Sarah Sommerfeld, PAg
Regional Forage Specialist, Outlook
Saskatchewan Ministry of Agriculture
Saline soils are commonly found throughout Saskatchewan. Soil salinity is often easily noticed and can be described as the white patch where nothing but kochia or 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, even though the actual site may be moist and nutrient rich. 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 enough to the 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 level of salinity often varies throughout an 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 alfalfa. Grasses are more salt tolerant than legumes. Most saline tolerant grasses have at least one production limitation, so including one or more desirable forage species can improve the yield and forage quality of the stand. The more desirable forage species will establish on the better quality soil and the more saline tolerant species will establish and grow on the poorer, more severely affected saline soil. 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 species based on availability, price and field conditions.
If a saline area is large enough to seed and manage separately from less saline areas, a specific saline forage mixture or more than one saline tolerant species can be used. The primary objective is ground cover, with the quantity and quality of forage grown being a secondary concern. The less saline areas could then be seeded to a more desirable (less saline tolerant) species which would be more productive and better forage quality.
Practicing good forage establishment techniques is essential. Seeding depth should not exceed one half to three-quarters 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.
More information on using forages to manage saline areas will be discussed during a Ministry of Agriculture webinar on March 26 from noon to 1:00 p.m. To register for this webinar, go to https://www2.gotomeeting.com/register/364702242.
For more information on using forages to manage saline areas or any other forage related topic contact Sarah Sommerfeld, Regional Forage Specialist, Saskatchewan Ministry of Agriculture at the Outlook Regional Office at 306-867-5559 or go to Ministry of Agriculture website at www.agriculture.gov.sk.ca.