidity (RH), and wind were varied separately. Drying runs were carried out in a cabinet with controlled temperature and humidity and also in the open laboratory. Most runs followed the exponential pattern, and the drying rates were measured in terms of the slope of the semilog graph of free moisture content versus time. The logarithm of this slope was found to be inversely proportional to the reciprocal of absolute temperature. The drying rate varied with 100 – RH at high RH but increased only slightly below 60% RH owing to the limiting effect of the wax and resin content on the rate of internal diffusion. Drying in wind proceeded in two stages, the first faster than the second. Wind was important at low speeds, and the drying rate increased but little above 2 km/h. These principles were used in the design of the drying equations of the Fine Fuel Moisture Code of the Canadian Forest Fire Weather Index.

Description: Previous studies of budworm impact on balsam fir stands have correlated the probability of tree damage and mortality with only a few broad stand characteristics. Improved predictability may be obtainable from a model incorporating foliage production of fir, budworm feeding rate, and tree vulnerability. Some data are presented on the first two variables with comments on further research requirement.

Description: Northern red oak seedlings were top-pruned in the seedbed each month from August until the next March. In late March, all trees were lifted, planted in the greenhouse, and harvested 30 days later. Any top-pruning treatment that directly or indirectly removed the leaves in late summer or early fall markedly reduced root regeneration and initial shoot growth after planting in March. Removal of all the visible buds at any date resulted in increased numbers of new shoots after planting, while pruning stems at the groundline reduced new shoot growth.In additional studies, shoots and roots of trees lifted in March were pruned to various levels before planting. Results indicated that root pruning influenced seedling growth much more than shoot pruning. The amount of new shoot growth was significantly correlated with root weight of seedlings when planted, whether differences in root weight were natural or obtained by pruning. The effects of shoot pruning and root pruning on seedling growth were largely independent of each other.

Description: New methods of simulating aggregated distribution of point spatial patterns have been developed. These methods aggregate points to a degree specified by Pielou's index of nonrandomness by reversing its sampling procedure. Included are a review of previous methods of simulating aggregation, a full description of the present approach, and examples of simulations with varying density levels.

Description: White spruce (Piceaglauca (Moench) Voss) seedlings were germinated and grown for 20 weeks in containers ranging in volume from 10 cm3 to 524 cm3. Containers for four of the six volumes were constructed in three different ratios of height to diameter (1:1, 3:1, and 6:1), with the remaining two volumes at 3:1. Both container diameter and volume had prounced effects on seedling growth. White spruce produced significantly more roots in the top quarter of the container than did lodgepole pine (Pinnscontorta Dougl. var. latifolia Engelm.), indicating that white spruce and lodgepole pine require containers of different configuration for optimum growth.

Description: An index was developed that takes into account the combined influence of air and soil temperatures, light, and the availability of soil moisture upon photosynthesis by a unit area of fully exposed foliage of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco). The index is derived from a summation of daily estimates of carbon assimilation (milligrams CO2 assimilation per decimeter per day) for an entire year. In a comparison of forest environments in western Oregon the index was correlated to a measure of forest productivity (r2 = 0.99). Furthermore, it suggests that much of the annual carbon fixation occurs during the mild winters characteristic of the region. The ability to assess the effects of frost, soil drought, and other variables separately was valuable in explaining differences between coastal, valley, and mountainous sites.

Description: Total aboveground dry weight biomass and annual production were determined for two sites of different soil texture in an alder swamp of Michigan's upper peninsula. The more poorly drained site A averaged 5300 g/m2 and 640 g/m2 per year while site B averaged 3100 g/m2 and 570 g/m2 per year. The smaller standing-crop biomass on the better-drained site B is due to greater abundance of Alnusrugosa. The tree stratum constitutes 97 and 93% of the total biomass and 84 and 80% of the total production on site A and B, respectively. The understory strata constituted the remaining 3 and 16% of the biomass and production on site A and 7 and 20% on site B.

Description: Distribution of N, P, K, Ca, and Mg in the tree, understory, forest floor, and mineral soil horizons was determined for two series of postfire forest stands in northeastern New Brunswick. Twelve pure jack pine stands (Pinusbanksiana Lamb.) and 11 mixed hardwood stands aged 7–57 years were examined. Regression equations relating aboveground tree nutrient content to diameter for eight tree species were calculated. The jack pine stands demonstrated variable stand density, but adjustment to normal stocking produced a sigmoid nutrient accumulation pattern in the tree layer during the 60-year period. Nutrient accumulation in the tree layer of both series of stands closely approximated biomass accumulation. Understory nutrients formed a significant fraction of the total aboveground pool, particularly in the younger stands. Organic and mineral soil horizon nutrients were found to be highly variable for both series of stands; this was postulated to be a result of the fire origin of the stands, with varying fire intensity and postfire conditions resulting in different nutrient losses from the site.

Description: The patterns of ring width throughout the root systems and stems of several 32- to 36-year-old, plantation-grown red pine were analyzed. All root systems showed a basic similarity in their radial sequences of ring width. Within a root system, individual sequences ranged from those similar to the radial sequence at the stem base to ones apparently dissimilar. At the stem–root base, the increasing distance to the tree crown with time and changes in mechanical stresses with increasing tree size appeared to play major roles in the development of the basic pattern. The position and type of root, the environment of its apices, and changes in the transportation pathways in the xylem and phloem at branching points may all have influenced the pattern in individual roots. The pattern of deposition of xylem at branching points was visualized as an interaction between the stream of growth regulators and assimilates towards the root tips and the stream of xylem water (and (or) dissolved substances) towards the root base. Discontinuities in the growth layers did not occur in the stem but increased with time in the roots, particularly in the surface horizontal roots. Moisture availability modified the radial sequence patterns and probably influenced the shifts in longitudinal distribution of radial increment from year to year within and between the stem and the root system. The maximum current annual increment in root wood volume occurred before that in the stem.

Description: Concentrations of N, Ca, K, P, Mg, Na, Zn, Mn, Fe, Al, B, and Cu were determined in the leaves of a 43-year-old stand of Populustremuloides Michx. by upper, middle, and lower crown positions and for seven sampling dates over the growing season. Concentrations of Ca and K in the upper third crown position were consistently lower than those in either the middle or lower third positions by an average of 0.19 and 0.20% ovendry weight, respectively. Concentrations of Mg and Na remained constant over time; concentrations of N, K, and P continually decreased over time; and minor elements showed a net increase over the growing season with an intermediate peak on June 30. Suggestions for sampling schemes are given.

Description: The area of root disease centers on the Coeur d'Alene National Forest in northern Idaho was effectively estimated from large-scale color infrared aerial photographs. An estimated 5.1% (12 160.7 ha) of the commercial forest land was occupied by infection centers. Root disease centers were identified in 113 of 364 stands actually surveyed. Although most of these 113 stands were of the Tsugaheterophylla – Pachistimamyrsinites habitat type, the highest percentage of stands with root disease was found in the Abiesgrandis – Pachistimamyrsinites habitat type.Observations made during these studies suggest that occurrence of Pseudotsugamenziesii (Mirb.) Franco, Abiesgrandis (Dougl.) Lindl., or both in a stand is the most important factor in the expression of root disease centers. Accuracy of interpretation of photographs was 92%; incorrect interpretations were consistently associated with stands in the Abieslasiocarpa series of habitat types or with stands stocked with conifers tolerant of root pathogens.

