Rice planting method for reducing soil microplastic pollution

Abstract

The invention belongs to the technical field of rice planting, and particularly relates to a rice planting method for reducing soil microplastic pollution. By applying the soil conditioner, the pea crop rotation, the compost treatment and the specific irrigation strategy, the soil micro-plastic pollution can be effectively reduced; the pea plants can enrich micro-plastic particles in the soil through root exudates and self metabolic activities to a certain extent, and the pea plants are subsequently composted, so that the micro-plastic particles enriched in the pea plants can be further degraded; biochar in the soil conditioner can adsorb micro-plastic particles, the free state of the micro-plastic particles in soil is reduced, and the phanerochaete chrysosporium, the rhodococcus fence celebrating and the trichoderma harzianum can synergistically degrade the micro-plastic particles; the dry-wet alternate cycle treatment can further reduce the absorption of the rice plants to the micro-plastics, can promote the development of rice roots and the absorption of nutrients, and improves the stress resistance of the rice.

Description

Technical Field

[0001] The present invention belongs to the technical field of rice cultivation, and particularly relates to a rice cultivation method for reducing soil microplastic pollution. Background Art

[0002] With the extensive use and improper disposal of plastic products, microplastic pollution has become a global environmental problem. As one of the important destinations of microplastics, the pollution status of soil has a profound impact on the agricultural ecosystem, especially rice cultivation. Microplastics can block the micropores of rice seeds, significantly reducing the germination rate of seeds and the growth rate of seedlings. In addition, they can enter rice plants through root absorption and leaf stomatal absorption, block the channels for roots to transport water and nutrients, inhibit root development, and thus reduce the biomass and yield of plants. After entering rice plants, microplastics can induce oxidative stress responses in cells, damage the integrity of cell membranes, reduce the antioxidant capacity of cells, interfere with photosynthesis and chlorophyll synthesis in rice, and further affect the growth and development of plants. Moreover, microplastics are absorbed by rice roots and accumulate in plants, and may ultimately enter the food chain, posing a potential threat to human health. At the same time, harmful chemical substances such as plasticizers and monomers are released during the degradation of microplastics, further polluting the soil and water bodies.

[0003] Therefore, how to reduce soil microplastic pollution and its adverse effects on rice cultivation is an urgent problem to be solved. Summary of the Invention

[0004] The purpose of the present invention is to provide a rice cultivation method for reducing soil microplastic pollution, reduce the adverse effects of soil microplastic pollution on rice, and reduce the absorption of microplastics by rice.

[0005] The present invention provides a rice cultivation method for reducing soil microplastic pollution, comprising the following steps: After the previous rice harvest, a soil conditioner is applied to the paddy field soil, and then peas are sown; after the peas are mature, all the pea plants are collected, crushed and composted to obtain the degraded fertilizer; after collecting the pea plants, rice is planted, and from the tillering stage of rice to the end of the jointing stage, periodic irrigation is carried out, and the paddy field is kept in a wet-dry alternating cycle treatment during the periodic irrigation stage; the periodic irrigation stops at the booting stage of rice, and constant humidity irrigation is carried out. During the constant humidity irrigation stage, the soil water potential of the paddy field is maintained between -5 kPa and -10 kPa; irrigation is stopped 7 to 14 days before harvest, and the paddy field is drained and then the rice can be harvested. After the rice is harvested, the degraded fertilizer is applied to the paddy field; the wet-dry alternating cycle treatment includes a cycle of the first stage - the second stage - the third stage; in the first stage, the water potential of the paddy field is controlled between 0 kPa and -5 kPa and maintained for 3 to 5 days; in the second stage, the water potential of the paddy field is controlled between -5 kPa and -20 kPa and maintained for 2 to 3 days; in the third stage, the water potential of the paddy field is controlled between -20 kPa and -40 kPa and maintained for 1 to 2 days.

[0006] Preferably, in parts by mass, the soil conditioner includes: 100 - 200 parts of biochar, 1 - 2 parts of Phanerochaete chrysosporium bacterium agent, 2 - 3 parts of Rhodococcus qingshengii bacterium agent, and 2 - 3 parts of Trichoderma harzianum bacterium agent.

