In the 1970s an extensive fertilizer trial was conducted on a large number of farmers’ fields in Greece. Nitrogen and phosphorus at different levels were applied to five different crops. Almost half of the fields responded very little to nitrogen and very few to phosphorus. The yields were such that other limiting factors could be part of the reason for the poor responses, but the biggest reason was over‐application in prior years. Estimates of unused nitrogen varied from 56 to 99 percent, and its fate was not determined. Ecological problems could result. The tests indicate urgent need for soil testing to avoid fertilizer use where it is not needed. Advantages include economics and a better environment.