Description: More decay (higher incidence and greater total length of column) was associated with tapholes in mature sugar maples (Acersaccharum Marsh.) treated with a 250-mg paraformaldehyde pill than with control tapholes. This was apparent 20 months after treatment and at each successive examination to the final measurement at 56 months. Discoloured columns associated with pill-treated tapholes were longer than those associated with control tapholes for the first 8 months. From that time until the final measurement there were no statistically significant differences between lengths of discoloured columns associated with pill-treated and control tapholes. Cambial dieback occurred adjacent to many tapholes but there was no significant difference in closure rates of treated and control tapholes. Results were obtained from dissections and studies of 180 mature trees over a 56-month period in six locations in Vermont in one experiment, and from 75 trees over a 20-month period in three locations each in Vermont, Maine, New York, Pennsylvania, and Michigan in another experiment. The results indicate that repeated use of paraformaldehyde will lead to rapid development of decay in sugar maple trees.

Description: Twenty-three sugar maple trees, Acersaccharum Marsh., that had been defoliated by hand for 3 consecutive years (1971, 1972, and 1973) and nine undefoliated trees were wounded with a drill bit in March 1974. After two full growing seasons, wound areas on defoliated trees were larger than those on undefoliated trees because more bark tissue died originally around the wounds on defoliated trees, and because there was less wound closure resulting from poorer radial growth. There was no significant increase in internal discoloration, but decay was found in two defoliated trees. In undefoliated trees, wound area was highly correlated with annual growth increment and resistance to pulsed electric current. In defoliated trees, wound area was highly correlated with starch content of the roots; trees with lower starch content had larger wounds.

Description: Thinning in a white spruce, Piceaglanca (Moench) Voss, forest in interior Alaska stimulated organic matter decomposition in the forest floor as indicated by weight loss of litter and cellulose bags. The general higher weight loss in the most heavily thinned plot is attributed to observed higher average seasonal temperatures. Cellulose bags placed in the boundary between the fermentation–humus and the humus–mineral soil layers of the forest floor showed a significantly higher weight loss than those placed on top of the litter layer. This was attributed to more favorable moisture conditions and a more direct contact with the decomposing microbial populations in the fermentation–humus and humus–mineral soil layers.Regardless of thinning treatment, elements were grouped according to their rate of release from decomposing organic matter as follows: K 〉 Mg 〉 C ≈ P ≈ N ≈ Ca, where potassium is lease resistant. Since relatively small differences in weight loss of litter bags were observed between the treatments, similar studies should extend over a longer period in order to obtain a better understanding of the decomposition processes.

Description: The allocation of biomass and the turnover time of various components were measured from August 1976 to August 1977 in a young, second-growth Douglas-fir stand in the Oregon Coast Range. Allocation of biomass among the tree components was 14 732 kg foliage ha−1, 30 455 kg branches ha−1, 212 941 kg boles ha−1, 49 289 kg nonmycorrhizal roots ha−1, and 15 015 kg host portion of mycorrhizae ha−1. Biomass allocation of fungal components was 10 009 kg mycorrhizal mantles ha−1, 2785 kg Cenococcumgeophilum sclerotia ha−1, 65 kg sporocarps ha−1, 369 kg litter hyphae ha−1, and 6666 kg soil hyphae ha−1. The forest floor was composed of 6970 kg fine (25 mm) litter ha−1. Soil organic matter (

Description: The forests of northern Ontario are damaged frequently by strong winds that develop along cold fronts. Deterioration of spruce (Picea spp.) and jack pine (Pinusbanksiana Lamb.) saw timber because of wood-boring insects was studied in an extensive area of blowdown between 1969 and 1972. Sawyer beetles (Monochamus spp.) were the most important agents of degrade, but a surprising amount of damage was caused in spruce by Tetropium spp. Broken trees fared worst, but all uprooted trees were heavily attacked by 2 years after the storm. Milling studies showed about a 10% loss in all material combined 1 year after the storm, with the loss in general more than doubling in the 2nd year. The greatest loss occurred in white spruce (Piceaglauca (Moench) Voss), which was of greater original value than jack pine. Trees left standing were not attacked by emerging beetles but were subject to windthrow by relatively light winds. Salvage operations, when desirable, should begin as soon as possible after a blowdown and all stems, including those left standing, should be harvested at once.

Description: Extension of the root system and stem during the first 30 years of growth of plantation-grown red pine (Pinusresinosa Ait.) on four sites was deduced by root and stem analyses. Maximum rooting depth was reached in the first decade and maximum horizontal extension of roots was virtually complete between years 15 and 20. The main horizontal roots of red pine seldom exceed 11 m in length. Elongation of vertical and horizontal roots was examined in relation to moisture availability and some physical soil conditions. The changing relations within the tree in lineal dimensions and annual elongation of the roots and stem are illustrated. The development of intertree competition above and below ground is considered.

Description: Projected levels of nitrogen availability resulting from seven different harvesting regimes in northern hardwoods were used as inputs to a forest growth model. Results were analysed in terms of differences in net production and total yield by treatment. Production was highest under long (90-year) rotations and was reduced under short (45- and 30-year) rotations. Intensive harvesting (whole tree and complete forest cutting) removed a greater percentage of net production than clear-cutting. Complete forest utilization on a 90-year rotation produced the greatest total yield assuming that all harvesting treatments had the same effect on rates of regeneration and successional changes in litter input to the forest floor.

Description: A stepwise discriminant function analysis, based on soil chemical properties at the growing site, was used to differentiate conifers with root decay caused by Armillariellamellea (Vahl. ex Fr.) Karst. from conifers without A. mellea decay. Discriminant functions developed for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and grand fir (Abiesgrandis (Doug.) Lindl.) were significant. Low soil nitrogen and pH were associated with decayed Douglas-fir; low soil calcium and phosphorus and high soil potassium were associated with decayed grand fir.

Description: The survival of lodgepole pine (Pinusconforta Dougl.) planted in the spring under a variety of conditions was found to be closely related to its root growth capacity as measured by two newly developed methods. One method employed a displacement technique to measure the root volume of test seedlings, nondestructively, both at the beginning and end of a period of growth under standard conditions. The change in root volume that occurred during the test was taken as a measure of root growth capacity. The other method for measuring root growth capacity was to record, by means of a semiquantitative scale, the number of newly elongated roots possessed by test seedlings after a 1-week period of growth under standard conditions. For comparative purposes, it was found that very similar results were obtained in root growth capacity tests of this type run at two widely differing temperatures (30 °C day – 25 °C night temperature, and a constant temperature of 15 °C).

Description: A user-oriented approach to allocate inventory resources for multiple-use planning is presented. The sequence used in the approach is to determine (1) the decisions to be made with the aid of inventory data, (2) the data needed to soundly base the decisions, and (3) the impact of sampling error in the data on the decisions. Sample intensities that minimize the cost of obtaining data plus the expected losses from using the data to make decisions were determined. A cost plus loss minimization framework for multiple-use planning inventory was developed and applied to a case study on a U.S. Forest Service planning unit. Results indicated that the procedure should provide useful guides for allocating sampling resources.

Description: The beta, Johnson's SB, Weibull, lognormal, gamma, and normal distributions are discussed in terms of their flexibility in the skewness squared (β1) − kurtosis (β2) plane. The SB and the beta are clearly the most flexible distributions since they represent surfaces in the plane, whereas the Weibull, lognormal, and gamma are represented by lines, and the normal is represented by a single point.The six distributions are fit to 21 data sets for which both diameters and heights are available. The log likelihood criterion is used to rank the six distributions in regard to their fit to each data set. Overall, Johnson's SB distribution gave the best performance in terms of quality of fit to the variety of sample distributions.

