Saline-alkali soil improvement fertilization method based on unprocessed waste double-layer salt isolation

Abstract

The invention discloses a saline-alkali soil improvement fertilization method based on unprocessed waste double-layer salt isolation, belongs to the field of saline-alkali soil improvement, and relates to a saline-alkali soil improvement fertilization method. The invention aims to solve the problems of high cost and long process period of the existing saline-alkali soil treatment method. The method comprises the following steps: step 1, pretreatment; step 2, laying a salt isolation layer; step 3, application of an improved layer; 4, activating and maintaining, and irrigating after construction and thoroughly watering; 5, before crops are planted, chemical fertilizer can be applied to surface soil along with seeds, and then the saline-alkali soil improvement fertilization method based on unprocessed waste double-layer salt isolation is completed. Unprocessed waste is directly used, complex procedures such as firing and modification are omitted, and the material cost is reduced by 30%-70% compared with that of an existing patent.

Description

Technical Field

[0001] This invention belongs to the field of saline-alkali soil improvement and relates to a fertilization method for saline-alkali soil improvement. Background Technology

[0002] Saline-alkali soils present the dual challenges of "saltiness and infertility," and existing traditional methods for treating saline-alkali soils have the following drawbacks:

[0003] (1) Most technologies separate salt removal and fertilization into separate steps: for example, first remove salt through deep ditches (1-2m deep), and then add organic fertilizer to improve the soil. This process is time-consuming (2-3 years for moderately saline-alkali land), and the fertilizer is difficult for crops to absorb before the salt content stabilizes, resulting in a waste of resources.

[0004] (2) Existing technologies rely on planting single salt-tolerant crops such as alfalfa and Suaeda salsa for desalination, but these plants have limited economic value and cannot simultaneously achieve the connection between soil improvement and high-yield crop planting. After improvement, additional steps are still required to switch to grain crops.

[0005] (3) Existing technologies are complex, have high implementation costs, and involve complicated material preparation processes. The use of chemical reagents increases environmental risks and costs.

[0006] (4) Low resource utilization efficiency and secondary waste: Existing methods often involve complex processing of solid waste before utilization, which not only increases process costs but also weakens the natural characteristics of solid waste itself, limiting its large-scale application. Summary of the Invention

[0007] The purpose of this invention is to solve the technical problems of high cost and long process cycle of existing methods for treating saline-alkali soil, and to provide a method for improving and fertilizing saline-alkali soil based on double-layer salt isolation of unprocessed waste.

[0008] A method for improving and fertilizing saline-alkali soil based on a double-layer salt barrier using unprocessed waste is as follows:

[0009] Step 1, Pre-treatment: After the autumn harvest, level the land when the soil temperature is 5~25℃, and then dig trenches 60cm deep with a row spacing of 40~50cm.

[0010] Step 2, laying the salt barrier layer: First, lay corn stalks, wheat stalks, or rice stalks with a moisture content of 15%~20% and a length of 8~12cm flat at the bottom of the trench. Compact the layer to a density of 0.3~0.5g / cm³, and the thickness after compaction should be 2cm. Then, cover the surface of the straw layer with a 2cm thick layer of fly ash or slag, and compact it to a density of 0.3~0.5g / cm³. Backfill and compact the soil so that the backfill soil is 20cm away from the ground.

[0011] Step 3, application of the improved layer: Apply fly ash to the backfill soil at a rate of 1t~3t / acre, and plow deeply and mix evenly until it is level with the soil surface;

[0012] Step 4: Activation and curing; irrigate thoroughly after construction.

[0013] Step 5: Before planting crops, apply fertilizer along with the seeds to the topsoil at a rate of 100-150 kg / mu. This completes the fertilization method for improving saline-alkali soil based on a double-layer salt barrier using unprocessed waste.

[0014] The fly ash or slag mentioned in step two has a particle size of 50~100μm and a loss on ignition of ≤8%.

[0015] The N:P:K mass ratio in the fertilizer mentioned in step three is 15:15:15.

