Acetobacter type bio-organic fertilizer for controlling accumulation of heavy metal cadmium in rice as well as preparation method and application method of acetic bacteria type bio-organic fertilizer

Abstract

The invention discloses an acetic bacteria type bio-organic fertilizer for controlling accumulation of heavy metal cadmium in rice, and a preparation method and an application method thereof, according to the bio-organic fertilizer with the water content of 30%, 0.001 billion to 0.5 billion per gram of active unit acetic bacteria are added; the preparation method comprises the following steps: 1) preparing a common organic fertilizer into a granular common organic fertilizer; and 2) spraying a mixed concentrated bacterial liquid of bacillus subtilis, bacillus licheniformis, brevibacillus laterosporus and acetic acid bacteria on the surface of the granular common organic fertilizer to prepare the acetic acid type biological organic fertilizer. The prepared organic fertilizer is researched and developed on the basis that the organic fertilizer generates targeted organic acid in the decomposition process of multiple microorganisms, has the advantages of being convenient to apply, low in use amount, low in price and low in use cost, is generally suitable for farmlands with heavy, medium and light cadmium pollution in China, and has wide adaptability.

Description

Technical Field

[0001] The invention belongs to the technical field of fertilizer preparation, and in particular relates to an acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice, and a preparation method and an application method thereof. Background Art

[0002] Cadmium is the most important toxic element threatening the quality of agricultural products in my country. Rice is the main staple food in my country. How to control the pollution of heavy metals such as cadmium in rice is very urgent. Studies have shown that the content of cadmium, lead and mercury in soil, especially the effective content (i.e., the content that can be absorbed by the root system), is the key factor affecting the root absorption of soil cadmium, lead and mercury. Therefore, reducing and controlling the effective cadmium and lead in soil through various agronomic measures has always been a hot research topic at home and abroad. For example, in acidic and acidic soils, increasing the soil pH by applying lime can significantly reduce the effectiveness of soil cadmium, lead and mercury, and ultimately reduce the absorption of these heavy metals by the root system. However, the application of lime also has many side effects. For example, when lime is applied, the increase in soil pH leads to the effective reduction of these heavy metals, but also leads to a significant decrease in the content of various trace elements such as iron, manganese, zinc and other essential elements, which can easily cause crop deficiency and poor growth; on the other hand, due to the large differences in pH values ​​and pH buffering capacity in different regions and soil types, the amount of lime application is difficult to accurately control. For rice, flooding can promote the increase of soil reducibility, increase the divalent iron in the soil and promote the precipitation of cadmium, lead and mercury in the form of sulfides, which can reduce the soil effectiveness of these heavy metals on the one hand, and reduce the root system's absorption capacity of these elements on the other hand, which can significantly reduce the root system's absorption and accumulation of toxic heavy metals in the soil. However, for rice, long-term flooding is not conducive to rice growth and can easily lead to increased arsenic absorption by crops. Adding a solidifying agent or adsorbent to the soil to bind and fix or adsorb heavy metals in the soil, such as cadmium, lead and mercury, has always been an important research direction at home and abroad. The solidifying agents or adsorbents reported so far mainly include zeolite, diatomaceous earth, sepiolite, bentonite and limestone, and even alkaline coal slag, but there is no soil heavy metal solidifying agent or adsorbent for large-scale production application. The development of a simple, easy-to-implement, and ecologically safe rice cadmium control technology is one of the important directions in the future.

[0003] Organic fertilizer is an important material in agricultural production, but since organic fertilizer is generally applied in large quantities, it will incur a large application cost, and is less used in rice. Previous generations have also tried to control cadmium pollution in rice by applying organic fertilizer, but found that the effect of ordinary organic fertilizer is not obvious; at the same time, it was found that conventional biological organic fertilizers on the current market have no obvious effect on cadmium pollution in rice; even many agricultural producers and scientific researchers suspect that organic fertilizers have a promoting effect on cadmium pollution in crops. However, Patent ZL201911129227.5 discloses the use of organic fertilizers with appropriate proportions of trace elements (iron, manganese and zinc) added to control cadmium pollution in rice. But overall, my country's products and technologies for controlling cadmium pollution in rice with strong implementation and ecological safety are still scarce. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide an acetic acid-based bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice, as well as a preparation method and an application method, which are specifically achieved through the following technical solutions:

[0005] An acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice, wherein 0.001 to 0.5 billion / gram active units of acetic acid bacteria are added to the bio-organic fertilizer with a water content of 30%.

