Xinhua News Agency, Urumqi, December 21 (Reporter Guan Qiaoqiao) On December 21, the Economic Reference News published a report titled "New ideas for industry insiders in the control of "white pollution"". The article said that since the late 1970s, my country has introduced the plastic film covering cultivation technology and has gradually promoted and applied it in crops such as corn and cotton. This technology has greatly increased the yield of crops in my country and achieved significant economic benefits. It is hailed as the "white revolution" in agriculture.
In recent years, due to the obvious effect of increasing production, mulch covering technology has been rapidly popularized in China's agricultural production. However, some agricultural ecological experts pointed out that the residual film " white pollution " has exceeded the upper limit that the local farmland ecological environment can bear. If governance and prevention are not accelerated, the farmland ecology will further deteriorate. Some industry insiders have high hopes for full biodegradable agricultural mulch, saying that accelerating the national promotion of full biodegradable agricultural mulch will help solve the problem of "white pollution".
↑ Zhao Naiyu Painted
From "white revolution" to "white pollution" Residual film control is imminent
In my country, mulch film has become one of the important material materials for agricultural production, and the types of cover crops have also expanded from cash crops to field crops such as cotton, corn, and wheat. This "white revolution" has made significant contributions to ensuring my country's agricultural product supply and food security.
After the 1980s, Xinjiang began to promote the use of plastic film covering technology on cotton planting. From the Altay grassland in the northernmost part of Xinjiang to the Pamir Plateau with icebergs, the film seeding technology is quickly mastered by most local farmers. By the end of 2015, the mulch covering area in Xinjiang had reached 57.35 million mu, with an annual usage of 280,000 tons, making it the area with the largest mulch covering planting area, the most mulch consumption and the highest popularity rate in China.
The huge role played by mulch covering cultivation technology in agricultural production is obvious to all. my country's mulch covers an area of about 300 million mu, with an annual usage of more than 1.2 million tons, ranking first in the world. However, the widespread use of mulch film also brings new problems. At present, traditional agricultural plastic plastic film materials are mainly polyethylene (PE), which are difficult to degrade under natural environmental conditions. In addition, there is a lack of effective governance measures, waste plastic films have increased year by year in farmland soil, and pollution continues to intensify. According to statistics, my country's farmland will add 200,000 to 300,000 tons of undegradable residual soil film every year, causing the land to solidify, reduce crop yields, and destroy the ecological environment.
In , Shihezi City, one of the main cotton production areas in Xinjiang, the Cotton Governor King Gaoyin began to turn the floor and wrap the film for the first time after finishing the annual cotton picking. In the past five years, cotton farmers have become increasingly aware of the importance of recycling residual films. "At least twice a year after the cotton is harvested and before sowing in spring, otherwise it will be difficult for crops to survive on the mulch." Wang Gaoyin had just harvested 150 acres of cotton and was preparing to plow the ground before winter to recycle large pieces of residual film. This work needs to be repeated before sowing in the spring to recycle the small pieces of residual film, which costs at least 13 yuan per mu more than before.
"Although I hug it once in winter, at least one urea bag of residual film can be recycled before spring every year. There is no yield without the use of the plastic film, but it is very polluted after use." Wang Gaoyin also lost the residual film. He told reporters that he didn't know that the residual film needed to be recycled before. "In those two years, cotton died in large patches. At first, I thought the cotton field was infected, but later I dug up the rhizome and found that the seeds were sown on the residual film." Wang Gaoyin said that it was not until the last five years that cotton farmers began to recycle residual films and consciously recover the residual films. But even so, due to the uneven quality of agricultural mulch, the recycling rate of some defective mulch is less than 50%.
Because traditional PE plastic film is difficult to completely recycle after being discarded and difficult to degrade in the natural environment, the reuse over the past 30 years has accumulated a large amount of residual film in the farmland in Xinjiang. The residual film pollution hinders the penetration of soil capillary water and natural water, reduces soil permeability, destroys the soil structure, endangers the rural ecological environment, and affects the sustainable development of agriculture. At the end of 2015, the residual film retained per mu of farmland in Xinjiang was still 12.4 kg, far higher than the national average.It is determined that the seeds sown on the residual film can rot the seed rate of 6.92%, the bud rate can reach 5.17%, and the yield reduction is about 12%. In addition, residual film fragments may be mixed with crop straw and feed, and cattle, sheep and other livestock accidentally eat it, causing gastrointestinal dysfunction or even death; the residual film flying all over the sky affects the environmental landscape, causing "visual pollution", etc. In short, the residue of mulch has had serious adverse effects on agricultural production and the environment.