[0016] In step three, when the total salt content of the soil is less than 6 g / kg, the amount of fly ash used is 1 t / mu.

[0017] In step three, when the total salt content of the soil is 6-10 g / kg, the amount of fly ash used is 3 t / mu.

[0018] In step three, when the total salt content of the soil is greater than 10g / kg, the amount of fly ash used is 3t / mu.

[0019] This invention utilizes the natural properties of unprocessed waste through a vertical structural design of "minimalist double-layer salt barrier layer + surface directional improvement layer" to achieve efficient improvement of saline-alkali soil.

[0020] This invention utilizes the structure of straw fibers to 100% block capillary water rise, preventing groundwater from carrying salt back to the surface. Direct contact between the two layers enhances the synergistic effect; backfilling and compacting the soil on both sides of the trench ensures no gaps; the fly ash layer covering the straw layer requires no additional isolation, and its aluminosilicate lattice can adsorb over 90% of surface basic ions (Na⁺, Cl⁻), while simultaneously releasing its own phosphorus and potassium elements, achieving a synergistic effect of salt absorption and nutrient pre-storage.

[0021] For the first time, a double-layer salt barrier structure was constructed using unprocessed natural waste, breaking through the dependence of existing methods on complex material processing. By combining the functions of "physical blocking by straw + chemical adsorption by fly ash", the salt barrier is guaranteed to be durable while reducing costs and environmental risks.

[0022] In response to the "high salt and low fertilizer" characteristics of saline-alkali soil, a "chemical fertilizer + fly ash" targeted fertilization system was designed to overcome the limitations of existing methods, such as lack of fertilization design and unstable nutrient release, and to achieve precise matching of nutrient supply with crop needs.

[0023] Qualitative advantages of this invention:

[0024] 1. Leading in both cost and efficiency: Unprocessed waste can be used directly, eliminating complex processes such as burning and modification, reducing material costs by 30% to 70% compared to existing patents; construction requires no special equipment, mechanized operation is highly efficient, and it is suitable for large-scale saline-alkali land development.

[0025] 2. Enhanced functional synergy: Breaking through the limitations of existing technologies with "single function", the salt barrier layer achieves dual salt blocking through "physical blocking + chemical adsorption", effectively reducing the frequency of salt return; the surface improvement layer forms a "fast-acting + slow-release" fertilizer gradient, increasing corn yield by 36.75%, truly realizing "improvement equals production".

[0026] 3. Significant environmental and resource benefits: Each hectare consumes 18 tons of straw and 30 tons of fly ash, solving the problem of solid waste disposal, and without the input of chemical reagents, avoiding secondary pollution; compared with the firing of ceramsite, it greatly reduces energy consumption and meets the needs of green agricultural development.

[0027] 4. Wider range of applications: It is suitable for light (total salt content 3~6g / kg) and moderate (6~10g / kg) saline-alkali soils. Severe saline-alkali soils can be used after simple leaching pretreatment. Materials can be flexibly replaced (straw can be replaced with rice / wheat straw, fly ash can be replaced with slag), with an effect deviation of ≤10%, making it more adaptable to large-scale applications.

[0028] The problem this invention aims to solve, and the performance and indicators it seeks to achieve:

[0029] (1) Construct a synchronous and synergistic system of "physical salt blocking + chemical salt absorption + targeted fertilizer supply" to break through the limitations of the single function of existing technologies, realize the improvement of moderate and mild saline-alkali land in 1 to 2 years, and directly adapt to the planting of economic crops such as wheat and corn without the need for salt-tolerant plants to transition.

[0030] (2) Using unprocessed waste (straw and fly ash) as core materials eliminates complex processing steps and reduces material costs. At the same time, it consumes 18 tons of straw and 30 tons of fly ash per hectare, achieving the dual environmental benefits of solid waste resource utilization and soil improvement.

