Activating agent for soil selenium and preparation method thereof

Abstract

The invention relates to the technical field of soil activation, and particularly discloses an activating agent for soil selenium and a preparation method of the activating agent. The activating agent for soil selenium comprises a calcium magnesium phosphate fertilizer, a bio-organic fertilizer and diatomite, wherein the weight ratio of the calcium magnesium phosphate fertilizer to the bio-organic fertilizer to the diatomite is (1-2): (1-2): (1-3). The invention provides a brand-new soil selenium activating agent. Researches show that the soil selenium activating agent can promote selenium absorption of crops and increase the selenium content in the crops; the important application value is realized.

Description

Technical Field

[0001] The invention relates to the technical field of soil activation, and in particular to an activator for soil selenium and a preparation method thereof. Background Art

[0002] Selenium is an essential trace element for humans and animals confirmed by the World Health Organization and the International Nutrition Organization. It plays a role in balancing redox, scavenging free radicals, enhancing immunity, and antagonizing harmful heavy metals. In addition, selenium plays an important role in maintaining plant growth and development, photosynthesis, and cell structure integrity. In agricultural production, selenium is used to prevent and treat various crop diseases to reduce losses. China is a country with a low selenium content, with more than two-thirds of the country being in a state of selenium deficiency to varying degrees. The human body cannot synthesize selenium on its own, and eating selenium-rich agricultural products is an effective way for the human body to supplement selenium.

[0003] Natural selenium-rich soil is the material basis for the production of selenium-rich agricultural products; however, studies have shown that if the selenium-rich soil is not treated, the absorption rate of selenium in the soil by crops is not high; it is usually necessary to add conditioners and compound nutrient element fertilizers to the natural selenium-rich soil to change the soil environment, activate the selenium in the soil, and improve the biological effectiveness of selenium, so as to achieve the purpose of improving the absorption of selenium by crops, improving the utilization rate of soil selenium, and producing high-quality selenium-rich agricultural products. Therefore, providing an activator for soil selenium has important application value. Summary of the invention

[0004] In order to overcome at least one of the technical problems existing in the prior art, the present invention provides an activator for soil selenium and a preparation method thereof.

[0005] The above technical problems to be solved by the present invention are achieved through the following technical solutions:

[0006] The present invention firstly provides an activator for soil selenium, which comprises calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth;

[0007] Among them, the weight ratio of calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth is 1-2:1-2:1-3.

[0008] The invention provides a soil selenium activator with a completely new composition; studies have shown that the soil selenium activator can promote the absorption of selenium by crops and increase the selenium content in the crops.

[0009] Preferably, the activator for soil selenium comprises calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth;

[0010] Among them, the weight ratio of calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth is 1:1:2.

[0011] Preferably, the effective P2O5 content in the calcium magnesium phosphate fertilizer is ≥17%.

[0012] Preferably, the organic matter content in the bio-organic fertilizer is ≥ 70%.

[0013] Preferably, the diatomaceous earth is modified diatomaceous earth, and the modified diatomaceous earth is prepared by the following method:

[0014] (1) taking diatomaceous earth, adding it into water and stirring it to obtain a diatomaceous earth mixed liquid;

[0015] (2) adding calcium nitrate to the diatomaceous earth mixture, and then adding potassium carbonate, stirring for 40 to 100 minutes, and then performing solid-liquid separation to obtain a solid;

[0016] (3) uniformly mixing the solid with an aqueous solution of ammonium nitrate, and then drying to obtain a solid mixture;

[0017] (4) calcining the solid mixture, and taking the calcined solid after the calcination to obtain the modified diatomaceous earth.

[0018] The inventors have shown in further studies that the addition of an activator made from modified diatomaceous earth prepared by the above method of the present invention can significantly increase the selenium content in crops compared to the addition of an activator made from unmodified diatomaceous earth.

[0019] Preferably, the weight ratio of diatomaceous earth to water in step (1) is 1:8-15;

[0020] Most preferably, the weight ratio of diatomaceous earth to water in step (1) is 1:10.

[0021] Preferably, in step (2), the weight ratio of the diatomite mixture to calcium nitrate and potassium carbonate is 100-200:15-18:13-15;

[0022] Most preferably, the weight ratio of the diatomaceous earth mixture to calcium nitrate and potassium carbonate in step (2) is 150:16:14.

[0023] Preferably, in step (3), the weight ratio of the solid to the aqueous ammonium nitrate solution is 1:1 to 2;

[0024] Most preferably, the weight ratio of solid to aqueous ammonium nitrate solution in step (3) is 1:1.5.

[0025] Preferably, the mass fraction of ammonium nitrate in the aqueous ammonium nitrate solution is 10-20%.

[0026] Most preferably, the mass fraction of ammonium nitrate in the aqueous ammonium nitrate solution is 15%.

