It was happened when President Kim Il Sung was passing a rugged ridgeway in Sakju County for field guidance to the remote areas.

He asked the driver to drive the car slowly on the steep road. The President was looking out of the window for a long time, his eyes catching a sloping field where cornstalks were swaying in the wind. He asked the driver to stop the car.

He got off the car and went through the maize field in the sweltering weather.

He touched the desirable ear of corn and pulled the corn from the stalk and removed the husk of the corn to measure the length and girth of the corn full of ripe grains and feel the weight. And then he carefully looked down at the stony field where the maize grew.

He asked the officials and farmers of the farm about the amount of manure and fertilizers. One of the farm officials told the President that every year a rich harvest visited the fields without the manure and fertilizers and so he thought that it was good. The President looked at the fields of ripe maize and millet without saying a single word for a while.

He said it seemed that there was apatite and maize and millet got so ripe on the sloping fields without the manure and fertilizers because the fields had phosphorous element.

Later there was prospecting work and the result was clear. It was confirmed that the area was a promising apatite field as the President said.