Manured fields are good candidates for the pre-sidedress soil nitrate test, but nitrogen credit following legume crops is unpredictable and will likely depend on the stand density and timely termination.

a recent summary of the available research has shown that red clover established in wheat or oats and then left to grow as a cover crop until the next season can contribute between 45 and 155 pounds of nitrogen per acre to the next corn crop.