Phosphate fertilizer application technology

Since the discovery of phosphate rock, the use of natural phosphate rock to produce phosphate fertilizer. Due to the different manufacturing methods, a wide variety of phosphate fertilizers can be produced.

Mechanical method: directly used by phosphate rock ore to form phosphate rock powder.
Acid production method: treatment of phosphate rock powder with sulfuric acid, nitric acid, hydrochloric acid, etc. The main products are: superphosphate, heavy superphosphate, precipitated calcium phosphate and so on.
The hot method: decomposing phosphate ore (powder) by high temperature generated by medium force or fuel to make various kinds of hot phosphate fertilizer, and the product has calcium magnesium phosphate fertilizer.

(1) Superphosphate and heavy superphosphate 1. Superphosphate is called calcium. It is the most widely produced phosphate fertilizer in China. It is made from phosphate rock treated with sulfuric acid. It is a water-soluble phosphate fertilizer, the main components are water-soluble monocalcium phosphate [ca(h2po4)•h2o] and calcium chloride (caso4), which are insoluble in water, accounting for 30%-50% and 40% of the weight of the fertilizer, respectively. about. Superphosphate mainly supplies phosphorus nutrition, but it also provides sulfur nutrition and also has the effect of improving soil. In addition, there are a small amount of phosphoric acid, sulfuric acid, water-insoluble phosphate (such as capo4, fepo4) and other impurities such as iron, aluminum and calcium salts. It is generally grayish white or light gray powder and also has a granular shape. The content of available phosphorus and other components in the finished product shall be classified according to the national standards and as shown in Table 6-1.

Because of the presence of free phosphoric acid and sulfuric acid, the fertilizer is acidic and hygroscopic. Under the condition of storage humidity, the superphosphate absorbs moisture and causes various chemical changes, which often make the water-soluble phosphorus become water-insoluble. This effect is usually called phosphate degradation. The phosphoric acid degradation caused by superphosphate during storage is mainly caused by impurities such as iron and aluminum in the ore. The iron sulfate, aluminum sulfate and monocalcium phosphate formed during the production are complexed to become low-soluble iron phosphate and aluminum phosphate. . Therefore, the water content and free acid content of the finished superphosphate should not exceed the national standard. At the same time, in the process of storage and transportation, pay attention to moisture.

Table 6-1
Superphosphate product grade specification
Special level first level second level third level four level
Effective phosphorus content (p2o5%)
>20
18
16
14
12

Free acid (5)
<3.5
4
4
5
5

Moisture content (%)
<8
10
10
14
14



2. Administration of superphosphate.

It can be seen from the change of superphosphate in the soil that the water-soluble monocalcium phosphate in the fertilizer is easily fixed by the soil and has little mobility. According to the movement of phosphorus in the soil on the calcareous soil in our province, it is proved that the movement of phosphorus generally does not exceed 1-3 cm, and most of it is concentrated within 0.5 cm around the fertilization point. Therefore, the rational application of superphosphate should be considered to reduce its contact area with the soil, and to increase its exposure to the root crops to increase the utilization of superphosphate.
According to the above principles, the following measures for rationally applying calcium phosphate are proposed.

(1) Centralized administration. Superphosphate can be used as base fertilizer, seed fertilizer and top dressing. Regardless of which application method is applied, the effect of concentrated administration is preferred. The reason is: after concentrated application, the fertilizer and soil contact surface is reduced, thereby reducing the fixation, and at the same time, increasing the depth of the local phosphoric acid, so that it can maintain the supply of phosphorus nutrition to the crop for a long time, and cause the fertilization point. The difference in concentration between the roots of the crops helps to promote the diffusion of phosphate ions into the roots and absorption by the roots.
When superphosphate is used as the base and top dressing, it should be applied in depth, and the effect of deep application as base fertilizer is obvious.

(2) Mixed application with organic fertilizer. The application of superphosphate mixed with organic fertilizer is an effective method to improve the effect of superphosphate. Because of the application after mixing, the contact surface with the soil is greatly reduced first, including the coating of the trioxide in the soil by the organic colloid, thereby reducing the contact fixation of the water-soluble phosphorus; meanwhile, the organic fertilizer is in the process of microbial decomposition. Produces many organic acids, such as oxalic acid, citric acid, malic acid, tartaric acid and lactic acid, which can chelate with calcium, iron and aluminum ions in the soil to form stable complexes, thereby reducing or even avoiding calcium in the soil. Iron, aluminum ions produce chemical precipitation on monocalcium phosphate, which plays a protective role, so that superphosphate maintains high effectiveness. The order of the complexing effect is: citric acid > oxalic acid > tartaric acid > malic acid > lactic acid. If superphosphate is mixed with organic fertilizer, it also has nitrogen retention effect and reduces nitrogen loss in organic fertilizer.