[0007] Preferably, the viable count of the Phanerochaete chrysosporium bacterium agent ≥ 10×10 10 cfu / mL; the viable count of the Rhodococcus qingshengii bacterium agent ≥ 10×10 8 cfu / mL; the viable count of the Trichoderma harzianum bacterium agent ≥ 10×10 8 cfu / mL.

[0008] Preferably, the sowing density of the peas is 12 - 15 kg of seeds per mu.

[0009] Preferably, the particle size of the crushing is 1 - 3 cm.

[0010] Preferably, the composting includes: all the pea plants are collected, crushed to obtain plant materials, then a compound bacterium agent is added for composting. When the composting temperature reaches 50°C - 60°C, turning is carried out, and then turning is carried out every 5 - 7 days. When the composting temperature is close to the ambient temperature and no longer rises, the composting ends to obtain the degraded fertilizer; the compound bacterium agent includes Phanerochaete chrysosporium, Rhodococcus qingshengii, and Trichoderma harzianum, and the ratio of the viable counts of Phanerochaete chrysosporium, Rhodococcus qingshengii, and Trichoderma harzianum is 1 - 10:1 - 5:1 - 5.

[0011] Preferably, the dosage of the compound bacterium agent is 0.5 wt% - 1 wt% of the mass of the plant materials Preferably, the height of the compost is 1 - 1.5 m and the humidity is 50% - 60%.

[0012] Advantages of the present invention: By applying soil conditioner, pea rotation, compost treatment and specific irrigation strategies, the present invention can effectively reduce soil microplastic pollution; to a certain extent, pea plants can enrich microplastic particles in the soil through root exudates and their own metabolic activities, and subsequent composting of pea plants can further degrade the microplastics enriched in pea plants; biochar in the soil conditioner can adsorb microplastic particles, reducing their free state in the soil, and Phanerochaete chrysosporium, Rhodococcus fangshengii and Trichoderma harzianum agents can synergistically degrade microplastic particles; the wet-dry alternating cycle treatment can further reduce the absorption of microplastics by rice plants, promote the development of rice roots and nutrient absorption, and improve the stress resistance of rice. Specific embodiments

[0013] To further illustrate the present invention, the following describes in detail a rice planting method for reducing soil microplastic pollution provided by the present invention in combination with embodiments, but they cannot be understood as limiting the protection scope of the present invention.

[0014] In the embodiments of the present invention, Phanerochaete chrysosporium ( Phanerochaete chrysosporium ) was purchased from Wuhan Warner Biotechnology Co., Ltd., with the product number WN-BZ37416; Rhodococcus fangshengii ( Rhodococcus qingshengii ) was purchased from Ningbo Mingzhou Biotechnology Co., Ltd., with the strain number KCTC 19205; Trichoderma harzianum ( Trichoderma harzianum ) was purchased from Ningbo Mingzhou Biotechnology Co., Ltd., with the product number BMZ073660.

[0015] Unless otherwise specified, the substances used in the embodiments of the present invention are all obtained by conventional purchase.

[0016] Example 1 Prepare the soil conditioner: Take 180 parts of biochar, 1 part of Phanerochaete chrysosporium agent (viable count 10×10 10 cfu / mL), 2 parts of Rhodococcus fangshengii agent (viable count 10×10 8 cfu / mL) and 2 parts of Trichoderma harzianum agent (viable count 10×10 8 cfu / mL) and mix them evenly.

[0017] After the previous crop of rice is harvested, put the soil conditioner into the paddy field soil, and then sow peas at a seeding rate of 12 kg per mu; after the peas are mature, collect all the pea plants, crush them to a particle size of 1 - 3 cm to obtain plant materials, and add a compound bacterium agent (viable count 10×108 cfu / mL, with the viable cell count ratio of Phanerochaete chrysosporium, Rhodococcus fanjingshengii, and Trichoderma harzianum being 2:3:3), and composting was carried out with a composting height of 1.2 m and a humidity of 60%. Turning of the compost was carried out when the composting temperature reached 55 °C, and then turning was carried out every 7 days. When the composting temperature was close to the ambient temperature and no longer increased, the composting ended, and the degraded fertilizer was obtained.

