Compound fertilizer：

The nitrogen, phosphorus and potassium content of high concentration compound fertilizer exceeds 40%, the nitrogen, phosphorus and potassium content of medium concentration compound fertilizer exceeds 30%, and the nitrogen, phosphorus and potassium content of low concentration compound fertilizer exceeds 25%.

High concentration compound fertilizer: nitrate nitrogen content is more than 1.5%, water-soluble phosphorus accounts for more than 60% of available phosphorus.

Medium concentration compound fertilizer: nitrate nitrogen content is more than 1.5%, water-soluble phosphorus accounts for more than 50% of available phosphorus.

Low concentration compound fertilizer: nitrate nitrogen content is more than 1.5%, water-soluble phosphorus accounts for more than 40% of available phosphorus.

First, high concentration compound fertilizer

1, the total nutrient content (pure nitrogen + phosphorus pentoxide + potassium oxide) more than 40%.

2, water-soluble phosphorus accounts for more than 60% of available phosphorus, nitrate nitrogen content is more than 1.5%, moisture content is less than 2%, and particles with particle size of 1-4.75mm (or 3.35-5.6mm) exceed 90%.

3. The chloride ion content of products not marked with chlorine is less than 3%, the chloride ion content of products marked with chlorine (low chlorine) is less than 15%, and the chloride ion content of products marked with chlorine (medium chlorine) is more than 30%.

4, effective calcium content more than 1%, effective magnesium content more than 1%, total sulfur content more than 2%, single trace element more than 0.02%.

Second, medium concentration compound fertilizer

1, the total nutrient content (pure nitrogen + phosphorus pentoxide + potassium oxide) more than 30%.

2, water-soluble phosphorus accounts for more than 50% of available phosphorus, nitrate nitrogen content is more than 1.5%, water content is less than 2.5%, and particles with a particle size of 1-4.75 mm (or 3.35-5.6 mm) exceed 90%.

3. The chloride ion content of products not marked with chlorine is less than 3%, the chloride ion content of products marked with chlorine (low chlorine) is less than 15%, and the chloride ion content of products marked with chlorine (medium chlorine) is more than 30%.

4, effective calcium content more than 1%, effective magnesium content more than 1%, total sulfur content more than 2%, single trace element more than 0.02%.

Third, low concentration compound fertilizer

1, the total nutrient content (pure nitrogen + phosphorus pentoxide + potassium oxide) more than 25%.

2, water-soluble phosphorus accounts for more than 40% of available phosphorus, nitrate nitrogen content is more than 1.5%, water content is less than 5%, and particles with a particle size of 1-4.75mm (or 3.35-5.6mm) exceed 90%.

3. The chloride ion content of products not marked with chlorine is less than 3%, the chloride ion content of products marked with chlorine (low chlorine) is less than 15%, and the chloride ion content of products marked with chlorine (medium chlorine) is more than 30%.

4, effective calcium content more than 1%, effective magnesium content more than 1%, total sulfur content more than 2%, single trace element more than 0.02%.