If rocket scientists practice higher math, then I guess down and dirty gardeners practice lower math. Whatever you call it, there's no escaping it. Math is everywhere - even in the garden! Besides curling up with a good seed catalog this winter, how about learning a little lower math so that you're ready to use it next spring when it's time to plant again?

For starters, let's suppose you have a garden that is 25 feet long and 30 feet wide that you want to fertilize. It's been recommended for your soil that you apply 2 pounds of nitrogen per 1000 square feet of garden area, and you have just purchased a 50 pound bag of 5-10-10 fertilizer that was on sale at the local garden supply store. How do you go about figuring out how much of it to apply to your garden?

The first step is to figure out how many square feet you have in your garden. That's not too difficult. Just multiply the length and width of your garden. In your case, 25 feet multiplied by 30 feet gives 750 square feet, assuming of course that your garden is rectangular. (If it isn't then you'll just have to make it rectangular!)

Before we continue, you must learn how to break the secret fertilizer code. Those three numbers that appear on the bag are the percentages by weight of nitrogen, phosphorus, and potassium, respectively. The law requires those three numbers to be reported, and they are always in the same order. In your case, the amount of nitrogen (which is what you are interested in) is 5 percent. That means that there are 5 pounds of nitrogen in every 100 pounds of the fertilizer.

The second step is to figure out how much nitrogen is required for your 750 square foot garden. Since your garden is smaller than 1000 square feet, it will require less than 2 pounds of nitrogen. To figure exactly how much, you need to divide the area of your garden (750 square feet) by 1000 square feet. The result is 0.75. If your garden is only 0.75 the size of a 1000 square foot area, then it will need only 0.75 times 2 pounds the amount of nitrogen. This is 1.5 pounds.

The third and final step is to figure out much of the 5-10-10 fertilizer will contain the 1.5 pounds of nitrogen you need. Since you know that 100 pounds of the fertilizer contains 5 pounds of nitrogen, you will need to apply something less than 100 pounds to your garden. To determine exactly how much, divide 1.5 pounds by 5 pounds. The answer, 0.3, tells you what fraction of 100 pounds to apply. In this case, 0.3 times 100 pounds or 30 pounds.

See how easy that was. With all the time between now and planting time next spring to practice, you should become' an expert lower mathematician.