Description: A new growth function, which is flexible enough in shape to accommodate most biological growth behavior, is created by adding an expanding factor to the Weibull distribution function. Many monotonically increasing biological growth phenomena can be excellently modelled by this function with various numerical values for the scale, the shape, and the upper asymptote parameters. The function is illustrated with height–age and volume–age curves for single trees and two polymorphic stand volume–age curves.

Description: The expected age-class structure of a forest dependent on random periodic fire for disturbance and renewal is derived and presented. It is simply the negative exponential distribution, well known in probability mathematics. An important feature of this concept is that the present age-class structure of such a forest is the key to its past fire history. Its limitations are discussed, and the computer simulation of variations, including the interaction of fire and logging, is described. Three examples of its use in interpreting fire history are given.

Description: A series of field, greenhouse, and laboratory studies were undertaken to elucidate the role of allelopathy in old-field sugar maple stands. Old-field weed residue inhibited germination and growth of maple even in the absence of competing vegetation. Goldenrod and aster were important producers of water soluble compounds that inhibited germination, nutrient uptake, and growth. These allelopathic chemicals were most readily extracted from putrefied plant residues, but they appeared to be natural plant products rather than microbial breakdown products. The deleterious effects of goldenrod on nutrition and growth of maple were overcome by large additions of soluble phosphorus fertilizer.

Description: Peatland types were compared to reveal differences in growth of dominant and codominant trees from undrained and artificially drained sites. The comparisons, based on tree height attained at the age of 100 years, indicate that growth improves by about 6 m in bog types and by about 4 m in fen–marsh types. To allow identification of similar sites in different localities and prediction of growth potential of sites not directly under study, 15 peatland types were assigned to five trophic groups on the basis of macronutrient content of the peat, using an automatic clustering method. The nutrient elements considered are known to influence growth on peatlands. The paper gives an account of site conditions. sampling technique, methods of comparison, and clustering. Detailed results are presented and explained.

Description: Distribution of nutrients after the Entiat fire in north central Washington was examined. This intense fire produced an average ash weight on the soil surface of 2900 kg/ha. The ash layer contained 23 kg/ha N, 314 kg/ha Ca, 54 kg/ha Mg, 70 kg/ha K, and 22 kg/ha Na. Nutrient losses during the fire as a result of combined volatilization and ash convection were 855 kg/ha N, 75 kg/ha Ca, 33 kg/ha Mg, 282 kg/ha K, and 698 kg/ha Na. Nitrogen loss apparently was proportional to fuel dry weight loss.Leaching of the ash layer in the 1st year after burning transferred a trace of N, 149 kg/ha Ca, 50 kg/ha Mg, 92 kg/ha K, and 33 kg/ha Na from the ash layer to the soil. Of the amounts leached from the ash, 134 kg/ha Ca, 48 kg/ha Mg, and 84 kg/ha K were retained in the 0-to 19-cm layer of soil. In the same interval a net loss of 29 kg/ha Na was observed from the 0-to 19-cm layer of soil.Cation leaching from ash layers was primarily related to water percolation through the ash. Equations are given that describe leaching of Ca, Mg, K, and Na from an average ash layer of the Entiat fire.

Description: This paper presents and compares two location-allocation models for assigning a limited number of airtanker groups among a larger number of potential bases. Model I selects bases to maximize the number of fires (weighted by value at risk) within range of an attack base. Model II trades off this goal with the minimization of mean fire to base distance. The models were applied to 1971–1974 fire totals in Alberta for three 10-day periods. As the number of airtanker groups was increased from one to the maximum, the performance of each model increased with smoothly diminishing returns. For all periods and at most levels of resource investment, the maximum coverage model served only a few more fires than did the other, sacrificing considerable distance in doing so. In view of the limitations of these simple models, a more comprehensive model was developed and discussed.

Description: The volume of intact plant parts can be measured rapidly by means of a simple displacement technique. The procedure is to dip the root, shoot, or other plant part to be measured into a vessel of water standing on a top-loading balance and take the resulting change in the reading of the balance as an estimate of tissue volume. The method has been found capable of yielding highly reproducible measurements of conifer seedling shoot and root volumes. One use that has been made of the technique is in the non-destructive determination of the shoot:root ratio of seedlings which are subsequently to be used in growth studies. Another has been in the estimation of root growth capacity from measurements of the root volume of test seedlings made both at the beginning and end of a period of growth under standard conditions.

Description: The aim of this investigation was to suggest a mechanism whereby the basic ferric sulfates, which occur in acid sulfate soils as a result of the microbial oxidation of pyrite in the original sedimentary parent material, can be microbiologically transformed back to pyrite when the soils are flooded. Three basic ferric sulfates were tested and it was found that in the presence of lactate and Desulfovibrio desulfuricans, 10 g of each mineral were reduced within 12 wk to mackinawite (FeS). Additional incubation, to a total of 33 wk, resulted in no further sulfidation. However, in the presence of elemental sulfur, the sulfidation process resumed and mackinawite was soon transformed into greigite (Fe3S4) and then, following an aging process of increased temperature and pressure, pyrite (FeS2) was produced. Under simulated flooding conditions of sea water and decomposing seaweed, the sulfates were converted to a black X-ray amorphous sulfide which is known to change to mackinawite and/or greigite. The ability of H2S-oxidizing bacteria to form elemental sulfur in sedimentary pyrite-forming systems is reviewed and interpreted as a factor in producing the necessary sulfur. Basic aluminum sulfates were stable to microbial reduction. The X-ray pattern for ammoniojarosite was refined.

Description: Eight soils in Manitoba, varying in texture, Great Soil Group and Subgroup, and amount of clay movement were analyzed for concentration of HNO3 + HClO4-extractable Zn, Fe, Al and Mn and percent sand, silt and clay. Soils were categorized into three textural groups, coarse, medium to fine and very fine. Statistical analyses were conducted to investigate the inherent associations between concentration of native Zn and concentrations of Fe, Al and Mn as well as sand, silt and clay contents for each textural group independently. Native soil Zn concentration was highly correlated with HNO3 + HClO4-extractable concentrations of Fe (r = 0.80, 0.89 and 0.90 for coarse, medium to fine and very fine-textured soils, respectively) and Al (r = 0.68, 0.79 and 0.81 for coarse, medium to fine and very fine-textured soils, respectively) and with clay content (r = 0.69, 0.64 and 0.82 for coarse, medium to fine and very fine-textured soils, respectively). Significant correlation between Zn concentration and clay content likely resulted from Fe and Al oxides coatings on silicate clays and from a large proportion of free Fe and Al oxides being clay-size. Correlation between Zn and Mn concentration was not significant for medium to fine and very fine-textured soils and was significant at only 5% level for coarse-textured soils. Large quantities of Zn (45–71% of HNO3 + HClO4-extractable Zn) were extracted along with the amorphous and organic complexed Fe and Al from four other Manitoba soils indicating, once again, that Zn was in some manner associated with oxides of Fe and Al in Manitoba soils.

