ALBERT

Description: Efforts to date have not advanced Indigenous participation, capacity building and knowledge in Arctic environmental science in Canada because Arctic environmental science has yet to acknowledge, or truly practice decolonizing research. The expanding literature on decolonizing and Indigenous research provides guidance towards these alternative research approaches, but less has been written about how you do this in practice and the potential role for non-Indigenous research partners in supporting Inuit self-determination in research. This paper describes the decolonizing methodology of a non-Indigenous researcher partner and presents a co-developed approach, called the Sikumiut model, for Inuit and non-Indigenous researchers interested in supporting Inuit self-determination. In this model the roles of Inuit and non-Indigenous research partners were redefined, with Inuit governing the research and non-Indigenous research partners training and mentoring Inuit youth to conduct the research themselves. The Sikumiut model shows how having Inuit in decision-making positions ensured Inuit data ownership, accessibility, and control over how their Inuit Qaujimajatuqangit is documented, communicated, and respected for its own scientific merit. It examines the benefits and potential to build on the existing research capacity of Inuit youth and describes the guidance and lessons learned from a non-Indigenous researcher in supporting Inuit self-determination in research. Pinasuktaujut maannamut pivaallirtittisimangimmata nunaqarqaarsimajunik ilautitauninginnik, pijunnarsivallianirmik ammalu qaujimajaujunik ukiurtartumi avatilirinikkut kiklisiniarnikkut kanata pijjutigillugu ukiurtartumi avatilirinikkut kiklisiniarnikkut ilisarsisimangimmata, uvaluunniit piliringimmata issaktausimangittunik silataanit qaujisarnirmut. Uqalimaagait issaktausimangittunit silataanit ammalu nunaqarqaarsimajut qaujisarningit piviqartittikmata tukimuagutaujunnarlutik asiagut qaujisarnikkut, kisiani titirartauqattanginnirsaukmat qanuq pilirigajarmangaata ammalu ilautitauningit nunaqarqaarsimangittut qaujisarnirmut ikajurtuilutik Inuit nangminiq qaujisaqattarnirmut. Taanna titirarsimajuq uqausiqartuq issaktausimangillutik iliqusiujumik nunaqarqaarsimangittut qaujisartiujut ammalu saqittillutik ikajurtigiiklutik pigiartittinirmik, taijaujuq sikumiut aturtanga, inungnut ammalu nunaqarqaarsimangittunut qaujisartinut pijumajunut ikajurtuilutik Inuit nangminiq qaujisarnirmut. Tavani aturtaujumi piliriaksangit Inuit ammalu nunaqarqaarsimangittut qaujisartiujut tukisinarsititaullutik, Inuit aulattillutik qaujisarnirmik ammalu nunaqarqaarsimangittut qausartit ilinniartittillutik ammalu pilimmaksaillutik makkuktunik inungnik nangminiq qaujisarunnarniarmata. Sikumiunut aturtaujuq takuksaujuq qanuq Inuit aaqiksuijiullutik Inuit pisimajiuniarlutik tinngirartaujunik, takujaujunnarningit ammalu aulatauningit qanuq inuit qaujimajatuqangit titirartaukmangaata, tusaumajjutaukmangaata ammaluikpigijaulutik kiklisiniarnikkut atuutiqarninginnik. Takunangniujuq pivaalliutaujunnartunik ammalu pirurpalliagajartunik maanna qaujisarniujumik pijunnarsiqullugit makkuktut Inuit ammalu uqausiulluni tukimuagutaujunnartut ammalu ilitausimajut nunaqarqaarsimangittunit qausartinit ikajurtuilutik inuit nangminiq qaujisarnirmut.

Description: A total of 344 soil cores were taken in annually cropped fields of Alberta, Saskatchewan, Manitoba, and Ontario from 2011 to 2013 in areas where the field shapes, or obstacles within fields, required the driving pattern of farm operations to overlap. Soil nitrate-N concentrations in overlapping areas were 60% greater, soil Olsen-P concentrations were 23% greater, and pH was 0.5 units greater at 0–15 cm depth compared with non-overlapping areas, suggesting smaller nutrient use efficiency and potential for greater nutrient loss.

Description: Differences in soil water retention (SWR) characteristics between soil types and the factors driving those differences provide important information for land management, particularly in regions such as the Colombian Andes, which have limited water-storage infrastructure and where soils provide plant-available water and other ecosystem services. The objective of this study was to explore relationships between SWR and physical, chemical, and mineralogical properties of Andisols and Inceptisols through a case study of two watersheds in the Colombian Andes. This study identified a complex relationship between total carbon (TC), short-range order (SRO) minerals, and SWR. Both soil types had high SWR, with volumetric water content at permanent wilting point between 39% and 53%. Principal component analysis showed association of SWR with TC, SRO minerals, and % clay in both soil types. The Andisols of this study were coarse textured, allophanic (rich in allophane and imogolite — up to 17% in the B horizon), and with up to 15% TC in the A horizon. In contrast, the Inceptisols were fine textured (〉30% clay) and higher in ferrihydrite than the Andisols. The formation of organo-metallic complexes was observed in A horizons; however, TC was lower under pasture than forest in both soil types. The addition of organic matter to soils with SRO minerals, such as the soils of this study, may foster the formation of organo-metallic complexes, stabilize soil C, and enhance SWR. Consequently, both study sites may benefit from management practices that increase soil organic matter.

Description: The paper describes the architecture for a data repository and distribution system to be used in the case of a SETI detection event. This system is conceptually modelled after the Deep Space Network, although the hardware and infrastructure involved are different and substantially less expensive to operate. The system is designed to accommodate a large number of users from a variety of fields who wish to contribute to the analysis and comprehension effort that would follow the detection of an information-bearing signal.

Description: Under the potential to reconstruct the past climatic and atmospheric conditions from a deep ice core in the coastal Antarctic site (Styx Glacier), an 8.84 m long firn core (73°50.975′ S, 163°41.640′ E; 1623 m a.s.l.) was initially studied to propose a reliable age scale for the local estimation of snow accumulation rate. The seasonal variations of δ18O, methanesulfonic acid (MSA) and non-sea-salt sulfate (nssSO42–) were used for the firn core dating and revealed 25 annual peaks (from 1990 to 2014) with volcanic sulfate signal. The observed declining trend in annual accumulation rate with a mean value of 146 ± 60 kg m–2 a–1 is likely to be linked to the changes of sea-ice extent in the Ross Sea region. Moreover, the temporal variation of the annual mean δ18O, an annual flux of MSA and nssSO42– also likely to be under the influence of ice-covered and open water area. This study suggests a potential to recover past changes in an oceanic environment and will be useful for the interpretation of the long ice core drilled at the same site.

Description: Clouds play an important role in the Arctic surface radiative budget, impacting the seasonal evolution of Arctic sea-ice cover. We explore the large-scale impacts of springtime and early summer (March through July) cloud and radiative fluxes on sea ice by comparing these fluxes to seasonal ice volume losses over the central Arctic basin, calculated for available observational years 2004–2007 (ICESat) and 2011–2017 (CryoSat-2). We also supplement observation data with sea-ice volume computed from the Pan-Arctic Ice–Ocean Modeling and Assimilation System (PIOMAS) during summer months. We find that the volume of sea ice lost over the melt season is most closely related to observed downwelling longwave radiation in March and early summer (June and July) longwave cloud radiative forcing, which together explain a large fraction of interannual variability in seasonal sea-ice volume loss (R2 = 0.71, p = 0.007). We show that downwelling longwave fluxes likely impact the timing of melt onset near the sea-ice edge, and can limit the magnitude of ice thickening from March to April. Radiative fluxes in June and July are likely critical to seasonal volume loss because modeled data show the greatest ice volume reductions occur during these months.