However, with the continued promotion and popularization of high-tech water-saving technology in Xinjiang and the interests of increasing production and income, farmland using plastic film is still increasing year by year, and it is becoming increasingly urgent to control "white pollution". It is against this background that Xinjiang, the largest cotton-producing area in China, decided to declare war on "white pollution" and introduced a series of residual film recycling policies, achieving positive results. However, for the sake of reducing costs, a large number of ultra-thin films are still used in agricultural production. The current situation of the incomplete recycling of residual films and its non-degradable properties restrict the further cure of "white pollution" in agriculture.
Biodegradable mulching film is costly and difficult to promote.
Polyester material made of polymerized dibasic acid and diol. The biodegradable mulching film produced by blow molding can be completely biodegradable by microorganisms in the soil after being discarded. The degradation principle is that the surface is adhered to by microorganisms. The microorganism uses the organic carbon in the polyester as the source of nutrient carbon. Under the action of enzymes, the polymer is decomposed into fragmented segments with lower molecular weight. The fragmented segments are absorbed or consumed by microorganisms. After metabolism, carbon dioxide, water, mineral salts and new biomass are finally formed, which are completely absorbed by nature.
"my country has made breakthrough progress in the research and development of fully biodegradable agricultural mulching films with independent intellectual property rights, becoming one of the countries with leading R&D levels." Weng Yunxuan, Secretary-General of the Plastics Degradation Professional Committee of the China Plastic Processing Industry Association, introduced that according to the results of the controlled tests of multiple crops in Xinjiang, Yunnan, Inner Mongolia, Shaanxi, Shanghai, Jiangsu, Zhejiang and Shandong, compared with traditional polyolefin mulching films, with agronomic measures, not only can they also have the effect of insulation, moisture conservation and yield increase, but they can also design and control the degradation speed according to the growth needs of specific crops in specific regions and specific climatic conditions, so that the increasingly serious "white pollution" can be effectively curbed and agricultural sustainable development.
"Traditional PE film will not degrade for decades or even hundreds of years. It is the root cause of the 'white pollution' of agricultural land and is visible pollution; the additive partial degradation of mulch film is incompletely degraded, and it disintegrates into film fragments that cannot be picked up. It is invisible pollution." Ding Jianping, general manager of the R&D Center of Xinjiang Lanshan Tunhe Chemical Co., Ltd., introduced that in 2012, Lanshan Tunhe Company cooperated with Tsinghua University to develop biodegradable membrane resins, carried out research on blended blown film technology, and has successively tested in 14 provinces and cities across the country, with good results.
After four years of field test, according to the monitoring data of Xinjiang Lanshan Tunhe Chemical Co., Ltd. at each planting point, after the crop growth cycle ends, biodegradable plastic film degrades more than 80%, and has little impact on the agronomic and growth of the crops. Processed tomatoes, potatoes and beets can increase yields by 5% to 20%. After biodegradable plastic film is used to plant, the number of soil microorganisms does not change significantly.
Weng Yunxuan believes that taking biodegradable plastic films nationwide as a breakthrough point can promote the widespread application of biodegradable plastics in other fields, thereby promoting the overall rise of the industry, and making the results of "plastic restriction" and "plastic ban" faster and more significant.
However, due to the lack of clear and specific and highly operable restrictions or prohibitions, the promotion and application of full biodegradable agricultural mulch is difficult, and the market is slow to develop and the prospects are not optimistic due to high production and use costs.
"Because the price of biodegradable membrane is too expensive, under the current economic conditions, farmers' environmental awareness is still in its infancy. If government subsidies and policy support are lacking, farmers are not able to buy it at all." Weng Yunxuan said that it is difficult to replace conventional general membranes and become the mainstream of plastic membranes. The comprehensive popularization and application of agricultural production still faces many constraints.
reporters found that at present, the promotion and application of biodegradable plastic film is still in the small-scale pilot stage, and no scale effect has been formed. Raw material companies have invested heavily in research and development and promotion, making the production cost of biodegradable plastic film higher than that of traditional PE films.
is located in a tomato field in Manas County, Xinjiang. Residual films of traditional mulch film can be seen everywhere in the soil. "From the price of biodegradable plastic film of 26 yuan per kilogram, the cost of a mu of land ranges from 120 to 180 yuan, which is 2.5 times that of PE film, and it is difficult to be accepted by farmers. In addition, farmers do not care about recycling and residues." Zhao Ruiming, director of the Comprehensive Office of COFCO Tunhe, introduced that this land was transferred from farmers, and there were many residual films in the ground before. However, after using biodegradable plastic film for experiments, the reporter opened the soil and saw that the biodegradable residual film had gradually been "encroached" by microorganisms.
Nowadays, in cotton planting areas where mulch is widely used, most farmers are only in the "heard-of-telling" stage for . In Shihezi City, where the cotton farmer Wang Gaoyin is located, Wang Gaoyin also heard that the local area tested the degradable plastic film in 2016, but believed that the cost was high and the degradation time was not ideal.