[0018] Then rice was planted, and irrigation started from the tillering stage of rice. The day of irrigation was recorded as the 1st day. The soil water potential on the 1st day was 0 kPa, and on the 2nd day, the soil water potential dropped to -5 kPa. The water volume in the paddy field was controlled so that the soil water potential remained at -5 kPa for another 2 days (maintained until the 4th day). Starting from the 5th day, the paddy field was allowed to dry out again. By the 7th day, the soil water potential dropped to -20 kPa. The water volume in the paddy field was controlled so that the soil water potential remained at -20 kPa for 1 day (maintained until the 8th day). On the 9th day, the paddy field was allowed to dry out again. By the 10th day, the soil water potential dropped to -40 kPa; on the 11th day, irrigation started again to make the soil water potential reach 0 kPa, and the above cycle was maintained until the end of the jointing stage of rice.

[0019] When the booting stage of rice began, the above cycle was no longer maintained. The water volume in the paddy field was always controlled so that the soil water potential of the paddy field soil remained between -5 kPa and -10 kPa until irrigation was stopped 7 days before harvest. After the paddy field dried out, the rice was harvested.

[0020] After the rice was harvested, the degraded fertilizer was applied to the paddy field.

[0021] Example 2 Prepare a soil conditioner: Take 100 parts of biochar, 1 part of Phanerochaete chrysosporium inoculant (viable cell count 10×10 10 cfu / mL), 2 parts of Rhodococcus fanjingshengii inoculant (viable cell count 10×10 8 cfu / mL), and 3 parts of Trichoderma harzianum inoculant (viable cell count 10×10 8 cfu / mL) and mix them evenly.

[0022] After the previous rice crop was harvested, the soil conditioner was put into the paddy field soil, and then peas were sown at a seeding rate of 12 kg per mu; after the peas matured, all the pea plants were collected and crushed to a particle size of 1 - 3 cm to obtain plant materials. A composite inoculant (viable cell count 10×10 8 cfu / mL, with the viable cell count ratio of Phanerochaete chrysosporium, Rhodococcus fanjingshengii, and Trichoderma harzianum being 1:5:5) was added at 0.5 wt% of the mass of the plant materials, and composting was carried out with a composting height of 1.2 m and a humidity of 60%. Turning of the compost was carried out when the composting temperature reached 55 °C, and then turning was carried out every 7 days. When the composting temperature was close to the ambient temperature and no longer increased, the composting ended, and the degraded fertilizer was obtained.

[0023] Then plant rice. Start irrigation from the tillering stage of rice. The day of irrigation is recorded as the 1st day. The soil water potential on the 1st day is 0 kPa. On the 2nd day, the soil water potential drops to -5 kPa. Control the water volume in the paddy field to keep the soil water potential at -5 kPa for another 1 day (maintaining until the 3rd day). On the 4th day, continue to drain the paddy field. By the 6th day, the soil water potential drops to -20 kPa. Control the water volume in the paddy field to keep the soil water potential at -20 kPa for another 1 day (maintaining until the 7th day). On the 9th day, continue to drain the paddy field. By the 10th day, the soil water potential drops to -40 kPa. On the 11th day, start irrigation again to make the soil water potential reach 0 kPa. Maintain the above cycle until the end of the jointing stage of rice.

[0024] At the beginning of the booting stage of rice, no longer maintain the above cycle. Always control the water volume in the paddy field to keep the soil water potential of the paddy field between -5 kPa and -10 kPa until 7 days before harvest. Stop irrigation. After the paddy field dries out, harvest the rice.

[0025] After harvesting the rice, apply the degraded fertilizer to the paddy field.

[0026] Example 3 Prepare the soil conditioner: Take 200 parts of biochar, 2 parts of Phanerochaete chrysosporium bacterium agent (viable count 10×10 10 cfu / mL), 3 parts of Rhodococcus qingshengii bacterium agent (viable count 10×10 8 cfu / mL) and 3 parts of Trichoderma harzianum bacterium agent (viable count 10×10 8 cfu / mL), and mix them evenly.

