A mineralogical and chemical study was conducted on the clay fractions of lower Fraser River alluvial sediments. The major objectives of the study were to characterize the mineralogy of these sediments and to evaluate the influence of a marine environment and sedimentary phases of deposition on their mineralogical content. Twenty-one sampling sites representing the four major soil series developed on these sediments and six sea bottom samples were collected. Surface and subsurface samples were taken for the soil series. X-ray diffraction analyses were conducted on the coarse and fine clay fractions of all samples and the total K, Mg and Ca contents of the clay fractions were also investigated. With the exception of samples from the Pitt Meadows area, there was a marked similarity in the clay mineral suite present in these sediments. The major clay mineral components of the coarse clay fraction were montmorillonoid and chlorite. Lesser amounts of micaceous material and several interstratified clay minerals were also present. The interstratified clay minerals identified included a randomly interstratified chlorite-montmorillonoid and chlorite-mica and in a limited number of cases regularly interstratified chlorite-montmorillonoid. The identification of a regularly interstratified chlorite-mica was quite questionable. Positive identification of kaolin was prevented in most instances by a heat unstable chlorite. However, kaolin was identified in a sample from the Pitt Meadows area and there was strong evidence to suggest its presence in other samples. Quartz, feldspars and amphiboles were the only non-phyllosilicates identified. The fine clay fractions were dominated by montmorillonoid and much lesser amounts of chlorite. Micaceous material, inter-stratified clay minerals and quartz were present in only questionable amounts and in some instances appeared to be absent. The chlorite was identified as an iron rich variety possessing thermally unstable higher order reflections. A progressive decrease in the relative intensity of these reflections was observed on heating from 4OO to 450°C. Further heating to 500°C resulted in the disappearance of the peaks. The montmorillonoid component identified appeared to be of two types: An octahedrally substituted member and a tetrahedrally substituted member. The presence of the latter mineral prevented identification of vermiculite. The results support the findings of other workers that marine deposited sediments are highly detrital in nature, dominantly reflect their source area and are influenced by sea water to only a minor extent. Diagenesis of 14+ A° material of the marine sediments was indicated by X-ray diffraction analyses. Chemical analyses were also indicative of the minor influence of a marine environment. Mineralogical variations within and among soil series were largely quantitative in nature. These variations tended to be minimized within a particular soil series. Mineralogical differences between the two clay fractions were observed, however these were to be expected. The variations noted in the mineralogy of the clay fractions of these sediments were attributed to sedimentary processes, seasonal variations in the detrital components carried by rivers, yearly variations in particular source areas and the local influence of sediments carried by several tributaries of the lower Fraser River that flow out of the Coast Mountains. The X-ray and chemical analyses indicated that there was a valid basis for continued mapping of the Pitt soil series separate from the Monroe and Fairfield series. The two sampling sites from the Pitt Meadows were considerably higher in randomly interstratified chlorite-montmorillonoid and lower in micaceous material than those of the other sediments. Chemical analyses were also indicative of these differences. The variability noted in soils from the Pitt Meadows area may be related to the influence of sediments carried by the Alouette River. / Land and Food Systems, Faculty of / Graduate