Description: In severely deficit soil, lentil (Lens culinaris Medic) crop requires micronutrients for increased production. Micronutrient management is, therefore, very important for lentil productivity but mostly ignored. This study was carried out from 2014–2015 to 2016–2017 to understand the effects of zinc (Zn), boron (B), and molybdenum (Mo) on lentil productivity, nodulation, and nutrient uptake and how these elements improve soil micronutrient fertility. The experiment was laid out in randomized complete block design, and the treatments were replicated thrice. Different combinations of Zn, Mo, and B were contrasted with no application of micronutrients. The treatments were Zn alone (Zn), B alone (B), Mo alone (Mo), Zn combined with B (ZnB), Zn with Mo (ZnMo), B with Mo (BMo), and Zn combined with B and Mo (ZnBMo). Doses of Zn, B, and Mo were 3, 2, and 1 kg ha−1, respectively. In this trial, the highest average seed yield (1807 kg ha−1) and yield increment (44%) was obtained in ZnBMo combined application with macronutrients. Single, dual, and combined application of Zn, B, and Mo had significant effects on yield parameters and yield of lentil (P 

Description: There is a need to provide quantitative relationships that will allow agronomists to estimate accurately the nitrogen-supplying power of soils while taking into account both temperature and soil moisture variations. The procedure for estimating net nitrogen mineralization proposed by Stanford and co-workers was used to determine Arrhenius relationships between the rate constants (k) and absolute temperature (°K) for 33 virgin and cultivated Western Canadian prairie surface (0–15 cm) soils. There was no significant difference in Arrhenius relationship between soils within each soil zone; thus, a single average Arrhenius equation was calculated per soil zone. Average Q10 for the Brown chernozemic soils was 2.75, for the Dark Brown, thin Black and thick Black chernozems, 2.18, and for the Gray luvisols, 2.0. These Q10 values are as high or higher than those reported in other parts of the world and may be related to the degree of degradation of the soil organic matter in these various soils. Culture had no marked effect on Q10 but sandy soils had higher Q10 than loams and clays. An equation for estimating net nitrogen mineralization for the Wood Mountain loam (a Brown chernozem) was tested using data from a previous study. The results were quite satisfactory, especially when the test data were derived under laboratory conditions where moisture was well controlled. The temperature functions presented herein can be used together with moisture functions and potentially mineralizable nitrogen results published earlier to make first estimates of net nitrogen mineralized during the growing season in the soils tested. Key words: Q10, Arrhenius relationship, potentially mineralizable nitrogen

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

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

Description: Content of mercury in organic soil horizons was monitored to ascertain seasonal changes in background levels. L, F, and H horizons were relatively enriched in mercury in early spring. Levels then diminished and reached seasonal low values in August. Content of mercury then increased twofold during September after which levels declined to summer values. F horizons had the highest content of mercury and H horizons had the lowest. Key words: Mercury cycling, mercury dynamics, heavy metal

Description: The sulfur status of rapeseed (Brassica napus and Brassica campestris) plants grown in field studies was assessed using a variety of plant indices; percent sulfur, percent hydriodic acid reducible sulfur (HI-S in plant dry matter), HI-S:total S ratio, and total N:total S ratios. Of these, HI-S:total S determined at the rosette growth stage was the most accurate and consistent index of seed yield. A growth chamber study indicated that the HI-S:total S ratio would not be affected by nitrogen fertilizer application at normal field rates. Key words: Sulfur, deficiency, rapeseed (Brassica spp.), plant analysis

Description: The objective of this study was to compare the effects of various pretreatments on the X-ray identification and quantification of clay-sized minerals from some podzolic B horizons. After soil samples were treated with H2O2 to remove organic matter, clay fractions were dispersed, separated, and freeze-dried. A portion of each clay sample was subjected to the following pretreatments: ultrasonic bath, extraction by citrate-dithionite, extraction by 0.5 N NaOH, and extraction by Tiron. Oriented slides were used for identification and quantification of clay minerals after each pretreatment. The X-ray patterns for ultrasonically dispersed samples were used as a basis for evaluating the effectiveness of the three chemical pretreatments. Tiron pretreatment was found to be the most suitable method for removal of amorphous material from clay separates of podzolic B horizons. The traditional citrate-dithionite method was not effective in removing amorphous Si from clays. The 0.5 N NaOH method is not recommended because it resulted in significant destruction of phyllosilicates and it was not effective in removing amorphous Fe.

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

Description: The effects of surface mining for coal on soil respiration (CO2), microbial biomass C, ATP levels, bacterial and actinomycete numbers, bacterial taxa, hyphal lengths, fungal taxa, N2 fixation and decomposition potential were determined for a short-grass prairie site in southern Alberta, Canada. Soil respiration, microbial biomass C, ATP, actinomycete numbers, hyphal lengths and N2-fixing potential were significantly lower in the mined soil particularly when compared to the undisturbed topsoil. Bacterial numbers were, however, greater in the mined soil than in the unmined soil. The bacteria isolated from the undisturbed soil were dominated by Bacillus spp., coryneforms and non-pigmented Gram-negative rods, while those from the disturbed soil belonged mainly to the coryneform group. Mining also caused the fungal community to shift from one dominated by Chrysosporium-Pseudogymnoascus and sterile dark organisms to one dominated by Alternaria spp., Cladosporium spp., sterile dark forms and yeasts. Decomposition of filter paper, 24 mo after their placement in the field, was significantly faster on the disturbed site than on the undisturbed site. Key words: Surface mining, microbiology, prairie soil

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

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

Description: A single batch application of phosphorus once in several years might be a more economical practice for wheat production in Western Canada than the traditional annual application at seeding time. Annual phosphorus applications and batch applications once every 8 yr were compared. Response functions were estimated for annual applications for two locations in Saskatchewan and two in Manitoba. The response functions were used to determine the optimum application rates at each location. These optimums were compared with the profitability of the batch application to determine the economic optimum phosphorus application strategy. Three wheat/fertilizer price ratios were used in the analysis to examine the effect of changes in relative prices. The 100-kg batch application was economically preferred to annual applications for all three price ratios at three of the four locations. Only at Swift Current, Saskatchewan was the batch application not economically justified. The 100-kg batch application was economically superior to the 200-kg application at all locations studied.

Description: The effect of labile inorganic phosphate (Pi) status of the soil on the decomposition of added cellulose and on the immobilization, mineralization, and redistribution of native and added P in soils was studied in a greenhouse incubation experiment. Cellulose was added at 765 μg C∙g−1 soil with and without P (9 μg∙g−1 soil) every 30 days under adequate N, H2O, and constant tempreature to two soils of different available P status. Lack of P eventually slowed down decomposition of added C, but this effect was partially compensated for by increased mineralization of organic P (Po) forms. Added P was redistributed to both P, (58–69%) and Po (42–31%) forms; higher amounts of Po were found in the soil with the highest Pi status. The correlation between microbial P uptake and solution P values was significant, and microbial C:P ratios ranged from 12:1 under high available P conditions to 45:1 where P was in low supply.

