Superphosphate is often called ordinary superphosphate, or superphosphate for short. It is a commonly used variety of phosphate fertilizer in my country. However, for many farmers, there are still questions about how to use superphosphate correctly. Here is a guide for everyone. Let’s take a look at the correct usage of superphosphate.
What is superphosphate
Superphosphate is a chemical acid fertilizer, suitable for use in neutral, Apply to slightly alkaline and alkaline soils. Since superphosphate contains a large amount of gypsum and free acid, its application on alkaline soil has the effect of improving the soil. Superphosphate is suitable for various crops and can be used as base fertilizer, seed fertilizer, top dressing and root top dressing. When making seed fertilizer, direct contact with the seeds should be avoided.
Correct use of superphosphate
1. Making base fertilizer
Superphosphate has little mobility in soil, even after superphosphate application Within 2-3 months, more than 90% of the phosphate fertilizer is still concentrated within 0.5 cm and 0-5 cm deep of the fertilization point. After superphosphate comes into contact with the soil, it is easily fixed by the soil. Therefore, concentrated application should be promoted and concentrated near the seeds or crop roots. This can reduce the chemical fixation of phosphorus and help improve the utilization rate of phosphorus fertilizer.
Mixing superphosphate with organic fertilizer as base fertilizer is an effective measure to reduce phosphorus fixation and improve fertilizer efficiency. The organic colloids and crude organic matter in organic fertilizers can play a protective role in preventing water-soluble phosphoric acid from coming into contact with iron, aluminum, calcium and other ions. In addition, organic fertilizers can form a variety of organic acids during the decomposition process. On the one hand, they have strong ability to complex iron, aluminum, calcium and other ions, making them more stable organic complexes to reduce the chemical fixation of phosphorus. It can also promote the dissolution and release of poorly soluble phosphates. When applying superphosphate and organic fertilizer together, a ratio of 1:4 is more appropriate.
When superphosphate is used as base fertilizer, 15-25 kilograms of Tosoh should be used per acre. If the amount is large, it can be applied in layers, that is, apply it deeply when plowing the ground and shallowly when raking the ground. If the amount of fertilizer is small, it can be applied in a shallow layer (9-15 cm deep) before sowing, which will facilitate root absorption during the seedling stage.
2. Top dressing
Superphosphate can be used as early top dressing. The method of reasonable application is to dig trenches or holes at a certain distance (6-10 cm) from the plants. Generally about 10 cm deep, superphosphate is applied in the trench and covered with soil after application. Be careful not to mix it with alkaline substances such as plant ash, lime nitrogen, lime, etc.
3. Extra-root top dressing
Superphosphate has good effect as extra-root top-dressing. Topdressing outside the roots can not only avoid the fixation of phosphorus in the soil, but also saves the amount and has fast fertilizer effect. Especially in the later stages of crop growth, when the roots’ ability to absorb nutrients is weakened, topdressing phosphate fertilizers outside the roots can promptly make up for the lack of phosphorus absorption by the roots. insufficient. Before spraying, soak superphosphate in 10 times of water, stir, filter and clarify, dilute the supernatant, and spray in the early morning or evening when there is no water falling. The spray concentration for monocotyledonous plants is 1%-3%. The spray concentration for dicotyledonous plants is. 0.5%-1.0%, 50-10 kg of aqueous solution per acre, spray once every 5-7 days, and can be sprayed 2-3 times.