Some of the physical and chemical properties of the stony marine clays recently described by Armstrong and Brown in the Lower Fraser Valley area of British Columbia were investigated. Mechanical analysis of samples taken from four depths from the Murrayville, Jackman and Lehman sites showed that the amount of clay material less than 2 microns in diameter increased from a range of 4 to 18 per cent in the surface foot to 20 to 40 per cent at a depth of 18 feet. The silt and fine sand material varied conversely, the surface foot containing from 77 to 96 per cent while the material from; 18 feet contained from 61 to 68 per cent. The textural classification of the samples ranged from sandy loam to silt loam in the surface, and from loam to clay loam at depth. The material collected from the fourth site, Haney, had a somewhat higher content of clay material, 42 to 46 per cent, and a smaller percentage of coarse skeleton, fine sand and silt. Samples from the surface were not available, but the textural classification at depth was clay to silty clay. The mechanical analysis and other physical and chemical information support the suggestion that the material at the Haney site differs significantly from that at the others. The apparent and real densities of the material at all four sites increased with depth, the range in apparent density being from about 1.1 to 1.4 at the surface to 1.4 to 1.8 at 18 feet. In the case of the real density the range was from about 2.69 on the surface to 2.74 to 2.82 at depth. There was a corresponding reduction in total porosity from about 60 per cent of the soil volume at the surface to 35 per cent at depth. The moisture tension determinations showed that to a large extent this reduction was at the expense of large or macro pores. Hydraulic conductivity determinations with soil cores showed that close to the surface the material is reasonably permeable to water, but that it decreases to a very low value at depth. The cation exchange capacity of the material was found to vary considerably ranging from 7 to 23 milli-equivalents per 100 gm. In general the deeper samples gave somewhat lower and more constant values than the surface, ranging from 10.2 to 16.5 milli-equivalents per 100 gm. Reaction and exchangeable cation determinations showed that at the one-foot depth the material is acid, pH 5.0 to 5.8, and from 40 to 73 per cent base saturated. However, the reaction and degree of base saturation was found to increase with depth until in the deeper samples the reaction ranged from pH 7.4 to 9.4> and the clay material was completely base saturated. Highly significant quantities of exchangeable sodium and free lime were found in all the deep samples. Material with effective diameter less than 2 microns was separated from all samples, and from the 18-foot samples less than .5 micron material as well. The free-oxide content of the less than 2 micron material was found to range from about 8.7 per cent at the surface to 3.9 per cent at depth. Sodium carbonate fusion analysis showed the fine material to contain from 50 to 60 per cent silica, and have a high silica-sesquioxide ratio ranging from 3.02 to 6.41. The fine material was found to contain significantly more total magnesium and potassium at depth. These results, together with the high exchange capacity and dehydration values obtained suggest that the fraction smaller than .5 microns contains a significant amount of clay material of the montmorillonite, illite, or hydrous mica types, and that the proportion of this material is somewhat higher at the surface. / Land and Food Systems, Faculty of / Graduate

The study included field, greenhouse and laboratory experiments with sawdust used as mulch and incorporated with soil. The field experiments were conducted with hemlock sawdust mulches on Lynden silt loam at Abbotsford and on Everett sandy loam at Aldergrove. In both cases the crop was strawberries. Two depths of sawdust were used, two and four inches, and these were compared with clean cultivation, with and without sprinkler irrigation. Soil samples were taken in triplicate from three depths at intervals throughout the 1951 growing season and used for the determination of soil moisture. The 1951 season was one of the driest recorded and both depths of sawdust were very effective in conserving soil moisture. On the Lynden silt loam the sawdust maintained soil moisture at a satisfactory level for growth throughout the growing period and was as effective as sprinkler irrigation for this purpose. However, on Everett sandy loam, sprinkler irrigation maintained soil moisture in a more satisfactory manner. Samples taken from the Lynden soil after the mulches had been down a year, indicated a reduction in Humin I nitrogen and nitrate nitrogen had occured as a result of mulching. However, the differences were not great and a more significant reduction of total nitrogen and nitrate nitrogen was noted on the irrigated plots. In the greenhouse experiment, two sizes of cedar and hemlock sawdust were incorporated at two rates with Alderwood sandy loam, fertilized at two rates and planted with lettuce. After one year it was found that hemlock sawdust had increased the moisture equivalent and wilting percentage more than cedar had, but that the cedar mixtures gave a higher yield of lettuce. In all cases the differences were small but significant. Sawdust, when incorporated with the acidic soil, raised the pH slightly and increased the moisture equivalent, permanent wilting percentage and cation exchange capacity of the soil, the effect being greater for the higher rate of incorporation. Sawdust had the opposite effect on available moisture and lettuce yield. Apparent specific gravity of the soil was noticeably decreased as a result of the sawdust additions and a very large increase in non-capillary pore space occured. This was associated with a large increase in percolation rate. Capillary porosity was affected to a very small extent by the sawdust. Nitrogen fertilization (NH₄NO₃) increased soil acidity in the control soil and in the soil sawdust mixtures. Tests were conducted to determine the absorptic capacity of sawdust for water and ammonia. Size of sawdust affected the amount of water absorbed but not the amount of ammonia absorbed. / Land and Food Systems, Faculty of / Graduate

