Does when you apply such fertilizers affect how your crops will grow? A farmer I know [who also keeps poultry] always uses chicken manure whenever he's planting anything [poultry manure has a high nitrogen content by the way], and continues applying it until his crops are ready for harvesting. And he usually gets the best yield. Since this farmer uses nitrogenous manure all the time, does it mean that one can use nitrogen fertilizer at any time without negatively affecting your vegetables, fruits or whatever it is you grow in your garden?