The classification of fertilizers

ers. It can also be divided into farm fertilizer and chemical fertilizer by source. According to the nutrient content, it is divided into complete fertilizer and incomplete fertilizer; according to the characteristics of fertilizer supply, it is divided into direct fertilizer and indirect fertilizer; according to the composition, it is divided into nitrogen fertilizer, potassium fertilizer, trace element fertilizer and rare earth element fertilizer

Kinds

Ammonium phosphate fertilizer

Phosphoric acid (including polyphosphoric acid) and ammonia are neutralized and processed into nitrogen and phosphorus compound fertilizers. This is one of the largest and most popular fertilizers. It is suitable for almost all soils and crops. It has a high concentration of active ingredients and is not easy to absorb moisture and agglomerate. Ammonium phosphate can also be used as a flame retardant for fabrics and fibers, culture fluid in the fermentation industry, food additives and feed additives, acidifiers in the printing and dyeing industry, and dry powder fire extinguishing agent ingredients for fire fighting. The production process of ammonium phosphate fertilizer is a combination of the phosphate fertilizer production process and the ammonia processing process in the nitrogen fertilizer production, which is economically reasonable.

Industrial production of ammonium phosphate began in the 1920s, but on a small scale. In the early 1960s, the production technology of wet-process phosphoric acid became more and more perfect, and ammonium phosphate had relatively cheap raw materials, and its production developed rapidly, with the United States developing fastest. In 1968, the output of ammonium phosphate fertilizers in the United States (in terms of P2O5) was about half of the total output of phosphate fertilizers, which increased to 74.1% in 1981.

Varieties of ammonium phosphate fertilizers can be divided into three categories.

(1) Ammonium orthophosphate is the category with the largest output. The main varieties are diammonium phosphate, monoammonium phosphate and a mixture of the two.

(2) Ammonium polyphosphate is a mixture of ammonium orthophosphate and ammonium phosphate with different polymerization degrees. Most of them are used to make fluid compound fertilizers.

(3) A compound fertilizer made from ammonium phosphate and other nitrogen fertilizers.

Macro-element water-soluble fertilizer

Water Soluble Fertilizer (WSF) is a multi-element compound fertilizer that can be completely dissolved in water. It can be quickly dissolved in water and is easier to be absorbed by crops, and its absorption and utilization rate is relatively high. More importantly, it can be used in facility agriculture such as spray irrigation to realize the integration of water and fertilizer, and achieve the efficiency of saving water, fertilizer and labor. Generally speaking, water-soluble fertilizers can contain all the nutrients needed for crop growth, such as N, P, K, Ca, Mg, S, and trace elements. In this way, people can design formulas based on the characteristics of the nutritional requirements required for crop growth. The scientific formula will not cause waste of fertilizers, making the fertilizer utilization rate almost 2-3 times that of conventional compound chemical fertilizers (in China, The fertilizer utilization rate of ordinary compound fertilizer is only 30%-40%) Secondly, water-soluble fertilizer is a quick-acting fertilizer, which allows growers to see the effect and performance of fertilizer quickly, and can make fertilizer formula according to different crops at any time. Adjustment. Of course, the application method of water-soluble fertilizer is very simple. It can be fertilized during irrigation with irrigation water including sprinkler irrigation and drip irrigation. It saves water, fertilizer, and labor. This is because labor costs are increasing. Under the circumstances, the benefits of using water-soluble fertilizer are obvious. Because the application method of water-soluble fertilizer is irrigation with water, it makes the fertilization extremely uniform, which also lays a solid foundation for improving yield and quality. Water-soluble fertilizers generally have less impurities, low conductivity, and the use of concentration is very convenient to adjust, so it is safe even for young seedlings, and there is no need to worry about harmful consequences such as burning seedlings. At the same time, in accordance with the requirements of crops, the following technical characteristics of macro-element water-soluble fertilizers must be present at the same time:

(1) The water-soluble chelated trace element composition added to the ingredients should avoid antagonistic effects with phosphorus.

(2) For crops, it has the characteristics of resistance and yield increase, which can significantly improve the photosynthesis of crops, increase the yield and quality of crops, increase the sugar content, and enhance the resistance to cold, drought, disease, and lodging. Extend the shelf life.

(3) The addition of high-potassium formula can quickly meet the demand for potassium when fruits and seeds are enlarged, increase fruit sweetness, improve fruit coloring, and extend storage time.

Medium element fertilizer

Also known as minor macro-element fertilizers, a type of fertilizer containing one or more of the crop nutrient elements calcium, magnesium, and sulfur, and the content must be indicated. The minor constants are compared with the production and application scales of the major majors nitrogen, phosphorus, and potassium. In addition to providing nutrients to crops, this type of fertilizer can also adjust the physical properties of the soil and increase agricultural production. In the past 30 years, high-concentration fertilizers in the structure of chemical fertilizers have gradually replaced low-concentration fertilizers, reducing the calcium, magnesium and sulfur elements brought into the soil. Some soils have a shortage of medium nutrients, especially sulfur. Thus, the production and use of medium element fertilizers have been paid more attention. Limestone powder, dolomite powder, hydrated lime, shell powder and other industrial wastes containing calcium and magnesium are widely used as soil conditioners and provide calcium and magnesium nutrients. Its soil conditioning effects are: ①Improve the effectiveness of phosphate fertilizer in the soil. In soils with high iron and aluminum oxides, the effectiveness of phosphate fertilizers is reduced due to the reaction of phosphate with iron and aluminum compounds. The application of calcium and magnesium conditioners to keep the soil pH at 6-7 can retard the progress of the above-mentioned reaction. ② Facilitate the conversion of ammonium nitrogen into nitrate nitrogen in the soil, and most nitrifying bacteria require calcium. ③Promote the process of biological nitrogen fixation. ④ Adjust the crop's absorption of trace elements. When the soil pH is maintained at 6-7, the micronutrient elements maintain a certain degree of effectiveness for crops. ⑤Improve the physical properties of the soil, mainly to improve the particle size distribution of the soil. Common calcium-magnesium phosphate fertilizers (see Phosphate Fertilizers) also have the above effects.

Sulfur-containing fertilizers are mainly used to adjust the alkalinity and salinity of the soil (the soil contains too much sodium chloride and carbonate). A large amount of calcium sulfate (gypsum) is used to improve saline-alkali land or soil that has been submerged by seawater, with good effects. India has successfully used pyrite to improve alkaline soil or calcareous soil. For some magnesium-deficient soils with high pH, ​​dolomite powder should not be used. Magnesium sulfate or anhydrous magnesia can be used, or serpentine magnesium silicate powder can be used. In recent years, a new technology has been developed to coat molten elemental sulfur on the surface of urea particles. On the one hand, it provides sulfur to the soil, and on the other hand, makes urea a slow-acting nitrogen fertilizer to increase the utilization rate of nitrogen.

About us

Alfa Chemistry is an analytical testing company that provides one-stop testing, analysis and technical support services in the areas of pharmaceutical analysis: pharmacological testing, environmental analysis, consumer product analysis: Beauty Products analysis, food analysis: edible oil testing, and material analysis: building products testing. As a professional testing and analysis organization, Alfa Chemistry has an experienced technical team that uses advanced analytical equipment and technology to meet the needs of different customers.