Fertilizer can be used on crops on tilled ground. Using fertilizer consumes the item.

Fixed jute not always giving harvest due to green bell pepper copy/paste.
Crops who die from any method other than the old age config option will give a seed back. This way if you accidentally plant a crop when it's too cold for it to survive, you get that seed back.
Added missing parenthesis to fix java.lang.IllegalArgumentException: n must be positive.