A salt-tolerant artificial soil based on soda-saline alkali soil and its preparation method

Abstract

The application provides a kind of iron tailings salt-tolerant artificial soil based on soda salted alkali soil and a preparation method thereof, and belongs to the technical field of artificial soil.The artificial soil comprises, by weight, 5-20 parts of salted alkali soil, 40-65 parts of sodium removal modifier, 30-50 parts of livestock and poultry manure, 1-2 parts of strong seedling agent and 1-2 parts of nitrogen fertilizer.The sodium removal modifier comprises 35-50 parts of sodium exchanger, 3-10 parts of acid activator and 1-2 parts of bacterial agent.The sodium exchanger comprises 20-30 parts of iron tailings and 15-20 parts of calcium salt.The application makes up for the deficiencies of salted alkali soil in various indicators, interacts, realizes the resource utilization of solid waste, develops the utilization value of salted alkali soil, has low cost, and at the same time, good artificial soil effect can be obtained, and the adaptability of seedlings cultivated in salted alkali soil is higher.

Description

Technical Field

[0001] This invention relates to the field of artificial soil technology, and in particular to a salt-tolerant artificial soil based on soda salinized alkaline soil and its preparation method. Background Technology

[0002] Saline-alkali soil is a general term for saline soil, alkaline soil, and saline-alkali soil, widely distributed in arid and semi-arid regions worldwide, resulting from the accumulation of soluble salts on the soil surface. my country has a wide distribution of saline-alkali land, and the salt composition of saline-alkali soil varies in different regions. Records show that in Northeast China, it is mainly soda saline-alkali soil, while coastal saline-alkali soil contains large amounts of sodium salts. Salinity is a significant factor contributing to the deterioration of soil physicochemical properties and the decline in land productivity. Severe soil salinization severely restricts agricultural production and ecological economic development. Therefore, the remediation of saline-alkali soil is of great significance for the utilization of saline-alkali land resources, improvement of the ecological environment, and increase of grain production capacity.

[0003] Currently, publicly available artificial soil technologies mainly focus on using arable soil, silt, waste soil, or nutrient soil available in planting areas, supplemented with materials such as peat moss, vermiculite, or industrial and agricultural waste. This approach suffers from problems such as damaging natural resources, difficulty in obtaining soil, and high raw material costs. For example, patent application number 201810135550.2 discloses a rice carbon-based seedling substrate and its preparation method. The ingredients include oilseed cake, inorganic compound fertilizer, diatomaceous earth, tailings, and biochar, which improves the properties of the seedling substrate, increasing seedling survival and growth rates, and comprehensively improving cultivation quality. Patent application number 201510383848.1 discloses a rice seedling substrate and its preparation method, which involves mixing crushed rice husks, crushed topsoil, mushroom residue, and cow manure in a specific ratio for composting and fermentation to obtain the rice seedling substrate. This achieves resource utilization of agricultural waste and results in better seedling cultivation.

[0004] The key focus of existing saline-alkali soil remediation technologies mentioned above is on improving the physical and chemical properties of saline-alkali soil to increase crop yield, with little attention paid to reducing the toxic effects of sodium salts in saline-alkali soil. However, the high cost and difficulty in preparing seedling soil remain pressing issues when planting crops in saline-alkali soil areas. While saline-alkali land resources are abundant, the excessive salt and alkaline content restricts root development and nutrient absorption, resulting in poor seedling growth. Therefore, effectively reducing the impact of salt stress on seedling growth is crucial for improving the quality and efficiency of seedling cultivation in saline-alkali soil areas. Furthermore, some patents suffer from complex preparation processes for soil conditioners, high energy consumption, and high costs.

[0005] In summary, there is a need for a method to prepare salt-tolerant artificial soil by adding a sodium-removing agent mainly composed of iron tailings to saline-alkali soil. This method is simple to operate, has low energy consumption, and is inexpensive. It can realize both seedling cultivation using saline-alkali soil and the resource utilization of solid waste. Summary of the Invention

[0006] The purpose of this invention is to provide a salt-tolerant artificial soil based on soda salinized alkaline soil and its preparation method. The method involves adding a sodium-removing agent and other auxiliary materials to the soda salinized alkaline soil, thereby significantly improving the seedling survival rate under saline conditions and alleviating the inhibitory effect of salt stress on seedling growth. It is mainly used for the cultivation of seedlings in saline-alkali soil areas.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: On the one hand, a salt-tolerant artificial soil based on soda-saline alkaline soil tailings is provided, which, by weight, includes: 5-20 parts of saline alkaline soil, 40-65 parts of sodium removal amendment, 30-50 parts of livestock and poultry manure, 1-2 parts of seedling strengthening agent, and 1-2 parts of nitrogen fertilizer.