Description: The effluents and ochreous deposits in several partly blocked field drains in Ontario were microbiologically and chemically assayed. The effluents contained several million per milliliter of the iron-oxidizing bacterium Gallionella. Sphaerotilus, a sheath-forming bacterium, was also numerous. Both microorganisms were generally encrusted with amorphous ferric iron oxides. They were also found in the ochreous deposits inside the tiles and also in the deposits adjacent to plugged filters surrounding the tiles. The iron-oxidizing bacterium Thiobacillus ferrooxidans was not found. Filamentous structures resembling the iron-oxidizing bacterium Metallogenium were frequently observed but the experimental evidence indicated them to be aggregates of colloidal Fe(OH)3. Calcite, dolomite, quartz and feldspar were common constituents of the effluents and the ochreous deposits. In some cases, one or more of gypsum, plagioclase, chlorite and illite were present. The ochreous deposits were generally high in iron and contained elements normally found in soil. Occasionally the materials were found to contain traces of magnetite. Except for the iron in the silicates the remaining iron was non-crystalline, present as amorphous ferric oxyhydroxide. Amorphous manganese oxide was also found. It was recognized that chemical oxidation might be an important agent in oxidizing the FE+2; however, the results and a literature survey indicated that Gallionella plays a major role. It is theorized that following oxidation, a ferric hydroxide sol is produced, which in the presence of electrolytes forms aggregates of colloidal Fe(OH)3 that combine with microbes and ions in the tile water to produce an amorphous precipitate. In association with carbonates, quartz and clay minerals, the precipitate forms ochreous substances. The paucity of dissolved ferrous and ferric iron, the presence of organic matter and adsorbed anions inhibits crystallization of the amorphous ferric oxyhydroxide. Roots in conjunction with large numbers of Sphaerotilus formed effective plugs.

Description: A computerized soil information system has been established in Canada as a tool for making more efficient use of soil information. Its purpose is to characterize and quantify soil and land units, as a basis for providing decision makers with a better appreciation of the actual environment and the relationships between man and the land. The system is both national and provincial, consists of a collection of individual but mutually related, computer-oriented files, and handles site specific, geographic and evaluative data.

Description: The presence of magnesium-bearing calcites in secondary carbonate accumulation layers of soils is shown to be associated with soluble Mg++/Ca++ ratios of one or greater in the attendant or underlying layers. The dissolution of both calcite and dolomite within the solum and the precipitation of only calcite in the developing Cca leads to a buildup of Mg++ in the soil solution. If leaching depth is considerably below the Cca horizon, the secondary calcite is Mg free. If leaching is restricted to relatively shallow depths (2–4 m), the buildup of soluble salts and the increased soluble Mg++/Ca++ ratio which result are conducive to the precipitation of Mg-bearing calcites. Soluble salt distribution within a glacial till landscape suggests that surface runoff waters and snow accumulation in depressions are more important aspects of water distribution in such landscapes than is lateral movement within the soil itself. The accumulation of soluble salts in the 2 to 4-m zone of upland soils and the complete lack of salts to greater depths in depressions ties in well with the presence or absence of Mg-bearing calcites. The implications of the nature of the carbonates to soil salinization processes are indicated.

Description: Deep plowing was evaluated in the field and simulated in a greenhouse study in an attempt to isolate soil factors responsible for yield effects on a Duagh Solonetz soil. Generally, fertilization provided a more significant yield response than deep plowing in the field or horizon mixing in the greenhouse. In the field, however, deep plowing in combination with fertilization produced an additional 542 kg/ha of alfalfa-bromegrass forage over fertilization alone [Formula: see text]. Also, in fertilized greenhouse treatments, retaining the A horizon on the surface while mixing sub-horizons proved significantly beneficial over mixing all three horizons [Formula: see text]. The main factor responsible for yield effects appeared to be the Ca enrichment of surface and B horizon areas. An increase in the Ca:Na ratio improved water intake rates and reduced water-logging of the soil, thereby providing a more suitable medium for root development and a more efficient use of indigenous and applied N.

Description: not available

Description: A computer program that estimates changes in soil moisture was used to calculate fall soil moisture contents and possible deep drainage. Generally good agreement was obtained between the calculated and measured total moisture contents under continuous wheat and grass after each of four and six growing seasons, respectively. Estimates of soil moisture storage and deep drainage under summer fallow showed discrepancies because unsaturated moisture flow was not included in the model. However, a comparison of actual field and estimated moisture data indicated that in two of five growing seasons, 3.7–7.5 cm of water could have been lost from the root zone of fallowed land because of deep drainage.

Description: Paraquat (1,1′-dimethyl-4,4′-bipyridinium dichloride) and linuron [3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea] were applied to an organic soil, as spray treatments, at rates of 1.12 and 2.24 kg/ha, and 2.24 and 4.48 kg/ha, respectively. The persistence of the herbicides and their residues in lettuce (foliage), onions (root), and carrots (foliage and root) at harvest time were studied under field conditions. Proportionately more residues persisted in the soil from the higher rates of application of paraquat (2.24 kg/ha) and linuron (4.48 kg/ha). About 83–86% of the initial amounts of paraquat and 59–74% of the linuron remained in the soil 4 mo after application. Furthermore, about 50% of the paraquat was recovered from the treated soil 15 mo after application, whereas only about 20% of the linuron was recovered at the end of the same period. Carrots grown in this soil did not absorb detectable (〉0.005 ppm) amounts of linuron, while onions and lettuce grown 12 mo after application absorbed the herbicide in various amounts. At the lower rate of application (2.24 kg/ha) linuron residue in onions was 0.014 ppm and that from the higher application rate (4.48 kg/ha) was 0.046 ppm. Lettuce had about 0.009 ppm residue, irrespective of the rate of application. Onions and lettuce grown on paraquat-treated soil had low residue levels (0.001–0.011 ppm). The study demonstrates the potential of paraquat and linuron residues to persist in organic soil, and their uptake by vegetable crops.

Description: Barley was grown for 2 yr on Charlottetown fine sandy loam with various methods of application of fertilizers made from two nutrient source combinations. Grain yields were generally higher when fertilizer was placed 5 cm to the side of, and 5 cm below, the seed than when fertilizer was broadcast or drilled with the seed. Yields were higher with drilled than with broadcast fertilizer, except when urea and diammonium phosphate were used as N and P sources. High yields were obtained when P was drilled with the seed and N and K broadcast. Throughout the growing season, the uptake of P was lower from broadcast than from drilled or placed fertilizer. Low yields with broadcast fertilizer were attributed to the low availability of P. When N was broadcast and P drilled, yields were similar for broadcast and drilled K, although the uptake of K was lower when K was broadcast. Yield reduction where fertilizers containing urea and diammonium phosphate were drilled with the seed was attributed to damage from ammonia released by urea and diammonium phosphate.

Description: A 3-yr study was conducted in Manitoba to evaluate the influence of several climatic variables on corn maturity. Results indicated that efficiency of heat in maturing corn was lower at the northerly sites than in the corn-growing areas of southern Manitoba. This led to analysis to determine quantitatively the effect of latitude on heat accumulation – maturity relationship of corn. Corn maturity, as measured by kernel moisture, was related to latitude, corn heat units, degree days above 50 F, solar radiation and planting date. The highest contribution to regression was made by a variable involving an interaction between heat accumulation and latitude. Approximately 90% of the variation in kernel moisture was accounted for by the variation in climatic variables.

Description: Fresh soil (0- to 7.5-cm depth) was collected at intervals of approximately 2 wk during the growing season from a maple woodlot and an abandoned pasture. When samples were perfused with a solution of (NH4)2SO4 containing 20 ppm N, the rate of nitrification diminished during the summer and, for both soils, halved between mid-June and mid-July. Nitrification in the woodlot soil was nearly twice as rapid as in the pasture soil. Perfusion of soil, that had been stored for 2 mo at 0 C and to the surface of which granular fertilizer was then added, showed that urea and (NH4)2SO4 were nitrified very rapidly in woodlot soil but more slowly in pasture soil. Ureaform was nitrified slowly in both soils. It was concluded from these laboratory experiments that for experimental trials of fertilization (of sugar maple) in the field, the most suitable nitrogenous fertilizer to apply to woodlot soil could be ureaform, and to pasture soil could be (NH4)2SO4. Probably the most effective time at which to apply the fertilizer would be mid-June.