[0027] After harvesting the previous crop of rice, put the soil conditioner into the paddy field soil, and then sow peas at a seeding rate of 12 kg per mu. After the peas are mature, collect all the pea plants and crush them to a particle size of 1 - 3 cm to obtain plant materials. Add a composite bacterium agent (viable count 10×10 8 cfu / mL, and the viable count ratio of Phanerochaete chrysosporium, Rhodococcus qingshengii and Trichoderma harzianum is 10:1:1) accounting for 1 wt% of the mass of the plant materials, and carry out composting. The height of the compost is 1.5 m, and the humidity is 60%. When the composting temperature reaches 55°C, turn the pile, and then turn the pile every 7 days. When the composting temperature is close to the ambient temperature and no longer rises, the composting ends to obtain the degraded fertilizer.

[0028] Then plant rice and start irrigation from the tillering stage of rice. The day of irrigation is recorded as the first day. The soil water potential on the first day is 0 kPa. On the second day, the soil water potential drops to -5 kPa. Control the water volume in the paddy field to keep the soil water potential at -5 kPa for another 3 days (maintaining until the fifth day). Starting from the sixth day, continue to drain the paddy field. By the seventh day, the soil water potential drops to -20 kPa. Control the water volume in the paddy field to keep the soil water potential at -20 kPa for 1 day (maintaining until the eighth day). On the ninth day, continue to drain the paddy field. By the eleventh day, the soil water potential drops to -40 kPa. On the eleventh day, start irrigation again to make the soil water potential reach 0 kPa, and maintain the above cycle until the end of the jointing stage of rice.

[0029] When the booting stage of rice begins, no longer maintain the above cycle. Always control the water volume in the paddy field to keep the soil water potential of the paddy field between -5 kPa and -10 kPa until 7 days before harvest, stop irrigation, and harvest the rice after the paddy field is drained.

[0030] After harvesting the rice, apply the degraded fertilizer to the paddy field.

[0031] Comparative Example 1 The difference from Example 1 is that no peas are intercropped, and only a soil conditioner is used, specifically as follows: Prepare the soil conditioner: Take 180 parts of biochar, 1 part of Phanerochaete chrysosporium bacterial agent (living bacteria count 10×10 10 cfu / mL), 2 parts of Rhodococcus qingshengii bacterial agent (living bacteria count 10×10 8 cfu / mL) and 2 parts of Trichoderma harzianum bacterial agent (living bacteria count 10×10 8 cfu / mL) and mix them evenly.

[0032] After harvesting the previous crop of rice, put the soil conditioner into the paddy field soil. Plant rice 2 months later. Start irrigation from the tillering stage of rice. The day of irrigation is recorded as the first day. The soil water potential on the first day is 0 kPa. On the second day, the soil water potential drops to -5 kPa. Control the water volume in the paddy field to keep the soil water potential at -5 kPa for 2 days (maintaining until the fourth day). Starting from the fifth day, continue to drain the paddy field. By the seventh day, the soil water potential drops to -20 kPa. Control the water volume in the paddy field to keep the soil water potential at -20 kPa for 1 day (maintaining until the eighth day). On the ninth day, continue to drain the paddy field. By the tenth day, the soil water potential drops to -40 kPa. On the eleventh day, start irrigation again to make the soil water potential reach 0 kPa, and maintain the above cycle until the end of the jointing stage of rice.

[0033] When the booting stage of rice begins, no longer maintain the above cycle. Always control the water volume in the paddy field to keep the soil water potential of the paddy field between -5 kPa and -10 kPa until 7 days before harvest, stop irrigation, and harvest the rice after the paddy field is drained.

[0034] After harvesting the rice, the degraded fertilizer is applied to the paddy field.

[0035] Comparative Example 2 The difference from Example 1 is that no soil conditioner is used, and only peas are used, as follows: After harvesting the previous crop of rice, peas are sown in the paddy field at a seeding rate of 12 kg per mu; after the peas mature, all the pea plants are collected and crushed to a particle size of 1 - 3 cm to obtain plant materials. Then, a compound microbial agent (the viable count is 10×10 8 cfu / mL, and the ratio of the viable counts of Phanerochaete chrysosporium, Rhodococcus fangshengii, and Trichoderma harzianum is 2:3:3) is added at 0.5 wt% of the mass of the plant materials, and composting is carried out. The height of the compost pile is 1.2 m, the humidity is 60%, and when the composting temperature reaches 55°C, the pile is turned over, and then the pile is turned over every 7 days. When the composting temperature is close to the ambient temperature and no longer rises, the composting ends, and the degraded fertilizer is obtained.

