Very saline (>8 dS/m):
Farmers who want to manage their soil salinity must first manage their water, a land management specialist told participants at a farm stewardship meeting.
“If you do anything to manage your soil salinity, you have to think about your water table. And if you’re managing your water table, you’re managing your salinity,” said Marla Riekman from Manitoba Agriculture’s Ag Resource Branch.
Salinity can be subtle or in places very obvious.
It’s not typically seen in wet years, but excess moisture raises the water table, which brings salts closer to the surface, Riekman said at the Saskatchewan Farm Stewardship Association’s meeting in Yorkton, Sask., Nov.16.
She described Saskatchewan as “pothole country” and many areas suffer from high salinity as seen by the “bathtub ring affect around the wetlands,” compared to the flatter land and milder salinity around Manitoba’s Red River Valley.
She said installing drainage tiles might lower salinity by artificially altering how water moves through the soil.
However, it’s not necessarily the most appropriate situation for every farm, she said.
“It’s an inherent soil problem and it’s just making sure that we manage water. And the best way that we can do that is by managing crops,” she said.
Many farmers may need to consider managing their crops from a different perspective and financial bottom line, she said.
“The tricky part about it is be-cause salinity is so landscape directed, around those low-lying areas or along the edge of fields, it means that we have to not necessarily think of the field as edge to edge, corner to corner,” she said.
“If you’re losing 20 percent of your crop to saline creep, but you take out five, maybe 10 percent of land to put into some kind of forage that’s going to manage that water and you get back that 10 percent, is that not better?”
Riekman compared it to variable rate fertilizer that divides the soil based on upper, middle and lower slopes instead of going up and down the field in a straight line.
“If you’re willing to give up yield in that area, you just keep farming through it, but if you’re not, you might have to drive around that spot,” she said.
“If you can manage that little spot and the salinity draws down everywhere else and you gain those acres back, is it worth it to drive around that spot from now on. So, do you give up that piece in order to gain on the rest of it. It’s a different kind of math.”
However, before planting forages, soil testing is an important first step to managing salinity.
And determining the level of salinity in the soil will dictate what forage is best suited to grow in it.
“If you are going to target something growing in there, you may want to match up the appropriate salinity tolerance of the forage with the amount of the salinity that you’re dealing with at the current time,” she said.
Wheat and canola handle saline conditions much better than field corn and particularly better than soybeans.
Riekman urged producers to do the research to see if the legume can be added to their rotation.
“I often joke that the most expensive salt map that you can create is by seeding an entire field from corner to corner to soybeans and then take a picture of it afterwards. Because everywhere that it goes yellow or does not grow is most likely going to be your salt spots,” she said. “It’s useful but unfortunately it’s an expensive test because there’s a lot of inputs that go into that as opposed to just doing an EM38 map or Veris soil mapping.”
- tall wheatgrass
- beardless wild rye
- salt meadow grass
- AC Saltlander
- red samphire
- sea blight
- slender wheatgrass
- Altai wild rye
- Russian wild rye
- western wheatgrass
- tall fescue
- foxtail barley
- Russian thistle
- sweet clover
- birdsfoot trefoil
- s. bromegrass
- meadow fescue
- crested wheatgrass
- intermediate wheatgrass
- fall rye
- alsike clover
- red clover
- white clover
- m. bromegrass
- perennial and annual ryegrass
- reed canary