A study of the potassium status of some Lower Fraser Valley soils was undertaken in order to supply data which would aid in the interpretation of fertility experiments and chemical tests for available soil potassium. Since the rapid chemical tests for available potassium now used in the Lower Fraser Valley leave much to be desired, several promising methods were studied and compared to a standard ammonium acetate extraction gravimetric analysis method for determining exchangeable potassium. The Morgan and Spurway rapid methods for available potassium estimation were not found precise or accurate enough for the purposes of the study. A technique described by Peech and English, which involves extraction of available potassium with normal sodium acetate of pH4.8 and subsequent precipitation of potassium as the di-potassium sodium cobaltinitrite in formaldehyde-isopropyl alcohol solution was tested. A modification of this method was adapted to estimation by the photometer and results for exchangeable potassium, although lower, correlated well with those of the standard determination. A technique which is more rapid and better adapted to studies in which potassium is the only cation to be tested is that described by Bray, who recommends extraction with sodium nitrate and precipitation of potassium with sodium cobaltinitrite in ethyl alcohol solution and subsequent photometric determination. This method extracted slightly more potassium than that of Peech but also showed a high correlation with the standard method used. Both and Bray and Peech procedures were found adaptable to line chart estimation for routine soil testing work. The Bray method was compared to the standard ammonium acetate-gravimetric procedure in potassium fixation and release studies in limed and unlimed soils. Two upland soils and three recent alluvial soils, on which fertility experiments with oats had been conducted, were studied. A greenhouse experiment using lettuce was designed to indicate any existing relation between chemical studies and plant response. In the laboratory fixation was induced by alternately wetting and drying the soils at 110⁰ C. All soils were found to have high fixing potentials when measured by both extraction methods, although the fixation was higher when determined by the standard method. The effect of lime on fixation in both the laboratory and greenhouse soils was determined. The soils generally showed an apparent release of potassium when measured by the ammonium acetate-gravimetric method and a fixation by the sodium nitrate technique. These differences were considered to be due to the relative replacing powers of Na+ and NH+ when Ca++ or H+ dominate the exchange complex. Thus the extraction of potassium by Na+ may be inhibited when calcium is the complementary ion on the colloid. The potassium status of the upland soils was less affected by lime than the lowland soils when fixation or release due to lime was measured by either method. The soils studied failed to release any potassium from the fixed form when leached of their exchangeable potassium and stored for three months in a moist condition, or when wetted and dried at 110 C. No relation was found to exist between exchangeable potassium or the relative potassium fixing and supplying powers of the soils, and oat response to potassium in the field or lettuce growth in the greenhouse. / Land and Food Systems, Faculty of / Graduate

A study was undertaken to determine some of the factors which affected the extraction of sulphur from seven selected soils of the Lower Fraser Valley and Vancouver Island; with particular reference to the effect of pH, concentration and cation of phosphate buffers. In all cases the presence of phosphate resulted in more sulphur being extracted, than extraction with water only. In every instance increasing the concentration of neutral sodium phosphate buffers from 0.005M to 0.5M resulted in increasing sulphur extraction. Using a 0.5H sodium phosphate buffer and increasing the pH from 4 to 8 generally resulted in maximum extraction at pH 7, except notably in the Langford soil in which the amount of sulphur extracted increased as the pH was changed from 4 to 8. The behaviour of four surface soils when extracted with 0.5M sodium phosphate at varying pH levels was quite similar, the mineralogy of the <2µ fraction was also similar. Gel filtration studies of the 0.5M phosphate extracts of the Langford showed that at pH 4 little inorganic sulphate was extracted, while from pH 6 to 8, the amount extracted remained almost constant, though more than three times that extracted at pH 4. The extracted organic fraction increased as the pH varied from 4 to 8. In soils with a low carbon content and a high content of free iron and aluminum oxides, the water extractable sulphur was very low, as was the amount of phosphate extractable organic sulphate. The amount of sulphate extracted from the original air dry samples by 0.5M phosphate was very much less than the sulphate adsorbed from a 50 ppm sulphur solution. It was found that a neutral 0.5M sodium phosphate solution extracted more sulphur in nearly all cases, than other extractants, and in the soils studied cold water did not seem suitable. The neutral 0.5M phosphate solution extracted inorganic and a portion of the organic sulphate and may be expected to be a suitable chemical extractant which will be able to indicate the sulphur status of soils of the Lower Fraser Valley. / Land and Food Systems, Faculty of / Graduate

