CARACTERISTIQUES MINERALOGIQUES ET CHIMIQUES DE QUELQUES SOLS SABLEUX DU QUEBEC EN REGARD DE LEUR EVOLUTION PEDOLOGIQUE

1981 ◽  
Vol 61 (2) ◽  
pp. 273-283 ◽  
Author(s):  
M. R. LAVERDIERE ◽  
C. R. DE KIMPE ◽  
A. D’AVIGNON

A, B and C horizons of 13 sandy soil series were sampled in the lowlands of southern Quebec. From the amounts of pyrophosphate-extractable Fe and Al and clay contents, nine of these profiles were classified as Podzolic soils while the others were Brunisols. Formation of montmorillonite and dissolution of chlorite in Ae horizons indicate intense weathering of the minerals at this level. In the B horizons, vermiculite that was present in the parent material or resulted from the alteration of illite was often chloritized. Values of pH measured in 1 M NaF were generally higher than 10.2 for the B horizons. The amounts of phosphorus retained by the samples varied in the following ranges: 23–397 μg P/g of soil for A horizons, 301–1578 μg P/g of soil for B horizons and 71–296 μg P/g of soil for C horizons. Cation exchange capacity of the soils was lower than 10 meq/100 g of soil, except in those horizons that contained high amounts of organic matter and where values up to 27.6 meq/100 g were measured. Using regression equations, values were obtained for the CEC of the organic matter and the clay fraction of these sandy soils.

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nenad Tomašić ◽  
Štefica Kampić ◽  
Iva Cindrić ◽  
Kristina Pikelj ◽  
Mavro Lučić ◽  
...  

AbstractThe adsorption properties in terms of cation exchange capacity and their relation to the soil and sediment constituents (clay minerals, Fe-, Mn-, and Al-oxyhydroxides, organic matter) were investigated in loess, soil-loess transition zone, and soil at four loess-soil sections in North-Western Croatia. Cation exchange capacity of the bulk samples, the samples after oxalate extraction of Fe, Mn and Al, and after removal of organic matter, as well as of the separated clay fraction, was determined using copper ethylenediamine. Cation exchange capacity (pH∼7) of the bulk samples ranges from 5 to 12 cmolc/kg in soil, from 7 to 15 cmolc/kg in the soil-loess transition zone, and from 12 to 20 cmolc/kg in loess. Generally, CEC values increase with depth. Oxalate extraction of Fe, Mn, and Al, and removal of organic matter cause a CEC decrease of 3–38% and 8–55%, respectively, proving a considerable influence of these constituents to the bulk CEC values. In the separated clay fraction (<2 μm) CEC values are up to several times higher relative to those in the bulk samples. The measured CEC values of the bulk samples generally correspond to the clay mineral content identified. Also, a slight increase in muscovite/illite content with depth and the vermiculite occurrence in the loess horizon are concomitant with the CEC increase in deeper horizons, irrespective of the sample pretreatment.


Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.


1976 ◽  
Vol 56 (3) ◽  
pp. 213-221 ◽  
Author(s):  
Y. A. MARTEL ◽  
M. R. LAVERDIERE

The objectives of this work were (1) to determine the relation existing between the organic matter contents of Ap horizons and their respective soil Orders, (Gleysolic and Podzolic), texture, pH and geographic locations in the different thermal regions of Quebec and (2) to determine the role of organic matter and soil texture on the cation exchange properties of the same Ap horizons coming from soils used for forage crops in Quebec. The cation-exchange capacity (CEC), the exchangeable bases and acidity were determined by using 1 N NH4OAC – pH 7. The results showed a variation in the carbon content ranging from 1.4 to 6.9%. The heat units accumulated in each region and the clay contents were correlated with the percentage of carbon and nitrogen. Soil pH and soil Orders (Gleysolic vs. Podzolic) did not seem to affect the organic matter content. The cation-exchange capacity (CEC) ranged from 10.6 to 42.6 meq/100 g soil; 40% of this was attributable to carbon and 32% to clay contents. Simple and multiple regression equations showed that carbon was correlated with the exchangeable acidity, while clay was related to the exchangeable bases. The CEC of organic matter and clay were respectively 161 ± 45 meq/100 g organic matter and 29 ± 6 meq/100 g clay. These values, lower than for Western Canada, reflected the nature of the organic matter that is less developed in Eastern Canada than in the Chernozemic soils; they also showed the effect of the predominant illite mineral found in the clay fractions compared to montmorillonite in Western Canada.


Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.


Soil Research ◽  
2020 ◽  
Vol 58 (4) ◽  
pp. 323 ◽  
Author(s):  
Murray Unkovich ◽  
Therese McBeath ◽  
Rick Llewellyn ◽  
James Hall ◽  
Vadakattu VSR Gupta ◽  
...  

