Fertilizer Calculation Worksheet

Fertilizer Calculation Worksheet

Read each question carefully and show all your work for calculations. Use the provided image of a fertilizer bag to answer relevant questions.

Refer to the image of the fertilizer bag below for the following questions.

Assume the NPK ratio for this fertilizer is 15-10-5.

1. The three primary macronutrients found in most fertilizers are Nitrogen (N), Phosphorus (P), and   (K).

2. An NPK ratio of 15-10-5 means that for every 100 kg of fertilizer, there are 15 kg of Nitrogen, 10 kg of Phosphorus, and 5 kg of  .

1. A farmer needs to apply 2 kg of actual Nitrogen per 100 square meters. If they are using the fertilizer shown in the image (15-10-5), how many kg of fertilizer should be applied to 100 square meters?

2. If a garden bed is 50 square meters, and the farmer wants to apply 1 kg of actual Phosphorus, how much of the 15-10-5 fertilizer is needed for this area?

1. What does the 'P' in the NPK ratio represent?

2. A fertilizer with an NPK ratio of 10-20-10 is considered high in which nutrient?

1. The numbers in an NPK ratio always represent the percentage by weight of Nitrogen, Phosphorus, and Potassium in that order.

A farmer has a field that is 200 meters long and 100 meters wide. They want to apply a 15-10-5 fertilizer to achieve an application rate of 30 kg of actual Nitrogen per hectare (1 hectare = 10,000 square meters). Calculate the total amount of fertilizer (in kg) the farmer needs to purchase for the entire field.