Boron, zinc and iron-rich swelling fertilizer special for apples and preparation method thereof

The invention discloses a boron, zinc and iron-rich swelling fertilizer special for apples and a preparation method thereof and belongs to the technical field of agricultural fertilizers. In order to solve the problems of low fruit swelling effect and influence on apple quality and yield of the fertilizer applied in an apple swelling period in the prior art, the boron, zinc and iron-rich swelling fertilizer special for apples disclosed by the invention comprises the following components in parts by weight: 250-450 parts of urea, 50-200 parts of monoammonium phosphate, 450-650 parts of potassium sulphate, 2-10 parts of a boron element component, 0.5-5 parts of a zinc element component, 0.5-5 parts of an iron element component and 0.2-1 part of a fruit swelling agent. The formula is configured according to the practical requirements for nutrition in the apple swelling stage; all the components can mutually promote and none is dispensable; the fertilizer can meet the nutrition requirement in the apple swelling s