Common Chemicals

Some farmers will use only animal manure as a fertilizer for their crops, and others will purchase commercial fertilizers to add nutrients to the soil instead. The fertilizer name is a sequence of three numbers separated by dashes. The first number tells the farmer what the nitrogen content is, the second number is the amount of phosphorous, and the third number is for potassium (also called potash.) You learned that these nutrients are important for healthy soil and crops.

Below you will find information for some popular commercial fertilizers, herbicides, and pesticides. Choose one fertilizer and one pesticide and calculate how much it will cost to treat 100 acres of crops. Hint: 1 ton= 2,000 pounds, 4 quarts (qts)= 1 gallon, 16 ounces (oz.)= 1 pound.

Two Common Fertilizers Used by Farmers in Knox County

Fertilizer NameTypeCost (per ton)Amount used per acre
9-23-30Dry$192.50300 lbs.
28-0-0Liquid$121.50250 lbs.

Some farmers may also use chemicals called pesticides. You learned that pesticides may kill unwanted insects (insecticides) or weeds (herbicides) that might threaten the life of a crop. Listed below are a couple of popular pesticides used on crops.

Four Pesticides Used by Farmers in Knox County

Chemical nameUseCostAmount used per acre
ExtrazineHerbicide for corn$16.70 per gallon3 qts.
BicepHerbicide for corn$28.95 per gallon3.5 qts.
CanopyHerbicide for soybeans$36.49 per pound8 oz.
LorsbanInsecticide for alfalfa or corn$52.50 per gallon4-16 oz.

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