Description: A field study was conducted to measure the effect of soil salinity on barley grown under irrigated conditions in Alberta. Salinity was measured by the saturated paste extract, 1:2 soil-to-water extract, vertical probe and horizontal surface array methods. Correlation coefficients were determined between salinity measurements and the yield of barley to establish the suitability of these methods for predicting the growth of barley. Nineteen fields over 2 yr were monitored and soil salinity and the yield of barley were determined at a number of sites in each field. All methods of measuring salinity were significantly correlated (P = 0.01) with the yield of barley. At an EC of 7.8, yields of barley were reduced by 50%. Sodium concentration and sodium adsorption ratio were closely correlated with yield of barley and with saturated-paste-extract salinity. Soil moisture and pH were not as effective as salinity and sodium measurements in predicting the yield of barley. The saturated-paste-extract salinity was more closely correlated with the 1:2 soil-to-water extract than with the vertical probe or the horizontal surface array. The latter three methods were effective for rapid determination of the yield reductions which would occur on saline soils. No difference in tolerance to salinity was found between Klages (two-row) and Galt (six-row) cultivars of barley. Key words: Salinity tolerance of barley, methods of measuring salinity, vertical probe EC, horizontal array EC, saturated paste EC, 1:2 soil-to-water extract EC

Description: A theory is presented for the distribution of load pressures over the different phases in an unsaturated soil. It provides differential and integral relations between the equilibrium liquid pressure, the equilibrium solid pressure and the load pressure. Mechanical and thermodynamic models are presented by which the effective stress in unsaturated soils is defined. The value of the effective stress is then calculated for a certain state of a clay soil.

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

Description: It is becoming common for soil surveys to be made of the same area at different intensities and published at different scales. The principles of cartographic generalization are discussed that control the relationships between the map units and delineations on maps made from such surveys. A study of two sets of maps showed that almost no lines were coincident. Up to 20% of the small scale delinations could be ’inliers’ of different soils and about 15% of the large scale delineations would be outside their small scale equivalents. The same discrepancies are to be expected between large scale soil maps and the smaller scale maps of physiography or vegetation that are often used to stratify soils. Reasons for these discrepancies are discussed under the headings of simplification and classification. Recommendations arc made to guide the preparation of maps and legends for different intensities and scales of survey in the same area. These recommendations have practical implications for the planning of surveys and the designs of computer-based autocartography systems.

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

Description: Perennial legumes in crop rotations increase soil C sequestration from greater productivity with N2 fixation. Here, we corroborated increases in soil organic carbon (SOC) and harvests modelled in 5 yr wheat–oats–barley–alfalfa/brome–alfalfa/brome (5Y) vs. 2 yr wheat–fallow (WF) rotations with those measured from 1929 to 2018. Harvest and SOC gains of 100–150 g C m−2 yr−1 and 15–25 g C m−2 yr−1 were modelled and measured in 5Y vs. WF rotations with different fertilizer and manure amendments. Modelled gains were closely related to annualized rates of N2 fixation by alfalfa of 8–10 g N m−2 yr−1. However, N2 fixation also drove increases in modelled N2O emissions of ca. 0.06 g N m−2 yr−1, which partially offset gains in SOC. Gains in harvest, SOC, and N2O emissions of 60–90 g C m−2 yr−1, 15 g C m−2 yr−1, and 0.05 g N m−2 yr−1 were modelled and measured in both rotations with amendments of N + P relative to unamended treatments. Harvest and SOC gains were smaller, and leaching and N2O losses larger, with amendments of N without P. After 100 yr of RCP 8.5 climate change, harvests in WF changed little from those in baseline runs, whereas those in 5Y rose with N + P because of increased N2 fixation. SOC declined in WF with all amendments and could only be raised in 5Y with N + P amendments. These model findings indicated the importance of N2 fixation and P amendments in determining responses of agroecosystem productivity and C sequestration to climate change.

Description: The objectives of this study were to find ways to improve the accuracy of soil fertilizer recommendations by taking into account the variation in bulk density (BD) of organic soils. To achieve this end, field BD values of 30 organic soils (0.100–0.504 g/mL) were used to evaluate methods of measuring the BD in the laboratory by means of correlation and regression techniques. A simple and rapid procedure using the reconstituted BD of field-moist soils was the most accurate means of determining the average field BD in the laboratory, as indicated by the correlation coefficient obtained between the BD values obtained by this method and those in the field (r = 0.975**). The second most accurate method relied upon the exponential relationship between the water content of soils and their BD (R2 = 91.1 %). The least exact method of correcting for BD variations was to scoop a volume of dried (65 °C) and sieved (2-mm) soils, as is done in some soil test laboratories. Although the values obtained by this method were related (r = 0.502**) to the field data, drying caused shrinkage of soils, thereby increasing their BD about twofold. Soil pH (r = 0.716**) and percentage ash contents (r = 0.851**) were also related to the field BD of soils. These tests could be used to estimate the BD of soils when the preferred method cannot be used. Regression equations are provided for relating appropriate test values to the BD of organic soils.

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

Description: In 1982, six crop rotation treatments that were initiated in 1967 on a Orthic Brown Chernozemic loam were sampled for soil NO3-N and moisture to a depth of 240 cm. Soil samples were taken on 18 May and 10 June from all treatments, on 2 Sept. on fallow treatments only, and on 14 Oct. from cropped treatments. Precipitation during the sampling period was about 23% above the long-term average. It was estimated that at least 123 kg NO3-N∙ha−1 were leached from the top 240 cm of fallow soils. Leaching appeared to result from a portion of the precipitation moving through macro soil pores. There was evidence that water and NO3-N might also move upwards from below the 240-cm depth. Of the six rotations examined, the 2-yr and 3-yr spring wheat (Triticum aestivum L.) rotations lost the most NO3-N. The presence of fall rye (Secale cereale L.) in a fallow-rye-wheat rotation was very effective in reducing NO3-N losses. Spring wheat, when grown continuously, was also very effective in reducing NO3-N losses but even here there was some evidence of leaching beyond the root zone. Application of fertilizer N and P at amounts based on soil test recommendations reduced NO3-N leached. It was estimated from long-term precipitation data, that over the past 100 yr about 20% of the soil organic N that was present at the time of breaking the land has been lost from the soil via leaching. It was concluded that leaching losses of N from the soils on the Canadian prairies had been greatly underestimated and were partly responsible for losses attributed to the more visible wind erosion. Key words: Nitrate movement, crop rotations, fertilizer and leaching, summerfallow and leaching, bimodal leaching

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

Description: The distribution of NO3-N in the soil, and N uptake by the crop during the first 12 yr of a long-term rotation study at Swift Current, Saskatchewan were studied. A considerable amount of NO3-N appeared to be leached beyond the rooting zone of the cereal crop in years of above average precipitation and also in some relatively dry years with heavy spring rains. Thus, leaching of NO3-N seemed to occur even under continuous wheat rotations. At all times there was considerable NO3-N situated at the 60- to 120-cm depth. In wet years N uptake by the plants reduced the amount of NO3-N located in the subsoil, but in dry years the amount of NO3-N in the subsoil remained higher throughout the growing season. The latter could result in groundwater pollution, especially if such a soil was fallowed the next year. Fall rye (Secale cereale L.) made more efficient use of mineral N than spring-sown crops. In dry years more NO3-N persisted in the root zone of N-fertilized wheat than in the root zone of unfertilized wheat, but in wet and average years there was little difference due to N application. The average rate of net NO3-N production in fallow land from spring thaw to freeze-up (166 days) was 107 kg∙ha−1. Values ranged from about 60 to 175 kg∙ha−1 with the lowest values being obtained during very dry or very wet years. The quantity of N mineralized (kg∙ha−1) between spring thaw and freeze-up was related to precipitation (mm) by the equation Nmin = 29.0 + 0.20 precipitation for the 0- to 60-cm depth (R2 = 0.65*). Key words: Nitrate leaching, N uptake, crop rotations, N mineralization rate