[0006] Furthermore, 0.005 billion to 0.1 billion / gram active units of acetic acid bacteria are added to the bio-organic fertilizer with a water content of 30%.

[0007] Furthermore, 100 million to 500 million active units of acetic acid bacteria are added to the bio-organic fertilizer with a water content of 30%.

[0008] Furthermore, the organic fertilizer is commercial common organic fertilizer.

[0009] Furthermore, Bacillus subtilis, Bacillus licheniformis and Brevibacillus laterosporus are also added to the acetic acid bacteria type bio-organic fertilizer.

[0010] A method for preparing an acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice comprises the following steps:

[0011] 1) using an extruder or granulator to make ordinary organic fertilizer into columnar particles with a diameter of 0.2-0.5 cm and a length of 0.3-0.5 cm, or spherical or oblate particles with a diameter of 0.2-0.5 cm, to obtain granular ordinary organic fertilizer;

[0012] 2) When the granular common organic fertilizer obtained in step 1) is cooled to room temperature, a mixed concentrated bacterial solution of Bacillus subtilis, Bacillus licheniformis, Brevibacillus laterosporus and acetic acid bacteria is sprayed on the surface of the granular common organic fertilizer, wherein the spraying amount of the mixed bacterial solution is such that the bacterial solution penetrates into the granules and maintains the integrity of the granules, thereby obtaining an acetic acid type biological organic fertilizer.

[0013] During the preparation process, special attention should be paid to the activity of the bacterial flora. After processing, the organic fertilizer granules must be cooled to room temperature before spraying the bacterial flora, and it must be ensured that the bacterial liquid can penetrate into the inner layer of the granules without the granules becoming loose.

[0014] The contents of Bacillus subtilis, Bacillus licheniformis and Brevibacillus laterosporus in the organic fertilizer meet the national standards for biological organic fertilizers. The content of acetic acid bacteria is based on the standard of adding 0.001 to 0.5 billion active units per gram of biological organic fertilizer with a water content of 30%.

[0015] A method for applying an acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice. The acetic acid bacteria type bio-organic fertilizer needs to be applied within 15 days after preparation, and 1-100 kg / mu is applied during the rice booting stage, and 1-100 kg / mu is applied during the rice break stage to the initial filling stage.

[0016] Furthermore, acetic acid-type bio-organic fertilizer is applied at 2.5-50 kg / mu during the rice heading stage, and 2.5-50 g / mu during the rice breaking stage to the initial filling stage.

[0017] Furthermore, acetic acid-type bio-organic fertilizer is applied at 5-25 kg / mu during the rice heading stage, and 5-25 g / mu during the rice breaking stage to the initial filling stage.

[0018] The organic fertilizer of the present invention will produce a variety of organic acids during the decomposition process of microorganisms; specific microorganisms will produce specific organic acids; organic acids have a significant activation effect on soil trace elements (such as iron, manganese and zinc); different organic acids have different activation abilities for different trace elements. Acetic acid bacteria have the ability to decompose organic matter. Previous researchers used ordinary organic fertilizers and biological organic fertilizers on the market to carry out research on rice cadmium pollution control, and found that the relevant organic fertilizers could not produce suitable organic acids or the amount produced was insufficient during the decomposition process; the present application found that after adding acetic acid bacteria to biological organic fertilizers, organic matter may decompose and produce more specific organic acids, such as acetic acid, under the action of multiple microorganisms, which can greatly improve the effectiveness of trace elements such as iron, manganese and zinc that have a vital impact on rice cadmium accumulation, and affect the entire gene network of cadmium accumulation in rice plants.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) The acetic acid bacteria type biological organic fertilizer of the present invention is reasonably designed, simple to make, has a wide source of raw materials, and is easy to operate for field application. It can not only increase soil organic matter, improve the physical and chemical environment of the soil, and ensure ecological safety; more importantly, it can reduce the effectiveness of heavy metal cadmium in the soil, prevent cadmium absorption by rice roots, improve the nutritional status of rice plants, prevent cadmium in the roots from being transported to the aboveground part (rice straw), and prevent cadmium in rice straw from migrating to rice grains, thereby reducing cadmium accumulation in rice and reducing heavy metal cadmium pollution;

[0021] 2) The organic fertilizer prepared by the present invention is developed based on the production of more targeted organic acids in the decomposition process of organic fertilizer by various microorganisms. It has the advantages of convenient application, low usage amount, low price and low use cost. It is generally applicable to farmlands with heavy, medium and light cadmium pollution in my country and has wide adaptability. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with specific embodiments to facilitate a better understanding of the present technical solution.