In acidic soils, the application of lime can increase the effectiveness of superphosphate. If organic fertilizer and lime are combined, it can improve its fertilizer efficiency. The application of lime can adjust the acidity of the soil, promote the activity of microorganisms, and increase the organic acid which can be complexed with iron and aluminum ions in organic fertilizer. At the same time, lime can raise the pH value in the soil and reduce the activity of iron and aluminum. It can reduce the fixation of phosphorus and improve its fertilizer efficiency. When applied, lime should be applied first, and after a few days, calcium phosphate is applied or applied with organic fertilizer.

(3) Making inorganic granular phosphate fertilizer. The small surface area of ​​the granular phosphate fertilizer reduces the contact surface between the fertilizer and the soil, thereby reducing the chance of soil fixation. Granular phosphate fertilizers generally have a particle size of 3 to 5 cm, and such phosphate fertilizers are very effective for application on soils having a high ability to fix phosphorus. At the same time, the granular phosphate fertilizer is also convenient for mechanical fertilization. However, as the particle size of the fertilizer increases, the distribution point decreases, the phosphorus mobility is small, and the contact surface with the crop roots is also lowered. It can be seen that the fertilizer efficiency of granular phosphate fertilizer is a comprehensive performance of the contradiction between the fixation of phosphorus and the contact probability of crop roots and phosphorus. Therefore, in the soil with small phosphorus fixation, or the cultivation of crops with developed roots, the powdered phosphate fertilizer can be widely contacted with the roots, which is more conducive to the absorption of phosphorus. The effect of powdered phosphate fertilizer is often better than that of granular phosphate fertilizer. Therefore, the application of granular phosphate fertilizer should be based on soil and crops.

(4) Use root dressing. Formulating the superphosphate into a solution and spraying it on the stems and leaves of the crop is also an effective method for economically applying the water-soluble phosphate fertilizer. It can prevent phosphorus from being contacted and fixed in the soil, and can directly absorb and utilize the crops, thereby increasing the 1000-grain weight of rice, wheat and other grain, and the fruit-bearing rate of cotton.

3. Properties and application of heavy superphosphate.

Heavy superphosphate is a high concentration of phosphorus, which is obtained by treating phosphate rock with sulfuric acid to obtain phosphoric acid, and then reacting with phosphoric acid and phosphorous powder. If the finished product is dark gray particles or powder, the main component is water-soluble monocalcium phosphate, containing phosphorus pentoxide 40% -52%, without gypsum, but containing 4% -8% free phosphoric acid, hygroscopicity and Corrosive is stronger than superphosphate. Therefore, the powdery heavy superphosphate is more likely to agglomerate, and since it does not contain impurities such as iron, aluminum, manganese, etc., there is no degradation of phosphoric acid after moisture absorption.

The method of effective administration of heavy superphosphate is the same as that of superphosphate. However, the content of active ingredients in heavy superphosphate is high, and the amount of fertilizer should be relatively reduced. At the same time, because of the absence of gypsum, crops that respond well to sulfur nutrition, such as potatoes, legumes, and cruciferous crops, are not as effective as calcium phosphate superphosphate.

(2) Calcium magnesium phosphate fertilizer 1, composition and properties.

Calcium magnesium phosphate fertilizer is a eutectic of phosphate rock and an appropriate amount of magnesium-containing silicon minerals such as serpentine, olivine, dolomite and silica at a high temperature (above 1350 ° C), so that the crystal of calcium fluorophosphate is destroyed, and then the melt is melted. It is water quenched into glassy granules, which are then ground into fine powder. The color of the finished product is different, grayish green or grayish brown, the phosphorus content of phosphorus pentoxide is 14%-19%, and the phosphorus in the good quality calcium magnesium phosphate fertilizer is more than 95% soluble in 2% citric acid, but insoluble in water. It is a weak acid soluble phosphate fertilizer. The phosphorus compound in this fertilizer is generally considered to be [α-ca3(po4)], and also contains calcium oxide, magnesium, and is alkaline. High-quality calcium magnesium phosphate fertilizer, such as 2% aqueous solution, ph value of 8.0-8.5, no corrosive, no moisture, easy to package and store. It is one of the main phosphate fertilizer varieties currently produced in China.