Description: Field spectroscopy and other efficient hyperspectral techniques have been widely used to measure soil properties, including soil organic carbon (SOC) content. However, reflectance measurements based on field spectroscopy are quite sensitive to uncontrolled variations in surface soil conditions, such as moisture content; hence, such variations lead to drastically reduced prediction accuracy. The goals of this work are to (i) explore the moisture effect on soil spectra with different SOC levels, (ii) evaluate the selection of optimal parameter for external parameter othogonalization (EPO) in reducing moisture effect, and (iii) improve SOC prediction accuracy for semi-arid soils with various moisture levels by combing the EPO with machine learning method. Soil samples were collected from grassland regions of Inner Mongolia in North China. Rewetting laboratory experiments were conducted to make samples moisturized at five levels. Visible and near-infrared spectra (350–2500 nm) of soil samples rewetted were observed using a hand-held SVC HR-1024 spectroradiometer. Our results show that moisture influences the correlation between SOC content and soil reflectance spectra and that moisture has a greater impact on the spectra of samples with low SOC. An EPO algorithm can quantitatively extract information of the affected spectra from the spectra of moist soil samples by an optimal singular value. A SOC model that effectively couples EPO with random forest (RF) outperforms partial least-square regression (PLSR)-based models. The EPO–RF model generates better results with R2 of 0.86 and root-mean squared error (RMSE) of 3.82 g kg−1, whereas a PLSR model gives R2 of 0.79 and RMSE of 4.68 g kg−1.

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

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

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

Description: A preliminary field study was conducted to investigate the influence of fall applications of nitrogen and phosphorus on winter survival of winter wheat on zero-tilled and conventionally tilled land. Nitrogen fertilization tended to decrease winter survival while phosphorus fertilization tended to increase survival. A N-P interaction was observed, with the decrease in survival in response to added N being more evident in the absense of applied P. Balanced N-P fertilization may therefore result in highest winter survival in both conventionally tilled and zero-tilled winter wheat. Key words: Zero-tillage, winter survival, nitrogen, phosphorus, winter wheat

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

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

Description: Increased use of sulphur (S) fertilizers in southern Alberta led to a series of field and phytotron experiments to investigate the importance of S fertilizers and the role of subsoil reserves of sulphate sulphur (SO4-S) for barley (Hordeum vulgare) and rapeseed (Brassica napus). Two types of experiments were conducted. In the field-plot studies, barley was grown on dryland soils low in surface SO4-S but underlain by subsoil high in SO4-S. Neither elemental nor SO4 forms of S significantly increased barley yields in a series of 10 experiments on those soils. The comparisons were made at three levels of N fertilizers. In a series of lysimeter studies, three successive crops were grown in soil low in inorganic S (2.0 μg SO4-S∙g−1), or soil supplemented with 25 μg 35SO4-S∙g−1 soil at specified depths in the lysimeters. Barley was adequately supplied with S from SO4-S at a depth of 54–72 cm. It obtained 55% of its S from a high SO4-S (25 μg∙g−1) layer of soil at that depth, although 40 days growth were required before the S was effectively utilized. Five times as much S was taken up by the barley when the entire soil received an additional 25 μg SO4-S∙g−1 as when only the 54- to 72-cm depth was supplemented; however, the yields were unaffected. Most of the excess S was retained in the straw. Rapeseed took up an increasing amount of SO4-S as the proportion of the lysimeters that initially contained SO4-S was increased. Rapeseed was also able to utilize SO4-S from a depth of 54–72 cm. Rapeseed showed deficiency symptoms when most of the added and soil reserves of S had been depleted by previous crops; its growth habit became indeterminate and seeds did not develop. Although total dry matter yield was not greatly affected, seed yield was markedly reduced in S-deficient rapeseed. Rapeseed took up 10 times as much S as did barley when the S supply was just adequate for seed production. Although rapeseed had a much higher S requirement than barley, both crops were adequately supplied by subsoil reserves of SO4-S under the field and controlled environment conditions studied. The studies suggest that fertilizer recommendations should be based on soil analysis to a depth of at least 60 cm. Key words: Sulphur fertilizer, sulphates, 35S, barley, rapeseed, nutrient uptake

Description: The effect of 10, 15, 20 and 25 °C soil temperatures on the extractability of soil and fertilizer phosphorus (P) was examined in two soils, one containing free carbonate (pH 7.8) and the other non-carbonated (pH 6.9). The time course of fixation and desorption reactions were monitored. The extractability of P was also assessed using sodium bicarbonate (NaHCO3) extractions, desorption curves, and short-term uptake by wheat seedlings. Phosphorus-32 was used throughout. Opposing effects of temperature were found. An increase in incubation temperature from 10 to 25 °C decreased the amount of applied P extracted probably due to accelerated fixation reactions. This effect was established 1 day after the P was applied and persisted for 57 days. An increase in extraction temperature over the corresponding incubation temperature increased the extractability of P, indicating endothermic desorption reactions. This effect was established 1 h after the extraction began and persisted for 48 h. Hence, the net effect of temperature on the extractability of P will depend upon the balance of these opposing processes. The time course of these processes had two phases. The effects of temperature were established during the initial phase (

Description: Functional relationships between soil water content and water suction were examined and related to textural and organic carbon content data. Soil water retention curves between 5 and 10 000 kPa were determined on disturbed samples of 18 soils representing various soil Great Groups in the Canadian prairies. The best fit was obtained with a two-straight-line regression model. Correlation and regression analysis showed that texture was the main soil property influencing the shape and position of the water retention curve. Organic matter influenced primarily the water content at which a break in the curve occurred. Soil zone and cultivation history had little effect on water retention. Key words: Water retention, texture, organic matter, two-straight-line regression

Description: Field investigations between 1970 and 1980 revealed frequent carry-over residues of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and its major metabolite, N-de-ethyl atrazine (2-chloro-4-amino-6-isopropylamino-s-triazine) in soils and many were associated with visible crop damage. Susceptible crops in rotation with corn appeared to tolerate a carry-over of 0.1 mg/kg Σ-atrazine (atrazine plus metabolite) under field conditions. Where the carry-over residues were above 0.1 mg/kg the severity of injury appeared to be related to the amount of residue, the soil type, the crop species, and the weather conditions. A growth cabinet experiment was designed to study the response of five susceptible crop species to simulated carry-over levels of atrazine between 0.05 and 0.70 mg/kg active ingredient added to a sandy loam, a loam and an organic loam soil, that contained 1.0, 3.5 and 10% organic matter (OM), respectively. Additions of as little as 0.10 mg/kg atrazine to soils with 1.0 and 3.5% OM caused visible injury to develop on the foliage of all five crop species. Alfalfa (Medicago sativa L.) appeared to be the most sensitive crop species, being affected by atrazine at 0.05 mg/kg. On soils with 10% OM the phytotoxic effects of atrazine were considerably reduced and all five crops tolerated residue levels up to 0.70 mg/kg without serious injury. Key words: Atrazine, N-de-ethyl atrazine, residue, crops, field, growth chamber

