RM of Westbourne Bulletin 99-36 - Agriculture and Agri-Food Canada
RM of Westbourne Bulletin 99-36 - Agriculture and Agri-Food Canada
RM of Westbourne Bulletin 99-36 - Agriculture and Agri-Food Canada
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Page 6 Information <strong>Bulletin</strong> <strong>99</strong>-<strong>36</strong> Rural Municipality <strong>of</strong> <strong>Westbourne</strong><strong>of</strong> the Lower Assiniboine Delta are subject to potential wind erosion<strong>and</strong> droughtiness <strong>and</strong> the glacial till soils are moderately toexcessively stony. Soils throughout the municipality are generallynon-saline except for scattered occurrences <strong>of</strong> weak salinity in the<strong>Westbourne</strong> soils.Just over 3 percent <strong>of</strong> the soils are rated Class 1 for agriculturalcapability <strong>and</strong> 49 percent are rated in Class 2. Soils affected byincreasing severity <strong>of</strong> droughtiness, wetness <strong>and</strong> stoniness are ratedas Class 3 <strong>and</strong> cover 23 percent <strong>of</strong> the area. Nearly 14 percent <strong>of</strong>the soils are placed in Class 4, primarily due to s<strong>and</strong>y texture <strong>and</strong>low moisture holding capacity. About 4 percent <strong>of</strong> the soils arerated in Class 5 due to excess wetness while soils affected byextreme droughtiness <strong>and</strong> excess wetness rated in Class 6 occupyless than 2 percent <strong>of</strong> the area. Organic soils which have verylimited capability for agriculture in their native state cover 5 percent<strong>of</strong> the area (page 17). The irrigation suitability (page 19) <strong>of</strong> the soilsvaries from Good (39 percent) to Fair (35 percent) <strong>and</strong> Poor (21percent).One <strong>of</strong> the issues currently receiving considerable attention is thesustainability <strong>of</strong> agricultural practices <strong>and</strong> their potential impact onthe soil <strong>and</strong> groundwater environment. To assist in highlighting thisconcern to l<strong>and</strong> planners <strong>and</strong> agricultural producers, an assessment<strong>of</strong> potential environmental impact (EI) under irrigation shown onpage 21 varies from Minimal on the clayey soils to Low on the tillsoils <strong>and</strong> Moderate on the loam to clay loam textures. S<strong>and</strong>y soilsin the Lower Assiniboine Delta with high permeability <strong>and</strong> typicallyhigh watertables are at High potential risk. This EI map is intendedto be used in association with the irrigation suitability map.Another issue <strong>of</strong> concern to producers, soil conservationists <strong>and</strong>l<strong>and</strong> use specialists is soil erosion caused by agricultural cropping<strong>and</strong> tillage practices. Areas with potential for water erosion areshown on page 23. The glacial till soils <strong>and</strong> the s<strong>and</strong>y lacustrinesoils, together occupying about 40 percent <strong>of</strong> the l<strong>and</strong> area, areestimated to have a Negligible risk <strong>of</strong> degradation due to watererosion. Water erosion risk varies from Low on the clayey soils toModerate on loam textured soils. However, the s<strong>and</strong>y soils are ata greater risk <strong>of</strong> erosion by wind. Current management practicesfocus on maintaining adequate crop residues to provide sufficientsurface cover to adequately protect the soils from both wind <strong>and</strong>water erosion.<strong><strong>Agri</strong>culture</strong> is the dominant l<strong>and</strong> use in the <strong>RM</strong> <strong>of</strong> <strong>Westbourne</strong>. Anassessment <strong>of</strong> the status <strong>of</strong> l<strong>and</strong> use in 1<strong>99</strong>4, obtained through ananalysis <strong>of</strong> satellite imagery, showed annual crops occupying 60percent <strong>of</strong> the area, forages nearly 2 percent, grassl<strong>and</strong>s about 27percent <strong>and</strong> treed areas 5 percent. The grassl<strong>and</strong> <strong>and</strong> treed areasprovide forage <strong>and</strong> grazing capacity as well as wildlife habitat.Wetl<strong>and</strong>s occupy between 2 <strong>and</strong> 3 percent <strong>of</strong> the area <strong>and</strong> alsoprovide wildlife habitat. Various non-agricultural uses such asinfrastructure for urban areas, transportation <strong>and</strong> recreation occupyabout 3 percent <strong>of</strong> the municipality (page 25).The majority <strong>of</strong> soils in the <strong>RM</strong> <strong>of</strong> <strong>Westbourne</strong> have moderate tomoderately severe limitations for arable agriculture. The claytextured soils require management practices which maintainadequate surface drainage, soil structure <strong>and</strong> tilth <strong>and</strong> the s<strong>and</strong>y soilsrequire protection against wind erosion. This includes leavingadequate crop residues on the surface during the early spring period,provision <strong>of</strong> shelter belts <strong>and</strong> use <strong>of</strong> minimum tillage practices <strong>and</strong>crop rotations which include forages. A major portion <strong>of</strong> themunicipality has low relief <strong>and</strong> a dominance <strong>of</strong> imperfectly topoorly drained soils. These soils are frequently saturated <strong>and</strong>subject to surface ponding, particularly during spring run<strong>of</strong>f orfollowing heavy rains. Consequently, improvement <strong>and</strong>maintenance <strong>of</strong> water management infrastructure on a regional basisis required to reduce surface ponding while maintaining adequatesoil moisture for crop growth.