By John Hauer P.Ag.
Regional Forage Specialist
Saskatchewan Ministry of Agriculture, Kindersley
Over the last few seasons you may have noticed your saline sloughs expanding. With the wetter than normal seasons the past few years your one to two acres saline patch has increased to five to 10 acres or worse. Seeding this saline patch to a forage mix is one way to stop the spread of this salinity.
Saline soils are soils that contain high concentrations of soluble salts such as: sodium sulphate, magnesium sulphate, calcium sulphate, sodium chloride (table salt). These salts, when present in high concentrations, limit or prevent plant growth of crops and forages. In extreme concentrations a white crust forms on the soil surface and nothing grows.
Saline soils are formed by the movement of excess moisture through the soil into groundwater. The ground water will dissolve salts in the soil profile in low concentrations and will travel down until it reaches a layer it cannot pass through. The groundwater will then travel laterally until it comes close (within 1.5 metres) to the soil surface where it is wicked back to the soil surface by capillary action. The water then evaporates away and the salt is left. If this happens repeatedly the salts become concentrated and a saline patch is formed.
Salinity can be controlled by planting perennial forages that can help to lower the existing groundwater levels. This allows the salts to be flushed down lower in the rooting zone. Forages also provide ground cover and shading to help reduce evaporation of water at the soil surface, thereby reducing the capillary rise of salty water compared with bare soil areas.
The forage species chosen to control salinity will depend on several factors. One factor is the severity of the salinity. Some forage species tolerate high levels of saline salt better than others. Another factor is the planned use of the forage such as hay, grazing or idling for wildlife. Some forage species are more palatable than others. Another factor to consider is whether this saline area is prone to flooding. Some forage species tolerate flooding better than others. Consult your local Regional Forage Specialist to get the best forage mix to seed into your saline area.
Through the Farm Stewardship Program of Growing Forward II there is funding available to assist with the cost of seeding forages into saline areas. The funding limits are 50 per cent of your seed cost up to a limit of $5,000 (based on a seed cost of $35.00/acre). You must have completed your Environmental Farm Plan within the last 10 years and you must meet the program eligibility requirements. The forage seed mix must be acceptable to the Regional Forage Specialist.
For more information on this program go to our website at www.gov.sk.ca//GF2-FarmStewardship and look at Land Management Beneficial Management Practises (BMPs).
For more information on selecting forage seed for saline areas and about the Farm Stewardship Program contact John Hauer, Regional Forage Specialist, Saskatchewan Ministry of Agriculture at the Kindersley Regional Office at 306-463-5507.