If you’re struggling with saline soils, no-till is probably a better management option than tillage.
That’s the conclusion of the Red River Basin Commission, a regional group that is assessing land and water management issues in North and South Dakota, Minnesota and Manitoba. In a nutshell, the commission’s goal is to come up with management plans to deal with a host ofchallenges, from flooding and drainage problems to drought to aquatic invasive species.
The group says most fields in crop production are tilled one or more times each year with cultivators, discs or deep tillers. But farmers are noticing field areas that haven’t been producing well in recent years.
Tillage, the group says, is a primary way salts trapped in deeper layers of the basin’s soil rise to the surface and into the root zone, which uses a decline in crop production.
The reason is that salts tend to follow water in the soil, and tillage causes water to rise in the soil profile. Because tillage also dries out the worked soil, salts that followed the water upwards get stranded in upper layers.
A long-term study undertaken by North Dakota State University Extension is applying various practices to saline soils under real farming conditions to keep economics in the equation while improving soil health.
Here are some suggestions shared by David Franzen, soil scientist at NDSU Extension, to address soil salinity issues:
• Reduce Or Eliminate Tillage. No-till or mintill is recommended for seedbed preparation in saline soils. Salts leached away by winter snow melt and spring rains can be returned to the surface by deep spring tillage.
• Explore Tile Drainage. There hasn’t been much interest in tiling in North Dakota until recently, he says. Some tile installed has reduced salinity in some fields. He notes farmers should consider the outlet and not drain their saline flows into a neighbor’s field.
• Soil Testing. Soil areas severely affected by salts often have a bright white, crusty appearance when dry, but the severity of the saline area usually extends beyond this area, he says. Soil testing for salinity levels can identify the extent of problems in individual fields.
• Examine Rotations. Crops like dry beans have a low tolerance to salts during germination and establishment, while other crops have higher tolerances. But Franzen notes this only reveals differences among plants, and other stresses can be a factor. He suggests continuous cropping with late-maturing, salttolerant, deep-rooted crops.
• Re-Examine Fallow. Growers should avoid fallowing if available water in the top 4 feet of soil is sufficient to grow a minimal crop.