It’s estimated that crop yields more than doubled between 1908 and 2008, with synthetic nitrogen fertilizer responsible for up to half that growth.

Some researchers have tied the massive growth in human population in the last seventy years to the increased use of nitrogen fertilizer.

Nitrogen fertilizer increases leaf yields 1.5-2.5 fold.

However, applying too much nitrogen fertilizer throughout the spring, may result in an abundance of young foliage tissues that could be susceptible to disease.

On the other hand, if levels are above this range, addition of nitrogen fertilizer will not increase crop yield.