® Ontario ontario institute of pedology - Agriculture and Agri-Food ...
® Ontario ontario institute of pedology - Agriculture and Agri-Food ...
® Ontario ontario institute of pedology - Agriculture and Agri-Food ...
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Class 6 - Soils in this class are only capable <strong>of</strong> producing perennial forage crops, <strong>and</strong>improvement practices are not feasible . These soils provide some sustained grazing for farmanimals, but the limitations are so severe, that improvements by use <strong>of</strong> farm machinery areimpractical . The terrain may be unsuitable for use <strong>of</strong> farm machinery, or the soils may not respondto improvement or the grazing season may be very short .Class 7 - Soils in this class have no capability for arable culture, or permanent, pasture .This class includes marsh, rockl<strong>and</strong> <strong>and</strong> soil on very steep slopes .Soil Capability SubclassesSubclasses are divisions, within classes, that have the same kind <strong>of</strong>limitations for agriculturaluse as a result <strong>of</strong> soil <strong>and</strong> climate . Thirteen different kinds <strong>of</strong> limitations have been recognized,at the subclass level, <strong>and</strong> are described in CLI Report No . 2 (14) . Only those subclasses used toclassify the soils <strong>of</strong> the Ville-Marie area are described .Subclass C Adverse climate caused by low temperatures .Subclass DSubclass FUndesirable soil structure <strong>and</strong>/or permeability.Low natural fertility, which may or may not be possible to correct by additions <strong>of</strong>fertilizers or manure.Subclass I Inundation by flooding <strong>of</strong> streams or lakes limits agricultural use .Subclass MMoisture limitations due to low moisture-holding capacities, cause droughtiness thatlimits agricultural use .Subclass P Stoniness . Stones interfere with tillage, planting <strong>and</strong> harvesting .Subclass RShallowness to bedrock, which is less than one metre from the soil surface.Subclass S Adverse soil characteristics . Used when two or more <strong>of</strong> the limitations representedby Subclasses D, F or M are present, or when two <strong>of</strong> the limitations represented bySubclasses D, F or M are present <strong>and</strong> some additional limitation occurs, e .g. T.Subclass TAdverse topography due to steepness, or complexity <strong>of</strong>slopes, limits agricultural use,by increasing the cost <strong>of</strong> farming over that on level l<strong>and</strong>, by decreasing theuniformity <strong>of</strong> growth <strong>and</strong> maturity <strong>of</strong> crops, <strong>and</strong> by increasing the hazard <strong>of</strong> erosiondamage by water .Subclass W Excess water, other than from flooding, limits use for agriculture . The excess watermay be due to poor drainage, a high water table, seepage, or run<strong>of</strong>f fromsurrounding areas .AssumptionsBefore using the soil capability tables, it is important that the user have an underst<strong>and</strong>ing<strong>of</strong> the following assumptions, upon which the classification is based :(a)The soils will be well-managed <strong>and</strong> cropped under a largely mechanized system.(b) L<strong>and</strong> requiring improvements, e.g. drainage, that can be done economically by the farmerhimself, is classed according to its limitations or hazards, in use, after the improvementshave been made.