Low yields and fertility

I recently read and article on soil fertility and drought.  It really applies to any low yield situation.  Generally, nutrients applied and not used by the crop, should be available nest year.  I would urge caution in counting on unused nitrogen being available.  If you think nitrogen might be available you should use a presidedress nitrate test to determine how much additional nitrogen to apply.  In our program we encourage annual testing for other nutrients.  With close monitoring, you will have confidence in your nutrient levels.