[0036] Then, rice is planted, and irrigation starts from the tillering stage of the rice. The day of irrigation is recorded as the 1st day. The soil water potential on the 1st day is 0 kPa, and on the 2nd day, the soil water potential drops to -5 kPa. The water volume in the paddy field is controlled so that the soil water potential remains at -5 kPa for another 2 days (maintained until the 4th day). On the 5th day, the paddy field continues to dry out. By the 7th day, the soil water potential drops to -20 kPa. The water volume in the paddy field is controlled so that the soil water potential remains at -20 kPa for 1 day (maintained until the 8th day). On the 9th day, the paddy field continues to dry out. By the 10th day, the soil water potential drops to -40 kPa; on the 11th day, irrigation starts again to make the soil water potential reach 0 kPa, and the above cycle is maintained until the end of the jointing stage of the rice.

[0037] When the booting stage of the rice begins, the above cycle is no longer maintained, and the water volume in the paddy field is always controlled so that the soil water potential of the paddy field soil remains between -5 kPa and -10 kPa until 7 days before harvest, when irrigation stops. After the paddy field dries out, the rice is harvested.

[0038] After harvesting the rice, the degraded fertilizer is applied to the paddy field.

[0039] Comparative Example 3 The difference from Example 1 is that Trichoderma harzianum is not used in the bacteria in the soil conditioner, as follows: Prepare the soil conditioner: Take 180 parts of biochar, 1 part of Phanerochaete chrysosporium microbial agent (the viable count is 10×10 10 cfu / mL) and 2 parts of Rhodococcus fangshengii microbial agent (the viable count is 10×10 8 cfu / mL) and mix them evenly.

[0040] After the previous rice harvest, a soil conditioner is applied to the paddy field soil, and then peas are sown at a seeding rate of 12 kg per mu; after the peas mature, all the pea plants are collected and crushed to a particle size of 1 - 3 cm to obtain plant materials. A compound microbial agent (the viable count is 10×10 8 cfu / mL, and the ratio of the viable counts of Phanerochaete chrysosporium, Rhodococcus fanyangii, and Trichoderma harzianum is 2:3:3) is added, and composting is carried out. The height of the compost is 1.2 m, the humidity is 60%, and when the composting temperature reaches 55°C, turning is carried out, and then turning is carried out every 7 days. When the composting temperature is close to the ambient temperature and no longer rises, the composting ends, and the degraded fertilizer is obtained.

[0041] Then rice is planted, and irrigation starts from the tillering stage of rice. The day of irrigation is recorded as the 1st day. The soil water potential on the 1st day is 0 kPa. On the 2nd day, the soil water potential drops to -5 kPa. The water volume of the paddy field is controlled so that the soil water potential remains at -5 kPa for 2 days (maintained until the 4th day). On the 5th day, the paddy field starts to dry out again. By the 7th day, the soil water potential drops to -20 kPa. The water volume of the paddy field is controlled so that the soil water potential remains at -20 kPa for 1 day (maintained until the 8th day). On the 9th day, the paddy field continues to dry out. By the 10th day, the soil water potential drops to -40 kPa; on the 11th day, irrigation starts again to make the soil water potential reach 0 kPa, and the above cycle is maintained until the end of the jointing stage of rice.

[0042] When the booting stage of rice begins, the above cycle is no longer maintained, and the water volume of the paddy field is always controlled so that the soil water potential of the paddy field soil remains between -5 kPa and -10 kPa until 7 days before harvest, irrigation is stopped. After the paddy field dries out, the rice is harvested.

[0043] After the rice is harvested, the degraded fertilizer is applied to the paddy field.

[0044] Comparative Example 4 The difference from Example 1 is that the rice is not subjected to wet-dry cycling treatment, and the water potential during the growth period of rice is always maintained between -5 kPa and -10 kPa, specifically as follows: Prepare the soil conditioner: Take 180 parts of biochar, 1 part of Phanerochaete chrysosporium microbial agent (the viable count is 10×10 10 cfu / mL), 2 parts of Rhodococcus fanyangii microbial agent (the viable count is 10×10 8 cfu / mL), and 2 parts of Trichoderma harzianum microbial agent (the viable count is 10×10 8 cfu / mL) and mix them evenly.

