The Ontario Processing Vegetable Growers, OMAFRA and Nortera Foods have partnered to conduct a soil nitrate survey of sweet corn fields.  On-farm research conducted in Ontario from 2003 to 2010 found that the pre-side dress nitrate test (PSNT) can be a useful predictor of sweet corn fertilizer response.

The week of June 12, 2023 samples were taken at five farms in the Glanworth and Lambeth areas.  Note that these sites had applied 50-75 lbs actual N/acre pre-plant. These amounts are somewhat higher than the pre-plant rates (maximum 25 lbs actual N/acre) used in the 2003-2010 study.

Soil nitrate levels at all the sites fell into a moderate range.  Dry soil conditions and generally cool temperatures over the last month may have slowed down the rate of mineralization.

The 2023 Soil Nitrate Survey is being conducted by OMAFRA staff Elaine Roddy, Danny Jeffries and Colin Elgie with the support of Dan Oliver (Nortera).  This project has been funded by the Ontario Processing Vegetable Growers.

Source:  Ontario Ministry of Agriculture, Food & Rural Affairs June 19, 2023 ON Vegetable News