[0027] Preferably, the calcination in step (4) refers to heating the temperature to 700-950° C. at a heating rate of 8-15° C. / min, and calcining at 700-950° C. for 2-4 hours.

[0028] Most preferably, the calcination in step (4) refers to heating the temperature to 850°C at a heating rate of 10°C / min and calcining at 850°C for 3h.

[0029] Preferably, the calcination specifically refers to first heating the temperature to 250-350°C at a heating rate of 8-15°C / min, and calcining at 250-300°C for 1-3h; then heating the temperature to 700-950°C at a heating rate of 8-15°C / min, and calcining at 700-950°C for 1-3h.

[0030] Preferably, the calcination specifically refers to first heating the temperature to 280°C at a heating rate of 10°C / min, and calcining at 280°C for 2 hours; then heating the temperature to 850°C at a heating rate of 10°C / min, and calcining at 850°C for 2 hours.

[0031] The inventors further discovered in the study that the calcination conditions in the preparation process of the modified diatomite of the present invention are also very critical; adding the modified diatomite prepared under the above-mentioned two-step calcination conditions to the activator can further significantly increase the selenium content in crops compared to adding the modified diatomite prepared under one-step calcination conditions.

[0032] Preferably, the activator for soil selenium refers to an activator for soil selenium that increases the selenium content in crops.

[0033] Preferably, the crop is rice.

[0034] Beneficial effects: The present invention provides a new soil selenium activator; studies have shown that the soil selenium activator can promote the absorption of selenium by crops and increase the selenium content in crops; and has important application value. DETAILED DESCRIPTION

[0035] The present invention is further explained below in conjunction with specific examples, but the examples do not limit the present invention in any form.

[0036] The calcium magnesium phosphate fertilizer in the following embodiments is a calcium magnesium phosphate fertilizer with an effective P2O5 content ≥17% produced by Guangxi Luzhai Wanqiang Fertilizer Co., Ltd.; the bio-organic fertilizer used is a bio-organic fertilizer with an organic matter content ≥70% and an effective viable count ≥200 million / g produced by Genliduo Biotechnology Co., Ltd.; other raw materials without indicating the source are conventional raw materials that can be purchased by those skilled in the art.

[0037] Example 1 Preparation of an activator for soil selenium

[0038] The activator for soil selenium is obtained by mixing calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth in a weight ratio of 1:1:2.

[0039] Example 2 Preparation of an Activator for Soil Selenium

[0040] Calcium magnesium phosphate fertilizer, biological organic fertilizer and modified diatomaceous earth are mixed evenly in a weight ratio of 1:1:2 to obtain the activator for soil selenium;

[0041] The modified diatomaceous earth is prepared by the following method:

[0042] (1) taking diatomaceous earth, adding it into water and stirring it to obtain a diatomaceous earth mixed liquid; wherein the weight ratio of diatomaceous earth to water is 1:10;

[0043] (2) adding calcium nitrate to the diatomaceous earth mixture, and then adding potassium carbonate, stirring for 80 minutes, and performing solid-liquid separation to obtain a solid; wherein the weight ratio of the diatomaceous earth mixture to the calcium nitrate and potassium carbonate is 150:16:14;

[0044] (3) uniformly mixing the solid with the aqueous ammonium nitrate solution, and then drying to obtain a solid mixture; wherein the weight ratio of the solid to the aqueous ammonium nitrate solution is 1:1.5; and the mass fraction of ammonium nitrate in the aqueous ammonium nitrate solution is 15%;

[0045] (4) calcining the solid mixture, and taking the calcined solid after the calcination to obtain the modified diatomite; the calcination refers to: heating the temperature to 850°C at a heating rate of 10°C / min, and calcining at 850°C for 3h.

[0046] Example 3 Preparation of an Activator for Soil Selenium

[0047] Calcium magnesium phosphate fertilizer, biological organic fertilizer and modified diatomaceous earth are mixed evenly in a weight ratio of 1:1:2 to obtain the activator for soil selenium;

[0048] The modified diatomaceous earth is prepared by the following method:

[0049] (1) taking diatomaceous earth, adding it into water and stirring it to obtain a diatomaceous earth mixed liquid; wherein the weight ratio of diatomaceous earth to water is 1:10;

[0050] (2) adding calcium nitrate to the diatomaceous earth mixture, and then adding potassium carbonate, stirring for 80 minutes, and performing solid-liquid separation to obtain a solid; wherein the weight ratio of the diatomaceous earth mixture to the calcium nitrate and potassium carbonate is 150:16:14;

[0051] (3) uniformly mixing the solid with the aqueous ammonium nitrate solution, and then drying to obtain a solid mixture; wherein the weight ratio of the solid to the aqueous ammonium nitrate solution is 1:1.5; and the mass fraction of ammonium nitrate in the aqueous ammonium nitrate solution is 15%;

[0052] (4) calcining the solid mixture, and taking the calcined solid after the calcination to obtain the modified diatomite; the calcination refers to: firstly heating the temperature to 280°C at a heating rate of 10°C / min, and calcining at 280°C for 2h; then heating the temperature to 850°C at a heating rate of 10°C / min, and calcining at 850°C for 2h.