[0045] After the previous rice harvest, a soil conditioner is applied to the paddy field soil, and then peas are sown at a seeding rate of 12 kg per mu; after the peas are mature, all the pea plants are collected and crushed to a particle size of 1 - 3 cm to obtain plant materials. A compound microbial agent (the viable count is 10×10 8 cfu / mL, and the ratio of the viable counts of Phanerochaete chrysosporium, Rhodococcus fansiaei, and Trichoderma harzianum is 2:3:3) is added, and composting is carried out. The height of the compost is 1.2 m, the humidity is 60%. When the composting temperature reaches 55°C, turning is carried out, and then turning is carried out every 7 days. When the composting temperature is close to the ambient temperature and no longer rises, the composting ends, and the degraded fertilizer is obtained.

[0046] Then rice is planted, and irrigation starts from the tillering stage of rice. The water volume in the paddy field is always controlled so that the soil water potential of the paddy field soil remains between -5 kPa and -10 kPa until 7 days before harvest, irrigation is stopped. After the paddy field dries out, the rice is harvested.

[0047] After the rice harvest, the degraded fertilizer is applied to the paddy field.

[0048] Comparative Example 5 The difference from Example 1 is that the pea straw is not composted and is directly returned to the field, specifically as follows: Prepare the soil conditioner: Take 180 parts of biochar, 1 part of Phanerochaete chrysosporium microbial agent (the viable count is 10×10 10 cfu / mL), 2 parts of Rhodococcus fansiaei microbial agent (the viable count is 10×10 8 cfu / mL), and 2 parts of Trichoderma harzianum microbial agent (the viable count is 10×10 8 cfu / mL) and mix them evenly.

[0049] After the previous rice harvest, a soil conditioner is applied to the paddy field soil, and then peas are sown at a seeding rate of 12 kg per mu; after the peas are mature, all the pea plants are collected and crushed to a particle size of 1 - 3 cm.

[0050] Then rice is planted, and irrigation starts from the tillering stage of rice. The day of irrigation is recorded as the 1st day. The soil water potential on the 1st day is 0 kPa. On the 2nd day, the soil water potential drops to -5 kPa. Control the water volume in the paddy field so that the soil water potential remains at -5 kPa for another 2 days (maintained until the 4th day). On the 5th day, the paddy field starts to dry out again. By the 7th day, the soil water potential drops to -20 kPa. Control the water volume in the paddy field so that the soil water potential remains at -20 kPa for 1 day (maintained until the 8th day). On the 9th day, the paddy field continues to dry out. By the 10th day, the soil water potential drops to -40 kPa; on the 11th day, irrigation starts again to make the soil water potential reach 0 kPa, and the above cycle is maintained until the end of the jointing stage of rice.

[0051] When the booting stage of rice begins, the above cycle is no longer maintained, and the water volume in the paddy field is always controlled so that the soil water potential in the paddy field remains between -5 kPa and -10 kPa until irrigation is stopped 7 days before harvest. After the paddy field dries out, the rice is harvested.

[0052] After the rice is harvested, pea straw is applied to the paddy field.

[0053] Test Example 1 Seven days before the application of the soil conditioner (before treatment) and seven days after the application of the degraded fertilizer in the paddy fields of Examples 1 to 3 and Comparative Examples 1 to 5, soil samples from the 0-20 cm soil layer were randomly collected. The collected soil samples were passed through a 5-mm sieve to remove residues or stones. The soil samples were placed in a beaker, saturated CaCl2 solution was added, and after stirring evenly, they were left standing for 12 hours to allow the soil particles to precipitate. Then, the suspension was filtered through slow quantitative filter paper to collect microplastics. Then, according to the method described in the article (Chen Ronglong et al., Residual and accumulation characteristics of plastic fragments and microplastics in farmland soil of the Guanzhong Plain in Shaanxi [J]. Chinese Journal of Eco-Agriculture (Chinese & English), 2022, 30(10): 1649-1658. DOI: 10.12357 / cjea.20220137), the content of soil microplastics was calculated. Combining hyperspectral imaging (HSI) and atomic force microscopy-infrared spectroscopy combined technology (AFM-IR), the content of microplastics in rice grains was detected, and the results are shown in Table 1.