[0031] (3) Optimize the technical structure and construction process, simplify the operation procedures, do not require special equipment, can be implemented quickly by mechanization, greatly reduce the construction difficulty, and are suitable for large-scale agricultural development of saline-alkali land. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a soil cross-section in the soil improvement and fertilization method for saline-alkali soil based on a double-layer salt barrier using unprocessed waste, as described in this invention. Detailed Implementation

[0033] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

[0034] Specific Implementation Method 1: This implementation method is based on a double-layer salt-barrier fertilization method using unprocessed waste for saline-alkali soil improvement, as follows:

[0035] Step 1, Pre-treatment: After the autumn harvest, level the land when the soil temperature is 5~25℃, and then dig trenches 60cm deep with a row spacing of 40~50cm.

[0036] Step 2, laying the salt barrier layer: First, lay corn stalks, wheat stalks, or rice stalks with a moisture content of 15%~20% and a length of 8~12cm flat at the bottom of the trench. Compact the layer to a density of 0.3~0.5g / cm³, and the thickness after compaction should be 2cm. Then, cover the surface of the straw layer with a 2cm thick layer of fly ash or slag, and compact it to a density of 0.3~0.5g / cm³. Backfill and compact the soil so that the backfill soil is 20cm away from the ground.

[0037] Step 3, application of the improved layer: Apply fly ash to the backfill soil at a rate of 1t~3t / acre, and plow deeply and mix evenly until it is level with the soil surface;

[0038] Step 4: Activation and curing; irrigate thoroughly after construction.

[0039] Step 5: Before planting crops, apply fertilizer along with the seeds to the topsoil at a rate of 100-150 kg / mu. This completes the fertilization method for improving saline-alkali soil based on a double-layer salt barrier using unprocessed waste.

[0040] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the length of the corn stalk segment in step two is 10cm. Everything else is the same as in Specific Implementation Method One.

[0041] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 or 2 in that the fly ash or slag in step 2 has a particle size of 50~100μm and a loss on ignition of ≤8%. Everything else is the same as in Specific Implementation Method 1 or 2.

[0042] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the N:P:K mass ratio in the fertilizer described in step three is 15:15:15. Everything else is the same as in Specific Implementation Methods One to Three.

[0043] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that, in step three, when the total soil salinity is less than 6 g / kg, the fly ash application rate is 1 t / mu. Everything else is the same as in Specific Implementation Methods One to Four.

[0044] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that, in step three, the total soil salinity is 6-10 g / kg, and the fly ash usage is 3 t / mu. Everything else is the same as in Specific Implementation Methods One to Five.

[0045] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that, in step three, when the total soil salinity is greater than 10 g / kg, the fly ash application rate is 3 t / mu. Everything else is the same as in Specific Implementation Methods One to Six.

[0046] The following experiments were used to verify the effectiveness of the invention:

[0047] Experiment 1:

[0048] The following is an improved fertilization method based on the double-layer salt barrier of unprocessed waste in saline-alkali soil (initial total salt content 10.04 g / kg, pH 7.94, electrical conductivity 2.63 ms / cm):

[0049] Step 1, Pre-treatment: After the autumn harvest, level the land when the soil temperature is 5℃, and then dig trenches 60cm deep with a row spacing of 50cm.

[0050] Step 2, laying the salt barrier layer: First, lay corn stalks with a moisture content of 15% and a length of 10cm flat at the bottom of the trench, flatten and compact them to a bulk density of 0.4g / cm³, and a thickness of 2cm after compaction. Then, cover the surface of the stalk layer with a 2cm thick layer of fly ash, flatten and compact it to a bulk density of 0.4g / cm³, and backfill and compact the soil so that the backfill soil is 20cm away from the ground.

[0051] Step 3, application of the improved layer: Apply fly ash to the backfill soil at a rate of 1t~3t / acre, and plow deeply and mix evenly until it is level with the soil surface;

[0052] Step 4: Activation and maintenance. Irrigate after construction, watering thoroughly up to the salt barrier layer to accelerate the adsorption of soil salt ions by the underlying fly ash.

