Method for improving soda-saline soil by artificially designed molecular sieve

Abstract

The application discloses a method for improving soda saline-alkali soil by artificially designed molecular sieve, which comprises an artificially designed molecular sieve improver, and the main component is calcium ion exchanged LTA type molecular sieve with a molecular formula of Ca6[(AlO2) 12 (SiO2) 12 ]:27H2O. The method comprises the following steps: diagnosing and evaluating soda saline-alkali soil; adding the artificially designed molecular sieve according to different pH indexes; throwing the corresponding amount of the improver on the surface of the soil, rotary plowing into the soil by 20 cm; irrigating the saline-alkali dry field to make the 20 cm soil layer reach the field water holding capacity, naturally drying to the water content of less than 20%, and starting to plant dry field crops; irrigating the saline-alkali paddy field to soak the field by 8-10 cm, stirring the slurry with a harrow for 36 hours, draining the soil after sedimentation, and irrigating the field by 3 cm for the second time and then transplanting rice seedlings. The application has the calcium-sodium replacement effect on the soil, can permanently lock the excess sodium ions in the soil by one-time treatment, and can solve the problem of heavy metal ion pollution in the soil.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of saline-alkali soil agricultural utilization, and particularly relates to a method for improving soda saline-alkali soil by artificially designed molecular sieve. BACKGROUND

[0002] Soda saline-alkali soil has the special physical and chemical barrier characteristics of high exchangeable sodium, high pH and high salt content, low permeability and low nutrient availability, and its treatment technology mainly includes water conservancy engineering, agronomic measures, irrigation leaching, chemical improvement, guest soil improvement and rice planting in saline-alkali soil. Compared with other improvement measures, the chemical improvement, mainly the improvement method mainly using gypsum, is widely used because it can quickly reduce soil salinity and achieve the purpose of improvement. For severe soda saline-alkali soil, due to the extremely deteriorated soil structure and the highly dispersed soil clay particles, chemical improvement is a necessary improvement measure. Chemical improvement can replace the sodium ions adsorbed in the soil colloid through Ca-Na replacement, reduce the dispersion of soil clay particles and improve the soil structure, and is a fundamental measure for improving soda saline-alkali soil. However, the chemical improvement material itself is also a salt, which will cause a significant increase in soil salinity and salt damage within a certain period of time after application, so chemical improvement must be carried out with a large amount of irrigation to wash and discharge salt, and salt damage must be controlled. However, the discharged salt water can cause environmental pollution, and a large amount of water is also needed, resulting in waste of water resources. Some chemical improvement agents are industrial waste and contain heavy metal ions, which can pollute the soil. Therefore, it is urgent to develop a method for improving saline-alkali soil without salt damage, saving water resources and ensuring environmental safety.

[0003] The artificially designed molecular sieve is a crystalline microporous silico-aluminate, and the main component is a calcium ion-exchanged LTA (Ca-LTA) type molecular sieve with a molecular formula of Ca6[(AlO2) 12 (SiO2) 12 ]:27H2O. The pore size of the Ca-LTA type molecular sieve is 0.5 nm, which can screen substances with a molecular diameter less than 0.5 nm, has high adsorption of small molecules and ion exchange capacity, and can realize the adsorption of heavy metals (the diameter of heavy metal ions is between 0.1-0.3 nm) and Na +The diameter of sodium ion is about 0.204 nm) is adsorbed. The Ca-LTA type molecular sieve crystal framework carries a negative charge, and calcium ions exist in the artificially designed molecular sieve crystal as a balance of positive charge. Under the action of water molecules, the calcium ions can migrate out of the artificially designed molecular sieve crystal into the environment, but must simultaneously obtain two sodium ions from the environment into the artificially designed molecular sieve crystal to meet the principle of electrical neutrality universally followed in nature, that is, the ion exchange of the artificial molecular sieve is completed, and the calcium ions in the soil solution are replaced with the sodium ions adsorbed on the soil colloids. Therefore, the artificially designed molecular sieve can not only provide calcium ions to replace sodium ions in the soil, but also fix the replaced sodium ions in the molecular sieve framework, and can also adsorb and immobilize heavy metal ions. SUMMARY

[0004] The purpose of the present application is to solve the problems existing in the prior art and to provide an improved method for improving soda saline soil by using artificially designed molecular sieves. Artificially designed molecular sieves have special advantages as soil improvers and will play an important role in improving saline-alkali soils in the future.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] An improved method for improving soda saline soil by using artificially designed molecular sieves, comprising an artificially designed molecular sieve improver, wherein the main component of the artificially designed molecular sieve improver is a calcium ion exchanged LTA type molecular sieve with a molecular formula of Ca6[(AlO2) 12 (SiO2) 12 ]:27H2O, and specifically comprising the following specific steps:

