Analysis of Calcium Ammonium Nitrate Fertilizer

From Percentage to Pounds

• Fertilizer products are labeled according to nutrient percentages, but fertilizing recommendations refer to the weight of nutrients applied per square foot of lawn or garden area. To apply the correct amount of actual nutrients, you need to determine the weight of fertilizer that corresponds to the recommended nutrient application. For example, most lawns need about 3 pounds of actual nitrogen per 1,000 square feet per year. A typical lawn fertilizer may carry an analysis of 32-0-4, meaning it contains 32 percent nitrogen by weight, and 3 pounds divided by 0.32 equals about 9.4. This means that you would need to apply 9.4 pounds of this fertilizer over the course of a growing season to supply 3 pounds of nitrogen.

Nutrients in Calcium Ammonium Nitrate

• Calcium ammonium nitrate is produced by combining ammonium nitrate with calcitic limestone, dolomitic limestone, chalk marl or some other source of calcium carbonate. Ammonium nitrate is a standard synthetic fertilizer that contains 33 percent nitrogen, and calcium carbonate is a chemical compound that is approximately 38 percent calcium. The manufacturing process that combines these two materials results in products containing 17 to 27 percent nitrogen and varying amounts of calcium. One standard formulation of calcium ammonium nitrate is known as CAN-17; this fertilizer has 17 percent nitrogen and 8.8 percent calcium, which corresponds to a nutrient analysis of 17-0-0-8.8Ca.

Balanced Nutrition

• The nutrient analysis of calcium ammonium nitrate has zeros in the second and third positions, meaning that it contains no phosphorus and no potassium. For optimal growth, plants need adequate quantities of numerous elements. Phosphorus and potassium are particularly important because the soil's supply of these nutrients is often low enough to limit crop production. Regardless of its nitrogen and calcium content, calcium ammonium nitrate is not a balanced fertilizer. To provide a better balance of plant nutrients, apply it in conjunction with a potassium fertilizer such as potassium chloride and a phosphorus fertilizer such as rock phosphate.

The Benefits of Calcium Ammonium Nitrate

• Calcium ammonium nitrate has two desirable aspects that are not common among nitrogen fertilizers. First, it supplies calcium along with nitrogen, and the calcium is in a form that is readily available to plants. Calcium is an essential plant nutrient, and deficiencies can lead to problems such as blossom-end rot of tomatoes (Lycopersicon esculentum). Second, calcium ammonium nitrate is recommended for acid soils, whereas other nitrogen fertilizers -- including ammonium nitrate, ammonium sulfate and urea -- contribute to additional soil acidity.