A study was undertaken on the pedogenesis of a Podzol sequence of soils on the West Coast of Vancouver Island. The area is one of abundant rainfall and rather luxuriant vegetation. The soils occur on relatively level topography (glacial fluvial deposits) and have varying degrees of development of placic (pan) horizons. The objectives of the study included characterization, classification and genesis of the soils, based on physical, chemical and mineralogical investigations. Four soils were chosen for the study. Three of the soils comprised the Ucluelet soil series, while one soil was a member of the Wreck Bay soil series. The soils were described morphologically, sampled and selected analyses were performed on the major genetic horizons. More detailed analyses, including differential thermal analyses, were conducted on the placic materials. The soils were classified into the Canadian Classification Scheme as as follows: Ucluelet I Placic Ferro-Humic Podzol Ucluelet II Orthic Humo-Ferric Podzol Ucluelet III Placic Humo-Ferric Podzol Wreck Bay Gleyed Placic Ferro-Humic Podzol Analyses of the placic materials indicated, that although the material appeared vitreous in the field, no crystallinity could be determined by X-ray diffraction. It appeared that the major component of the placic horizon is composed of iron and organic matter, probably in some intimate association. It was observed that the placic horizon could form in materials of initially low iron contents. From the foregoing observations the following chronosequence of soil development appears to be justified: Orthic Humo-Ferric Podzol (Ucluelet II) → Placic Humo-Ferric Podzol (Ucluelet III) → Placic Ferro-Humic Podzol (Ucluelet I) → Gleyed Placic Ferro-Humic Podzol (Wreck Bay) The differences in pedogenic age of the three Ucluelet sites can be attributed to degrees of "churning" by the trees at these sites. / Land and Food Systems, Faculty of / Graduate

A study was undertaken to determine some of the factors which affected the extraction of sulphur from seven selected soils of the Lower Fraser Valley and Vancouver Island; with particular reference to the effect of pH concentration and cation of phosphate buffers. In all cases the presence of phosphate resulted in more sulphur being extracted, than extraction with water only. In every instance increasing the concentration of neutral sodium phosphate buffers from 0.005M to 0.5M resulted in increasing sulphur extraction. Using a 0.5M sodium phosphate buffer and increasing the pH from 4 to 8 generally resulted in maximum extraction at pH 7, except notably in the Langford soil in which the amount of sulphur extracted increased as the pH was changed from 4 to 8. The behaviour of four surface soils when extracted with 0.5M sodium phosphate at varying pH levels was quite similar, the mineralogy of the <2μ fraction was also similar. Gel filtration studies of the 0.5M phosphate extracts of the Langford showed that at pH 4 little inorganic sulphate was extracted, while from pH 6 to 8, the amount extracted remained almost constant, though more than three times that extracted at pH 4. The extracted organic fraction increased as the pH varied from 4 to 8. In soils with a low carbon content and a high content of free iron and aluminum oxides, the water extractable sulphur was very low, as was the amount of phosphate extractable organic sulphate. The amount of sulphate extracted from the original air dry samples by 0.5M phosphate was very much less than the sulphate adsorbed from a 50 ppm sulphur solution. It was found that a neutral 0.5M sodium phosphate solution extracted more sulphur in nearly all cases, than other extractants, and in the soils studied cold water did not seem suitable. The neutral 0.5M phosphate solution extracted inorganic and a portion of the organic sulphate and may be expected to be a suitable chemical extractant which will be able to indicate the sulphur status of soils of the Lower Fraser Valley. / Land and Food Systems, Faculty of / Graduate

In mature forests, gains and losses of nitrogen may be dominated by the gaseous transformations, asymbiotic nitrogen fixation and biological denitrification. Both are reduction reactions and are affected by moisture conditions, temperature, pH, supply of organic carbon and the availability of mineral nitrogen. Gaseous nitrogen inputs, due to asymbiotic nitrogen fixation, and outputs, due to biological denitrification were quantified for a mature coniferous forest in southwestern British Columbia. Forest floor material, mineral soil, decaying wood, foliage and bark were incubated in an atmosphere of 0.1 atm acetylene to allow the simultaneous measurement of N₂0 production by denitrifying bacteria and acetylene reduction by free-living bacteria and blue-green algae. Forest floor material accounted for 80% of a total annual input of 0.8 kg N ha⁻1 a⁻1. Relatively small amounts of nitrogen were fixed in mineral soil, decaying wood and foliage and no indication of nitrogen fixation activity in bark was detected. Traces of denitrification were found, but gaseous output of nitrogen was effectively 0.0 kg N ha⁻1 a⁻1. It is hypothesized that this forest may prevent nitrogen Joss by outcompeting other sinks for mineral nitrogen, thereby allowing a slow accretion of nitrogen by asymbiotic nitrogen fixation and bulk precipitation input. / Forestry, Faculty of / Graduate