[0007] S1: application process:

[0008] S1a: diagnosis and evaluation of moderate to severe soda saline soil: select moderate to severe soda saline soil, measure the soil pH, and divide it into three grades, namely moderate soda saline soil, severe soda saline soil and extremely severe soda saline soil;

[0009] S1b: according to different pH indicators, that is, different degrees of soda saline soil, different amounts of artificially designed molecular sieves are applied, and the application amounts are 0.65 tons / acre, 1 ton / acre and 3 tons / acre respectively;

[0010] S1c: according to the grade of soil pH, the corresponding amount of artificially designed molecular sieve improver is uniformly scattered on the soil surface and rotary plowed into the soil to a depth of 20 cm;

[0011] S2: irrigation process:

[0012] S2a: after the improvement of saline-alkali dry land with the improver, water is irrigated to make the water content of the 20 cm soil layer reach the field water holding capacity, then the soil layer is naturally dried to a water content of less than 20%, and then dry land crops are planted.

[0013] S2b: After the saline-alkali paddy field is implemented with the modifier, water is poured to soak the field, the irrigation water surface is 8-10 cm, the water pouring is stopped, the soil is stirred after 36 hours of soaking, then the water is drained, and then the rice is transplanted after the second water pouring to 3 cm of water surface.

[0014] As a further technical solution of the present application, in S1a, the moderate soda saline-alkali soil is 9.0 < pH ≤ 9.5, the severe soda saline-alkali soil is 9.5 < pH ≤ 10, and the extremely severe soda saline-alkali soil is pH > 10.

[0015] As a further technical solution of the present application, in S1b, when 9.0 < pH ≤ 9.5, that is, the moderate soda saline-alkali soil, the artificial design molecular sieve modifier is applied at 0.65 tons per mu.

[0016] As a further technical solution of the present application, in S1b, when 9.5 < pH ≤ 10, that is, the severe soda saline-alkali soil, the artificial design molecular sieve modifier is applied at 1 ton per mu.

[0017] As a further technical solution of the present application, in S1b, when pH > 10, that is, the extremely severe soda saline-alkali soil, the artificial design molecular sieve modifier is applied at 3 tons per mu.

[0018] The present application has the following beneficial effects:

[0019] 1. It has the function of replacing calcium and sodium in the soil, and can permanently lock the excess sodium ions in the soil through one-time treatment.

[0020] 2. It can improve the soil without increasing the soil salinity.

[0021] 3. The materials used are the same as the composition of the soil, and there is no problem of soil pollution.

[0022] 4. It can simultaneously solve the problem of heavy metal ion pollution in the soil.

[0023] 5. It does not need to wash the field, and saves water resources. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a soil EC and pH graph of different artificial design molecular sieve application amounts in Example 1;

[0025] Figure 2 It is a saline-alkali soil and water field effect graph of the artificial design molecular sieve modifier in Example 1;

[0026] Figure 3 It is a graph of the influence of different amounts of the modifier on the germination rate, seedling height and root length of wheat seeds in Example 2;

[0027] Figure 4Figure for the effect of different amounts of the modifier on the dry weight and fresh weight of the wheat seedling roots and stems in Example 2;

[0028] Figure 5 Figure for the growth of the wheat in Example 2;

[0029] Figure 6 Figure for the growth of the wheat in Example 2 after harvesting;

[0030] Figure 7 Figure for the effect of different amounts of the modifier on the seed germination rate, seedling height and root length of the wheat in Example 3;

[0031] Figure 8 Figure for the effect of different amounts of the modifier on the dry weight and fresh weight of the wheat seedling roots and stems in Example 3;

[0032] Figure 9 Figure for the growth of the wheat in Example 3;

[0033] Figure 10 Figure for the growth of the wheat in Example 3 after harvesting;

[0034] Figure 11 A flow chart of a method for improving soda saline soil by using an artificially designed molecular sieve. DETAILED DESCRIPTION

[0035] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the present application will be further described below in combination with specific embodiments.

