This Isn’t A Year To Skip Soil Testing

Soil scientists and crop advisers have for years preached from the agronomy pulpit about the value of soil testing, but for farmers in those parts of Western Canada where it was really, really wet this year, it appears to be really, Really, REALLY important to consider soil testing this fall.

After all this rain, in most areas except for the Peace River region, the fact is you just don’t know what’s down there this fall, or where it is, for that matter.

Nitrogen is always the big one, but there are other important nutrients too. How much has leached down through the soil and where is it sitting — at six inches, 15 inches, 24 inches or deeper? Find out.

Soil scientist Cynthia Grant with Agriculture Canada at Brandon, Man., says there’s even a big question mark about soil nutrient levels on fields that weren’t seeded this year. Usually on fallow fields farmers assume in a year of rest soil nutrient reserves improve. But, Grant says with saturated soils and standing water on fields, even that is unknown unless a soil sample is taken.

“With such abnormal conditions, we have to expect at lot of variability,” she says. “Many producers, under more average conditions, go along sort of on autopilot and assume there are certain nutrient levels in the soil. Last year was unusual too, but in many respects it was still more normal. This year conditions were very different, so there will be much more variability.”

She says with most farmers knowing the high-, medium-and lower-yielding areas of their fields, soil testing needs to be done in those various production zones.

In Alberta, soil specialist Ross McKenzie with Alberta Agriculture has similar advice. He says once the crop is off and the soil cools heading into fall, it will be important to make a soil analysis through that top 24 inches to learn what nutrients are sitting where.

With wet conditions this year soil nutrients can leach down into the soil profile and in the case of nitrogen, under wet conditions it can also be lost to the atmosphere through volatilization and denitrification. So under these extreme conditions it is impossible to guess at nutrient reserves.

Elston Solberg, a soil specialist with Agri-Trend Agrology says even as nitrogen (and other nutrients) leach down into the soil profile, they are not lost to next year’s crop.

“Even if nitrogen is sitting two feet down, crop roots can easily grow three to four feet deep in the soil,” he says. With soil sampling through that zero-inch to 24-foot soil profile producers can manage their fall-or seed-applied nutrients to support the crop until it reaches those deeper reserves.



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