[0023] The commercially available common organic fertilizers used in the following examples all use dairy cow dung as the main raw material, with a nitrogen, phosphorus and potassium content of about 5% and a cadmium content of less than 0.8 mg / kg.

[0024] The Bacillus subtilis, Bacillus licheniformis and Brevibacillus laterosporus powders used in this application are all commercially available and provided by Zhejiang Ruijue Biotechnology Co., Ltd. The added amount is in accordance with the national standard requirements for biological organic fertilizers.

[0025] Example 1: Preparation of an acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice Raw materials: 50 kg of commercially available common organic fertilizer with a water content of <30%; commercially available Bacillus subtilis, Bacillus licheniformis, and Brevibacillus laterosporus powders; 10 g of food-grade acetic acid bacteria powder (3 billion active units). Each strain of bacteria was dissolved in 1 kg (liter) of water to prepare a bacterial solution.

[0026] Preparation steps:

[0027] 1) Use a feed pellet machine to make organic fertilizer into pellets, which are columnar pellets with a diameter of about 0.4 cm and a length of about 0.5 cm. After screening, the pellet integrity is more than 95%;

[0028] 2) When the temperature of the columnar particles drops to room temperature, one liter of bacterial solution is sprayed on the surface of the particles in a thin mist while being stirred by a uniform slow-speed mixer, and quickly penetrates into the inner layer of the particles, thereby obtaining an acetic acid bacteria-based bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice.

[0029] Example 2: An acetic acid bacteria-based bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice

[0030] Preparation of raw materials: 50 kg of commercially available common organic fertilizer with a water content of <30%; commercially available Bacillus subtilis, Bacillus licheniformis, and Brevibacillus laterosporus powders; 25 g of commercially available food-grade acetic acid bacteria powder (3 billion active units). Dissolve each strain in 1 kg (liter) of water to prepare a bacterial solution.

[0031] Preparation steps:

[0032] 1) Use a feed pellet machine to make organic fertilizer into pellets, which are columnar pellets with a diameter of about 0.4 cm and a length of about 0.5 cm. After screening, the pellet integrity is more than 95%;

[0033] 2) When the temperature of the columnar particles drops to room temperature, one liter of bacterial solution is sprayed on the surface of the particles in a thin mist while being stirred by a uniform slow-speed mixer, and quickly penetrates into the inner layer of the particles, thereby obtaining an acetic acid bacteria-based bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice.

[0034] Example 3: An acetic acid bacteria-based bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice

[0035] Preparation of raw materials: 50 kg of commercially available common organic fertilizer with a water content of <30%; commercially available Bacillus subtilis, Bacillus licheniformis, and Brevibacillus laterosporus powders; 50 g of commercially available food-grade acetic acid bacteria powder (3 billion active units). Dissolve each strain in 1 kg (L) of water to prepare a bacterial solution.

[0036] Preparation steps:

[0037] 1) Use a feed pellet machine to make organic fertilizer into pellets, which are columnar pellets with a diameter of about 0.4 cm and a length of about 0.5 cm. After screening, the pellet integrity is more than 95%;

[0038] 2) When the temperature of the columnar particles drops to room temperature, one liter of bacterial solution is sprayed on the surface of the particles in a thin mist while being stirred by a uniform slow-speed mixer, and quickly penetrates into the inner layer of the particles, thereby obtaining an acetic acid bacteria-based bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice.

[0039] Experimental Example 1: Experimental study on the control of cadmium accumulation in rice by acetic acid bacteria-based bio-organic fertilizer

