Low water levels on the Mississippi River in the United States could have an impact on corn and other grain prices, but are unlikely to affect fertilizer deliveries into Canada, say officials. The Mississippi River is considered low if the stage falls below five feet in Memphis, Tennessee. On Oct. 20 it hit a record low of -10.74 feet. The stage bounced back to -0.79 feet on Nov. 18, due to rains in Kentucky and Tennessee that made their way into the river basin.