[0054] Table 1 Microplastic content

[0055] As can be seen from Table 1, the method of the present invention can effectively reduce the content of soil microplastics. Intercropping peas combined with the application of a soil conditioner can significantly reduce the content of soil microplastics. And after composting and returning the pea plants enriched with microplastics to the field, the content of microplastics in the soil will not increase again, indicating that the composting operation effectively degrades the microplastics enriched by the peas; Combining Comparative Example 4 with Example 1 shows that the wet-dry cycling treatment operation of the present invention can effectively reduce the enrichment of microplastics by rice, which is beneficial to food safety.

[0056] Although the above embodiments have described the present invention in detail, they are only a part of the embodiments of the present invention, rather than all embodiments. People can also obtain other embodiments according to these embodiments without creative efforts, and these embodiments all belong to the protection scope of the present invention.

Claims

1. A rice planting method for reducing soil microplastic pollution, characterized in that, It includes the following steps: After the previous rice crop is harvested, a soil conditioner is applied to the paddy field soil, and then peas are sown; After the peas are mature, all the pea plants are collected, crushed and composted to obtain the degraded fertilizer; After collecting the pea plants, rice is planted. From the tillering stage of rice to the end of the jointing stage, periodic irrigation is carried out, and the paddy field is maintained with a wet-dry alternating cycle treatment during the periodic irrigation stage; Periodic irrigation is stopped at the booting stage of rice, and constant humidity irrigation is carried out. During the constant humidity irrigation stage, the soil water potential of the paddy field is maintained between -5 kPa and -10 kPa; Irrigation is stopped 7 - 14 days before harvest. After the paddy field dries out, the rice can be harvested. After the rice is harvested, the degraded fertilizer is applied to the paddy field; The wet-dry alternating cycle treatment includes a cycle of the first stage - the second stage - the third stage; in the first stage, the water potential of the paddy field is controlled between 0 kPa and -5 kPa and maintained for 3 - 5 days; in the second stage, the water potential of the paddy field is controlled between -5 kPa and -20 kPa and maintained for 2 - 3 days; in the third stage, the water potential of the paddy field is controlled between -20 kPa and -40 kPa and maintained for 1 - 2 days.

2. The method according to claim 1, wherein By mass, the soil conditioner includes: 100 - 200 parts of biochar, 1 - 2 parts of Phanerochaete chrysosporium bacterium agent, 2 - 3 parts of Rhodococcus fangiisoli bacterium agent, and 2 - 3 parts of Trichoderma harzianum bacterium agent.

3. The method according to claim 2, characterized in that, The viable count of the Phanerochaete chrysosporium bacterial agent ≥ 10 × 10 10 cfu / mL; the viable count of the Rhodococcus fanqingii bacterial agent ≥ 10 × 10 8 cfu / mL; the viable count of the Trichoderma harzianum bacterial agent ≥ 10 × 10 8 cfu / mL.

4. The method according to claim 1, characterized in that, The sowing density of the peas is 12 - 15 kg of seeds sown per mu.

5. The method according to claim 1, characterized in that, The particle size of the crushing is 1 - 3 cm.

6. The method according to claim 1, wherein The composting includes: all the pea plants are collected, crushed to obtain plant materials, then a compound bacterium agent is added for composting. When the composting temperature reaches 50℃ - 60℃, turning the pile is carried out, and then turning the pile is carried out every 5 - 7 days. When the composting temperature is close to the ambient temperature and no longer rises, the composting ends to obtain the degraded fertilizer; The compound bacterium agent includes Phanerochaete chrysosporium, Rhodococcus fangiisoli and Trichoderma harzianum, and the ratio of the viable bacteria numbers of Phanerochaete chrysosporium, Rhodococcus fangiisoli and Trichoderma harzianum is 1 - 10:1 - 5:1 - 5.

7. The method according to claim 6, characterized in that, The dosage of the compound bacterium agent is 0.5 wt% - 1 wt% of the mass of the plant materials.

8. The method according to claim 6, characterized in that, The height of the composting is 1 - 1.5 m, and the humidity is 50% - 60%.

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