[0053] Comparative Example 1 Preparation of an Activator for Soil Selenium

[0054] Calcium magnesium phosphate fertilizer, biological organic fertilizer and modified diatomaceous earth are mixed evenly in a weight ratio of 1:1:2 to obtain the activator for soil selenium;

[0055] The modified diatomaceous earth is prepared by the following method:

[0056] (1) taking diatomaceous earth, adding it into water and stirring it to obtain a diatomaceous earth mixed liquid; wherein the weight ratio of diatomaceous earth to water is 1:10;

[0057] (2) adding calcium nitrate to the diatomaceous earth mixture, and then adding potassium carbonate, stirring for 80 minutes, and performing solid-liquid separation to obtain a solid; wherein the weight ratio of the diatomaceous earth mixture to the calcium nitrate and potassium carbonate is 150:16:14;

[0058] (3) uniformly mixing the solid with the aqueous ammonium nitrate solution, and then drying to obtain a solid mixture; wherein the weight ratio of the solid to the aqueous ammonium nitrate solution is 1:1.5; and the mass fraction of ammonium nitrate in the aqueous ammonium nitrate solution is 15%;

[0059] (4) calcining the solid mixture, and taking the calcined solid after the calcination to obtain the modified diatomite; the calcination refers to: first heating the temperature to 180°C at a heating rate of 10°C / min, and calcining at 180°C for 2h; then heating the temperature to 850°C at a heating rate of 10°C / min, and calcining at 850°C for 2h.

[0060] Comparative Example 2 Preparation of an Activator for Soil Selenium

[0061] Calcium magnesium phosphate fertilizer, biological organic fertilizer and modified diatomaceous earth are mixed evenly in a weight ratio of 1:1:2 to obtain the activator for soil selenium;

[0062] The modified diatomaceous earth is prepared by the following method:

[0063] (1) taking diatomaceous earth, adding it into water and stirring it to obtain a diatomaceous earth mixed liquid; wherein the weight ratio of diatomaceous earth to water is 1:10;

[0064] (2) adding calcium nitrate to the diatomaceous earth mixture, and then adding potassium carbonate, stirring for 80 minutes, and performing solid-liquid separation to obtain a solid; wherein the weight ratio of the diatomaceous earth mixture to the calcium nitrate and potassium carbonate is 150:16:14;

[0065] (3) uniformly mixing the solid with the aqueous ammonium nitrate solution, and then drying to obtain a solid mixture; wherein the weight ratio of the solid to the aqueous ammonium nitrate solution is 1:1.5; and the mass fraction of ammonium nitrate in the aqueous ammonium nitrate solution is 15%;

[0066] (4) calcining the solid mixture, and taking the calcined solid after the calcination to obtain the modified diatomite; the calcination refers to: firstly heating the temperature to 380°C at a heating rate of 10°C / min, and calcining at 380°C for 2h; then heating the temperature to 850°C at a heating rate of 10°C / min, and calcining at 850°C for 2h.

[0067] Experimental Example 1

[0068] A test on the effect of rice potted planting was carried out. The test soil was taken from the natural selenium-rich soil (soil pH 4.32, Se content 0.83 mg / kg) in Xinhui, Jiangmen, Guangdong Province; the weight of dry soil in each pot was 4 kg, and 0.5% of the soil weight of the activator for soil selenium to be tested was added to the potted plants in the experimental group; the control group did not add the activator for soil selenium, and the other treatment conditions were consistent with the treatment in the embodiment. After the soil was balanced for 15 days, the rice seedlings were transplanted, and the rice variety planted was Xiangsi seedlings, and routine management was performed during the planting period. Five treatments were set up in the experimental group and the control group respectively. After the rice in each group was harvested, the average selenium content in the brown rice of each group was measured, see Table 1.

[0069] Experimental groups 1 to 5 tested the activators for soil selenium prepared in Examples 1 to 3 and Comparative Examples 1 to 2, respectively.

[0070] Table 1. Results of determination of average selenium content in brown rice of each group

[0071] Types of activators for soil selenium Average selenium content Control group - 0.274mg / kg Experimental Group 1 Example 1: Activator for soil selenium prepared 0.291mg / kg Experimental Group 2 Example 2 Activator for soil selenium prepared 0.426mg / kg Experimental Group 3 Example 3: Activator for soil selenium prepared 0.503mg / kg Experimental Group 4 Comparative Example 1: Activator for soil selenium prepared 0.407mg / kg Experimental Group 5 Comparative Example 2: Activator for soil selenium prepared 0.441mg / kg

[0072] It can be seen from the experimental results in Table 1 that the rice grown in Experimental Group 1 using the soil selenium activator prepared in Example 1 has a higher selenium content in brown rice than that in the Control Group; this indicates that the soil selenium activator of the present invention can promote the absorption of selenium by crops and increase the selenium content in rice.