Weng Yunxuan and other industry insiders believe that although biodegradable materials are costly, they have many advantages that are difficult to replace. The United States, Europe, Japan and other countries have introduced a series of policies to support the research, development, production, and promotion of such new materials.
Weng Yunxuan introduced that the environmental projects jointly promoted by Germany and Italy have proved through ten years of experiments that as long as the plastic film that meets the EU biodegradation standards can solve the pollution problem of traditional plastic films; Japan established the Japan Biodegradable Agricultural Materials Association in 2009 to specifically study and promote the use of biodegradable plastic films. Currently, biodegradable plastic film accounts for more than 5% of the total amount of Japanese plastic films. It is precisely because of the introduction of these policies and measures that biodegradable materials and agricultural mulch have been rapidly developed and promoted in Europe, the United States, Japan and other countries and regions, thus rapidly improving and effectively protecting the ecological environment.
Accelerate the improvement of the incentive mechanism for promotion and application
Some industry insiders believe that with the continuous optimization of production processes, my country can currently fully meet large-scale and mechanized production operations, and basically form a relatively complete biodegradable plastic film industry chain. In this regard, industry insiders recommend accelerating the improvement of incentive mechanisms for promotion and application, curbing the increasingly serious "white pollution", and achieving sustainable agricultural development.
——The country should issue corresponding policies and regulations as soon as possible, take practical measures, carry out publicity and guidance, strengthen market supervision, and improve the incentive mechanism for promoting and applying biodegradable plastic films. Production and use are completely prohibited for products that seriously pollute the environment; tax rates are increased for old products that can be replaced by fully degraded materials, or environmental resource fees are levied to support the research, development and production of environmentally friendly new products and promote industrial upgrading.
- Establish a group of enterprises with independent intellectual property rights, master core technologies, and can drive the healthy and rapid development of the entire industry, further carry out the research and development of new technologies and new processes, and strive to reduce product costs, narrow the price difference with traditional plastic film, and improve the performance of use. At present, it is still necessary to implement special fund subsidies for the production and sales of key enterprises through special industrialization funds to solve the problem of high early R&D production costs.
Because the price of biodegradable plastic film is too expensive, under the current economic conditions, farmers' environmental awareness is still in its infancy. If government subsidies and policy support are lacking, farmers are unable to purchase it at all. It is difficult to achieve the mainstream of biodegradable plastic film by replacing conventional general films. The comprehensive popularization and application of agricultural production will face many constraints. Therefore, it is recommended that manufacturers strengthen the research and development of synthetic technology, improve production technology, expand the scale, and increase farmers' enthusiasm for applying biodegradable plastic film. Plain film processing enterprises strengthen processing technology research and development, and further reduce costs and improve the physical properties of biodegradable plastic film by improving blending and modification. Study the feasibility of establishing factories in centralized use of mulch.
- Establish special funds for demonstration and promotion, increase promotion and application efforts, select different regions, and expand experimental projects and scope for different crops. Like promoting electric vehicles and agricultural machinery, fiscal subsidy policies are adopted to provide price subsidies for the purchase and use of degraded mulch, and improve farmers' enthusiasm and awareness of using biodegraded mulch.
Weng Yunxuan and other experts suggest that based on prominent key areas and key crops, and based on comprehensive factors such as mulch usage and convenient transportation, we should make reasonable plans, and select provinces and cities with widespread mulch usage for experiments and demonstrations, and gradually expand promotion on the basis of demonstration applications to achieve sustainable agricultural development.
"From the current usage of mulch in my country, Shandong, Xinjiang, Hebei, Sichuan, Yunnan, Gansu, Henan, Hunan, Heilongjiang and other provinces and cities consume a large amount. Therefore, some provinces and cities with large dosages and representative climates can be selected from the above provinces and cities for pilot application of biodegradable mulch." Weng Yunxuan suggested that several relatively typical crops such as corn, cotton, potato, tobacco, watermelon, etc. should be selected as research objects.
- Use low tax rates for the import of raw materials related to completely biodegradable materials, formulate a more reasonable export tax rebate rate, and exempt income tax for enterprises related to biodegradable raw materials, processing, products and equipment, and the value-added tax will be collected first and then rebate; encourage and support the development of high-quality enterprises related to biodegradable, and implement preferential policies for reduction and exemption in accordance with the provisions of the new corporate income tax regulations; provide price subsidies or tax exemptions to production units, and provide appropriate subsidies to farmers in use; establish special funds, conduct technical training, project demonstration and promotion and application research.
- It is recommended that all parties concerned form alliance operation mode in the demonstration stage, form alliances between raw material enterprises, between raw material enterprises and processing enterprises, between processing enterprises and farmers, farmers and recycling units, as well as enterprises, farmers, associations and scientific research units, so that from production to application, from application to processing and evaluation, a network of operation can be formed, thus forming a multi-party linkage pattern, such as production, application, recycling, degradation, etc. (End)