[0036] Please refer to the accompanying Figure 11 The method for improving soda saline soil by using an artificially designed molecular sieve comprises an artificially designed molecular sieve modifier, and the main component of the artificially designed molecular sieve modifier is calcium ion-exchanged LTA type molecular sieve with a molecular formula of Ca6[(AlO2) 12 (SiO2) 12 ]:27H2O, and specifically comprises the following specific steps:

[0037] S1: application process

[0038] S1a: diagnosis and evaluation of moderate and severe soda saline soil: select moderate and severe soda saline soil, measure the soil pH, and divide it into three grades, i.e., moderate soda saline soil 9.0 < pH ≤ 9.5, severe soda saline soil 9.5 < pH ≤ 10, and extremely severe soda saline soil pH > 10;

[0039] S1b: According to different pH indexes, that is, different degrees of soda saline-alkali soil, different artificially designed molecular sieve application rates were applied, 9.0 <pH≤9.5、即中度苏打盐碱土时,人工设计分子筛改良剂施用量为0.65吨 / 亩;9.5<pH≤10、即重度苏打盐碱土时,人工设计分子筛改良剂施用量为1吨 / 亩;pH> 10. For extremely heavy soda saline-alkali soil, the artificially designed molecular sieve modifier application rate is 3 tons / mu;

[0040] S1c: According to the soil pH level, evenly spread the corresponding amount of artificially designed molecular sieve amendment on the soil surface and till the soil 20cm deep;

[0041] S2: Irrigation and drainage process:

[0042] S2a: After the saline-alkali dryland is treated with the amendment, irrigation is stopped until the moisture content of the 20cm soil layer reaches the field water holding capacity. The soil is then allowed to dry naturally until the moisture content of the soil layer is below 20%, and then dryland crops are planted.

[0043] S2b: After the saline-alkali paddy field is improved, water is irrigated to soak the field. When the water surface is 8-10 cm, stop watering. After soaking the field for 36 hours, stir the slurry with water and harrow it. After the soil settles, drain it. Then irrigate the field for the second time until the water surface reaches 3 cm, and then transplant rice seedlings.

[0044] Example 1

[0045] Moderate soda saline soil (9.0 <pH≤9.5)人工设计分子筛施用量试验

[0046] Experimental location: The experimental area is located in Honggangzi Village, Honggangzi Township, Da'an City, Jilin Province, with coordinates of 45°36′33″N, 123°52′49″E.

[0047] The soil is moderate soda saline-alkali soil with a pH of 9.34 and an electrical conductivity of 0.36mS / cm. The crop grown is rice, and it is a soda saline-alkali paddy field.

[0048] Experimental treatment: 4 treatment plots were treated with 3 groups of dosages according to the weight ratio of 0.5% (0.65 tons / mu), 1.0% (1.3 tons / mu), and 1.5% (1.95 tons / mu). The fourth group was the control, with an application rate of 0. After evenly spreading the application, the application was rotary tilled to 20 cm and thoroughly mixed with the soil.

[0049] The specific groups are as follows:

[0050] Group 1: The dosage of artificially designed molecular sieve amendment for soda saline-alkali soil is 0.5% (NM2).

[0051] Group 2: The dosage of artificially designed molecular sieve amendment for soda saline-alkali soil is 1.0% (NM3).

[0052] The third group: the dosage of the artificially designed molecular sieve modifier for soda saline soil is 1.5% (NM3).

[0053] The fourth group: the dosage of the artificially designed molecular sieve modifier for soda saline soil is 0% (NM0).

[0054] Test results: after applying the artificially designed molecular sieve, the soil EC significantly decreased, and the 0.5% and 1.5% application treatments reduced the EC by 30% compared to the control. After applying the artificially designed molecular sieve, the soil pH decreased by 0.5% and 1%, with the 0.5% treatment reducing by 0.05 and the 1% treatment reducing by 0.07, and the difference between the two treatments was not significant.

[0055] After applying different amounts of molecular sieve, the rice yield significantly increased, with the 0.5% application increasing by 46.4%, and the 1% and 1.5% applications increasing by 63.6%. Considering the soil improvement effect, yield, and molecular sieve input, the 0.5% application is the most suitable.

[0056] Table 1 Rice yield under different artificially designed molecular sieve application amounts

[0057]

[0058] Example 2

[0059] Artificially designed molecular sieve application amount test for severe soda saline soil (9.5≤pH≤10)

[0060] The soil is severe soda saline soil (9.5≤pH≤10) with a soil pH of 9.62. Five treatments of 1 ton / acre, 2 tons / acre, 3 tons / acre, 4 tons / acre, and 5 tons / acre of artificially designed molecular sieve modifier are selected, and the test crop is wheat. The effects of different amounts of artificially designed molecular sieve modifier on severe soda saline soil and wheat growth are explored.

[0061] The specific grouping is as follows:

[0062] The first group: the dosage of the artificially designed molecular sieve modifier for soda saline soil is 1 t / acre (NM1).