2. Application of calcium magnesium phosphate fertilizer.

After the application of calcium magnesium phosphate fertilizer, there is a dissolution process in order to absorb the crop. Therefore, its fertilizer efficiency has a certain relationship with the fineness of the particles. Test on calcareous soil: If the fertilizer efficiency through the 100 mesh sieve is 100%, the fertilizer efficiency through the 80 mesh sieve is 94%, and the fertilizer efficiency through the 60 mesh sieve is 80.6%, while the coarse fertilizer is The fertilizer efficiency is only 25%. Because the solvency of different soils to calcium, magnesium and phosphorus fertilizers varies greatly, the requirements for their fineness are also different. When applied on acidic soil, the particle size of calcium magnesium phosphate can be larger; on calcareous soil, it should be finer. Generally, 90% can pass through 80 mesh sieve and the particle size is 0.177 mm.

Although the phosphorus in the calcium magnesium phosphate fertilizer is insoluble in water, it is soluble in weak acid, and can be dissolved by the acid (such as carbonic acid) secreted by the crop roots and microorganisms and the acid in the soil, and is supplied to the crop for absorption and utilization. In addition, it can also supply nutrients such as calcium and magnesium. Although its fertilizer efficiency is not as fast as superphosphate, it has a longer aftereffect.

Practice has shown that calcium magnesium phosphate fertilizer is generally effective in different soils in different crops. In acidic soils, most of the seasonal fertilizers are equivalent to superphosphate, and sometimes slightly higher than superphosphate; in calcareous soils, the effect is often slightly lower than that of superphosphate. Therefore, calcium magnesium phosphate fertilizer is most suitable for application in acidic soils such as red soil and yellow soil, and some non-acid soils with low effective phosphorus content, such as white soil, bauxite, duck mud, cold soaked fields, low temperature, high humidity, Heavy soil also has a good effect. Because it has the function of neutralizing soil acidity and reducing iron and aluminum in soil, at the same time, in addition to supplying phosphorus, it can also supplement elements such as calcium, magnesium and silicon in soil, which can improve soil physical and chemical properties and improve crops. Nutritional conditions.

The effect of calcium magnesium phosphate fertilizer has a great relationship with crop types. Its effect on rice, corn, wheat and other crops is generally about 70%-80% of superphosphate. For rapeseed and green manure, its fertilizer efficiency is slightly higher. Different crops have different utilization capacities for calcium magnesium phosphate. Therefore, in the rotation, calcium magnesium phosphate should be applied preferentially to crops with strong absorption capacity such as rape, radish, legume green manure, beans, and melons.

Calcium magnesium phosphate fertilizer can be used as base fertilizer, seed fertilizer and top dressing. However, deep application with base fertilizer is the best. The base fertilizer and top dressing should be applied in a concentrated manner, and the topdressing should be applied early.

Calcium, magnesium and phosphorus fertilizers can also be applied after organic fertilizers are piled up. With the action of microorganisms, the dissolution of calcium, magnesium and phosphorus fertilizers can be promoted and the fertilizer efficiency can be improved.

(III) Application of Phosphate Fertilizer in Rotation 1. Water and drought rotation is one of the main rotation systems in rice areas of China. Most of them use wheat, rapeseed-rice and green manure-rice rotation. According to the requirements of phosphorus for rice and dry farming, in this rotation, the distribution of phosphate fertilizer should be based on the principle of “dry and heavy water”, that is, in a rotation cycle, the focus of phosphate fertilizer should be applied to dry farming. Therefore, in wheat, rapeseed-rice rotation, the focus of phosphate fertilizer should be applied to wheat or rapeseed, and rice can be used for its aftereffect. Because the phosphorus fertilizer applied to the dry crop has a large residual effect on the post-rice rice, the phosphorus applied to the rice, due to the dry cropping, causes the soil to strongly fix the phosphorus when the soil is dried, reducing the residual soil. The availability of phosphorus in the future affects the supply of phosphorus in the post-production (dry cropping) and does not fully exert the fertilizer efficiency of the phosphate fertilizer. When green-rice rotation is implemented, the phosphate fertilizer should be absorbed by the green manure (especially the legume green manure) and then applied to the rice, which not only makes the rice yield increase and stable, but also fully exerts the "phosphorus-increasing nitrogen" effect. According to observations, in general soil, the direct application of phosphate fertilizer to rice yield is not effective. Generally, 0.5-kg of rice per kg of phosphate fertilizer is increased or no increase is produced. For green manure, per kg of phosphate fertilizer can indirectly increase yield of rice 1.5-2.5. jin. Therefore, in areas where there are legume green manure, the phosphate fertilizer is distributed in legume crops such as broad beans, peas or green manure. In the case of southern green manure and a double-season rice rotation, in the phosphorus-deficient soil, the phosphate fertilizer should be applied to the green manure, and the appropriate amount of phosphate fertilizer should be applied to the early rice. The late rice is appropriately lower according to the phosphorus fertilizer application rate, and the roots have poor absorption capacity for phosphorus. Phosphorus conversion is slow after flooding, and relying on the aftereffect of phosphate fertilizer, there will still be phosphorus deficiency and dead seedling phenomenon. In order to meet the needs of phosphorus in the early stage of early rice, enhance the resistance of seedlings, prevent the phenomenon of dead seedlings, promote early growth, apply phosphate fertilizer in the field or apply it to the field fertilizer, or use a small amount of phosphate fertilizer to dip the roots during transfer. necessary. In late rice, if the amount of phosphate fertilizer is large, it can be appropriately supplemented, which also has a good effect on the growth and development of late rice.