[0040] The organic fertilizer prepared in Example 2 was used to carry out an early rice cadmium pollution control experiment in Kaihua, Quzhou in 2021. The total cadmium content in the rice field was 0.8 mg / kg, and the soil pH was about 5.8. The rice varieties were Zhongjia Zao 17 and Zhongzao 39. A small plot comparison experiment was set up with an area of ​​20 square meters. Direct seeding was adopted on April 1. Treatment settings 1. blank control (CK1), 2. commercial organic fertilizer (CK2, prepared into particles according to the preparation steps of Example 2, without adding bacterial liquid, hereinafter referred to as ordinary organic fertilizer), 3. biological organic fertilizer (CK3, prepared into particles according to the preparation steps of Example 2, containing Bacillus subtilis, Bacillus licheniformis, Brevibacillus laterosporus, hereinafter referred to as biological organic fertilizer), 4. organic fertilizer treatment made by Example 2 (containing Bacillus subtilis, Bacillus licheniformis, Brevibacillus laterosporus and acetic acid bacteria, hereinafter referred to as acetic acid bacteria type biological organic fertilizer), 5. organic fertilizer treatment made by Example 2 (prepared into particles containing only acetic acid bacteria according to the preparation steps of Example 2, hereinafter referred to as acetic acid bacteria organic fertilizer), three repetitions. The treatment period is the early booting stage and the breach stage; each application amount is 0.75 kg / plot (equivalent to 25kg per mu), and a shallow water layer (<2cm) is maintained during application, and then naturally dried (the surface layer water is not seen in the surface layer after about 3 days in this test). During the harvest period, the rice was harvested by sampling at five points in each plot, dried in the sun according to the conventional method, ground into rice, and then crushed (ground) into brown rice flour. The pretreatment was carried out by using concentrated hydrochloric acid and concentrated nitric acid to prepare aqua regia. The cadmium content of the nitrified solution was determined by ICP-OES. The experimental results are shown in Table 1.

[0041] Table 1: Cadmium content in brown rice

[0042]

[0043] Note: The relevant organic fertilizer is used in the field 7 days after production. The organic fertilizer with acetic acid bacteria added has a slight sour taste when applied.

[0044] The results showed that compared with CK1, the effects of ordinary organic fertilizer and biological organic fertilizer on the cadmium content of the two rice varieties were different, but there was no significant difference, and both seriously exceeded the national standard of 0.2 mg / kg. After the treatment with acetic acid bacteria type biological organic fertilizer, compared with CK1, ordinary organic fertilizer (CK2), and biological organic fertilizer (CK3), there was a significant reduction. Among them, the cadmium content of brown rice of Zhongjia Zao 17 was lower than 0.2 mg / kg; but similarly, the cadmium content of rice in the two rice varieties also dropped significantly after acetic acid bacteria organic fertilizer compared with the three CKs, but the cadmium content of rice still exceeded the standard, and the cadmium reduction effect was much lower than that of acetic acid bacteria type biological organic fertilizer. It is speculated that it may be related to the fact that acetic acid bacteria produces a variety of organic acids in the process of decomposing organic matter in organic fertilizer, thereby increasing the content of effective trace elements in the soil, and ultimately reducing the cadmium accumulation of rice.

[0045] Experimental Example 2: Experiment on the application period of acetic acid bacteria type bio-organic fertilizer to control cadmium accumulation in rice

[0046] In the autumn of 2021, an experiment on the application period of acetic acid bacteria-based bio-organic fertilizer to control the accumulation of cadmium in rice was carried out in Kaihua and Jiangshan, Quzhou. Zhongjia Zao 17 and Zhongzao 39 were used as experimental materials in both places (early rice varieties were planted in autumn and sown directly on July 18). The total cadmium content of paddy soil in the Kaihua test site was 0.8 mg / kg, and the soil pH was 5.8. The total cadmium content of soil in the Jiangshan test field was 0.5 mg / kg, and the soil pH was 5.5. A plot experiment was adopted, with 20 square meters per plot. In view of the fact that the most critical period for cadmium accumulation in rice is from the booting stage to the filling stage (about 15 days), the experiment set up ① blank control, ② booting stage, ③ break stage, ④ booting stage + break stage, and each application amount was 1.5 kg / plot (equivalent to 50 kg per mu), repeated three times, and a shallow water layer (<2 cm) was maintained during application, and then naturally dried (no surface water was seen on the surface after about 3 days in the Kaihua test; no surface water was seen in Jiangshan for about 5 days). During the harvest period, the rice was harvested by sampling at five points in each plot, dried in the sun according to the conventional method, ground into rice, and then crushed (ground) into brown rice flour. Concentrated hydrochloric acid and concentrated nitric acid were used to prepare aqua regia for pretreatment. The cadmium content of the nitrification solution was determined by ICP-OES. The experimental results are shown in Tables 2 and 3.

[0047] Table 2: Control effect of acetic acid bacteria type bio-organic fertilizer prepared in Example 2 on cadmium accumulation of rice in Kaihua test site at different periods

[0048]

[0049] Note: Acetic acid bacteria bio-organic fertilizer should be applied on the 10th day after production. Organic fertilizer with acetic acid bacteria added has a slight sour taste when applied.

