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Popular drain spacings on mineral soils are 50 ft (15 m) and 100 ft (30 m), with economicsat the time of installation playing a more significant role in determining spacings than soil type .Drain spacings calculated from hydraulic conductivities, estimated from in-situ measurements on2 fields of Earlton silty clay and New Liskeard clay, were between 12 and 23 m (12) . The intuitivedrainage spacings appear to be close to those calculated using current methodologies, such as theHooghoudt method .Consideration must be given to the difference between the vertical and horizontal hydraulicconductivities of the varved clays . Horizontal hydraulic conductivities may be 2 to 3 times or moregreater than those in the vertical .Lenses of silt and sand are common in the soils that lie close to the Blanche River.envelopes have been installed as a precautionary measure on these soils.WovenSpecial drainage problems have been noted on the Cane series . Sufficient silt has movedinto drains to block them. The surface above the drains has actually subsided . A trial of differentinstallation techniques did not provide a solution . A wheel trencher was compared to a plow forinstallation of the drains with no effect on silting. Woven envelope materials had no effect either .Surrounding the drain with sawdust, to reduce inflow velocities, reduced silting for 2 years ; but thedrains eventually filled with silt.ErosionStreambank and gully erosion, and landslides adjacent to water courses, are striking evidenceof erosion problems . Lake Timiskaming and its contributing streams are heavily laden withsediments throughout the year . This may be attributed, in part, to the high silt content of many ofthe soils found in the area and the ease of movement of silt by water . The landslides have beencalled `rotational slumps'. Their cause may be partially attributed to the fluid nature of the claysubsoils (see section on engineering) and to lateral seepage .Landslides of up to 2 ha are not uncommon during spring. Maintenance of cover onstreambanks, stilling structures and maintenance of buffer strips, as well as many other methods oferosion control, must be practiced.EngineeringThe first vertical silo that was constructed in the area (circa 1965) promptly fell over afterfilling. An overpass of Hwy 11 over the CNR tracks near New Liskeard was never completedbecause it kept sinking during construction (13) .The varved cla- and silty clay soils deform easily under pressure . Limitations have beenplaced on silo height . Special footings for silos and floating slab foundations have been designedto deal with the fluid nature of the subsoil .InfrastructureEquipment sales and service, seed, feed, agrochemical, accounting and other agriculturalservices are available in the immediate area. There are also many custom farm services available .Shopping and banking facilities are above the average of most rural southern areas .The New Liskeard College of Agricultural Technology, located at New Liskeard, is engagedin many research activities geared at improving the profitability of agriculture in all of northernOntario . Staff also carry on extension activities .30