[0073] It can be seen from the experimental results in Table 1 that the selenium content in the brown rice of the rice planted in Experimental Group 2 using the activator for soil selenium prepared in Example 2 is much higher than that in Experimental Group 1; this indicates that the addition of the activator of modified diatomaceous earth prepared by the method of the present invention can greatly increase the selenium content in the rice compared to the addition of the activator of unmodified diatomaceous earth.

[0074] It can be seen from the experimental results in Table 1 that the rice grown in Experimental Group 3 using the activator for soil selenium prepared in Example 3 has a significantly higher selenium content in brown rice than that in Experimental Group 2; this indicates that the roasting conditions in the preparation process of the modified diatomaceous earth of the present invention are also very critical; adding the modified diatomaceous earth prepared under the two-step calcination conditions of the present invention to the activator can further significantly increase the selenium content in the rice compared to adding the modified diatomaceous earth prepared under the one-step calcination conditions.

[0075] It can be seen from the experimental results in Table 1 that the rice planted with the activator for soil selenium prepared by Comparison 1 in Experimental Group 4 has no further improvement in selenium content in brown rice compared with Experimental Group 2; the rice planted with the activator for soil selenium prepared by Comparison 2 has an improvement in selenium content in brown rice compared with Experimental Group 2, but the improvement is not large; this shows that the roasting conditions in the preparation process of the modified diatomite of the present invention are very critical; the modified diatomite prepared under the two-step calcination conditions of the present invention (i.e., firstly heating to 280°C at a heating rate of 10°C / min, and roasting at 280°C for 2h; then heating to 850°C at a heating rate of 10°C / min, and roasting at 850°C for 2h) must be added to the activator to further significantly increase the selenium content in rice; however, adding the modified diatomite prepared under other two-step calcination conditions to the activator does not further significantly increase the selenium content in rice.

Claims

1. An activator for soil selenium, characterized in that: Contains calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth; Among them, the weight ratio of calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth is 1-2:1-2:1-3.

2. The activator for soil selenium according to claim 1, characterized in that Contains calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth; Among them, the weight ratio of calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth is 1:1:

2.

3. The activator for soil selenium according to claim 1, characterized in that: The effective P2O5 content in calcium magnesium phosphate fertilizer is ≥17%.

4. The activator for soil selenium according to claim 1, characterized in that: The organic matter content in biological organic fertilizer is ≥70%.

5. The activator for soil selenium according to claim 1, characterized in that: The diatomaceous earth is modified diatomaceous earth, and the modified diatomaceous earth is prepared by the following method: (1) taking diatomaceous earth, adding it into water and stirring it to obtain a diatomaceous earth mixed liquid; (2) adding calcium nitrate to the diatomaceous earth mixture, and then adding potassium carbonate, stirring for 40 to 100 minutes, and then performing solid-liquid separation to obtain a solid; (3) uniformly mixing the solid with an aqueous solution of ammonium nitrate, and then drying to obtain a solid mixture; (4) calcining the solid mixture, and taking the calcined solid after the calcination to obtain the modified diatomaceous earth.

6. The activator for soil selenium according to claim 5, characterized in that: In step (1), the weight ratio of diatomaceous earth to water is 1:8-15; Most preferably, the weight ratio of diatomaceous earth to water in step (1) is 1:

10.

7. The activator for soil selenium according to claim 5, characterized in that: In step (2), the weight ratio of the diatomite mixture to calcium nitrate and potassium carbonate is 100-200:15-18:13-15; Most preferably, the weight ratio of the diatomaceous earth mixture to calcium nitrate and potassium carbonate in step (2) is 150:16:

14.

8. The activator for soil selenium according to claim 5, characterized in that: In step (3), the weight ratio of the solid to the aqueous ammonium nitrate solution is 1:1-2; Most preferably, the weight ratio of solid to aqueous ammonium nitrate solution in step (3) is 1:1.

5.

9. The activator for soil selenium according to claim 5, characterized in that: The calcination in step (4) refers to heating the temperature to 700-950°C at a heating rate of 8-15°C / min and calcining at 700-950°C for 2-4h.

10. The method for preparing the activator for soil selenium according to any one of claims 1 to 9, characterized in that: The activator for soil selenium is obtained by uniformly mixing calcium magnesium phosphate fertilizer, biological organic fertilizer and diatomaceous earth or modified diatomaceous earth.