[0050] Table 3: Control effect of applying acetic acid bacteria type bio-organic fertilizer prepared in Example 2 at different periods on cadmium accumulation of rice in Jiangshan test site

[0051]

[0052] Note: Acetic acid bacteria bio-organic fertilizer is applied on the 12th day after production; organic fertilizer with acetic acid bacteria added has a slight sour taste when applied.

[0053] Table 2 shows that the cadmium content of the two rice varieties can be significantly reduced regardless of the growth stage in which the acetic acid bacteria type bio-organic fertilizer is applied. However, topdressing at different stages has obvious differences in the accumulation of cadmium in rice. Among them, topdressing at the booting stage and the rupture stage can significantly reduce the cadmium content of the two varieties of rice, but the cadmium still exceeds the standard. When applied at the booting stage + rupture stage, the acetic acid bacteria type bio-organic fertilizer can significantly reduce the cadmium content of rice. In the experiment, the cadmium content of the two varieties was less than 0.2 mg / kg. This shows that the combined application of the two growth stages can make the acetic acid bacteria type bio-organic fertilizer play the best cadmium control effect.

[0054] The results obtained from the experiment conducted in Jiangshan (Table 3) were similar to those of the Kaihua experiment, but because the cadmium content in the soil of the Jiangshan experimental field was lower than that in Kaihua, the cadmium content in the two rice varieties was also relatively low.

[0055] Experimental Example 3: Study on the Control of Cadmium Accumulation in Rice by Different Application Rates of Acetobacter Bio-organic Fertilizer

[0056] This experiment was conducted in Kaihua and Qujiang, Quzhou in the spring of 2022 to control cadmium in early rice. Zhongjia Zao 17 and Zhongzao 39 were used as test materials in both places (early rice varieties were planted in autumn and sown directly on March 30). The total cadmium content of paddy field soil in Kaihua test site was 0.8 mg / kg, and the soil pH was 5.8. The total cadmium content of soil in Qujiang test field was 0.9 mg / kg, and the soil pH was 5.3. A plot experiment was adopted, with each plot of 20 square meters. Considering that the most critical period for cadmium accumulation in rice is from the booting stage to the filling stage (about 15 days), acetic acid bacteria type bio-organic fertilizer is applied once at the booting stage and the breaking stage, and the application amount is set as follows: ① blank control, marked CK, ② 0.15 kg / plot (equivalent to 5 kg per mu), marked T1, ③ 0.3 kg / plot (equivalent to 10.0 kg per mu), marked T2, ④ 0.6 kg / plot (equivalent to 20 kg per mu), marked T3, ⑤ 1.2 kg / plot (equivalent to 40 kg per mu), marked T4, ⑥ 2.4 kg / plot (equivalent to 80 kg per mu), marked T5. Repeat three times, keep a shallow water layer (<2 cm) when applying, and then let it dry naturally. At the harvesting stage, the five-point sampling method is adopted for each plot, and the rice is harvested, dried in the sun according to the conventional method, ground into rice, and then crushed (ground) into brown rice flour. Use concentrated hydrochloric acid and concentrated nitric acid to prepare aqua regia for pretreatment. The cadmium content of the nitrification solution was determined by ICP-OES. The results are shown in Tables 4 and 5.

[0057] Table 4: Effects of different application rates of acetic acid bacteria-based bio-organic fertilizers on cadmium accumulation in rice (Kaihua)

[0058]

[0059] Note: Acetic acid bacteria bio-organic fertilizer should be applied on the 8th day after production; organic fertilizer with acetic acid bacteria added has a slight sour smell when applied

[0060] Table 5

[0061]

[0062] Note: Acetic acid bacteria bio-organic fertilizer should be applied on the 10th day after production; organic fertilizer with acetic acid bacteria added has a slight sour taste when applied.