[0063] The second group: the dosage of the artificially designed molecular sieve modifier for soda saline soil is 2 t / acre (NM2).

[0064] The third group: the dosage of the artificially designed molecular sieve modifier for soda saline soil is 3 t / acre (NM3).

[0065] The fourth group: the dosage of the artificially designed molecular sieve modifier for soda saline soil is 4 t / acre (NM4).

[0066] The fifth group: the dosage of the artificially designed molecular sieve modifier for soda saline soil is 5 t / mu (NM5).

[0067] The sixth group (contrast): the dosage of the artificially designed molecular sieve modifier for soda saline soil is 0 t / mu (NM0).

[0068] The test results show that Table 2 is the influence of different dosages of the modifier on the pH, electrical conductivity (EC), total alkalinity and sodium adsorption ratio of the severe soda saline soil. As shown in Table 2, the application of the artificially designed molecular sieve modifier can significantly reduce the total alkalinity. Compared with the control, the soil pH is reduced by 0.04-0.06 units; the electrical conductivity EC is reduced by 0.06-0.12 units; the total alkalinity is reduced by 39.73-42.60%; there is no significant difference in soil pH and EC between the 5 dosages of the modifier.

[0069] Figure 3 The influence of different dosages of the modifier on the germination rate, seedling height and root length of wheat is shown in Table 3. Figure 3 As shown in Table 3, the application of the artificially designed molecular sieve modifier can improve the germination rate of wheat. The germination rate of the first group in the embodiment is significantly higher than that of the control group. Compared with the control group, the germination rate is improved by 15.38%. The application of the artificially designed molecular sieve modifier can improve the seedling height and root length of wheat. The seedling height of the first group to the fifth group is higher than that of the control group, and the root length of wheat is improved by about 1.33-4.00 cm.

[0070] Figure 4 The influence of different dosages of the modifier on the dry weight and fresh weight of the roots and stems of wheat seedlings is shown in Table 4. Figure 4 As shown in Table 4, the application of the artificially designed molecular sieve modifier in the soda saline soil can improve the dry weight and fresh weight of the underground part of the wheat seedlings. The fresh weight of the aboveground part of wheat in the first group, the fourth group and the fifth group is significantly higher than that of the control group, and the dry weight of the aboveground part of wheat in the fourth group is significantly higher than that of the control group.

[0071] The test results show that the artificially designed molecular sieve modifier has a certain improvement effect on the severe soda saline soil (9.5≤pH≤10). Considering the economic benefits of field application and other factors, the best dosage is 1 t / mu.

[0072] Table 2 Influence of different dosages of the modifier on the pH, electrical conductivity and total alkalinity of the severe soda saline soil (9.5≤pH≤10)

[0073]

[0074] Example 3

[0075] Experiment on the dosage of the artificially designed molecular sieve for extremely severe soda saline soil (pH>10)

[0076] The soil is very severe soda saline-alkali soil, the soil pH (1:5 soil water ratio) is 10.10, and the test crop is wheat.

[0077] The specific grouping is as follows:

[0078] The first group: the dosage of the artificial design molecular sieve modifier for soda saline-alkali soil is 1 t / mu (NM1).

[0079] The second group: the dosage of the artificial design molecular sieve modifier for soda saline-alkali soil is 2 t / mu (NM2).

[0080] The third group: the dosage of the artificial design molecular sieve modifier for soda saline-alkali soil is 3 t / mu (NM3).

[0081] The fourth group (contrast): the dosage of the artificial design molecular sieve modifier for soda saline-alkali soil is 0 t / mu (CK).

[0082] The results show that Table 3 is the influence of different dosages of the modifier on the pH, electrical conductivity and total alkalinity of the soda saline-alkali soil. As shown in Table 3, the application of the artificial design molecular sieve modifier has no significant effect on reducing the pH of the severe soda saline-alkali soil, but can significantly reduce the soil electrical conductivity and total alkalinity. Among them, the soil electrical conductivity and total alkalinity of the third group are the lowest, which are reduced by 33.33% and 27.90% compared with the control group.

[0083] Figure 7 The influence of different dosages of the modifier on the wheat seed germination rate, seedling height and root length is shown in Table 4. Figure 7 As shown in Table 4, the application of the artificial design molecular sieve modifier can significantly improve the wheat emergence rate, which is increased by about 366.65% compared with the control group. The wheat seedling height and root length of the second group and the third group are significantly higher than those of the control group, which are increased by about 133.36%-262.5% and 293%-295.21%.

