ALBERT

Description: Experiments were made to determine the relative amounts of solid phase hydroxyaluminum to polynuclear ionic hydroxyaluminum formed, according to methods developed by one of the authors, during titrations of dilute AlCl3 solutions with a base. With both 10−3 and 10−2 M AlCl3 solutions, and with both fast (less than 5 minutes) and slow (12 hours) titrations, the solid phase and the polynuclear ions were present at each degree of neutralization at which measurements were made. During the greater part of the titrations the solid phase was the major product with the fast titrations, and the polynuclear ions were the major product with the slow titrations. Beyond about 80% neutralization the polynuclear ions began to decrease in concentration until at 100% the solid phase approached 100% of the products regardless of the rate of titration. There was a considerable amount of Cl associated with the solid phase during most of each titration, but the Cl/Al molar ratio of the solid approached zero as neutralization approached 100%.

Description: Potassium deficiency in grapes, as well as in other fruit crops grown on soils in the Niagara peninsula, is a common and often serious problem. Ap horizon samples from 12 of these soils and grape petiole samples from nine of the soil locations were analyzed to elucidate the behavior of the soil K and its availability to grapes. The soils ranged in texture from sandy loam to silty clay and their clay mineralogy was relatively uniform with mica as the main layer silicate. Vermiculite was quantified by potential K fixation methods and was concentrated in the clay. Up to 5.8% vermiculite was present in the soils which seemed to be sufficient to reduce K availability by K fixation. Amounts of exchangeable K extracted with NaCl or NH4Cl were relatively high (0.46–2.09 meq/100 g) but were not correlated with K uptake by grapes. Energies of K exchange obtained from immiscibly displaced soil solutions were closely related to vermiculite contents and amounts of K fixed after air drying. Energies of K exchange and ratios of exchangeable K over exchangeable Ca + Mg were highly correlated with K uptake by grapes. Soils with energies of K exchange less than or equal to −2800 cal/equiv. or K exch./(Ca + Mg) exch. equal to or more than 7% appeared to have adequate amounts of available K for grapes. These two analyses therefore show promise for predicting K availability to grapes. Key words: Exchangeability of K, energy of K exchange, fixation of K, soil mineralogy, availability of K to grapes

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

Description: In a field experiment in which heavy applications of liquid dairy manure were added annually for 6 yr to a vermiculite-containing corn-cropped sandy clay loam soil (Mountain series), fixation potential and X-ray diffraction analyses were done to determine if fixation of added K+ and NH4+ had occurred and clay mineralogical changes could be detected. Of the 850 kg K+ and the 460 kg NH4+ added per hectare each year, approximately 28% of the K+ and 24% of the NH4+ remained fixed. This caused a marked increase in the 1.0-nm peak at the expense of the 1.4-nm peak due to collapse of vermiculite layers to form pedogenic mica. Thus, changes in soil management, specifically in fertilizer practices, can result in significant changes in clay mineralogy within a short period of time. Such changes are agronomically important and should be taken into account in the interpretation of clay mineralogical data. Key words: Potassium and ammonium fixation, vermiculite to pedogenic mica transformation, liquid manure application

Description: A study was made of the native clay-fixed NH4+ of some typical soils of Eastern Canada. Usually the amount of fixed NH4+ was related to the clay contents and increased down the profile but there were frequent exceptions to both of these generalizations. The amounts found ranged from 12 to 450 μg fixed NH4+–N/g soil. In general, with some cultivated soils, the cropped areas had lower native fixed NH4+ contents than areas that were in sod. The capacity to fix added NH4+ was usually low in the sandy soils and in general the B and C horizons fixed more NH4+ than the A horizons. For the soils that did fix NH4+, a larger amount but lower percentage was fixed as the amount of added NH4+ was increased. The amount of water in which the NH4+ was added had a slight effect on the percentage fixed, being a little lower as the amount of water was increased. The cultivated New Brunswick surface soils had low NH4+ fixing capacities. Analysis of the clay mineralogy of some soils showed a fairly close relationship between vermiculitic clay content and NH4+ fixation.