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

Description: Growth chamber and field studies were conducted to assess the relative utilization of placed and broadcast 15N-urea by spring wheat. The field studies were conducted on zero and conventional (shallow) tillage systems, of 4-yr duration, located on Chernozemic soils at two locations in Saskatchewan. Placement below the seeding depth in comparison to broadcast application, generally reduced fertilizer N immobilization and increased fertilizer N uptake, recovery, and efficiency. Under moisture stress, placed applications were effective in enhancing dry matter yield and total N uptake. It is concluded that fertilizer N placement for these two contrasting tillage systems should be identical, thus some soil disturbance under zero tillage may be necessary to achieve optimum crop use of applied fertilizer N. The dominant N transformation processes and possible tillage induced differences, in regard to methods of N application, are discussed. Key words: Placed and broadcast N application, N efficiency, N utilization, 15N-urea, zero tillage, soil moisture

Description: The forest floor of a mature, naturally regenerated conifer stand on a well-drained podzolic soil in the Central Uplands of New Brunswick was sampled systematically. The forest-floor properties measured were: oven-dried mass per unit area, depth, moisture content, pH, potassium-chloride-extractable NH4-N and NO3-N, water-soluble phosphate, and ammonium-acetate-extractable K, Mg, and Ca. Total elemental C, N, P, K, Mg, Ca, Al, Fe concentrations were also determined. Coefficients of variation varied from 0.066 (total C) to 1.78 (2 N KCl-extractable NO3-N). Concentrations (measured in ppm or percent) were in each case less variable than absolute amounts (measured in kilograms per hectare). Frequency distributions were positively skewed (except for total C and N) and appeared to follow a gamma or Weibull distribution pattern. Key words: Ferro-Humic-Podzol, forest floor, lateral variability, spruce-fir forest, systematic sampling

Description: A descriptive system is outlined for characterizing, in thin sections, the micromorphology of organic soils and organic layers. In each thin section, distinct regions of morphology, fabric zones, can be recognized. Each fabric zone may be composed of various combinations of organic constituents. These constituents are designated as basic morphologic units and four main types are defined: particulate material, granular units, discrete compound particles, and massive-appearing fabric. The fabric zone and basic morphologic units can be coded in a fabric description symbol of the following simple general form [Fabric Unit]1 …[Fabric Unit]n, where [Fabric Unit] represents a particular fabric zone and its basic morphologic units. For example, [PpGa] [Ma] is a fabric description symbol indicating that two fabric zones are identified in the thin section. The first [PpBa] is the dominant fabric zone in the thin section (areal proportion) and is composed of two basic morphologic units, mainly recognizable plant fragments, Pp, and a lesser occurrence of amorphous granular material, Ga. The second fabric unit [Ma] indicates a fabric zone composed of one basic morphologic unit: amorphous massive-appearing fabric, Ma. The system is applied to the micromorphological characterization of a Typic Mesisol from Keswick, Ontario. Key words: Microcorphology, organic soils, descriptive method, characterization

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

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

Description: Soils ranging in texture from loamy sand to clay that had been tilled annually for at least 35 yr were compared with adjacent unfilled soils. Properties considered important to plant growth were measured: water-stable aggregate size distributions, bulk density (BD), organic carbon (OC), penetrometer resistance (PR), oxygen diffusion rates (ODR), pH, hydraulic conductivity (Kaep), air-filled porosity (AFP), total porosity (TP), degree of air occupation of pores (AFP/TP) and soil moisture desorption curves. AFP, AFP/TP, ODR, BD, Kaep and soil moisture desorption curves suggested that the tilled sites in all soil types had become compacted below 10-cm depth relative to the undisturbed sites. OC, PR, BD and aggregate size distributions were strongly influenced by soil textural differences. OC appeared to increase with cultivation in sandy soils compared with the undisturbed. PR was increased by tillage in the coarse-textured soils, but decreased in the fine-textured soils. Acidity increased under long-term tillage in all soils except the clay. Large degrees of variability of ODR data require further investigation. Rapid in situ techniques for measuring Kaep and AFP are needed, as these parameters appeared to best reflect the effect of long-term tillage on soil physical quality. Key words: Soil structure, soil degradation, soil compaction, soil management, tillage effects

Description: The effect of fertilizer P on the salt tolerance of barley grown on previously summerfallowed land was studied under dryland field conditions. Linear regression equations showed that the yield response to added fertilizer P did not change significantly over the full range of salinity levels experienced. Linear regression equations using mean soil salinity levels to a 60-cm depth equal to or greater than 6 mS∙cm−1 appeared to describe the yield function of barley more realistically than did equations using the entire range of salinity levels. Both fertilized and unfertilized barley yields were not affected by salinity until a level of 4 mS∙cm−1 had been reached. Beyond this point yields were reduced by approximately 9–10% per unit increase in salinity. It was concluded that added fertilizer P did not improve the salt tolerance of barley grown under dryland conditions in Saskatchewan. Key words: Salinity, barley, P fertilizer, salt tolerance, yield

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

Description: Two field experiments were conducted, each over a 3-yr period, to compare the availability of N from liquid cattle manure (LCM) with that from urea and anhydrous ammonia to corn. Two times of application (preplant vs. sidedress) and two methods of application (surface vs. injection) of LCM were compared with respect to corn grain yield and soil NO3− concentration during two periods of the growing season. The availability of LCM N was approximately one-half that of fertilizer N. Injection of LCM either before planting or as a sidedressing between the corn plant rows resulted in LCM N being approximately 60% as available as fertilizer N. Application of LCM to the soil surface, as a side dressing resulted in LCM N being approximately one-third as available as anhydrous ammonia N. The data were discussed and interpreted on the basis that manure N is made up of two principal fractions, "organic" and ammoniacal N. The organic N fraction, consisting of all the N other than ammonia, becomes only partly available to the crop through mineralization whereas the ammoniacal N fraction is subject to volatilization if not incorporated into the soil immediately. Soil NO3− concentrations in the June-July period showed the surface preplant LCM N availability to be approximately one-half that of preplant applications of urea. Nitrate concentrations during the September-October period suggested that LCM showed no greater levels of NO3− than urea even at twice the rate of N application. Key words: Corn, nitrogen, preplant and sidedress applications, liquid dairy cattle manure

Description: 137Cs from the atmospheric testing of nuclear devices in the 1950s and 1960s was used to estimate soil erosion in eight small basins in hummocky topography. Three basins had not been cultivated since the 1950s and in these 137Cs showed little or no separation according to landscape position. In the cultivated basins, 137Cs increased from the top to the bottom of the slopes reflecting the simultaneous occurrence of soil erosion on the upper slopes and deposition on the lower slopes. The redistribution of 137Cs was least in a cultivated basin where water erosion was minimal. From the 137Cs it was estimated that over the past 20–25 yr the upper slopes in the cultivated basins had lost 20–60 kg soil/m2, whereas the lower slopes had gained 25–80 kg/m2. Some middle-slope positions lost soil, others gained. An attempt to construct 137Cs and soil balances for each of the cultivated basins was only partially successful. The inability to accurately delineate areas of erosion and areas of deposition is probably the major obstacle in calculating accurate balances for the basins. The 137Cs balances did show promise of being able to separate soil losses by wind and water erosion. Key words: Water erosion, wind erosion, 137Cs, deposition, universal soil loss equation

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

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

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

Description: In a recent cooperative study, in which four laboratories participated, organic matter in a large number of Canadian soil samples was characterized by relatively simple methods. As result of this work we are proposing a procedure for the extraction, separation and characterization of soil organic matter. The procedure includes determinations of organic C and total N in initial soils, followed by the isolation from the soils of humic and fulvic acids. Total C and N and E4/E6 ratios are then determined in the latter fractions. From these data, proportions of extractable soil-C and soil-N and HA/FA ratios are computed.