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

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

Description: Wind is one of the mechanisms causing saline soil in Saskatchewan. This type of salinity is always adjacent to intermittant saline ponds or lakes.

Description: The distribution of individual amino acids and monosaccharides in fulvic acid and its fractions separated by polyamide chromatography was investigated in five different Italian soils. Although little differences were generally found in the two polyamide fractions (FI and FII), the highest percentage content of acidic amino acids and the lowest percentage content of neutral amino acids have been found in the second one (FII); monosaccharides composition was more irregular, but generally FII contained more pentoses. Both chromatographic fractions (FI and FII) have been chromatographed on Sephadex G-25. The composition in carbohydrate and amino acid components of the further different fractions resolved by gel filtration showed great differences depending on the molecular weight distribution.

Description: The objective of this work was to determine the effect of sampling time and field heterogeneity on the soil fertility tests (pH, organic matter, N, P, K, Ca, Mg). The sampling on Ap horizons was repeated in May, July and October of 1976 at 25 locations of a clay loam soil (Kamouraska Series) and a sandy soil (Vien Series). The results indicated that the coefficients of variation were lower than 7% for the pH analyses but exceeded 30% for the other analyses. For the latter, sampling time showed a significant decrease in the P, K and Mg values from May to October on the sandy soil but showed no effect on the clay loam soil. Field heterogeneity was found to be a greater factor of variation than sampling time. It explained an average of 26% of the variation obtained on the sandy soil and 74% on the clay loam soil where the cultural practice of raising the center of the field, for better surface drainage, caused great variations in the depth of the Ap horizons in relation to the width of the field.

Description: In a pot experiment with additions of Zn, Cu and Ni to a loam soil (pH, 6.3) at rates up to 480 ppm, sewage sludge eliminated the toxic effect of Cu and reduced the toxic effect of Ni on corn, reduced the concentrations of Zn and Ni in the plants, and reduced the amounts of DTPA-extractable metals and of 0.01 M CaCl2-soluble Zn and Ni in the soil. Lettuce grown with the metals and sludges was more susceptible than corn to the toxic effects of the three metals in the loam soil and to Zn in a clay soil (pH 5.9). In the latter soil, Ni was less toxic to lettuce than to corn. The concentrations of metals were considerably higher in lettuce than in corn. Liming of the clay soil to a pH of 6.5 eliminated the toxic effect of Ni on corn and of Zn and Ni on lettuce and reduced the concentrations of the metals in the plants and the amounts of DTPA-extractable and CaCl2-soluble metals in the soil. The order of magnitude of the DTPA-extractable metals was Cu 〉 Zn 〉 Ni whereas the order for CaCl2-soluble metals was Ni 〉 Zn〉 Cu. Variability in the effect of the metals between crops and soils precluded the use, except as a preliminary guide, of a Zn equivalent concept based on the assumption that Cu is twice as toxic and Ni is eight times as toxic as Zn.

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

Description: Seven soil supplement products did not affect grain or straw yields, or any of the measured yield components of unstressed wheat or of wheat subjected to an 8-bar soil water stress at early heading. Soil water stress reduced yields by reducing the number of spikes per plant and, to a lesser but significant degree, the number of kernels per spike and the average kernel weight.

Description: Seven agricultural watersheds in southeastern Ontario and southwestern Quebec with varying land uses and soil types were sampled 14 times between 7 May 1974 and 21 May 1975. Discharge volume, suspended sediment concentrations and soluble and sediment (NH4oAc exchangeable) Ca, Mg and K concentrations were measured each time. Significantly decreased pK – 1/2p (Ca + Mg) values occurred in watersheds with more impermeable soils and greater corn and small grain land uses. The relatively higher stream K concentrations were attributed to K-enriched surface runoff and leaching loss from K fertilization of corn and small grains. Seasonal variations in the Gapon exchange constants or exchangeable cations associated with suspended sediment probably related to variation in surface soil erosion. Estimated annual soluble cation losses varied by watershed but were highest from watersheds with the largest proportions of corn, cultivated land and calcareous soils.

Description: Barley growing on a Gleysolic soil was subjected to short-term periods of flooding (2–10 days) at four stages of development. The treatments resulted in a reduction in dry matter accumulation proportional to the duration of flooding. Furthermore, plants 14 and 21 days old at flooding were most affected immediately following inundation whereas, at maturity, plants flooded at 28 and 35 days old were the most affected in that head emergence was delayed and grain yield was reduced by as much as 55%. Flooding increased the soil-produced ethylene from 0.15 to 3.78 ppm after 10 days. Ethylene production was related to a lowering of the soil Eh below 340 mV. It is suggested that the poor growth of barley, while in part due to an O2 deficiency, may also be a result of ethylene formation during flooding.

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

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

Description: The effects of lime and gypsum applications were determined on lettuce yields, soil pH and extractable aluminum for 10 organic soils. No increase in yield attributable to liming was found beyond pH 4, and a significant yield depression occurred with gypsum treatments. Further, the more acid soils outyielded the less acid but denser cultivated soils. Although the limestone applications increased soil pH significantly, significant treatment–soil interaction effects were found, and were ascribed to lower soil-limestone reactivities of the denser, less acid organic soils. Consequently, soil pH change upon liming was significantly correlated with bulk density and percent ash. Maximum yields were obtained at extractable aluminum levels lower than 0.1 meq/100 g soil. Further, potentially toxic levels of extractable aluminum disappeared at the same pH as maximum attainable lettuce yields; consequently, its possible toxicity was associated with pH effects in these soils. Field experiments with radishes grown on two organic soils gave initial increases in yields. This effect was surmised to be due to increased N-mineralization, because subsequently the controls outyielded the liming treatments.

Description: Relations between the site index of red pine (Pinusresinosa, Ait.) and foliar concentrations in N, P, K, Mg, Ca, and Mn, the soil content in O.M., total N, available P, exchangeable K, HNO3 extractable K, exchangeable Mg and Ca, and the percentage of silt plus clay of 23 sample plots on fluvio-marine or associated deposits in the St-Lawrence plain were studied. The site index varies between 28 and 42 at 20 years b.h. There are significant and positive linear correlations between the site index and concentrations in K, Mg, and Ca in the needles. The linear correlation for Mn is significant but negative. However, multiple regression analysis indicate that only potassium and magnesium were significantly associated with the regressions.There are significant and positive linear correlations between the site index and the soil content in HNO3 extractable K, exchangeable K and Mg. However, multiple regression analysis indicate that only HNO3 extractable K has a significant contribution to variations of site index and the contribution of exchangeable Mg is almost significant at 0.05. There are also significant and positive linear correlations between the foliar concentrations of potassium and magnesium and the respective soil contents in HNO3 extractable K and exchangeable Mg. Height growth of red pine in St-Lawrence plain is closely related to the nutrient status of potassium and magnesium in the sites under investigation.

