Essentials for purchasing compound fertilizer.
Look at the logo on the outer packaging
1. Content identification: 15% of nitrogen, phosphorus, and potassium, which means that each effective nutrient cannot be less than 15%, and the total nutrient of 45±1 means that the three nutrients together cannot be less than 44%. But the meaning of total nutrients is: nominally 45 nutrients, if there are only 43 nutrients in the actual test results, the two nutrients that are poor are also considered as prices, and the two less nutrients are worth nearly 100 yuan/ton.
2. Trace elements: Trace elements have a certain effect on the growth of crops, but they do not have a decisive effect. Some manufacturers exaggerate the role of trace elements, multi-label the content of trace elements, and then raise prices. Therefore, when buying, do not judge the price by the number of trace elements, but calculate the price according to the content of nitrogen, phosphorus, and potassium. Pay special attention to the label. If it is nitrogen + potassium + middle and trace elements (such as sulfur), this fertilizer is only a two-element fertilizer, and the middle and trace elements cannot be counted as total effective nutrients.
3. Types of elements contained: Three-element fertilizers refer to fertilizers made of nitrogen, phosphorus, and potassium. These three elements are the three important nutrients necessary for crop growth. As the name suggests, a fertilizer made of any two of the three elements nitrogen, phosphorus, and potassium is called a two-element fertilizer. Some dealers use two-element fertilizers instead of three-element fertilizers to sell to farmers and persuade them to use them. Such long-term use will cause the decline of soil fertility and affect the growth of crops. In addition to nitrogen, phosphorus, and potassium, fertilizers that also contain other middle and trace elements are called multi-element fertilizers. At present, most of the trace elements in the packaging labels of multi-element fertilizers on the market are not added at all or the added amount is very small, which can't play a real role. It is just to mislead consumption and promote sales. Don't be fooled.
Look at the chemical fertilizer test report
Whether it is imported fertilizer or domestic fertilizer, you must check the chemical fertilizer test report. The test report was tested by this geological inspection department.
1. Look at the content of nitrogen, phosphorus, and potassium. Whether the content of water-soluble phosphorus is high, the higher the water-soluble phosphorus, the better.
2. Look at the total nutrient content (nitrogen, phosphorus, potassium).
3. Look at the particle strength and moisture content. The ones with high strength and low moisture content are better, and then compare with the label on the outer packaging. Pay attention to the nutrient deviation of the label. The smaller the deviation, the better.
4. Whether the chemical fertilizer contains chlorine or not, and the chlorine content is too high, which will have an adverse effect on chlorine-free crops. For example, when applying chlorine-containing fertilizers to vegetables, citrus, potatoes and other crops, the quality of the fertilizer will be affected, and the yield will be reduced.
Choose some reputable fertilizer distributors to buy fertilizers. When buying, try to choose some brands or compound fertilizers that have been used before and have good effects.