The Soils of Elgin County - Agriculture and Agri-Food Canada

Soil Moisture CharacteristicsMiddlemarch soils are imperfectly drained andrapidly permeable. High water table levels occurnear the surface, mainly during the winter andearly spring. They have low water holdingcapacities and slow to moderate surface runoff .General Soil CharacteristicsThe Ap and Bm horizons usually have loamyfine sand, loamy sand, or fine sandy loamtextures . Clay enriched Btgj horizons, whichusually have fine sandy loam or loamy fine sandtextures, usually occur above the calcareous IlCkgjhorizons. The underlying calcareous materialsusually consist of alternating layers of sandy andgravelly materials . The sandy layers commonlyhave loamy fine sand, fine sand, or sand textures .The gravelly layers frequently have gravelly loamyfine sand, gravelly fine sand, or gravelly sandtextures .Distinct to prominent, strong brown to darkyellowish brown mottles occur within the profile.Soil reaction ranges from medium acid to neutralin theAp horizons, to mildly alkaline in the IICkgjhorizons . Soil classification is typically GleyedBrunisolic Gray Brown Luvisol .Soil VariabilityMiddlemarch soils occur mainly in thenorthern portion of Southwold Township, and thenorth-east.portion of DunwichTownship . In thoseareas they are underlain by clayey till materials ofthe St . Thomas Moraine. The sandy layers whichoccur in the underlying materials are variable inthickness and usually contain some gravel, whichmay be greater than 10% in some layers .Occasionally,. loamy or clayey layers also arepresent within the profile .In transition areas between the sandy ridgesand the surrounding till moraines, shallowMiddlemarch soils may occasionally occur wherethe underlying clayey till materials occur within100 cm of the surface . Most often Middlemarchsoils were mapped in combination with Shedden(SH) soils .Land Use/Management CommentsMiddlemarch soils are rated Class 2F forcommon field crops when topography is not alimitation . They are suitable for a wide range ofspecial crops if their surface slopes are not toosteep . Suitability increases for many special cropsif they are tile drained, or if supplementalirrigation is carried out. Suitability ratings forselected special crops are given in Tables 6, 7, and8.Middlemarch soils are susceptible to winderosion. Planting cover crops, establishingwindbreaks, and carrying out managementpractices whichmaintain organic matter levels willaid in reducing the risk of erosion by wind .Conservation tillage practices, particularly no-tillpractices, should be considered for these soils .Muirkirk Soils (MK)Landform and TopographyMuirkirk soils have developed on 40 to 100 cmthick veneers of coarse textured lacustrinematerials which are underlain by gravelly coarsetextured lacustrine beach materials . They usuallyoccur in depressions or on the lower slopes ofbeach ridges which are located near the flanks ofterminal moraines . Slopes are usually less than2% .Soil Moisture CharacteristicsMuirkirk soils are poorly drained and rapidlypermeable . The poor drainage conditionsassociated with these soils are due to high watertable levels which occur near the surface forprolonged periods during the year. They havelow water holding capacities and slow surfacerunoff.General Soil CharacteristicsThe Ap and Bg horizons usually have sandyloam, fine sandy loam, or loamy fine sandtextures . The underlying IIBg and calcareousIICkg horizons, which occur in the underlyingbeach materials, usually have gravelly coarse sandand gravelly loamy coarse sand textures.Gray gley colours are dominant in the profile,and prominent strong brown to dark yellowishbrown mottles are also present. Soil reactionranges from neutral in the Ap horizons to mildlyalkaline in the underlying IICkg horizons . Soilclassification is typically Orthic Humic Gleysol.Soil VariabilityThe aerial extent of Muirkirk soils in theCounty is limited . Frequently the underlyingbeach materials consist of alternating layers ofsand and gravel . Muirkirk soils may occur inlandscapes where Kintyre (KT) or Highgate (HI)soils were mapped .