Corn yield forecasts by the USDA are down sharply in 2010 for Maryland, Delaware, and Virginia, as compared with 2009. The soil test summary report for 2010 is in preparation. Preliminary indications are that the distribution of soil test K levels has shifted downward substantially since 2005.

Soon forage plants will enter the critical fall growth period, during which they store the carbohydrates they need to survive the winter.  Adequate K is essential for this carbohydrate storage.  August is an excellent time to apply K fertilizers.  Potassium is particularly likely to run short if previous harvests have been heavy.  The amount to apply is an important decision.  Make sure it’s based on a recent soil test.  It’s also helpful to look at the analysis results for K if you’ve sent forage from earlier cuts this year to the lab.  Calculating a nutrient budget – nutrients removed by previous harvests minus the amounts supplied in manures and fertilizers – can also help determine the right amount to replace.