What is the Pearson Square Method primarily used for?

• A. A simple way to hand calculate a ration for an animal
• B. A method to determine water quality
• C. A method to compute crop yield
• D. A technique for soil sampling

Answer: (A)

The Pearson Square helps you balance two feed ingredients to hit a target nutrient level in a ration. It’s a quick, visual way to mix two feeds with different nutrient contents so the final mix has the desired percentage. You place the two ingredient values on the sides, put the target value on top, and subtract diagonally to find how much of each feed to use. The amount of the low-nutrient ingredient is the difference between the high ingredient’s content and the target, and the amount of the high-nutrient ingredient is the difference between the target and the low ingredient’s content. For example, to reach 12% protein with one feed at 9% and another at 36%, you compute 36 − 12 = 24 (left) and 12 − 9 = 3 (right). That gives a low-to-high feed ratio of 24:3, simplifying to 8:1, meaning eight parts the 9% feed and one part the 36% feed to target around 12%. This method is practical for forming simple two-ingredient rations in animal nutrition; it isn’t used for water quality, crop yield, or soil sampling, which require different approaches.