[0008] Preferably, by weight, the sodium removal improver comprises: 35-50 parts sodium exchanger, 3-10 parts acid activator, and 1-2 parts bacterial agent.

[0009] Preferably, the sodium exchanger comprises, by weight, 20-30 parts of iron tailings and 15-20 parts of calcium salt.

[0010] Preferably, the total iron content in the iron tailings is 8-20%, the iron oxide content is 4-10%, and the silicon dioxide content is 65-85%.

[0011] Preferably, the calcium salt is one or more of gypsum, phosphogypsum, calcium chloride, and superphosphate.

[0012] Preferably, the acid activator is one or more of oxalic acid, citric acid, malic acid, acetic acid, etc. Compared with inorganic acids such as sulfuric acid, organic acids avoid the drawbacks of being environmentally unfriendly due to excessive concentration.

[0013] Preferably, the bacterial agent is one or more of Bacillus subtilis, Pseudomonas phosphate-solubilizing bacteria, lactic acid bacteria, and yeast.

[0014] Preferably, the livestock and poultry manure is a harmless and matured product of composting animal manure and crop straw.

[0015] Preferably, the nitrogen fertilizer is one or more of ammonium sulfate, urea, and ammonium chloride.

[0016] On the other hand, a method for preparing the above-mentioned salt-tolerant artificial soil made from iron tailings is also provided, which includes the following steps: Material preparation: Weigh the materials according to the following weight parts: 35-50 parts sodium exchanger, 3-10 parts acid activator, and 1-2 parts bacterial agent.

[0017] Mixing and aging: Mix all materials evenly, add water to the mixture at a solid-liquid ratio of 1:(1 to 1.5), stir, and let stand for aging for 10 to 18 days.

[0018] Natural air drying: The aged material is naturally air dried until the moisture content is 25-35% to obtain the sodium removal improver.

[0019] Add saline-alkali soil, livestock and poultry manure, seedling strengthening agent and nitrogen fertilizer in proportion, stir in a stainless steel mixer for 30 minutes, and age for 24 hours to obtain iron tailings salt-resistant artificial soil.

[0020] The advantages of this invention are as follows: The organic acids and inorganic materials in this invention undergo a physicochemical reaction with the saline-alkali soil. Calcium ions in calcium sulfate and cations in iron tailings exchange ions with sodium ions in the saline-alkali soil, improving sodium removal efficiency. The acidity of calcium sulfate and organic acids reduces the alkalinity of the saline-alkali soil, improving the crop growth environment. The organic acids also have a slow-release function during the adjustment process. The structural characteristics of iron tailings improve the soil's physicochemical properties, increase soil permeability and aeration, effectively improving the saline-alkali soil and promoting plant growth. The decomposed organic fertilizer provides a large amount of organic matter. Microbial agents work synergistically, increasing soil fertility through nitrogen fixation and phosphorus release. These factors compensate for the deficiencies in various indicators of the saline-alkali soil, interacting to achieve the resource utilization of solid waste, develop the utilization value of saline-alkali soil, and achieve excellent artificial soil effects at a low cost. The seedlings cultivated in this way exhibit higher adaptability to saline-alkali soil. Attached Figure Description

[0021] Figure 1 This is a flowchart illustrating the preparation process of artificial soil according to the present invention. Figure 2 This is a flowchart illustrating the preparation process of the sodium removal modifier of the present invention. Figure 3 Rice seedling raising effect (control group); Figure 4 Rice seedling raising effect (Example 1); Figure 5 Rice seedling raising effect (Example 2). Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] Example 1: This example provides a salt-tolerant artificial soil made from iron tailings, comprising, by weight: 15 parts saline-alkali soil, 55 parts sodium removal modifier, 35 parts well-rotted cow manure, 1 part seedling strengthening agent, and 1 part nitrogen fertilizer. The sodium removal modifier, by weight, comprises: 40 parts sodium exchanger, 4 parts acid activator, and 1 part microbial agent. The sodium exchanger comprises: 20 parts iron tailings and 20 parts calcium salt.