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

Description: We, as well as others, have observed that nitrous oxide (N2O) fluxes increased markedly during soil thaw in early spring. This phenomenon was examined further by determining nitrous oxide concentrations in the soil profile and N2O fluxes from the soil surface during the winter-spring period and evaluating physical release and microbial production of N2O on thawing of frozen soil cores in the laboratory. In mid-winter, soil profile N2O concentrations were close to ambient and surface N2O fluxes were low. At thawing, high N2O concentrations (ranging from 1082 to 2066 mg∙m−3) were found at 10–30 cm in the soil profiles of a coniferous forest, and in manure- and straw-treated plots. Concurrently, N2O flux increased markedly and reached some of the highest values observed during the entire season. When thawing was complete, soil profile N2O concentrations and N2O flux declined. Soil cores were taken from frozen soil, warmed in the laboratory, and N2O release measured. Nitrous oxide was released on warming, and cores treated with CHCl3 had a slower release rate. The results indicate that some of the N2O flux occurring at thawing is due in part to physical release of N2O, and that additional N2O is likely produced by denitrification. Key words: Nitrous oxide, denitrification, frozen soils, nitrogen loss

Description: The objective of this study was to determine the magnitude of biologically immobilized and/or chemically fixed N (N retained) resulting from N addition to soils under laboratory conditions. Urea (200 μg N/g of soil) tagged with 21.0 atom % 15N was added to 11 Manitoba soils. The relationship between microbial immobilization and/or chemical fixation of added N and soil characteristics was determined using forward stepwise and multiple linear regression analyses. Three to 32 ppm of added N was immediately retained by the soils after urea was added. Biological immobilization and/or chemical fixation was virtually completed within the first 4 wk of incubation with only one soil showing continuous increase in the retention of applied N during the remainder of the experiment. Amounts of urea N retained in soils during the 12-wk incubation period ranged from 16 to 91 ppm. The initial retention of N was positively correlated with sand + silt fraction and negatively correlated the pH of the soil, the R2 value being 0.86**. Correlations between, 15N retained and organic matter (OM) content for 4 and 8 wk of incubation were positive (R2 = 0.40* and 0.53*, respectively). After the 12 wk of incubation, the retention of added N by soils was positively correlated with OM and negatively correlated with soil pH (R2 = 0.74**). The retention of N with pooled data of 4, 8 and 12 wk of incubation was positively correlated with OM and negatively correlated with both pH and CEC of the soils (R2 = 0.73**). Mineralization of soil N and retention of added N for 4, 8 and 12 wk of incubation were found to be positively correlated, the r2 values being 0.42*, 0.52* and 0.42*, respectively. Gaseous losses of applied N appeared to be appreciable in only one soil. Ten of the eleven soils showed no or little N interchange, suggesting that a significant proportion of the applied urea N appeared to be truly immobilized and/or fixed in soils.

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

Description: Two shallow mineral overburdens, a deep mineral overburden and a peat overburden from northern Alberta were examined to determine effects of each on the growth of jack pine and slender wheatgrass. Plants were grown in the greenhouse in 30-cm-deep cores in which the overburdens were placed in either 5- or 15-cm-deep layers over oil sand tailings. For comparison with current reclamation practices, cores containing a mixture of sand, peat and deep overburden were also used. The growth of slender wheatgrass was best in the peat and very poor in the deep overburden. Jack pine also grew very poorly in the deep overburden but reasonably well in the other three overburdens. There was extensive root development of both species in the sand layer beneath all four overburden types. Increasing the depth of peat from 5 to 15 cm resulted in a decrease in the growth of both plants whereas increasing the depth of the mineral overburdens had favorable effects. The amount of available P was much higher in sand under the 5-cm layers than sand under the 15-cm layers. Iron and Mn uptake was suppressed with the thick layer of peat. Mixing 15 cm of peat with deep overburden and sand did not affect the growth of slender wheatgrass but reduced shoot production of jack pine. Key words: Reclamation, oil sands, jack pine, slender wheatgrass, plant growth, peat

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

Description: Soil-landscape relationships were studied in detail at a site comprised of Dark Brown and related soils of the Weyburn Association in central Saskatchewan. Detailed soil observations along transects identified actual soil series and related their distribution to landscape parameters. A slope-profiling approach, involving division of slopes according to angular differences between measured lengths along the transects, revealed that while soil distribution varied in terms of slope position, slope length, slope gradient and sequence, the most significant relationship lies between soil distribution and shape of slopes. Most slopes could be subdivided readily into convex units, concave units, usually short rectilinear units joining them, and depressional units. Such divisions generally coincided with observable soil divisions, corresponding, respectively, with shallow, deep and gleyed soils. The convex units comprised Regosols and Rego, Calcareous and ’shallow Orthic’ Dark Brown Chernozemic soils. The concave units included ’deep Orthic,’ ’AB Orthic’ and Eluviated series. The depressional units were generally composed of Gleyed Orthic or Gleyed Eluviated series. Both field and laboratory analyses confirm that the soils within landscapes form a continuum, but that recognition of the soil groupings suggested provide a practical and feasible field separation in mapping soils. A combination of aerial photos, field examination of soils and an evaluation of slopes and particularly slope changes could be used to recognize and map these broad, landscape-related soil groupings. Key words: Soil association, soil catena, soil series, slope analysis, topography, map units

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

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

Description: Rounding of the lands in a field involves changes in the surface horizons. The thickness of Ap horizons at various sites in corn fields varied from 15 to 41 cm. In these horizons, the organic matter content that ranged between 10 and 250 t/ha influenced the real density of the particles, the bulk density of soils with similar texture, and also the shape of the water retention curves at tensions from 0 to 1.5 MPa. Maximum available water in the Ap horizons between 33.3 kPa and 1.5 MPa varied from 0.5 to 4 cm H2O. Yield differences reached 74% while the standard deviations were generally lower than 15%. Higher yields were observed at higher, intermediate and lower sites of the fields. The differences in the yield were not entirely accounted for by the variations in the chemical and physical properties of the soils.

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

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

Description: A loamy soil amended with sewage sludges chemically treated with Ca(OH)2, Al2(SO4)3 or FeCl3 was used for P adsorption studies. Phosphate adsorption was increased by sludge application in the order: Ca-sludge 〉〉 Al-sludge = Fe-sludge 〉 untreated soil, and was associated wtih the increase in CaCO3 and hydrous iron and aluminum oxide countents resulting from sludge application.