Sandy soils make up a substantial fraction of cropping land in low rainfall (&lt;450 mm p.a.) south and south-eastern Australia. In this paper we review the possible soil constraints to increased production on these soils in this region. Many of these soils have a very low (&lt;3%) clay content and suffer from severe water repellency, making crop establishment and weed control problematic. Crops which do emerge are faced with uneven soil wetting and poor access to nutrients, with crop nutrition constraints exacerbated by low fertility (soil organic matter &lt; 1%) and low cation exchange capacity. Zones of high penetration resistance appear common and have multiple causes (natural settling, cementation and traffic induced) which restrict root growth to &lt;40 cm. Crop water use and grain yield are therefore likely to be well below the water-limited potential. Water repellency is readily diagnosed and where apparent should be the primary management target. Repellency can be mitigated through the use of furrow and other sowing technologies, along with soil wetting agents. These techniques appear to be affected by site and soil nuances and need to be refined for local soils and conditions. Once crop establishment on water repellent soils has been optimised, attention could be turned to opportunities for improving crop rooting depth through the use of deep tillage or deep ripping techniques. The required ripping depth, and how long the effects may last, are unclear and need further research, as do the most effective and efficient machinery requirements to achieve sustained deeper root growth. Crop nutrition matched to the water-limited crop yield potential is the third pillar of crop production that needs to be addressed. Low soil organic matter, low cation exchange capacity, low biological activity and limited nutrient cycling perhaps make this a greater challenge than in higher rainfall regions with finer textured soils. Interactions between nutrients in soils and fertilisers are likely to occur and make nutrient management more difficult. While amelioration (elimination) of water repellency is possible through the addition of clay to the soil surface, the opportunities for this may be restricted to the ~30% of the sandy soils of the region where clay is readily at hand. The amounts of clay required to eliminate repellency (~5%) are insufficient to significantly improve soil fertility or soil water holding capacity. More revolutionary soil amelioration treatments, involving additions and incorporation of clay and organic matter to soils offer the possibility of a more elevated crop yield plateau. Considerable research would be required to provide predictive capacity with respect to where and when these practices are effective.


1957 ◽  
Vol 8 (2) ◽  
pp. 179 ◽  
Author(s):  
CH Williams ◽  
CM Donald

A further investigation has been made on soils examined by Donald and Williams (1955) in a survey of the influence of superphosphate and subterranean clover (Trifolium subterraneum L.) on podzolic soils formed on granodiorite in the Crookwell district of New South Wales. The soil organic matter was found to have approximately constant proportions of carbon, nitrogen, sulphur, and phosphorus in the ratio 155 : 10 : 1.4 : 0.68, and it is suggested that the rate of build-up of soil organic matter under the clover pastures may have been limited by the amounts of sulphur supplied in the superphosphate top-dressings. The soil organic matter was found to have a cation-exchange capacity a t pH 7.0 of about 220 m-equiv./100 g, and increases in soil organic matter have led to substantial increases in the cation-exchange capacity of the soil. About 75 per cent. of the total cation-exchange capacity of the unimproved soils was due to organic matter while, in the most improved soils, this figure approached 90 per cent. The increases in cation-exchange capacity included increases in exchangeable hydrogen and were accompanied by decreases in soil pH. There were increases equivalent to 6.5 lb of exchangeable potassium, 25.5 Ib of exchangeable calcium, and 5.2 lb of exchangeable magnesium per acre in the surface 4 in. of soil for each hundredweight of superphosphate applied per acre. Increases in soil organic matter also resulted in increases in the field capacity which may reflect improvements in soil structure. Results indicate that heavier rates of superphosphate application would increase the rate of fertility build-up.


1983 ◽  
Vol 34 (4) ◽  
pp. 341 ◽  
Author(s):  
SC Jarvis ◽  
AD Robson

Subterranean clover was grown, under leaching conditions, in pots on cultivated and virgin acidic sandy soils from two sites in Western Australia. Nitrogen (N) was supplied to the plants either as NH+4, NO-3 or through symbiotic fixation. There were marked changes in the acidity of the soil as the result of the differences in catiot/anion balance induced by the different forms of N supplied. Thus plants supplied with NH+4 depressed the pH by 0.9 pH units, and those dependent upon fixation by 0.5 pH units. There was little change in pH when NO-3 was supplied. Changes in soil pH were strongly related to cation/ anion balance, with increasing acidity resulting from the decreasing ash alkalinity of shoots of plants supplied with NH+4. There were marked differences both between the two soils from the same site, as well as between soils from the two different sites, in the relationships between pH and soluble aluminium and pH and exchange acidity. It is suggested that differences in the form, as well as differences in the total amount, of organic matter could play a major role in controlling the development of acidity in such soils of low, permanent cation exchange capacity.


1971 ◽  
Vol 51 (1) ◽  
pp. 105-111 ◽  
Author(s):  
J. A. McKEAGUE ◽  
J. H. DAY ◽  
J. A. SHIELDS

Data for 16 measured and seven calculated properties of 461 samples from 115 soils occurring in various parts of Canada were coded, and a correlation analysis was run on the data for various groups of samples. In general, correlations of color value and organic matter were moderately high (|r| > 0.5) and significant, but for 21 Podzol Ae horizons the correlation was very low (r = −0.13) and not significant. Chroma and dithionite Fe were significantly correlated for several groups of samples but not for Podzolic B (spodic) horizons or Bm horizons. Linear regression equations expressing cation exchange capacity and pH-dependent charge as functions of organic matter and other variables fitted the data reasonably well. The danger of generalizing from presumed relationships among soil properties was indicated but, for some groups of samples, useful relationships existed between visible soil properties and properties measured in the laboratory.


Weed Science ◽  
1974 ◽  
Vol 22 (5) ◽  
pp. 454-459 ◽  
Author(s):  
J.B. Weber ◽  
S.B. Weed ◽  
T.W. Waldrep

An organic muck and a montmorillonite clay were incorporated into the surface 7.6 cm of a structureless sandy soil at rates ranging from 26,880 to 89,600 kg/ha. Prometryne [2,4-bis(isopropylamino)-6-(methylthio)-s-triazine] and fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] were surface-applied and trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) were incorporated at two rates each in 1968, 1969, and 1970. Organic matter greatly reduced the biological activity of all three herbicides. Montmorillonite clay greatly reduced the activity of prometryne, slightly decreased the activity of fluometuron, and had no significant effect on trifluralin activity in all but the first year of the study. Both soil additives increased the cation exchange capacity of the soil. Muck decreased soil pH while montmorillonite increased it.


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