Corn tassels. Credit: Huw Williams.

In mid-April, a humongous explosion rocked the Texas town of West when a fire broke out at an agriculture retail facility storing ammonium nitrate. The blast killed 14 people, injured more than 200, and left a crater 93 feet wide and 10 feet deep. If this and other forms of ammonia are so explosive before being used as fertilizer, what happens when it is used in agriculture? More at National Geographic’s NewsWatch blog, http://on.natgeo.com/10oCQjh.