Description: Long-term (8 yr) K+ fertilization experiments were started in 1983 on Jeddo clay loam, Smithville silt loam, Oneida loam, and Vineland sandy loam in the Niagara region of southern Ontario to study K+ exchange and fixation in relation to K+ uptake by grapes. Potassium fertilization at rates of 0, 100, 200, 400, and 600 kg K+ ha−1 was discontinued after 4 yr to record the build-up of soil K+ with fertilization and its decline after fertilization ceased. This paper reports the results on K+ exchange and fixation during the 4-yr K+ fertilization period. The clay mineralogy of the soils was similar with their clays containing mainly mica and smaller amounts of vermiculite, chlorite, quartz, and feldspars. There was a highly significant linear relationship between rates of applied K+ and K+ fractions of exchangeable cations for every soil in every year of K+ application. Exchangeable K+ concentrations in the coarse-textured Vineland soil increased sharply from the first to the second year of K+ application. However, there was no consistent increase of exchangeable K+ concentrations with time in the finer-textured soils for the first 2-4 years of K+ application. This was attributed mainly to K+ fixation. This interpretation was supported by chemical and X-ray evidence that showed reduced K+ fixation capacity and transformation of vermiculite to a mica-like mineral at the high rate of K+ application. Potassium exchange equilibria and standard Gibbs free energies for the exchange of (Ca2+ + Mg2+) by K+ were calculated using the theory of multiple ion exchange equilibria. Standard Gibbs free energy values for this exchange became more negative with increase in clay and vermiculite contents of the soils which was attributed to the strong adsorption of K+ in vermiculite and vermiculite-like minerals that were concentrated in the clay fraction. Clay content is therefore the dominant factor determining K+ exchangeability in the soils of the Niagara region of southern Ontario. Key words: soil mineralogy, vermiculite contents, potassium exchange equilibria, standard Gibbs free energy

Description: The chemical and mineralogical characteristics of a Gleyed Sombric Brunisol (Keld Series) of the Grandview area of Manitoba were analyzed in detail to determine the influence of acid sulfate weathering. The Keld soil has developed in till derived from underlying soft Cretaceous pyrite-containing shale of the Ashville Formation. The major chemical features of this soil are low pH (3.3) and high amounts of exchangeable Al (15 cmol(+) kg−1) of the Cg and Bg horizons. In addition, amounts of As are high (18–25 mg kg−1) throughout the profile. This element seems to be associated with iron oxides but not with jarosite-type minerals. Pyrite and gypsum were found in the IICkg horizon but jarosite-type minerals, consisting mainly of natrojarosite with ≈ 40% jarosite, were detected in the Cg horizon only. Aluminium-substituted goethite is present in the Bmgj horizon. Smectite, which is partly beidellitic and has an average layer charge density of 0.32 equivalents per formula unit, is the dominant clay mineral in the soil profile and is inherited from the underlying shale along with associated kaolinite and mica. The oxidation and decomposition of pyrite and the formation of sulfuric acid, jarosite-type minerals and aluminum substituted goethite are typical of acid sulfate weathering reactions. The dominant effect of acid sulfate weathering on the clay minerals is their extensive structural breakdown towards the surface of the profile. This is also indicated by the high amounts of Si and Al extracted from weathered mineral residues in the surface horizons. The IICkg horizon of the keld profile is in the pre-sulfuricization stage, the Cg horizon expresses the active sulfuricization stage, and the Bg, Bmgj, and Ah horizons represent the postsulfuricization stage. Key words: Keld series, acid sulfate weathering, natrojarosite, As levels

Description: In Kings County Nova Scotia, soils have developed over pre-Wisconsinan basaltic saprolite and basaltic and granitic till. The clay fraction of the soil developed on the saprolite is predominantly a trioctahedral smectite and apparently has not been significantly changed by post-Wisconsinan weathering. The clay fraction of the Aej horizon of the soil developed on granitic till is dominantly composed of dioctahedral layer silicates, mainly mica with some montmorillonite and vermiculite, and that developed on basaltic till by smectite and vermiculite. Key words: Basaltic saprolite, trioctahedral smectite, post-Wisconsinan weathering

Description: Surface samples of five Quebec soils (St. Bernard, Ormstown, Howick, Dalhousie and Bearbrook) were selected to represent typical agricultural soils with a range of parent material. Soil minerals were fractionated by size into five separates and examined using X-ray diffraction (XRD) techniques and chemical analyses. In nearly all cases the non-clay separates (250–2.0 μm) contained feldspars, amphiboles and quartz as dominant minerals with only small amounts of layer silicates. Feldspars, amphiboles and quartz were also relatively abundant in the clay separates. The layer silicates in the clay separates consisted mainly of mica, chlorite and vermiculite. The soils had similar mineral suites, considered indicative of a low degree of weathering. Considering the mineral composition and the low degree of weathering, it is proposed that primary K-bearing minerals, including K-feldspars, are important sources of K in these soils. Key words: K release, particle size, soil mineralogy

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