Description: The addition of sludge to a Fox sandy loam (sl), Granby sl and Rideau clay (c) soil increased soil pH, total C, NaHCO3-extractable P, cation exchange capacity and exchangeable Ca. Sludge application increased DTPA-extractable Cd 2 to 5 times, Pb 2 to 3 times, Cu 3 to 7 times and Zn 7 to 31 times. Metal extractability in Granby and Fox sl soils was not greatly changed after 11 mo incubation but extractable Zn, Cu, Pb and Cd were reduced in the clay soil following incubation. Cropping to lettuce reduced the quantity of metal extracted from Fox sl soil and to a lesser extent from Rideau c soil but not from Granby sl soil. Lettuce (Lactuca sativa L.) yields were significantly reduced for the first crop grown on sludge + fertilizer-treated Rideau c and Granby sl soils and for all three harvests from similarly treated Fox sl soil compared to harvests from soils treated with fertilizer only. Yield reduction for the first crop was attributed to a salt effect, as subsequent yields on Rideau c and Granby sl soils were similar to harvests from fertilized treatments. Saturation extract conductivities for all sludge treatments were higher for incubated than for cropped soils. Generally Zn, Cu and Pb tissue concentrations in lettuce harvested from sludge + fertilizer-treated Fox and Granby sl soils were significantly increased but total uptake was only increased for Zn. Metal uptake and tissue concentrations for lettuce grown on similarly treated Rideau c soil were equal to or less than those found in lettuce harvested from the fertilizer-only treatment. To a lesser extent similar trends were observed with the tomato (Lycospersicon esculentum Mill.) crop.

Description: not available

Description: The mineralization of soil sulfur, as measured by calcium chloride extraction of fresh samples, was compared and discussed with carbon-dioxide-evolved, nitrogen mineralized, sodium-bicarbonate-extractable phosphate, lipid phosphorus and arysulfatase activity. The amount of sulfur mineralized after 14 wk was compared with various initial soil values, such as the form of sulfur and ratios among C, N and S. In general, the samples with larger C:S and C:N ratios resulted in lower sulfur- and nitrogen-mineralizable values; however a complex interrelationship among C, N and S was evident. A high N:S ratio (produced by addition of nitrogen) resulted in a decrease in mineralization of sulfur in the soil sample during an 8-wk incubation.

Description: Anaerobically digested sewage sludge was applied to a loam soil at rates of 1.25, 2.5 and 5.0 cm ha−1. Treatments were replicated four times, and all plots were cropped to corn. The soil in the 0- to 90-cm profile under each plot was sampled every month from May to October in 1972 and analyzed for NO3−-N and NH4+. The two highest sludge application rates resulted in significant increases in soil NO3−-N in the 0- to 90-cm soil profile, which persisted until October following crop harvest. Of the N supplied by the sludge, only about 3–12% was recovered by the corn crop. At the conclusion of the experiment, in October, 6–10% of the N supplied by the sludge remained in the soil and on the soil surface in the residual solids. Sludge applications in excess of 1.25 cm ha−1 did not produce significant increases in the yields of grain or stover.

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

Description: not available

Description: Eleven physical and chemical properties of 26 peat materials from a total of five virgin profiles were determined and statistically analyzed for correlations among attributes that relate to the degree of decomposition, and with the rates at which the materials biodegraded. Estimation of fiber content made routinely by pedologists in the field correlated with relative, biodegradability better than any other criterion of decomposition and humification.

Description: The adsorption/desorption potential of several phenylurea herbicides was studied on representative prairie soils, using slurry-type adsorption experiments. The herbicides showed the following order of increasing tendency to be adsorbed: fenuron 〈 monuron [Formula: see text] monolinuron 〈 metobromuron 〈 diuron [Formula: see text] linuron [Formula: see text] chlorbromuron. The relative adsorption of each herbicide on various soil types was significantly correlated with the soil organic matter content, but not with the clay content. The relationship between the k value and the soil organic matter content was found to be of the exponential type. The extent of adsorption was also inversely related to the order of their water solubilities. The urea herbicides were readily desorbed by water from the low to medium organic matter content sandy loam and heavy clay soils, but not from a loam with very high organic matter content. It is suggested that the relative adsorption/desorption potential of a herbicide may provide a mechanism by which soil applied herbicides can be biologically inactivated more readily in soils of high organic matter content.

Description: not available

Description: Cerenkov radiation counting was found to be an excellent method of radioassay of 210Pb in aqueous extracts of soils and acid digests of plant material. The use of polyethylene vials and a wavelength shifter 7-amino-1,3-naphthalene-disulfonic acid greatly improved the counting efficiency. Color quenching was the main factor in lowering counting efficiency but could be corrected using the channels ratio method. Extracts of soils having high organic matter contents showed severe color quenching. Pretreatment of these extracts with 30% H2O2 greatly increased the counting efficiency.

Description: The accumulation of dry matter and N in wheat (T. aestivum L. cv. Manitou) grown on stubble land in lysimeters at two moisture levels and seven rates of N was measured and related to moisture use at five stages of development. In the irrigated lysimeters, leaf areas, plant dry matter and N content increased with fertilizer N. In the dry lysimeters, low rainfall between the shot blade and anthesis stages produced moisture stress; consequently, dry matter production and leaf area were depressed and plants lost significant amounts of N at rates of N 〉 61.5 kg/ha. Rain in the latter part of the growing season permitted the plants to recover and by maturity plant dry matter and N content increased with N. Approximately twice as much plant dry matter was produced in the wet treatment as in the dry for all levels of N. Total evapotranspiration (ET) increased with applied N in the wet treatment, and was much higher than in the dry treatment. It was not affected by applied N in the dry lysimeters. Root weight increased exponentially up to the shot blade stage. Between anthesis and maturity, it decreased in the top 75 cm in the dry and top 30 cm in the irrigated soil profile, while in the deeper segments it remained constant. Root weight increased curvilinearly with increasing N under irrigation. On dryland, rates of N 〉 41 kg/ha depressed root growth at the shot blade stage and at anthesis. Average root yields under wet conditions were 220, 1,920 and 1,425 kg/ha at 3-leaf, anthesis, and maturity, respectively; under dry conditions they were 220, 1,535 and 875 kg/ha. The root weight constituted 76% of the total plant weight at the 3-leaf stage and 15.6% at maturity. The average root N content at maturity made up 9.4–11.5% of the mean plant N. Root density decreased curvilinearly with depth. At the 3-leaf stage about 62 and 23% of the root system was located in the top 15- and the 15- to 30-cm segments of the profile, respectively; at maturity these proportions were 46 and 15%. N did not influence root distribution but irrigation increased root growth in the top 15 cm of the profile by about 5%. Rate of moisture use was directly proportional to rate of root growth.

Description: Soils were sampled to 120-cm depths in the fall and again in the spring to determine the NO3N, NH4N and NaHCO3 extractable P content. The change in nutrient content of the soil between fall and spring was measured and related to the fall sampling values and to climatic conditions between samplings. The samples were taken for each 10 yr at several sites on different soil types. The average of all sites showed little change in the P content of the soil from fall to spring. There was some increase in NO3-N, particularly in the 0- to 60-cm depth but there was a larger decrease in NH4-N, resulting in a net decrease of N (NO3-N + NH4-N) or total available mineral nitrogen from fall to spring. The amount of change in NO3-N, NH4-N and the combination of these two (N) was inversely related to the amount of that form of nitrogen present in the soil in the fall. Weather also affected the amount of change. Consideration of the amount of nitrogen present in the fall and the weather from fall to spring will improve the accuracy of predicting the amount that will be present at seeding time.