Three soils occurring on a climosequence were studied to clarify certain aspects of Podzol genesis and Podzol classification. Data on physical, chemical, and soil solution characteristics of the three soils were collected and analysed. All measures of iron and aluminum were analysed and presented as mass per horizon. Rates of movement for calcium, magnesium, sodium, potassium, iron and aluminum between the canopy, forest floor, B₁ and B₂ horizons were also measured. The interpretations of different measures of iron and aluminum as an index of Podzol expression were shown to be inconsistent. A simple linear model was developed and applied to data from the three soils. The model defined the balance of additions, losses, transformations, and translocations within and between horizons for each site. The model results supported the following hypotheses: 1) The balance of additions, losses, translocations, and transformations vary across the climosequence. 2) The three soils studied can be identified by the balance of processes acting to produce sesquioxide rich B horizons. 3) Current Podzol classification criteria do not reflect differences in the balance of these processes. The model did not support the hypothesis that rates of biochemical cycling would be reflected in Podzol B horizon expression. Two distinct balances of processes forming iron and aluminum rich B horizons were shown to occur. In one site iron and aluminum accumulate primarily as a result of preferential loss of other soil constituents; in the other sites iron and aluminum are dominantly the product of eluviation from the Ae horizon and deposition in the B horizons. Current classification criteria grouped the two soils showing the most strongly contrasting genetic processes together as Brunisols while the intermediate balance was classified as a Podzol. The reasons for this inconsistency are discussed. / Land and Food Systems, Faculty of / Graduate

In the forest used as range several problems are encountered: (1) accessibility of ranges and (2) invasion of open or lightly timbered ranges by forest growth. For many years stockmen have advocated the use of controlled burning to overcome these problems. However, at present the value of fire for range improvement in this region is not definitely known. Experimental burns have been made to study the effect of fire on vegetation, but little or no work has been done to determine the effect of fire on the soil in such forest range areas. Accordingly, this investigation was initiated in order to determine to what extent soil characteristics in the forest range about Lac Le Jeune have been altered toy forest fires. As a result of forest fires the following changes occurred in the soil of the lodgepole pine, Douglas fir and mixed stands of lodgepole pine, Douglas fir, and spruce forests near Lac Le Jeune. (1) A reduction in percent porosity of the top O-3 inches of soil due to the destruction of both the porous organic horizon and the crumb structure of the upper portion of the B₂ horizon. A further reduction was the result of the soil pores toeing clogged toy ash and suspended soil particles. (2) Increased percentage of capillary pore space of the O-3 inch layer because of the destruction of the larger pores in the Ao horizon and the compaction of the bare soil toy rain. (3) 4 decrease in the percentage of non-capillary pore space or air volume in the O-3 inch layer resulting from the destruction of the Ao with large porese The compacting effect ofrain drops on the crumb structure of the B₂ horizon also aided in decreasing the non-capillary porosity. (4) An increase in volume weight of the O-3 inch layer due to compaction and destruction of the less dense Ao. (5) A decrease in the infiltration rate due to compaction and destruction of soil structure. (6) An increase in soil temperature at a depth of 3 inches resulting from the addition of charcoal which absorbs heat and the destruction of vegetation and forest litter which normally serve as insulating agents. (7) An increase in pH of the Ao and in some cases of the A₂ as a result of the release of basic minerals from the ash, and an Indication that the basic minerals may be leached downwards to the A₂. The pH of the Ao decreased 3 or 4 years after the fire. (8) A decrease in the organic matter content of the duff which had not been totally destroyed by fire. Below the Ao no change occurred. (9) A decrease in the total nitrogen content of the Ao due to volatilization of nitrogen during the fire. No definite trend could be established below the Ao. (10) An increase in total phosphorous in the Ao because of the release of this element from the litter. (11) A reduction in the carbonic acid soluble phosphorous in the Ao due to its combination with the excess calcium to form an insoluble compound. Similarly a decrease in CO₂ soluble phosphorous occurred in the A₂. (12) A decrease in CO₂ soluble potassium in the Ao and A₂ resulting from unrestricted leaching. An Increase in CO₂ soluble potassium in the B₂ horizon. (13) An increase in CO₂ soluble calcium in the Ao of recent burns due to the presence of large amounts of calcium in the ash. Apparently 8 or 9 years are required before ail the added calcium is leached to lower horizons. (14) An increase in CO₂ soluble magnesium in the Ao of the recent burns. The content decreased in the Ao of the older burns because of increased leaching. (15) A decrease in CO₂ soluble nitrates in the Ao. An increase in nitrates in the B₂ is probably a result of increased nitrification at the soil surface followed by considerable leaching. (16) A reduction in the base exchange capacity of the Ao. An increase in exchangeable calcium in the Ao and A₂. An increase in exchangeable magnesium in the Ao, A₂ and B₂ horizons. An increase in exchangeable potassium in the Ao, A₂, B₂, and B₃. An increase in percent base saturation in the Ao, A₂, B₂, and B₃ horizons. / Land and Food Systems, Faculty of / Graduate