[0063] The results of the two test sites in Kaihua and Qujiang (Table 4 and Table 5) show that compared with the control, all acetic acid bacteria bio-organic fertilizer treatments have a significant control effect on the accumulation of cadmium in rice. However, due to the high temperature and little rain from the booting stage to the filling stage, the rice in all the test plots exceeded 0.2 mg / kg and failed to meet the national standard; but there were still obvious differences between different dosages. With the increase in the treatment amount, the cadmium content of the two varieties of rice generally showed a decrease first and then an increase. Among them, the cadmium reduction effects of T2, T3, and T4 were similar and relatively ideal. T1 is estimated to have been applied too little; and T5 may be related to the increase in soil cadmium activity caused by excessive acetic acid bacteria bio-organic fertilizer. It can be seen that acetic acid bacteria bio-organic fertilizer can not only significantly prevent and control the accumulation of cadmium in rice, but also relatively small amounts (T2, T3, T4) will have better results. The results of the two tests are completely similar.

[0064] Experimental Example 4: Comparative test of the cadmium control effect of acetic acid bacteria type bio-organic fertilizer on mid-late rice

[0065] This experiment will conduct regional comparative tests on the cadmium control effects of acetic acid bacteria-based bio-organic fertilizers on different types of rice in Kaihua, Changshan, Qujiang, and Longyou in Quzhou in 2022. A regional comparative test of single-season rice was carried out in Kaihua and Changshan, Quzhou, and the varieties were all Zhongzheyou No. 8; a regional comparative test of late rice was carried out in Qujiang and Longyou, and the varieties were all Yongyou 1540. The total cadmium content of paddy field soil in the Kaihua test site was 0.8 mg / kg, and the soil pH was 5.8; the total cadmium content of paddy field soil in the Changshan test site was 1.0 mg / kg, and the soil pH was 5.5; the total cadmium content of paddy field soil in the Qujiang test site was 0.9 mg / kg, and the soil pH was 5.3; the total cadmium content of soil in the Longyou test field was 0.4 mg / kg, and the soil pH was 5.6. The area of ​​the region is 100 square meters, and there is no repetition. The experiment set up a blank control (CK) and acetic acid bacteria type bio-organic fertilizer treatment; the acetic acid bacteria type bio-organic fertilizer treatment period is the booting stage and the break stage, and the application rate in each period is 20kg / mu. When applying, a shallow water layer (<2cm) is maintained, and then it naturally dries up (according to actual production, shallow water can also be maintained continuously). At the harvesting period, the five-point sampling method is used to harvest rice, dry it in the sun according to the conventional method, grind it into rice, and then crush (grind) it into brown rice flour. Use concentrated hydrochloric acid and concentrated nitric acid to prepare aqua regia for pretreatment. The cadmium content of the nitrification solution is determined by ICP-OES, and the results are shown in Table 6.

[0066] Table 6: Comparative test results of acetic acid bacteria-based bio-organic fertilizer for controlling cadmium accumulation in rice in Kaihua, Changshan, Qujiang and Longyou, Quzhou

[0067]

[0068] Note: Acetic acid bacteria bio-organic fertilizer is applied on the 7th day after production (Kaihua), the 9th day (Changshan), the 7th day (Qujiang), and the 12th day (Longyou); the organic fertilizer with acetic acid bacteria added has a faint sour taste when applied.

[0069] From Table 6, we can see that no matter it is single-season rice or late-season rice, and no matter at which test point, acetic acid bacteria-based bio-organic fertilizer has shown a very significant control effect on rice cadmium accumulation. The cadmium control effect of Kaihua single-season rice reached 58.70%, and Changshan reached 65.69%; and for late-season rice, the cadmium reduction rate in Qujiang reached 55.07%, and in Longyou it was 59.57%.

[0070] Experimental Example 5: Demonstration of using acetic acid bacteria-based bio-organic fertilizer to prevent and control cadmium pollution in rice

[0071] This experiment will carry out a 100-acre demonstration of single-season rice and late rice in Kaihua and Qujiang, two high-cadmium geological background areas in Quzhou in 2023. At the Kaihua test site, the total cadmium content of paddy field soil in the 100-acre demonstration area is 0.6-0.8 mg / kg, the soil pH is 5.5-5.8, and the experimental variety is Zhongzheyou No. 8 (single-season rice); at the Qujiang test site, the total cadmium content of paddy field soil in the 100-acre demonstration area is 0.5-0.9 mg / kg, the soil pH is 5.3-6.0, and the variety is Yongyou 1540 (late rice). At each test site, 3 fields were selected in the demonstration area without acetic acid bacteria-type biological organic fertilizer as a control (each field area is 1.0-2.0 acres). The application method is: during the booting stage and the break stage, the application amount is 20kg / acre in each period, and a shallow water layer (<2cm) is maintained during application, and then it will dry naturally (according to actual production, shallow water can also be maintained continuously). At the harvest period, each control field was sampled at five points, and rice was harvested. There were three control samples at each test point. The demonstration treatment area had one sample per 15 mu (five sampling points, respectively), for a total of six samples. The rice was dried and ground into rice by conventional methods, and then crushed (ground) into brown rice flour. Concentrated hydrochloric acid and concentrated nitric acid were used to prepare aqua regia for pretreatment. The cadmium content of the nitrification solution was determined by ICP-OES, and the results are shown in Table 7.