Description: The accumulation of aboveground dry matter (DM) and nitrogen (N) by spring wheat (T. aestivum L. cv. Manitou) grown on stubble land in lysimeters at two moisture levels (irrigation and natural rainfall) and seven rates of N was measured at five sampling dates. With irrigation, DM increased exponentially with time and N fertilization. This also occurred on dryland except between shot blade and anthesis when DM accumulated more slowly and plants lost 20% of their N at application rates 〉 61.5 kg N/ha. Rainfall after anthesis increased grain yields of dryland crops fertilized with 〉 61.5 kg N/ha more than those receiving less N because the former plants still had residual fertilizer N available to them. Grain yield response to N fertility followed the law of diminishing returns on irrigated land, but on dryland the relationship fitted a logarithmic growth curve. Grain yield when neither water nor N was added was 1,600 kg/ha; it increased by 71, 47 and 300% when water, 164 kg N/ha, and water plus 164 kg N/ha, respectively, were applied. On dryland, grain protein was 15.4% with no N applied and 17.0% at rates 〉 61.5 kg/ha; on irrigation, it increased from 14.1 to 15.7% with increasing N levels. Number of heads and kernels and kernel weight were increased by irrigation but only the two former parameters were increased by N. Dry matter accumulation was related to N concentration in plants by: DM = (%N)−k where k was

Description: Soils representing the more important series on Prince Edward Island (P.E.I.) and forage and cereal crops grown on them were analyzed for Se content. Total soil Se content varied from 0.09 to 0.60 ppm and showed a positive significant correlation with the Se content of timothy (r = 0.40) and with soil pH (r = 0.29). The Se concentration of forage crop tissues and cereal grains from P.E.I. varied from 0.004 to 0.043 ppm. These concentrations of Se are considered to be deficiency levels for livestock feed. Wheat kernels contained a higher concentration of Se than barley kernels; however, barley tissue, sampled at the boot stage, contained higher quantities of Se than wheat sampled at the same stage. Addition of lime, S, B and Mo to the soil, under field conditions, did not affect the Se concentration of plant tissues.

Description: The nitrogenous products formed by 6 N HCl hydrolysis of a variety of peats including a cultivated mesic profile, a virgin humic profile, a sedge, a woody and a sphagnum fibric peat were studied. Peat fractions separated according to particle size, woody and herbaceous materials isolated from a peat sample, and Typha and Carex plants growing on peat soils were also analyzed. Of the two profiles examined, the cultivated mesic peat showed significant quantitative changes in the content of individual amino acids throughout the profile. Also the amino sugar and amino acid N increased to a maximum, then decreased. On the other hand, the virgin humic peat profile exhibited random variations in the content of the individual amino acids and in the amount of amino acid N. Of the other peats examined, the fibric sphagnum had the highest percentage of amino acid N. Among the separates, the 100- to 200-mesh material had the highest proportion of amino acid N. The amino acid composition of the plant remains from the peat was similar to that of the peat from which it was isolated. The amino acid composition of the Typha and Carex plants was different from that of peat in that 75% of their total N content could be accounted for on the basis of amino acid, amide and amino sugar N. The amounts of hydroxyproline and the amino sugars in peats vary more than that of the amino compounds. In contrast to inorganic soils, which tend to have a similar amino acid composition, these limited data suggest that the amino acid and amino sugar contents of peats may be characteristic of individual bogs.

Description: Purines and pyrimidines were determined by ion-exclusion chromatography in 15 soil samples of widely differing pedological origins and in humic fractions isolated from these soils. The nucleic acid bases tended to concentrate in humins and fulvic acids (FA) rather than in humic acids. N in purines and pyrimidines constituted up to 7.4% of the soil-N and up to 18.6% of the N in a FA. The distribution of nucleic acid bases in soils and humic fractions was similar. Guanine, cytosine and adenine were detected in all samples, and thymine in most, while uracil and 5-methyl cytosine were found less frequently. The predominance of guanine and cytosine suggested a microbial DNA origin for the nucleic acid bases. Evidence was obtained that the nucleic acid bases interacted not only with humic materials but also with inorganic soil components such as clays and hydrous oxides. Our data show that purines and pyrimidines accounted for up to 16% of the unidentified N in a soil and for up to 40% of the N in a FA so far not yet identified. This suggests that more attention be given to nucleic acid bases when considering the N status of soils.

Description: The response of corn (Zea mays L.) to manure that had been treated to minimize odor was investigated in a greenhouse trial with two silt loam soils of pH 4.2 and 7.1. Pretreatment of manure resulted in sources initially high in organic N and NH4+, but low in NO3−. One pretreatment gave high initial NO2− concentrations. In soil at pH 4.2, NH4+ was the major N source utilized by corn grown to 36 days, and dry matter yields were superior to those from soil at pH 7.1 where soluble NO3− was the major source of N. At pH 7.1, NO2− remained in significant quantities and decreased dry matter yields at 6 wk. Soil inorganic N concentrations varied between soils and was attributed to soil pH differences. Rate of NO2− disappearance decreased with increase in soil pH, and NH4+ accumulation increased with decrease in soil pH, whereas NO3+ production was favored by neutral pH conditions. Some NO3− production was observed in pH 4.2 soil after 36 days' incubation

Description: Fulvic acid from five different Italian soils was investigated by polyamide chromatography and resolved into two fractions. In all soils but one, carbon of fulvic acid is principally recovered in the retained second fraction, whilst the first fraction, which is not retained, contains the major part of nitrogen of fulvic acid. In all of the five fulvic acids, amino acid and carbohydrate components are mostly recovered in the first fraction; amino acid nitrogen, particularly, accounts for the major part of total nitrogen content. Amino acid and carbohydrate components in the second fraction seem to be linked to phenolic substances according to hydrolysis trials after which they are no longer retained by polyamide.

Description: A field experiment with an Ottawa area clay loam soil utilizing open-ended microplots and 15N-labelled fertilizer showed the relative importance of seasons on transformation and transport of nitrogen. Denitrification appeared to be appreciable during the growing season; about 39% of the fertilizer N was denitrified in 86 days (May–Sept.) and 65% was lost after 511 days but leaching losses were included in the latter period. Nitrification of fertilizer N was very rapid with extractable NH4+-N approximating background level within the first 43 days. Immobilization of fertilizer N was negligible in the first 159 days and only a small amount was immobilized during the remainder of the experiment. Mineralization of soil N averaged 0.77 and 1.10 kg N/ha/day in the first two sampling periods. Clay fixation of NH4+-N was significant in this soil with 59% of the 152 kg N/ha applied being immediately fixed. Over one-half (66%) of this recently fixed NH4+-N was released in the first 86 days of the experiment with the remainder held tightly through the sampling period. Movement of fertilizer N was greatest in the late fall and early spring, i.e. periods of high precipitation and low evaporation.

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

Description: In a field experiment with different crops on a loam and a sandy loam soil in a 3-yr period, N uptake by grasses accounted for 64–96% of the N fertilizer added at a rate of 112 kg N/ha annually. The recovery was 40–54% when the rate was 448 kg N/ha. The grass species were more effective than corn in removing N from the soils. Regardless of the rate of fertilizer used, however, the amounts of NO3-N in the soil of corn, fallow and grass plots sampled to a depth of at least 90 cm in the fall were high enough in many instances to account for much of the excess of added N not used by the crop. Corresponding data for NO3-N in the soils in the following spring showed that except for the moderately fertilized grass plots, the fertilized soils were susceptible to considerable loss of excess NO3-N from early fall to the following spring. In several instances, the data indicated a movement of NO3-N, since the amounts were reduced in the upper soil layers and increased in the lower ones during the fall–spring period.

Description: Aerobic incubation of soil from the Ap horizon of a Huron clay loam to which alfalfa as a carbon source was added resulted in rapid nitrification at 15 and 30 C and an apparent reduction in available carbon for denitrification. Use of the same soil in a subsequent study showed that aerobic incubation temperatures of 5, 10, 15 and 30 C did not influence its denitrification potential but that the level of available carbon probably did. Mean denitrification rates were 0.56, 1.23, 1.89 and at least 5.24 μg NO3−-N/g soil/h at 5, 10, 15 and 30 C, respectively, when carbon availability did not limit denitrification. At these rates, all NO3− applied or produced by nitrification, under normal soil fertility practices, could be denitrified within 1 or 2 days. Where readily available carbon was deficient, rates were 0.04, 0.18, 0.33 and 0.90 μg NO3−-N/g/h at 5, 10, 15 and 30 C, respectively. Reaction kinetics describing denitrification was of zero order when carbon was either available or seriously limiting; it was of first order where carbon availability changed from readily available to seriously limiting. Extrapolation of denitrification rates at various temperatures indicated that denitrification probably would occur at or near 0 C.