2. Application of phosphate fertilizer in dry crop rotation.

In the dry crop rotation, because the characteristics of phosphorus fertilizer efficiency can not be improved after flooding, the distribution and use of phosphate fertilizer should be determined according to the physiological characteristics of the crop, the ability to absorb phosphorus and the rotation system.

In the rotation of green manure or legume crops, as with water and drought crops, phosphate fertilizer should be applied preferentially to green manure crops or legume crops with more phosphorus and strong phosphorus absorption, see Table 6-3. In the area where the wheat-cotton rotation is used, since the requirement for phosphorus in cotton is more sensitive than that of wheat, the application of phosphate fertilizer to cotton can better exert the effect of increasing the yield of phosphate fertilizer.
Table 6-2
The effect of direct and indirect application of phosphate fertilizer on the yield increase of dry crops is increased by direct application of phosphorus per kg (jin)
Fertilizer effect per kilogram of phosphate fertilizer through green manure

(kg)

The average yield increase of crops is higher than that of direct application.

Corn 0.55
0.55
1.8
1.15
177

Cotton 0.2-0.8
0.5
1.4
0.9
180

Wheat 0.8-1.3
1.05
1.05
0.5
50


In addition, when the crops in the rotation are similar to the nutrient characteristics of phosphorus, the phosphate fertilizer is used for the wintering crops in autumn, which tends to be better than the spring crops. The key allocation of phosphate fertilizer should be wintering crops. Because the temperature gradually declines after the autumn sowing, the soil microbial activity is weakened, and the soil phosphorus supply capacity is poor. At this time, the phosphorus nutrition can be increased, the seedlings can be cultivated, the cold resistance can be enhanced, the early hair can be promoted, and the phosphate fertilizer can be increased. For example, in wheat, cereal (corn, millet, etc.) rotation areas, phosphate fertilizer should focus on wheat, and later season corn or millet can use its aftereffects.
【Comment】 【Print this article】 【Close this page】 【Large, medium and small】

Diesel Test Equipment

Diesel test equipment is used to test and diagnose different diesel injector and pump of diesel injection system.


There are mainly mechanical diesel injection system and electronic diesel injection system.


Three types diesel electronic injection systems are popular in the market, which is high pressure common rail injection system, HEUI injection system and EUI EUP injection system.


Common Rail Test Bench is for common rail injector of Bosch, Denso, Delphi, Cummins, Siemens, Caterpillar etc.

HEUI tester is for HEUI injector like CAT C7, C9, C-9, C3126A, C3126B, 3412E, FORD G2.8, FORD G2.9, NAVISTAR, ISUZU etc.

EUI tester is for unit injector and unit pump, such as Detroit 60 series N2/N3, Caterpillar C12/C13/C15/C18, Cummins N14/M11, Delphi E1/E3,Scania, Iveco, Benz Actors, Benz Atego, Land Rover, Volkswagen PD etc.


Besides, there is also diesel tester for Cummins PT injector and PT pump, X15 Q60 injector etc.

Diesel test bench is easy to operate and maintain, featured of highly accurate, reliable and durable.


Diesel Test Equipment,Diesel Injector Tester,Diesel Test Bench,Fuel Injector Test Bench

CHENGDU UNICO MACHINERY CO., LTD , https://www.injectortestbench.com