Crops respond quickly, growing taller, greener and more lush.
From the '70s to the early '90s, many farmers fed their fields with more nitrogen than was removed in harvested crops. And, in the last few years, the upward trend in the use of nitrogen fertilizer has resumed. Phosphate use reveals a similar story but potash tells a different tale. On a global scale, far less potash is applied by farmers than is removed by their harvested crops. Even the recent, slight increase in potash consumption is far too low to compensate for steadily increasing K removal.