How To Choose The Appropriate Compound Fertilizer

According to fertilizer science

A considerable portion of compound fertilizers sold in the market do not meet the national DB15063-94 standard. According to national standards, the effective nutrient content of compound fertilizer (compound fertilizer) should be ≥ 40% for high concentration nitrogen, phosphorus, and potassium, and ≥ 25% for low concentration nitrogen, phosphorus, and potassium, excluding trace and medium elements; Water soluble phosphorus content ≥ 40%, water molecule content less than 5%; The particle size is 1-4.75 millimeters, etc. So when choosing compound fertilizers, in addition to considering the trademark and nutrient content, attention should also be paid to the manufacturer and place of origin. In addition, there are two types of potassium in compound fertilizers, one is potassium chloride and the other is potassium sulfate. Potassium chloride contains chlorine and is not suitable for crops that are resistant to chlorine. Any compound fertilizer bag that is not marked with the "S" symbol is potassium chloride. Chlorine resistant crops such as grapes, potatoes, tobacco, sugar beets, etc. should not be used. It is necessary to choose compound fertilizer with the "S" symbol on the fertilizer bag, which is composed of potassium sulfate.

By crop variety

Generally, nitrogen phosphorus potassium compound fertilizer should be used for field crops, while nitrogen phosphorus potassium ternary compound fertilizer should be used for high-yield wheat fields; Wheat, rice, millet and other closely planted crops are suitable for using powdered compound fertilizers; Granular compound fertilizer should be used for sparse cultivation crops such as corn; Vegetables, especially fruit vegetables, root vegetables, and economic crops such as fruit trees, are in high demand, and nitrogen phosphorus potassium compound fertilizers with high potassium content and low nitrogen should be selected.

According to soil characteristics

For soils with slight alkalinity, low organic matter content (generally around 8.0 soil pH), and deficiencies in available nitrogen and phosphorus, acidic compound fertilizers such as ammonium phosphate or humic acid nitrogen phosphorus potassium compound fertilizers or nitrogen phosphorus compound fertilizers should generally be selected. But for a small number of red clay or acidic brown soil, alkaline compound fertilizers such as diammonium phosphate should be selected.

According to the fertilization method

To improve the fertilizer efficiency of compound fertilizers, different application methods should choose different dosage forms of compound fertilizers. When applying as base fertilizer, granular compound fertilizer must be selected, and the higher the hardness of the particles, the better, and the longest fertilizer efficiency. Choosing a compound fertilizer composed of ammonium nitrogen in the compound fertilizer is beneficial for improving nitrogen utilization efficiency. If applied as topdressing, powdered compound fertilizer should be selected, and it should be noted that the water-soluble phosphorus content in the compound fertilizer should be greater than 40%, while nitrogen should be composed of two types of nitrogen: ammonium nitrogen and nitrate nitrogen. The effect of basic application of humic acid compound fertilizer is generally better than that of topdressing.