Every day, we encounter labels of some sort. Their meaning isn’t always obvious. For example, you want to give the young trees and bushes in the back yard some plant food.
There are different bags of fertilizer at the store. But what do those three numbers on the labels mean? Fertilizers are identified by the main elements: nitrogen, phosphate and potassium or potash. They provide different benefits.
Nitrogen enables plants to produce chlorophyll, which makes for a rich green color of leaves and grass blades. The chlorophyll, in turn, lets plants produce their own nutrients from sunlight. The extreme would be to use a 34-0-0 fertilizer, or ammonium nitrate. Sales may be restricted in some locations due to safety regulations. But one also needs to be careful with this when feeding the plants, because too much nitrogen, administered in salt form, can burn leaves and kill plants.
The “P,” or phosphate proportion, is important for “root ’n fruit” — the establishment of roots in the ground, and production of seeds.
As the third element on the label, potassium gives the plant resistance to disease and extremes of weather.
In the garage, kitchen or bathroom, a different kind of label shows on buttons that are part of the electric outlet. One says “Test”, the other “Reset.” These outlets are GFCI, or ground fault circuit interrupters. If they work properly, they cut power off in a microsecond whenever there’s a danger of electric shock. To check if they do, pressing “Test” should cut the power. “Reset” will turn it back on. If this doesn’t work, the GFCI receptacle needs to be replaced.
Yet another safety-related label is present on all car tires. The first part shows maximum load allowed on each tire (say, 1,500 pounds). Multiply the number by 4 to know what the greatest safe weight is for your vehicle, loaded with groceries, kids and caboodle.
Following this is the maximum tire pressure in PSI (pounds per square inch). Most of the time, that’ll be a number between 35 and 75. I like to keep tire pressures at maximum for best road handling and fuel efficiency. Many modern vehicles now come with a “TMS,” or tire monitoring system. A dashboard warning from the TMS is serious, because an underinflated tire can make the car get out of control, or catch fire, or both.
Rudi Kiefer, Ph.D., is a professor of physical science and director of sustainability at Brenau University. His column appears Sundays and at gainesvilletimes.com.