[0024] The iron tailings contained 11.21% total iron, 4.9% ferric oxide, 75.8% silicon dioxide, 0.44% aluminum oxide, 0.12% magnesium oxide, and 0.28% calcium oxide.

[0025] The calcium salt is gypsum, and its main component is calcium sulfate.

[0026] The acid activator is selected from citric acid and oxalic acid, with a mass ratio of 1:5.

[0027] The bacterial agent is Bacillus subtilis.

[0028] The nitrogen fertilizer is ammonium sulfate.

[0029] The preparation method of the above-mentioned salt-tolerant artificial soil made from iron tailings includes the following steps: Material preparation: Weigh out the sodium exchange resin, acid activator, and bacterial agent according to the above weight proportions.

[0030] Mixing and aging: Mix all materials evenly, add water to the mixture at a solid-liquid ratio of 1:1, stir, and let stand for aging for 18 days.

[0031] Natural air drying: The aged material is naturally air dried until the moisture content is 30% to obtain the sodium removal improver.

[0032] Add 15 parts of saline-alkali soil, 35 parts of decomposed cow manure, 1 part of seedling strengthening agent, and 1 part of ammonium sulfate. Mix in a stainless steel mixer for 30 minutes and age for 24 hours to obtain salt-tolerant artificial soil from iron tailings.

[0033] This solution is specifically designed for seedling cultivation in soda-saline-alkali soil areas. It prepares a special artificial soil for seedling cultivation, which can be used directly as a seedling substrate to replace native saline-alkali soil. In this solution, calcium salts, iron tailings, organic acid activators, and microbial agents form a synergistic system that can assist in ion exchange, weaken salt stress, and adapt to the seedling environment. At the same time, it can also accelerate the weathering of minerals inside the iron tailings and promote the weathering of iron tailings into soil, transforming industrial solid waste iron tailings into an artificial soil framework with soil structure, aeration, and water permeability.

[0034] Example 2: The only difference between this example and Example 1 is that, by weight, the salt-tolerant artificial soil of iron tailings in this example is composed of the following components: 10 parts of saline-alkali soil, 58 parts of sodium removal conditioner, 33 parts of decomposed cow manure, 1 part of seedling strengthening agent, and 1 part of nitrogen fertilizer.

[0035] The sodium removal modifier comprises: 44 parts sodium exchanger, 5 parts acid activator, and 1 part bacterial agent.

[0036] The sodium exchanger comprises: 25 parts iron tailings and 20 parts calcium salt.

[0037] The acid activator is citric acid and oxalic acid in a mass ratio of 1:2.

[0038] Everything else is the same as in Example 1, and will not be repeated here.

[0039] Example 3: The only difference between this example and Example 1 is that, by weight, it includes: 5 parts of saline-alkali soil, 40 parts of sodium removal improver, 30 parts of livestock and poultry manure, 1 part of seedling strengthening agent, and 1 part of nitrogen fertilizer.

[0040] The sodium removal modifier comprises: 35 parts sodium exchanger, 3 parts acid activator, and 1 part bacterial agent.

[0041] The sodium exchanger comprises: 20 parts iron tailings and 15 parts calcium salt.

[0042] Example 4: The only difference between this example and Example 1 is that it includes: 20 parts of saline-alkali soil, 65 parts of sodium removal improver, 50 parts of livestock and poultry manure, 2 parts of seedling strengthening agent, and 2 parts of nitrogen fertilizer.

[0043] The sodium removal modifier comprises: 50 parts sodium exchanger, 10 parts acid activator, and 2 parts bacterial agent.

[0044] The sodium exchanger comprises: 30 parts iron tailings and 20 parts calcium salt.

[0045] The physicochemical properties of the iron tailings salt-tolerant artificial soil in Examples 1-4 were measured, and all indicators met the standard "Rice Seedling Substrate" (DB21 / T 2648-2016). The specific measurement results for Examples 1-2 are as follows.