[0084] Figure 8 The influence of different dosages of the modifier on the dry weight and fresh weight of the wheat seedling roots and stems is shown in Table 5. Figure 8 As shown in Table 5, the application of the artificial design molecular sieve modifier can significantly improve the underground fresh weight and dry weight of the wheat. Overall, the application of the artificial design molecular sieve modifier in the soda saline-alkali soil has a promoting effect on the growth and development of the wheat. The test results show that for the severe soda saline-alkali soil (pH>10), the best dosage of the artificial design molecular sieve modifier is 3 t / mu.

[0085] Table 3 Influence of different dosages of the modifier on the pH, electrical conductivity, total alkalinity and sodium adsorption ratio of the soda saline-alkali soil

[0086]

[0087] Example 4

[0088] Verification of artificially designed molecular sieve in typical area of soda saline-alkali soil

[0089]

[0090]

[0091] It should be understood by those of ordinary skill in the art that the above discussion of any of the embodiments is merely exemplary in nature and is not intended to imply limitations on the scope of the application, including the claims; nor has the applicant made any effort to exhaustively describe all possible embodiments and variants thereof that can be made and used to materialize the application's concepts; nor does the above discussion of the embodiments or technical features among different embodiments imply that they cannot be combined; nor does the order of the steps imply that they cannot be implemented in any order; nor are the above-mentioned variations of the different aspects of the application exhaustive; nor are they provided in details for the sake of brevity.

[0092] The present application is intended to cover all such alternatives, modifications, and variations as fall within the broad scope of the claims. Accordingly, any and all such modifications, variations, and equivalents that fall within the spirit and scope of the present application are intended to be included within the scope of the application.

Claims

1. A method for improving soda saline-alkali soil with artificially designed molecular sieves, characterized in that: The present invention comprises an artificially designed molecular sieve modifier, wherein the main components of the artificially designed molecular sieve modifier are LTA type molecular sieves exchanged with calcium ions and a molecular formula of Ca6[(AlO2) 12 (SiO2) 12 ]:27H2O, specifically comprising the following steps: S1: Application process: S1a: Diagnosis and evaluation of moderately and severely soda saline-alkali soil: Select moderately and severely soda saline-alkali soil, measure the soil pH, and divide it into 3 grades, namely moderately soda saline-alkali soil, severely soda saline-alkali soil and extremely severely soda saline-alkali soil; S1b: For different pH indicators, that is, apply different amounts of artificially designed molecular sieves to different degrees of soda saline-alkali soil, and the application amounts are 0.65 tons per mu, 1 ton per mu and 3 tons per mu respectively; S1c: According to the grade of soil pH, evenly spread the corresponding amount of artificially designed molecular sieve modifier on the soil surface and rotary till it into the soil by 20 cm; S2: Irrigation and drainage process: S2a: After applying the modifier to the saline-alkali dry farmland, irrigate until the water content of the 20-cm soil layer reaches the field water holding capacity, then stop irrigation, and then naturally dry until the water content of the soil layer is below 20%, and start planting dry farmland crops; S2b: After applying the modifier to the saline-alkali paddy field, irrigate and soak the field, stop irrigation when the irrigation water surface is 8 - 10 cm, carry out slurry stirring and water harrowing after soaking the field for 36 hours, drain the water after the soil settles, and then carry out the second irrigation until the water surface is 3 cm, and then carry out rice transplanting.

2. The method for improving soda saline-alkali soil with an artificially designed molecular sieve according to claim 1, characterized in that: In the above S1a, for moderately soda saline-alkali soil, 9.0 < pH ≤ 9.5, for severely soda saline-alkali soil, 9.5 < pH ≤ 10, and for extremely severely soda saline-alkali soil, pH > 10.

3. The method for improving soda saline-alkali soil with an artificially designed molecular sieve according to claim 2, characterized in that: In the above S1b, when 9.0 < pH ≤ 9.5, that is, for moderately soda saline-alkali soil, the application amount of the artificially designed molecular sieve modifier is 0.65 tons per mu.

4. The method for improving soda saline-alkali soil with an artificially designed molecular sieve according to claim 3, characterized in that: In the above S1b, when 9.5 < pH ≤ 10, that is, for severely soda saline-alkali soil, the application amount of the artificially designed molecular sieve modifier is 1 ton per mu.

5. The method for improving soda saline-alkali soil with artificially designed molecular sieve according to claim 4, characterized in that: In the above S1b, when pH > 10, that is, for extremely severely soda saline-alkali soil, the application amount of the artificially designed molecular sieve modifier is 3 tons per mu.

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