One flower at a time, all by fat! Phosphorus is one of the essential main nutrients for all crops. Farmers engaged in agricultural production can not be separated from the use of phosphate fertilizer. Understanding the role of phosphorus and the supply of phosphorus in soil and applying phosphorus scientifically and reasonably can make the fertilization effect of phosphorus fertilizer better and the utilization rate higher.

The results revealed by scientific research show that the content of phosphorus in all higher plant tissues is about 0.2%. Phosphorus is not only an important component in the nucleus of all crops, but also a necessary nutrient element for physiological metabolism of plants. Phosphorus plays an important role in cell division and differentiation and development of various organs and tissues, especially in flowering and fruiting. At the same time, phosphorus also has the ability to improve crop disease resistance, cold resistance, drought resistance and lodging resistance, and promote root development.

Phosphorus in farmland soil mainly includes water-soluble phosphorus compounds, weak acid-soluble phosphorus compounds and insoluble phosphorus compounds. Among them, insoluble phosphorus compounds belong to slow-acting phosphorus which is difficult to be utilized and absorbed by crops, and also account for the vast majority of inorganic phosphorus in soil. Only water-soluble phosphorus compounds and weak acid-soluble phosphorus compounds belong to available phosphorus. Water-soluble phosphorus compounds can be directly absorbed and utilized by crops, but the content in soil is very small. Generally speaking, there are only a few milligrams of water-soluble phosphorus compounds per kilogram of soil, and the content of water-soluble phosphorus compounds and even available phosphorus per kilogram of soil is less than 1 mg. Moreover, water-soluble phosphorus compounds are extremely unstable in soil and are easily converted into insoluble phosphorus compounds. Although the content of weak acid soluble phosphorus compounds is higher than that of water soluble phosphorus compounds, these phosphorus compounds can only be absorbed and utilized by crops in neutral and slightly acidic soils.

Available phosphorus content in farmland soil is an important index to measure soil phosphorus supply, and farmers can consider the scientific application amount of phosphorus fertilizer accordingly. However, after the application of phosphate fertilizer, the utilization rate of the season is not very high, generally between 10%-25%. There are two main reasons: First, phosphate fertilizer is easily fixed in soil. Once phosphate fertilizer is applied to the soil, it will undergo chemical, biological or biochemical transformation immediately, and finally react with calcium in the soil in the corresponding transformation process to generate precipitated calcium hydrogen phosphate, so that water-soluble phosphorus is fixed by the soil. Second, the fluidity of phosphate fertilizer in soil is poor, and phosphate fertilizer applied to soil cannot be naturally intercepted and absorbed if it cannot diffuse and contact with crop roots. Scientific fertilization proves that phosphate fertilizer belongs to lazy fertilizer, and the distance it moves in the soil in 24 hours is only 1-4 mm, but as a lazy fertilizer, phosphate fertilizer also has the characteristics of long aftereffect.

For farmers, in order to fundamentally improve the application effect and fertilizer efficiency utilization rate of phosphate fertilizer, it is necessary to consider relatively scientific application measures for different phosphate fertilizer varieties.

Water-soluble phosphate fertilizers such as superphosphate, superphosphate, monoammonium phosphate and diammonium phosphate are suitable for all kinds of soils and crops, but they are best used in neutral and calcareous soils. The phosphorus content of monoammonium phosphate and diammonium phosphate is mostly 3-4 times that of nitrogen. When applied to crops other than leguminous crops, an appropriate amount of nitrogen fertilizer must be applied to adjust the ratio of nitrogen to phosphorus. Otherwise, blind application of monoammonium phosphate or diammonium phosphate will not only fail to increase production, but may also lead to a decrease in production due to improper application ratio of nitrogen and phosphorus.

Nitrophosphate is a miscible phosphate fertilizer and a binary compound fertilizer, in which half of the nitrogen is ammonium nitrogen and the other half is nitrate nitrogen. It is directly effective for crops after application and dissolution, and it is most suitable for application in dry land even under the condition of low soil water content. However, it should be noted that in dry land with serious phosphorus deficiency, when choosing to apply phosphate fertilizer, high water-soluble nitrophosphate with phosphorus pentoxide water solubility greater than or equal to 50% should be selected. However, after the application of nitrophosphate in rice field, nitrate nitrogen in it is easy to form denitrification loss, so it is best to apply ammonium phosphate instead.

Calcium magnesium phosphate fertilizer and steel slag phosphate fertilizer are suitable for acid soil, and the application effect on acid soil is better than that on acid soil. However, this citric acid soluble phosphate fertilizer is slow to take effect and is best used as base fertilizer and seed fertilizer. If topdressing is to be done, it should be piled together with farmyard manure in advance and applied together to avoid dephosphorization of crops in the early stage of topdressing.

Insoluble phosphate fertilizer, such as phosphate rock powder, is only soluble in strong acid and is generally applied to soil with strong acidity. It is best to compost it with farmyard manure in advance before applying it to rape, buckwheat, pasture, beans and perennial economic trees.

In order to improve the fertilizer efficiency after phosphate fertilizer application, it is necessary to pay attention to fertilization methods. In dry land, furrow application or digging pit application can be considered, and centralized fertilization methods such as dipping seedling roots and plugging seedlings should be adopted in paddy field. The method of applying phosphate fertilizer and organic fertilizer together in advance can also improve the application effect and utilization rate of phosphate fertilizer.