Is it necessary?, Fertilizer dyeing enterprises | Fertilizer | Necessary
Fertilizer dyeing has a long history. As early as the 1980s, China's fertilizer products were mainly imported from countries such as the United States and Morocco, with most of the imported fertilizers being coffee colored particles. With the rapid growth of China's fertilizer production capacity, it has gradually replaced imported products. However, there is still a gap in the quality of fertilizers produced by domestic manufacturers compared to foreign brands. In order to better sell, dyes are used to dye fertilizers. Fertilizer dyeing increases the production costs of enterprises, which ultimately make farmers bear the cost and also increases the potential risk of soil pollution.
Why dye fertilizers?
At present, dyeing agents are widely used in the field of fertilizers. The interviewed agricultural experts believe that chemical fertilizer dyeing has two main purposes.
One is to make fertilizer particles more beautiful and meet the needs of fertilizer marketing. Lin Haitao, the head of the innovative team for the creation of new fertilizers at the Institute of Resources and Environment of Shandong Academy of Agricultural Sciences, said that after dyeing the fertilizer particles, different colored particles mixed together appear colorful, pleasing to the eye, invisibly enhancing the mystery and technological sense of the fertilizer, and increasing its selling point. Some fertilizer varieties are dyed just to cater to the inherent cognition formed by farmers over the years. Some farmers, due to long-term usage habits, often question the quality of their products due to appearance issues. After dyeing, enterprises can reduce unnecessary troubles.
The second is to play a discriminative role, improve the uniformity of fertilizer particle color, and improve the appearance quality. Tian Shugang, a senior expert in agricultural technology services at Guizhou Phosphate Group, introduced that diammonium phosphate is the main variety of high concentration phosphate compound fertilizer. Due to the different types of minerals contained in the raw material phosphate ore, the products produced without adding dyes are in their natural color, manifested as granular crystals such as milky white, beige yellow, and bluish white. In the production process, to prevent particle adhesion from affecting use, some companies use wrapping oil during the granulation process; Some companies add dyes in their production to differentiate the color of their products from others. Dyeing particles containing different nutrients into different colors can improve the recognition of fertilizers.
Experts believe that adding wrapping oil and coloring agents to fertilizers can only change the appearance of the product and has no effect on increasing fertilizer efficiency. Some coloring agents may also contain heavy metals or other harmful substances, which can have adverse effects on soil and crops.
Increasing the cost of agricultural inputs and potential pollution risks
The investigation found that there are four main types of fertilizer dyes: inorganic minerals, which are more commonly used in the red iron oxide series, and are mostly used in the dyeing of compound fertilizers and potassium fertilizers, without toxicity; Food grade coloring agents, with high prices and good dyeing effects, are commonly used in high value-added new fertilizers such as slow-release fertilizers and water-soluble fertilizers; Natural polymer nutrients, such as humic acid, polysaccharides, alginate, etc., are non-toxic; Organic dyes contain azo structures and pose safety risks.
Yuan Liang, a researcher at the Institute of Agricultural Resources and Agricultural Regionalization of the Chinese Academy of Agricultural Sciences, said that there are many types of dyes with complex classifications, and the price per ton ranges from several thousand yuan to tens of thousands of yuan. Enterprises will comprehensively consider the fertilizer product process, type, addition location, and price of the dyeing agent used, and choose the corresponding dyeing pigment variety, dosage form, and addition amount.
Fertilizer mainly includes urea, ammonium phosphate, compound fertilizer, water-soluble fertilizer and other products, with ammonium phosphate products having the highest dyeing ratio. Among them, more than 95% of diammonium phosphate in phosphate compound fertilizers are dyed with dyes. According to data from the phosphate compound fertilizer industry, China's compound fertilizer production was 33.93 million tons and diammonium phosphate production was 13.6 million tons in 2022. If calculated at a cost of around 30 yuan per ton of dyeing, the total cost of dyeing would reach 1.426 billion yuan. Dyeing agents are not nutritional elements and cannot promote plant growth. This unnecessary production cost is a waste of resources, which will ultimately be transferred to farmers.
Dyeing agents not only increase the cost of agricultural inputs, but also pose potential pollution risks. Experts explain that inorganic dyes in dyes, such as red ferric chloride and mineral dyes containing heavy metals, are relatively safe within the normal dosage range. However, adding dyes such as pyridine, anthraquinone, and azo to fertilizers, or dyeing fertilizers with dyes containing heavy metals, poses risks.
At present, China still lacks safety evaluation, admission supervision, and testing standards for the addition and application of some dyes. Industry insiders have pointed out that the types, dosages, and safety of dyes used by fertilizer companies have not received sufficient attention, and there is a lack of effective management. There is a lack of mature detection techniques and methods for extracting, qualitatively or quantitatively detecting dyes added to fertilizers.
First weight, affordable, ensuring safety
The issue of fertilizers is related to food security and ecological environment security, and cannot be ignored. Agricultural experts believe that fertilizers are designed to provide nutrients for crops, and should be based on the principle of affordability. On the basis of affordability, it is important to pay attention to the beauty of the product, and it is not advisable to add additional costs to dye it.
If dyeing is to be done, safety must be ensured. Experts suggest strengthening the safety supervision and inspection of fertilizer products to avoid direct use of fertilizers and dyes through simple physical mixing; Regulatory authorities should regulate the use of dyes in fertilizer production enterprises, limit the types and quantities of dyes that can be added.
At the same time, encourage and support fertilizer enterprises to seek technological innovation breakthroughs, strengthen research and development of dyeing agent materials, and develop non-toxic or residue free dyeing agents. Yuan Liang said that adding natural plant derived bioactive substances such as humic acid and alginate to change the color of fertilizers is a more scientific choice. This method can not only change the color of fertilizers, but also improve their application effectiveness.
In recent years, the production of value-added fertilizers characterized by the use of biologically active carriers to enhance efficiency has developed rapidly. At present, the annual production of value-added fertilizers in China has reached 15 million tons, becoming the largest green and efficient fertilizer product type in the world. Fertilizer companies should be guided to choose natural plant sources, safe and environmentally friendly fertilizer efficiency enhancing carriers to replace dyes.
Agricultural technicians should also spread the concept of scientific fertilizer use to the fields and fields. Half month talk reporters found in interviews that some industry associations have proposed initiatives not to add dyes, but the effect is not significant. The difficulty lies in the difficulty of changing the traditional perception of farmers towards dyeing fertilizers. "Natural fertilizers are milk colored and clean. It's easy to see which one is good for crops when used," Tian Shugang said. He wants to show the experimental results to farmers, improve their understanding of natural fertilizers, and increase their acceptance of natural fertilizers.
