Acidified fertilizer granules

A method for preparing a plant fertilizer comprising solid acidic fertilizer granules having greater than 10 wt. % up to 40 wt. % of an inorganic acid distributed evenly throughout the solid acidic fertilizer granules, the method comprising:

• (a) providing a plant nutrient comprising nitrogen (N), phosphorus (P) and optionally potassium (K), in a container;
• (b) feeding an acid solution comprising the inorganic acid into the container at a feeding rate comprising an average feed rate of 0.2 to 0.8 metric ton of the inorganic acid (MTacid) per hour per metric ton of the plant nutrient (MTnutrient) (MT acid.−1. MT nutrient−1) and contacting the inorganic acid and the plant nutrient to obtain acidified granules with average moisture content of 0.5% to 1.0%;
• and
• (c) drying the acidified granules to obtained dried acidic granules, having greater than 10 wt. % up to 40 wt. % of an inorganic acid distributed evenly throughout the dried acidic granules.