Editor’s note: In order to implement the important instructions of General Secretary Jin Ping’s”production”,”management” and”four strictest” , Resolutely maintain the bottom line of agricultural product quality and safety. In recent years, our company has organized relevant scientific research and technical units to focus on agricultural product varieties, risk factors, key links and agricultural inputs that may affect the quality and safety of agricultural products. Worked on risk assessment, supervision and spot checks. Each unit has successively submitted a batch of project reports, policy analysis, supervision suggestions and other materials, which are now selected and compiled as work briefs for reference in agricultural product quality and safety supervision work.
This journal publishes the”Investigation and Analysis and Evaluation of Organic Fertilizer Product Quality and Safety” contributed by the Agricultural Product Quality and Safety Risk Assessment Laboratory (Nanjing) of the Ministry of Agriculture and Rural Affairs. The report The quality and safety status of organic fertilizer products was investigated and analyzed, and then control measures and policy recommendations were put forward.
The resource utilization of agricultural waste is an important part of rural environmental governance. According to the “Plan on Promoting the Pilot Use of Agricultural Waste Resource Utilization” (Nongjifa  No. 90), it is estimated that the country produces 3.8 billion tons of livestock and poultry manure and nearly 900 million tons of straw each year. Agricultural wastes such as livestock and poultry manure, straw, tail vegetables, mushroom residue, rice husk, etc. are rich in organic matter and nutrients. The organic fertilizer made after composting and fermentation can improve soil fertility and provide required nutrients for crop production. Increase production, farmers’ income, and agricultural efficiency have made important contributions.
my country’s organic fertilizer industry started late, the standardization is not high, there are small mess and adulteration behaviors, the antibiotic residues in the animal manure of organic fertilizer raw materials exceed the standard, and the crops Pesticide residues in waste and heavy metals exceeding the standards affect the quality and safety of organic fertilizers, and severely restrict the development of the industry. The Agricultural Product Quality and Safety Risk Assessment Laboratory (Nanjing) of the Ministry of Agriculture and Rural Affairs relies on the National Agricultural Product Quality and Safety Risk Assessment Project to carry out environmental quality and agricultural product quality and safety risk assessment work around the risk factors in organic fertilizers. Through on-site investigation and sampling verification of commercially available organic fertilizer products, we strive to find out the hazards and quality status of the products, and propose targeted control measures.
1. Project implementation overview
According to the list of major animal husbandry counties in my country, demonstration counties for replacing chemical fertilizers with organic fertilizers, and the statistical data on the distribution of organic fertilizer companies in China in 2017, select Hebei, Jiangsu, Zhejiang, 9 provinces including Shandong, Henan, Hubei, Liaoning, Heilongjiang, Sichuan, etc., carried out organic fertilizer product quality and safety investigation, analysis and evaluation. Through on-site investigations in representative production companies and agricultural material shops, we can understand the source of raw materials, production technology, process control and sales of organic fertilizers. A sampling verification analysis of organic fertilizer products was carried out. Among them, 60 samples were collected on site and 34 samples were collected online, totaling 94 samples. The specific indicators include organic matter, total nutrients, heavy metals, antibiotics and pesticides.
2. Main problems found
At present, problems such as insufficient organic matter and total nutrients, residues of pesticides and veterinary drugs, and excessive heavy metals exist in organic fertilizer products to varying degrees.
(1) The labeling of product packaging is not standardized. The main manifestations are non-marking or irregular marking, confusion of naming, and exaggerated publicity. For example, mandatory standards are marked as recommended standards, organic fertilizer components are not marked on the label, named with functional fertilizers, Liuwei Dibao, etc., and fertilizers are exaggerated. Rooting, disease resistance and other effects.
(2) Adding external organic matter and chemical fertilizers in violation of regulations. Use rice husk, tail vegetables, pomace, mushroom residue and other materials to produce organic fertilizer, or use adulterated organic fertilizer such as coal residue, mushroom residue or bottom mud. Due to insufficient organic matter or nutrient content, foreign substances are added in the production process, so that The technical indicators of the product meet the standard requirements.
(3) Insufficient organic matter and nutrient content. Analysis and verification results found that the organic content of 20 samples was lower than the standard content, accounting for 21.3%of the total number of samples; the organic content of 20 samples was lower than the product packaging label, accounting for 21.3%of the number of samples; the total nutrient content of 29 samples The content is lower than the standard requirement, accounting for 30.9%of the total sample number; the nutrient content of 21 samples is lower than the product packaging label, accounting for 22.3%of the sample number.