Description: A quantitative mass spectrometric technique utilizing Ar of air as an internal standard was applied to investigate the denitrification process under air atmosphere in closed containers. The disappearance of O2 and nitrate and the production of CO2, N2O and N2 were investigated as a function of added NO3− concentrations, liming and flooding using a near neutral soil. The added NO3− acted as the electron acceptor whenever oxygen supply was depleted. The first product to appear was nitrite, and gaseous N2O and N2 followed. The microbial activity of unit weight of the soil as measured by CO2 production was not affected by the addition of varying concentrations of NO3−. Consequently, the initial rate of NO3− disappearnace which is probably proportional to microbial activity was independent of NO3− concentration. The accumulation of N2O gas as intermediate was dependent upon the NO3− concentration. Higher concentration of NO3− favored the accumulation of N2O, thus reducing the formation of N2 primarily because of the competitive nature of NO3− and N2O as electron acceptor under constant microbial activity. Thus, the initial rate of N2 formation was faster with lower NO3− concentration. Also the appearance of N2 due to reduction of N2O took place earlier when NO3− concentration was lower. Liming reduced the accumulation of N2O thus producing N2 early. However, flooding induced the accumulation of N2O. Increasing the microbial activity and lowering the NO3− concentration would decrease the N2O accumulation.

Description: Forms of nitrogen in 92 samples were measured in a study designed to determine the similarities and differences in the nitrogen distribution in various horizons of a wide range of Canadian soils. The samples, representing all of the nine soil orders, were chosen from different climate and vegetation zones. Some peat soils were analyzed also. The data were first grouped according to the nitrogen content of the samples, but the amino acid composition of the soil "protein" did not appear to be related to this. The data were then grouped according to LFH, A, B and C horizons and also according to the Ah, Ap, Ae, Bhf, Bh, Bm and Bt layers. Again, few significant differences in the amino acid composition could be found. Data for the average amino acid composition and standard deviations for 92 mineral soils, 6 LFH and 2 ’O’ horizons of these and 18 peat soils were calculated. Since the analytical and sampling errors appear to be relatively small and would not account for all the variation between samples, there appeared to be real but relatively small and random differences in the amino acid composition of the different samples. The data for the individual soils supported this conclusion; for instance, some samples had very small or barely detectable amounts of hydroxyproline, while with other soils it made up 1–2% of the amino acid nitrogen. The amino sugar composition was more variable and the glucosamine/galactosamine ratio varied from 2:1 for the LFH horizons to 1:1 for the peat soils. In general, however, the soil "protein", which is probably largely the result of microbial degradation and synthesis, is remarkably similar to its amino acid composition. Amino acid nitrogen made up over half of the total nitrogen of the LFH and O horizons. This underestimated the "protein" nitrogen, since there is probably some amide nitrogen (about 5%) not included. In the mineral soils probably about 40% was "protein" nitrogen (including aminde), 5% was amino sugar nitrogen, 18% hydrolyzable unidentified nitrogen and 13.5% was insoluble in the acid used for hydrolysis. Clay-fixed ammonium made up 17% of the total nitrogen and much of the hydrolyzable ammonium came from this.

Description: Rates of hydrolysis of water-soluble sodium pyrophosphate and sodium tripolyphosphate, applied to soil at 200 ppm P, were extremely rapid (about 2–7%/h) during the 0 to 24- or 0- to 48-h period following phosphate application but decreased with time of incubation. Rates of hydrolysis increased linearly and increased about two- to threefold as temperatures were increased from 5 to 35 C or from 5 to 50 C. Inconsistent results were obtained at temperatures above 50 C. Increases in incubation temperature increased the total amount of added polyphosphate hydrolyzed by the soil in 120 h from about 40 to 70% at 5 C to about 80 to 95% at 35 C and 50 C. Water-soluble polyphosphate hydrolyzed at a greater rate than 0.5 N H2SO4-soluble polyphosphate. However, the effects of temperature on rate of hydrolysis of acid-soluble polyphosphate and water-soluble polyphosphate were similar. Polyphosphate hydrolyzed at a greater rate in the noncalcareous Newdale soil than in the calcareous Lakeland soil. Rate of tripolyphosphate hydrolysis was usually greater than rate of pyrophosphate hydrolysis. Rate of hydrolysis of water-soluble polyphosphate, expressed as %/h, decreased exponentially as concentration of applied polyphosphate increased from 200 to 1,600 ppm. However, rate of orthophosphate production per unit time increased exponentially with increased substrate concentration.

Description: Six acid pyrite-bearing mine tailings samples, varying in pH from 1.9 to 2.9, yielded from 10.8 to 37.0 meq acid/100-g sample when leached with 1 liter H2O. In pot tests, the amounts of CaCO3 required to neutralize the initial acidity and that generated during cropping in four of the samples containing less than 5% S varied from 10,000 to 50,000 ppm. The acidity of the other two samples, which contained considerably more S, was corrected by liming initially, but the pH was less than 2.5 by the end of the cropping period despite high additions of CaCO3 (100,000, and 140,000 ppm). Reed canary grass was grown successfully in the limed and fertilized tailings except in an unweathered sample containing a relatively high amount of S. In most instances, the composition of the plants did not vary greatly from that reported for plants grown in soil, although the concentrations of S tended to be high. In this and another experiment with buckwheat, a soil layer on top of the tailings was used with varying effectiveness in establishing vegetation. With inadequate lime, the soil became very acid and released relatively high amounts of Mn, Fe and Al to the plants. Recovery of added K by extraction with 0.1 N acetic acid decreased with increasing acidity of the tailings.

Description: After 8 mo of decomposition, under laboratory conditions, the unlimed surface sample (0–15 cm, pH 3.8) of an acid peat bog contained about five times as many microbes as the unlimed subsurface material (15–41 cm, pH 4.1). As measured by CO2-C released and numbers of bacteria and actinomycetes, lime had greater effects on the microbial activity of the surface material. Nitrifying bacteria were present and needed lime to become active. Fungal numbers decreased with lime and only 12 genera were found. Temperature had little effect, whereas pH had a marked effect on the distribution of fungal genera. Fusarium oxysporum, Cephalosporium acremonium and a frequently isolated nematode-destroying fungus Harposporium lilliputianum were found only at pH 7.5 and thus appeared to be alien fungi that responded well to an environment of high pH and cultivation. Before incubation, the unlimed lower sample was higher in carbon, nitrogen and methoxyl but lower in hexose, pentose and uronic acid than the unlimed upper sample. During decomposition there was a tendency for hexose and pentose to decrease, this being more noticeable in the upper material. No appreciable changes in nitrogen, carbon, methoxyl and uronic acid content occurred in either sample. Dry matter lost in the surface ranged from 8 to 13% while in the lower material it was from 2.0 to 3.5%. Despite sufficient NPK and a substantial sugar content, Sphagnum litter decomposes at a slower rate than some tree leaf litters. From the literature it is speculated that the slowness is due to the presence of microbial-inhibiting substances such as phenolic compounds.

Description: The two poorly drained ortstein horizons contained very low amounts (

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