[0046] Table 1. Basic physical and chemical properties of salt-tolerant artificial soil made from iron tailings.

[0047] Evaluation of seedling cultivation effect: Rice varieties Tiannong 6 and Hongke 181 were selected for seedling cultivation experiments. After disinfection, soaking, and germination of the rice seeds, the salt-tolerant artificial soil prepared in Examples 1 and 2 was placed in seedling trays, with the salt-tolerant artificial soil at the bottom of the trays. Purchased seedling soil served as a control. After the seeds were placed in the trays, a layer of salt-tolerant artificial soil was covered. The temperature inside the greenhouse was controlled between 15 and 20°C. Watering was done daily, and ventilation was ensured during seedling management to prevent scorching. Seedlings were cultivated to the three-leaf stage before seedling quality testing was conducted.

[0048] Rice seedling raising effect Figures 3-5 As shown in the figure, the effects of Examples 1-2 are significantly better than those of the control group.

[0049] The quality of seedlings cultivated in the salt-tolerant artificial soil prepared by this invention was compared with that of seedlings cultivated in purchased seedling soil. The results are as follows: Table 2 Comparison of seedling quality

[0050] The above experimental results show that the seedlings cultivated using the iron tailings salt-tolerant artificial soil of the present invention have a higher root-to-shoot ratio and stronger seedling index, and grow better, thus realizing salt-tolerant seedling cultivation using saline-alkali soil as raw material.

Claims

1. A salt-tolerant artificial soil based on soda-saline alkaline soil tailings, characterized in that: The components include the following parts by mass: 5-20 parts of saline-alkali soil, 40-65 parts of sodium removal conditioner, 30-50 parts of livestock and poultry manure, 1-2 parts of seedling strengthening agent, and 1-2 parts of nitrogen fertilizer; The sodium removal modifier comprises: 35-50 parts sodium exchanger, 3-10 parts acid activator, and 1-2 parts bacterial agent; The sodium exchanger comprises: 20-30 parts of iron tailings and 15-20 parts of calcium salt.

2. The salt-tolerant artificial soil based on soda-salinated alkaline soil tailings as described in claim 1, characterized in that: The iron tailings contain 8-20% total iron, 4-10% iron oxides, and 65-85% silicon dioxide.

3. The salt-tolerant artificial soil based on soda-saline alkaline soil tailings as described in claim 1, characterized in that: The calcium salt is one or a mixture of several of the following in any proportion: gypsum, phosphogypsum, calcium chloride, and superphosphate.

4. The salt-tolerant artificial soil based on soda-salinated alkaline soil tailings as described in claim 1, characterized in that: The acid activator is one or a mixture of several of oxalic acid, citric acid, malic acid, and acetic acid in any proportion.

5. The salt-tolerant artificial soil based on soda-salinated alkaline soil tailings as described in claim 1, characterized in that: The bacterial agent is one or a mixture of several of Bacillus subtilis, Pseudomonas phosphate-solubilizing bacteria, lactic acid bacteria, and yeast in any proportion.

6. The salt-tolerant artificial soil based on soda-salinated alkaline soil tailings as described in claim 1, characterized in that: The livestock and poultry manure is the product of composting animal manure and crop straw.

7. The salt-tolerant artificial soil based on soda-salinated alkaline soil tailings as described in claim 1, characterized in that: The nitrogen fertilizer is one or a mixture of several of the following in any proportion: ammonium sulfate, urea, and ammonium chloride.

8. The method for preparing salt-tolerant artificial soil based on soda-salinated alkaline soil tailings as described in claim 1, characterized in that: Includes the following steps: Preparation of sodium removal modifier: Weigh iron tailings, calcium salt, acid activator and bacterial agent according to the weight parts, mix them evenly, add water and stir, then let stand and age for 10 to 18 days, and air dry naturally until the moisture content is 25 to 35% to obtain the product. Preparation of salt-tolerant artificial soil from iron tailings: Weigh out the saline-alkali soil, sodium removal modifier, livestock and poultry manure, seedling strengthening agent, and nitrogen fertilizer according to the weight proportions, mix and stir for 30 minutes, and age for 24 hours to obtain the final product.

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