Michael grew up on a corn farm and was finally old enough to help his father out with the family business. $$ le spreading fertilizer $($potassium a phosphorous rich fertilizer$)$ one day he thought to himself $"$If we need a good corn crop to make it$,$ maybe I should add a little extra fertilizer." Michael didn't tell his father about the extra fertilizer hoping to surprise him come harvest in a few months. A few weeks later after a big rain he ran down to the field expecting a large sea of green and to his dismay, the field was full of sickly looking plants, wilted, and pale green.

Hypothesis: Why has the crop wilted?