[0053] Step 5: Before planting crops, apply fertilizer along with the seeds to the topsoil at a rate of 100-150 kg / mu. This completes the fertilization method for improving saline-alkali soil based on a double-layer salt barrier using unprocessed waste.

[0054] The traditional method operates as follows:

[0055] Step 1: After the autumn harvest, level the land when the soil temperature is 5℃, apply 3t / mu of fly ash to the soil surface, and deep plow and mix it evenly into the 0-20cm topsoil layer.

[0056] Step 2: Before planting crops, apply fertilizer along with the seeds to the topsoil at a rate of 150 kg / mu. This is a traditional fertilization method for improving saline-alkali soil.

[0057] Table 1. Comparison of the effects of the present invention with traditional methods

[0058]

[0059] Implementation process: Soil samples were collected before the experiment to determine basic data. After the materials were applied, the monitoring frequency was once a month. Field management was consistent with the management methods of local farmers. No fly ash was added after the experiment.

[0060] Experimental results: After one growing season of improvement, the total soil salinity was measured to be 6.67 g / kg, pH=7.86, and cation exchange capacity was 20.88 cmol / kg; direct planting of maize resulted in a yield of 447 kg / mu (approximately 0.067 hectares). Maize yield increased by 36.75%.

Claims

1. A fertilization method for improving saline-alkali soil based on a double-layer salt barrier using unprocessed waste, characterized in that... The fertilization method for improving saline-alkali soil based on a double-layer salt barrier using unprocessed waste is as follows: Step 1, Pre-treatment: After the autumn harvest, level the land when the soil temperature is 5~25℃, and then dig trenches 60cm deep with a row spacing of 40~50cm. Step 2, laying the salt barrier layer: First, lay corn stalks, wheat stalks, or rice stalks with a moisture content of 15%~20% and a length of 8~12cm flat at the bottom of the trench. Compact the layer to a density of 0.3~0.5g / cm³, and the thickness after compaction should be 2cm. Then, cover the surface of the straw layer with a 2cm thick layer of fly ash or slag, and compact it to a density of 0.3~0.5g / cm³. Backfill and compact the soil so that the backfill soil is 20cm away from the ground. Step 3, application of the improved layer: Apply fly ash to the backfill soil at a rate of 1t~3t / acre, and plow deeply and mix evenly until it is level with the soil surface; Step 4: Activation and curing; irrigate thoroughly after construction. Step 5: Before planting crops, apply fertilizer along with the seeds to the topsoil at a rate of 100-150 kg / mu. This completes the fertilization method for improving saline-alkali soil based on a double-layer salt barrier using unprocessed waste.

2. The method for improving and fertilizing saline-alkali soil based on a double-layer salt barrier using unprocessed waste as described in claim 1, characterized in that... The corn stalk segment mentioned in step two is 10cm long.

3. The method for improving and fertilizing saline-alkali soil based on a double-layer salt barrier using unprocessed waste as described in claim 1, characterized in that... The fly ash or slag mentioned in step two has a particle size of 50~100μm and a loss on ignition of ≤8%.

4. The method for improving and fertilizing saline-alkali soil based on a double-layer salt barrier using unprocessed waste as described in claim 1, characterized in that... The N:P:K mass ratio in the fertilizer described in step three is 15:15:

15.

5. The method for improving and fertilizing saline-alkali soil based on double-layer salt barrier using unprocessed waste according to claim 1, characterized in that... In step three, when the total salt content of the soil is less than 6 g / kg, the amount of fly ash used is 1 t / mu.

6. The method for improving and fertilizing saline-alkali soil based on a double-layer salt barrier using unprocessed waste as described in claim 1, characterized in that... In step three, when the total salt content of the soil is 6-10 g / kg, the amount of fly ash used is 3 t / mu.

7. The method for improving and fertilizing saline-alkali soil based on a double-layer salt barrier using unprocessed waste as described in claim 1, characterized in that... In step three, when the total salt content of the soil is greater than 10g / kg, the amount of fly ash used is 3t / mu.

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