(4) The content of heavy metals exceeds the standard. Analysis and verification results found that the heavy metal concentrations of 10 samples exceeded the standard limit, accounting for 11.7%of the total number of samples. Among them, the lead over-standard rate was the highest, accounting for 5.3%, and the maximum detection value was 2511.9 mg/kg, followed by cadmium 3.2%, arsenic 3.2%, and chromium 2.1%. The maximum detection values were 11.4, 19.9 and 250.0 mg/kg, respectively. kg.
(5) Residues of veterinary drugs. Residues of veterinary drug antibiotics are mainly quinolone and tetracycline antibiotics. Ten antibiotic residues were detected in 38 samples (five types of tetracyclines, sulfonamides, quinolones, macrolides and amido alcohols), the positive rate of samples was 40.4%, and the detection concentration was 5.0-480.7 μg/kg, the residual concentrations of quinolones in 5 samples and tetracycline antibiotics in 1 sample exceeded 100 μg/kg; the residual concentrations of quinolones in 6 samples and tetracycline antibiotics in 4 samples exceeded 50 μg/kg. The detection rates of the five types of antibiotics were macrolides 18.1%, tetracyclines 13.8%, quinolones 12.8%, sulfonamides 6.4%, and amide alcohols 1.1%. The concentrations were 7.1-8.9, 8.5-137.9, and 11.5- 480.7, 5.0-11.1 and 44.5 μg/kg. Antibiotic residues are mainly quinolones and tetracyclines, and the maximum detectable concentration is 480.7 μg/kg danofloxacin, 118.5 μg/kg ciprofloxacin, 137.9 μg/kg oxytetracycline, and 121.4 μg chlortetracycline /kg.
(6) Pesticide residues. The pesticide residues were mainly cyromazine, and fipronil and its metabolites were not detected. 18 pesticide residues were detected in 48 samples, the positive rate of the samples was 51.1%, and the detection concentration was 2.2-828.8 μg/kg. Among them, the residual concentration of cyromazine exceeded 100 μg/kg in 4 samples; The residual concentration of tebuconazole in cyromazine and one sample exceeded 50 μg/kg, and no residual fipronil and its metabolites were detected. The detection rate of cyromazine and tebuconazole for pesticide residues was higher, the detection rate of cyromazine was 28.7%, the maximum detection concentration was 828.8 μg/kg, the detection rate of tebuconazole was 5.3%, and the maximum detection concentration was 86.7 μg/kg.
3. Analysis of the causes of organic fertilizer problems
(1) Reasons for adding external organic matter and chemical fertilizers in organic fertilizer production. First, the organic matter and nutrient content of some raw materials is low, and the production of organic fertilizer does not meet the standard requirements. Second, companies are pursuing profit adulteration of organic fertilizer. When organic fertilizer manufacturers use adulterated organic fertilizers such as coal slag, mushroom residue or bottom mud, they often add chemical fertilizers to increase the total nutrient content to meet the standard requirements to make profits. Third, the existing organic matter and nutrient content determination method standards cannot accurately distinguish externally added substances. Some illegal production companies use loopholes to dope with foreign materials.
(2) Reasons for excessive heavy metals. Heavy metals such as mercury, arsenic, cadmium, chromium, and lead are mostly caused by environmental contamination or input pollution. In this assessment, the maximum residual concentration of lead in organic fertilizer produced from soybean plant materials is 2511.9 mg/kg, and the maximum residual concentration of chromium in organic fertilizer from chicken manure materials is 250.0 mg/kg, which exceeds the standard by several to several tens of times. . The accumulation of heavy metals in the soil will affect the quality and safety of agricultural products.
