Soil nutrient levels a mystery

Growers in areas with excess moisture in 2010 or 2011 or both may not have a good handle on their soil nutrient reserves unless they get a soil test. Nitrogen levels may be very low in the top 6” due to denitrification and leaching, which both increase when soils are wet. Nitrogen reserves may be higher at lower depths, and this could be accessible as the crop matures, but growers cannot assume this reserve is present without a 24″ soil test.

Growers in the Peace River area of Alberta, where drought has been the issue, may be equally unsure of soil nutrient reserves — especially if they’ve been fertilizing for target yields that have not been reached for a few years. How much of that unused nutrient is still available?

And for growers all across the Prairies who have had higher yields lately, those higher nutrient removal rates need to be balanced against the combination of higher spring moisture and increased crop residues that may mean higher mineralization rates this year. Growers wondering if they’re applying enough fertilizer to maximize profit could try a test strip with a 50% higher rate and measure the yield at harvest.

Published on April 7,  2011