Question

Why the soil of agriculture lands get tested for $pH$?

Answer 1

$pH$ of the soil indicates the acidity or alkalinity of the soil. Plants need a specific $pH$ range for their healthy growth. So to know that the $pH$ of the soil, samples of the same soil are collected from various places and are tested. This helps farmers to understand the acidic or basic nature of soil accordingly they can use substances to maintain a required $pH$ range.