Description: The effect of phosphorus fertilization on potato yields (Solanum tuberosum L.) was studied on 24 experimental sites varying from 44 to 1000 kg/ha of soil test P. The respective relative yields (yield with P fertilizer/maximum yield with P fertilizer x 100) varied from 20.3 to 100%. The Mitscherlich equation was used to relate relative yields to soil test P. According to their soil test value, the soils were partitioned in three classes by the Cate-Nelson method to establish poor (300 kg/ha of available P or less), medium (301–400 kg/ha P) and rich 401 kg/ha P or more) soil fertility classes. It was found that 94 kg/ha fertilizer P was necessary for maximum yields with an increase of 10% or greater on poor soils. On medium and rich soils, the requirement was 50 kg P/ha for a yield increase of 1–10%. Below a 1% increase, the P application should be lowered. At high rates diammonium phosphate (DAP) has been found to give tuber yield equal to those of superphosphates. On the other hand, at low rates, DAP application was more effective. DAP induced a higher mid-season P concentration in the petiole tissue Acidification by superphosphates increased aluminum, iron and manganese availability in the soil and reduced P solubility in the band area, in contrast to DAP. Key words: Potato, soil test phosphorus, source of phosphorus fertilizer, phosphorus fertilization, superphosphate, ammonium phosphate

Description: Dicyandiamide has physical, chemical and biological properties that render it suitable for use as an inhibitor of nitrification of injected anhydrous ammonia (NH3). It is readily soluble and stable in NH3 and, when applied at 15 kg/ha, it effectively inhibited nitrification of injected urea for 3 mo in soil at ca. 5 °C. These properties are relevant to the practice of fall application of NH3, with its attendant risk of loss of some of the applied nitrogen before spring sowing, as a result of nitrification.

Description: The change in the extractability of soil phosphorus (P) in response to temperature was examined in 12 Manitoba soils. These soils varied in carbonate and P contents. The soil P was labelled with 32P to facilitate measurements. Sodium bicarbonate extractions, anion exchange resin extractions, P desorption curves and short-term plant uptake using wheat were used to measure P extractability. An increase in soil temperature increased the extractability of P. This was apparent for P extracted by NaHCO3 only in soils low in P. The P extracted by resin appeared to respond similarly but was quite variable. Effects of temperature on the desorption curve parameters were significant only in soils high in P. The latter may reflect the detection limits for P using the desorption curve extraction system. Plant uptake was closely correlated to root growth. Both increased markedly as temperature increased. However, in certain soils the increase in P uptake due to temperature was far greater than the corresponding increase in root growth. The estimates of the labile pool accessed by plants increased as temperature increased. The principle hypothesis, that the effect of temperature on P extractability changed from soil to soil, was confirmed. The only controlling soil factor that could be identified was the basic soil P content. Key words: Temperature, soil phosphorus, carbonated, non-carbonated, plant uptake, wheat

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

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

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

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

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

Description: Differences between analyses of washed and unwashed filbert leaves were found for N, P, Mg, S, B, Mn, Zn and Cu but not for K and Ca. The contamination was attributed primarily to particulates since washing reduced average leaf weight measurements. The magnitude of the contamination varied among orchards and between years. It was concluded that washing leaves is essential for both micro- and macronutrient considerations. Key words: Filberts, leaf washing, macronutrients, micronutrients, contamination

Description: The effects of long-term irrigation on soil salinity were studied at 13 selected sites within four major irrigation districts in southern Alberta. Of these sites, 10 have been under irrigation for over 60 yr and three for 25 yr. Soil textures ranged from sandy loam to clay. The total soluble salts in the soil profiles were either reduced or unchanged after long-term irrigation at all sites except one, which had an 11% increase but an EC of the saturation extract still less than 1 mS∙cm−1. The magnitude of reduction in soluble salts of the other soil profiles was related to the initial salt content and ranged from 0 to 82% of the original content. The SAR decreased in the subsoil at all sites. It is evident that long-term irrigation did not salinize the soils at these sites, which are considered to be representative of much of the irrigated land in this area.

Description: Potassium fertilizer requirement of rain-fed cotton was evaluated in a 3-yr field study conducted at three locations using four rates (0, 25, 50 and 75 kg∙ha−1)of K. Significant response was not obtained above 25 kg∙ha−1 applied K. Quadratic polynomials, using leaf K, exch. K, exch. (Ca + Mg)/K and applied K as independent variables, were fitted to the seed-cotton yield. As a single parameter, leaf K emerged the best predictor of yield with a coefficient of multiple determination (R2) of 86% and a corresponding regression equation of: Y (yield) = 3099.2 + 6031.6%K − 1643.3 (%K)2, followed by fertilizer K with a coefficient of multiple determination of 81% and a yield equation of: Y = 1302.3 + 53.96 app. K − 0.54 (app. K)2. Soil exch. K and (Ca + Mg)/K ratio were slightly less efficient in predicting yield giving R2 values of 0.62 and 0.76, respectively, when both the linear and quadratic terms were entered into their respective yield equations. When all the 12 possible entries (linear, and second-order terms and their square root transformations) were fed into the computer and regressed over cotton yield using a step-wise regression procedure, only two variables, leaf %K and (Ca + Mg)/K, significantly fitted the yield equation giving a predictive value of 87%. But the improvement in the precision of yield predictability as measured by the R2 value was only marginal and would not justify recommending the equation considering the extra laboratory work that will be needed to obtain the relevant variables. Critical values of 1.84% in index leaf, 0.19 meq/100 g exch. K and 50 kg∙ha−1 applied K were approximated for a maximum predicted yield range of 2440–2700 kg∙ha−1.

Description: not available

Description: The effects of soil and solution pH and Na:Ca ratio in solution on the exchangeable Na, Ca, and (Na + Ca) of a Na-saturated Dark Brown Chernozemic soil were studied. At soil pH 9.0, the exchangeable Na, Ca, and (Na + Ca) were 14.5, 25.4, and 21.8% greater than at soil pH 6.0. Solution pH (6.0–9.0) had small but statistically significant effects on the amount of Na and Ca adsorbed by the soil. The logarithm of exchangeable sodium percentage (ESP) was related to the Na fraction in the solution by a polynomial equation, log ESP = 0.93 [Na/(Na + Ca)]2 + 0.16 [Na/(Na + Ca)] + 0.82. Not only is replacement of exchangeable Na with Ca important in the reclamation of this soil, should it become sodic and have a high pH, but also lowering of its surface charge, through lowering of its pH, would be an important factor in its reclamation. It appears impractical to reduce soil pH by applying acidified irrigation water. Acidic amendments such as gypsum and sulfur may be more suitable. Key words: Cation exchange, solution pH, soil pH

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: Leaf tissue nutrient concentrations measured over 3 years in 17 filbert orchards showed consistent correlations between N/S, Cu/S, Zn/Cu, Ca/K, Mg/K and Mg/Ca. Optimum concentrations of 1.44% Ca, 0.27% Mg, 0.14% S, 8.8 ppm Cu, and 19.5 ppm Zn were calculated using regression equations of the various correlations and optimum values of N and K (2.2% N and 0.8% K) reported in the literature. Correlations between leaf and soil nutrient concentrations were observed but they were not consistent over the 2 years and all depths (0–15, 15–30, 30–60 cm) of soil samples taken. Average leaf weight measurements were sufficiently consistent within orchards to allow detection of orchard to orchard differences. Several nutrients appeared to affect or be affected by average leaf weight. Average leaf weights appear to have potential as a biologically important measurement but the significance has yet to be derived. Key words: Filberts, macronutrients, micronutrients, optimum leaf concentrations, leaf weights

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

Description: Colorimetric soil pH measurements made systematically across Burnaby Mountain in well-drained loamy soils of the rainforest of British Columbia over an 8-yr period from 1974 until 1981 showed that acidification of the subsoil increased after two consecutive drier-than-average years. This changing acidity contrasted with the relatively stable acidity of the subsoil in imperfectly drained soils, regardless of changing patterns of precipitation. Key words: pH, forests, loams, precipitation

