Salt Damage Mitigation LHAP 303

Slide 1 LHAP 303: Salt Damage Mitigation Slide 2 REVIEW: WHY do we care about soil salts? Slide 3 Review: HOW are aggregates destroyed by salt? HOW is pH affected by saline conditions? What are the primary causes of saline soils in Industry? Slide 4 REVIEW: What does the effect of salty soil look like in plants? How about when it is in soil? Slide 5 Symptoms of Salinity: Slide 6 Slide 7 Identify Salt Damage Slide 8 De-icing Impacts on the Environment Sodium Chloride (Road Salt) Make their way into the environment through: Runoff from rain Melting snow & ice Splash from vehicles Wind (airborne spray kills dormant buds) Move into the soil through: Infiltration into groundwater Storm drains Run off to surface waters Impacts vegetation and aquatic life Wildlife are affected as well by ingesting salt or drinking water runoff from snow or ice melt Road Salt History Slide 9 Approximately 5 million tonnes of road salt is released into the environment in Canada every year (15 million tonnes in the US) Damage does not become apparent till spring Affects trees in two ways: Penetrates leaf scars and kills buds Salt accumulates in the soil where it breaks down into two components sodium and chlorine Chlorine ions are transported to actively growing leaf margins Leaf scorch Necrosis Curling Death Sodium ions are absorbed the same way but block essential nutrients Magnesium & Potassium (essential for chlorophyll) Slide 10 Physiological drought - high salt near roots in soil - restricts water uptake Salt stress = more susceptible to insects & environmental stress (drought, wind & ice) Salt damage is most noticeable on conifers in the spring Yellow branches closest to the road Needles turn brown & fall off Young trees can be more susceptible than older Less roots Road Salt Threatening Lakes Slide 11 PREVENTION is the best start What Fertilizer practices can be used to reduce Salt damage? How can we reduce salt impacts in our deicing practices? Slide 12 How we can Mitigate Road Salt Damage Alternative products (to NaCl) Calcium chloride - very corrosive but doesn’t harm vegetation as much Beet juice & pickle brine - helps salt stick/minimize runoff Cut the salt with grit Using less salt Wetting the salt - more easily spread Pre-salting - spread 2 hrs before - help with preventing ice from sticking Not spreading salt when pavement is too cold Pre-wetted sand & salt mixture Early shoveling after a storm - don’t allow it to melt / pack down Avoid piling snow on lawns & garden/tree beds Plant salt sensitive plants away from the road or on a berm Alternative method - Wood Chips Slide 13 Cultural Methods to Decrease Salts Leaching - flush out excess salts watering thoroughly several times (large amounts of water will be needed) Collected rainwater is best (pure water)