(3) Reasons for antibiotic residues. The use of antibacterial agents in the process of livestock and poultry breeding is the main cause of antibiotic residues in animal-derived organic fertilizers. At present, my country’s livestock and poultry farming is dominated by small and medium-sized scales. The broad-spectrum antibacterial drugs used in the livestock and poultry farming process include tetracyclines (tetracycline, oxytetracycline, chlortetracycline, doxycycline) and quinolones (enrofloxacin). , Ciprofloxacin, danfloxacin), macrolides (tilmicosin, tylosin), sulfonamides (sulfamethoxazole, sulfamethazine, sulfamethoxine) and fluoro Benicol can be excreted in feces and urine in the form of parent drug. Farming companies have high risks and low profits. They have insufficient investment in high-priced biogas fermentation equipment with potential safety hazards. At the same time, under the pressure of environmental protection, composting treatment that takes up a large space and produces odors to the surrounding environment is not adopted by most farms. At present, small and medium-scale farms have simple manure treatment facilities, and the pursuit of short time and fast turnover in manure treatment results in the ineffective degradation of residual antibiotics, leading to the risk of antibacterial drug residues in organic fertilizers. In particular, tetracyclines and quinolones are commonly used antibacterial drugs in aquaculture. They are used in large amounts, have low body utilization, and have a long degradation cycle. At present, they have become the main residual risk drugs in organic fertilizer products using animal manure as raw materials.
(4) Reasons for pesticide residues. Based on various research and literature data, the analysis of the sources of pesticide residues in organic fertilizers may have two aspects:one is the use of pesticides in the breeding process. In order to control lepidopteran flying insects or parasites, farms often add insecticides to inputs such as feed or spray insecticides in feces storage places, such as the cyromazine premix (also Cyromazine), which is to control the reproduction of fly larvae in animal stables through mixed feeding. The second is the use of pesticides during planting. In the process of planting, pesticides sprayed to prevent and control plant diseases and insect pests cause residues in plant stalks. For example, tebuconazole is mainly used for the prevention and control of germs such as grains, oils, vegetables, and fruits, and plant wastes of tebuconazole are used as raw materials for making organic fertilizer. , Easy to cause the risk of pesticide residues.
4. Main recommended measures
(1) Strengthen the regulation of organic fertilizer production and supervision. Increase the supervision and inspection of organic fertilizer production and operation enterprises, standardize the management of materials for the production of organic fertilizer, and strengthen the purchase of raw materials and the inspection of the ledger. Strictly manage organic fertilizer packaging and labeling, correctly use standards, packaging labels and raw material labeling, severely crack down on false propaganda, counterfeit and shoddy, hidden additions and illegal production, and reduce irregular labeling and product quality and safety risks.
(2) Speed up the formulation and revision of standards for pesticide and veterinary drug residues in organic fertilizers. The lack of standards for the identification of adulteration of organic matter and total nutrients in organic fertilizers cannot meet the needs of organic fertilizer product supervision. Regarding the risk factors of agricultural and veterinary drugs in organic fertilizers, there are currently published”High Performance Liquid Chromatography Method for Determination of Oxytetracycline, Tetracycline, Chlortetracycline and Doxycycline in Organic Fertilizers” (GB/T 32951-2016),”Organic Fertilizers” Determination of the content of sulfonamides in liquid chromatography-tandem mass spectrometry (NY/T 3167-2017), compared with the types of agricultural and veterinary drugs used in production, the standards are insufficient. It is necessary to speed up the research and formulation of organic fertilizer quality and safety related methods and standards as well as full-process control technical specifications, promote industrial upgrading from technical regulations and standards, and provide technical support for scientific production and green development.
(3) Strengthen the scientific assessment of risk factors in organic fertilizers, and reduce the risk of heavy metals, pesticides and veterinary drugs. On the basis of the preliminary investigation, we focused on the hidden dangers of the problem, and further carried out risk assessment work for the discovered risk factors with large usage, wide application, long degradation cycle, and high degree of harm, such as heavy metals and pesticide residues. Metabolic pathways, elimination rules, etc., and then proposed targeted prevention and control measures.
(4) Strengthen the publicity and technical guidance of the scientific production and use of organic fertilizer. Combining the actual production of organic fertilizers, organize the formulation of technical regulations for the prevention and control of risk factors in organic fertilizers, and demonstrate and promote comprehensive prevention and control technologies. Strengthen the scientific publicity and training of organic fertilizer production, strengthen the publicity and implementation of organic fertilizer related standards, print a batch of easy-to-understand scientific application guides for organic fertilizer, guide large growers to choose correctly, expand the popularity of organic fertilizer application, and improve scientific production And the level of awareness and use.
Source:Agricultural Product Quality and Safety Risk Assessment Laboratory of the Ministry of Agriculture and Rural Affairs (Nanjing)