Description: The effect of fertilizer P, N and N-P combined on barley grain yield and protein content when grown on stubble land ranging widely in surface salinity (0–60 cm depth) was tested. Critical salinity levels were calculated from linear regression equations derived from sampling sites with surface salinity levels [Formula: see text]. Added P did not appear to affect the salt tolerance of barley. Yield increases due to fertilizer N were reduced rapidly as soil salinity levels increased and in one trial appeared to reduce the tolerance of barley to salinity. Calculated salinity levels at 50% and zero yield of N-fertilized barley were lower than for barley not fertilized with N. Calculated salinity levels at zero yield for the control and P treatments were 18.5 and 15.1 mS∙cm−1, respectively. These levels compared favorably with values reported in the literature for barley grown on saline fallowed land. Protein content of barley grain increased with an addition of N and with salinity. The latter fact could be largely explained by a strong positive correlation between soil salinity and soil NO3−-N levels and to a lesser degree by a reduction in yield with increasing salinity. Key words: Salinity, barley, fertilizer effects, yield, protein

Description: Soils affected by tree-throw (arbroturbation) at three sites in Nova Scotia varied in development and microrelief characteristics. Soil horizonation was strongly developed and continuous through the mound-and-pit sequence at one site but was intermittent and irregular at the other two sites. Analytical data, particularly those for oxalate- and pyrophosphate-extractable Fe and Al reflected the morphological variations observed in the pedons. Classification of the arbroturbated soils according to the Canadian system is not a problem though it is necessary to indicate turbation by appending a phase to the soil class name at levels above the series. Mapping areas of such soils involves no change from regular procedures except in the description of the soil units. Hummocky microrelief due to arbroturbation presents some limitations in the use of land. Key words: Physical disturbance, classification, mapping, land use

Description: Crop yields and soil data were obtained for 5 yr on 12, 1-ha plots of slight to moderately saline Solonetzic soil which had been plowed to a depth of 61 cm. Wheat, durum wheat, oats and flax were grown. Wheat yields range from a decrease of 0.25 t/ha to an increase of 0.74 t/ha. An average increase of 0.34–0.40 t/ha should be expected from deep plowing this type of soil. The surface soil following deep plowing increased in clay, fine clay, pH, CaCO3 and H2O-soluble Ca. It decreased in H2O-soluble Na. Water-soluble Mg remained relatively constant. With moderate fluctuations, these changes have persisted for 5 yr. Key words: Deep plowing, Solonetzic, sodium, calcium carbonate

Description: Two poorly humified peat soils, containing 23 or 1207 ppm (wt/wt) Cu, and two well-humified muck soils with 151 or 1264 ppm Cu, obtained from 3-yr-old field experiments on simulated extravagant applications of Cu for mitigation of organic soil degradation and subsidence, were used in this study. The aim was to determine whether the longevity of Escherichia coli (K12 JE 2517-a nonmotile mutant) cells inoculated into the soils would be affected by the soil Cu concentrations. The rapid spread plate method was used for counting viable cells of the coliform. Both microbially active and bromomethane-sterilized soils were aerobically incubated with the bacterium normally alien to the soils for 48 and 168 h, respectively, with or without further additions of 10 ppm Cu to the soils with the bacterial cells. A pulverized quartz sand was included in the experiments to provide comparison. Unlike the immediate and sustained lethality of Cu revealed in sand suspensions, neither the previously nor the newly added Cu had any negative influence on the survival or proliferation of the added E. coli cells. The results thus showed that the soil Cu had no direct bactericidal or bacteriostatic effect. These data were therefore in accord with earlier suggestions that the Cu mitigates decomposition and resultant subsidence by inactivating degradative and accumulated soil enzymes that contribute substantially to the dissipation of their substrate-rich milieux. Key words: Copper, bacteria, organic soils, subsidence

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

Description: Growth chamber studies were conducted on the effects of placing NH4H232PO4 either in a single band below and/or to the side of the seed at rates of 10–30 kg P/ha, or with the seed at 5 kg P/ha, on growth and on uptake of soil and fertilizer P by flax (Linum usitatissimum L. ’Linott’). Two P-deficient Chernozemic soils were used; one calcareous, the other non-calcareous. On both soils, all placements of applied P significantly increased yield of flax. For all application rates, P placed 2.0 cm directly below the seed (taproot placement) was more efficient in increasing yield than P placed 1.5 cm to the side at 0.5 or 2.0 cm below the seed (shallow- and deep-side placements). The greatest yield increase occurred with taproot placement of 10 kg P/ha. Maximum yield for the deep-side placement also occurred at this rate, whereas a two- to threefold higher rate was required for maximum yield for the shallow-side placement. Only taproot placement of 10–30 kg P/ha and shallow-side placement of 30 kg P/ha gave significantly greater yields than seed placement of 5 kg P/ha. However, crop uptake of fertilizer P for all away-from-seed placements was at least double that for P banded with the seed.

Description: A micromorphological feature, termed a grain sesquosiltan, was identified in the Bf and BC horizons of some podzols in Eastern Ontario. It is suggested that the inherited or cryogenically-derived dense silasepic fabric has been gradually modified over time by weathering, illuviation and pedoturbation. This has resulted in the formation of silt/sesquioxide coatings around sand grains.

Description: In 1975, hydrated lime and calcium sulfate were applied to a Rutland gravelly sandy loam under the canopy of mature apple trees (Malus domestica Borkh. ’Spartan’) on M16 at 3000, 6000, 3 × 2000 and at 3000, 6000, 3 × 4000 kg/ha, respectively, pH and exchangeable Ca, Mg and Mn were measured in the soil sampled in 1979 at 10-cm intervals to a 60-cm depth for each of the check, 6000 kg/ha Ca(OH)2 and 12 000 kg/ha gypsum treatments. The acidity of the surface soil was decreased significantly in the 6000 kg/ha Ca(OH)2 treatment. Negligible soil Ca accumulation occurred below the surface 10-cm depth for any treatment. Soil Mn was decreased from the surface to the 20-cm level in the Ca(OH)2 treatment while soil Mg was decreased from the surface to the 30-cm level in the gypsum treatment. Fruit Ca concentration at harvest, 1975–1979 was not increased by soil Ca treatments. Leaf Mg was often reduced by soil gpysum applications in excess of 3000 kg/ha. Leaf Mn reduction did not occur until the 4th and 5th yr of the experiment in the 6000 and the 3 × 2000 kg/ha Ca(OH)2 treatments.

Description: The kinds and concentrations of the major ion pairs were determined in saturation extracts of 141 soil samples collected from a Solonetzic soil treated with various kinds of tillage combined with surface-applied chemical amendments. The correlations between concentrations of ion pairs and EC and pH of saturation extracts were statistically tested. Sulfate ion pairs NaSO4−, MgSO40 and CaSO40 occurred in relatively high concentrations. The other ion pairs were of low concentrations. Of the total soluble Ca, ion pairs ranged from 20.8% in the Ap horizon to 50.5% in the Csk horizon and Mg was approximately the same. The comparable values for Na were 0.8% and 4.6%, respectively. Ion pairs NaSO4−, KSO4−, MgSO40 and CaSO40 were significantly correlated with EC. Only carbonate ion pairs were significantly correlated with pH. Correcting concentrations of Na, Ca and Mg for ion pairs and activities changed considerably the SAR values in the Bnt1 horizon. Key words: Ion pairs, Solonetzic soils, ion activities