By: Sarah Sommerfeld, PAg, Regional Forage Specialist, Outlook
Over the past few seasons, you may have noticed that saline areas on your farm operation are expanding. With the wetter than normal growing seasons, a one or two acre area may have increased to five or 10 acres, or larger. Seeding this saline area to perennial forages is a management option.
Saline soils are commonly found throughout Saskatchewan. Soil salinity is often easily noticed and can be described as the white patch where kochia and foxtail barley grow, or an area where plant growth is poor and crop yield is low. Salts in the soil prevent the uptake of water and nutrients by the plant. Plants become drought stressed and nutrient deficient.
The actual cause of soil salinity is not the salts in the soil, but attributed to when the water table is too close to the soil surface. If the water table is close to the soil surface, evaporation can move the ground water to the surface where salt particles are deposited. Salt accumulates when the amount of water leaving the soil through evaporation exceeds the amount of water that enters the soil through rainfall, runoff or irrigation.
Using perennial forages is an effective method to manage and improve the productivity of saline areas. Over time perennial forages lower the water table which prevents further accumulation of salts at the surface. The primary objective of saline areas should be ground cover, with the quantity and quality of forage grown being a secondary concern.
The level of salinity often varies throughout the area. Seeding a forage mixture that is able to withstand a range of salinity is recommended. Select forage species that are proven to work, such as tall wheatgrass, slender wheatgrass and smooth bromegrass. Grasses are more salt tolerant than legumes. Including productive forages into the forage mix, such as alfalfa, can improve the yield and quality of the stand. The more productive or desirable forages establish on better quality soil. The more salt tolerant forages can grow on the more severely affected saline areas. Adding a creeping rooted grass is also recommended. Selected forage species do require some degree of flooding tolerance as saline sites are often saturated for a period of time during the spring. Incorporate additional forages based on availability, price and field conditions.
Practicing good forage establishment techniques is essential. Seeding depth should not exceed ½ to ¾ of an inch. Perennial weeds must be controlled prior to forage seeding. Fields that are too wet to seed in the spring can be dormant seeded in the fall prior to freeze up. Germination then occurs in early spring when soil moisture levels are higher and salt concentration near the soil surface is lower, allowing for better establishment success.
Funding is available to producers under the Growing Forward 2 Farm Stewardship Program to convert highly erodible or saline land from annual grain production to permanent cover.
For more information on using forages to manage saline areas or the Farm Stewardship Program contact your local Regional Forage Specialist or the Agriculture Knowledge Centre at 1-866-457-2377