[0072] Table 7: Results of the 100-acre demonstration plots in Kaihua and Qujiang, Quzhou

[0073]

[0074] Note: Acetic acid bacteria bio-organic fertilizer is applied on the 8th day after production (Kaihua) and on the 13th day (Qujiang); organic fertilizer with acetic acid bacteria added has a slight sour taste when applied.

[0075] The results in Table 7 show that in the control area, whether in Kaihua or Qujiang, the cadmium content of single-season rice Zhongzheyou No. 8 and late rice Yongyou 1540 far exceeds the national standard of 0.2kg / kg. The former has an average of 1.194mg / kg and the latter has an average of 0.625mg / kg, even reaching 5-6 times and 3 times the national standard. In the demonstration area, after being treated with acetic acid bacteria type biological organic fertilizer, the cadmium content of the two varieties dropped significantly. The cadmium content of Zhongzheyou No. 8 (single-season rice) was between 0.162mg / kg-0.433mg / kg, with an average of 0.290mg / kg; the cadmium content of Yongyou 1540 (late rice) was between 0.190-0.333mg / kg, with an average of 0.268mg / kg. The results of the two demonstration areas show that acetic acid bacteria type biological organic fertilizer can significantly reduce the risk of cadmium pollution in rice production and has the value of promotion and application.

Claims

1. An acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice, characterized in that: According to the biological organic fertilizer with a water content of 30%, acetic acid bacteria are added in an active unit of 0.001 to 0.5 billion per gram.

2. The acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice as claimed in claim 1, characterized in that: According to the biological organic fertilizer with a water content of 30%, 0.005 billion to 0.1 billion active units of acetic acid bacteria are added per gram.

3. The acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice as claimed in claim 1, characterized in that: According to the biological organic fertilizer with a water content of 30%, add 100 million to 500 million active units of acetic acid bacteria per gram.

4. The acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice as claimed in claim 1, characterized in that: The organic fertilizer is commercial common organic fertilizer.

5. The acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice as claimed in claim 1, characterized in that: Bacillus subtilis, Bacillus licheniformis and Brevibacillus laterosporus are also added to the acetic acid bacteria type biological organic fertilizer.

6. The method for preparing an acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice according to any one of claims 1 to 5, characterized in that: The following steps are involved: 1) using an extruder or granulator to make ordinary organic fertilizer into columnar particles with a diameter of 0.2-0.5 cm and a length of 0.3-0.5 cm, or spherical or oblate particles with a diameter of 0.2-0.5 cm, to obtain granular ordinary organic fertilizer; 2) When the granular common organic fertilizer obtained in step 1) is cooled to room temperature, a mixed concentrated bacterial solution of Bacillus subtilis, Bacillus licheniformis, Brevibacillus laterosporus and acetic acid bacteria is sprayed on the surface of the granular common organic fertilizer, wherein the spraying amount of the mixed bacterial solution is such that the bacterial solution penetrates into the granules and maintains the integrity of the granules, thereby obtaining an acetic acid type biological organic fertilizer.

7. A method for applying acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice, characterized in that: The acetic acid bacteria type bio-organic fertilizer needs to be applied within 15 days after preparation, and 1-100 kg / mu can be applied during the rice booting stage, and 1-100 kg / mu can be applied during the rice break stage to the initial filling stage.

8. The method for applying an acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice as claimed in claim 7, characterized in that During the rice heading stage, 2.5-50kg / mu of acetic acid type bio-organic fertilizer should be applied; during the rice breaking stage to the initial filling stage, 2.5-50g / mu should be applied.

9. The method for applying an acetic acid bacteria type bio-organic fertilizer for controlling the accumulation of heavy metal cadmium in rice as claimed in claim 7, characterized in that Apply acetic acid type bio-organic fertilizer at 5-25kg / mu during the rice heading stage, and 5-25g / mu during the rice breaking stage to the initial filling stage.

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