Soil improvement method for extremely severe saline-alkali soil and application of soil improvement method

Abstract

The invention relates to the technical field of saline-alkali soil improvement. The invention provides an extremely severe saline-alkali soil improvement method which comprises the following steps: (1) ploughing soil to be improved, ditching, and spreading a material A into ditches; (2) irrigation is carried out after crops are sown in the ditches, and field management is carried out in the crop growth period; (3) after crops are harvested, crop straw is smashed and subjected to rotary tillage into soil; and (4) repeating the steps (1)-(3), and carrying out continuous soil improvement treatment. According to the technical scheme, the soil structure and the microbial environment are improved through soil preparation and fertilization before sowing, the salt content of soil of a plough layer is reduced through a salt reducing measure, soil osmotic pressure is reduced, and the salt content of the soil is continuously reduced through a crop planting measure. According to the scheme, the soil saline-alkali improvement effect is good, a good soil environment is created for seed budding and seedling emergence stages, and the seed emergence rate is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of saline-alkali land soil improvement, and in particular to a method for improving extremely severe saline-alkali land soil and application thereof. Background Art

[0002] Excessive soluble salt content in saline-alkali soil leads to soil structure deterioration and has a significant negative impact on permeability, water penetration and porosity. It hinders soil water conductivity and air permeability, while causing soil structure decomposition, organic matter loss and nutrient deficiency, resulting in a decrease in soil fertility, which ultimately affects crop growth and agricultural production. Soil management and improvement of saline-alkali land is an important measure to improve agricultural productivity and ensure food security.

[0003] At present, the soil improvement and management measures for saline-alkali land are mainly divided into physical improvement, chemical improvement, biological improvement, water conservancy project improvement and comprehensive management. Physical improvement destroys the capillary action of the soil and blocks the further accumulation of salt to the surface through engineering measures such as leveling the land, deep plowing and turning, soil filling, sand pressing, loosening the soil, and lifting the field. Chemical improvement mainly adds chemical substances such as gypsum, phosphogypsum, desulfurized gypsum, sulfur, humic acid, furfural residue, etc. to the soil to achieve the purpose of reducing soil pH, alkalinity and improving soil structure. Biological improvement mainly improves soil structure, improves soil fertility and reduces salt content by breeding and planting salt-alkali tolerant crops, increasing soil organic matter content, and using the metabolic activities of microbial technology. Water conservancy project improvement is based on the law of "water-salt movement", and discharges salt through underground infiltration pipes, combined with ditches and deep wells to achieve the purpose of preventing salt return.

[0004] The management of saline-alkali land is a complex issue, among which how to improve soil structure, reduce soil salinity and ensure the survival of crops is the primary technical difficulty in the management of saline-alkali land. Soil conditioners have become a hot topic in the research and application demonstration of saline-alkali land improvement in recent years because of their advantages such as being able to inhibit the stress of soil salt on crops and directly improve soil structure.

[0005] In actual application, since saline-alkali land soil improvement requires a large amount of improver application, the commonly used compound fertilizer-based soil conditioners make the soil improvement cost too high when used in large quantities, which is not conducive to farmers or small-scale agricultural cooperatives to independently carry out saline-alkali land improvement. Therefore, the use of low-cost improvers is considered to be the first choice for saline-alkali land soil improvement while ensuring a certain soil improvement effect.

[0006] Through the above analysis, the problems or barriers existing in the application of existing technologies in the improvement of extremely severe saline-alkali land are:

[0007] (1) At present, the "hidden pipe salt drainage" technology is not effective in semi-arid areas, especially in desertification transition zones, because the soil particles are very fine, the soil permeability is poor and the pipe pores are easily blocked, which ultimately leads to poor salt drainage effect.

[0008] (2) Currently, the material transportation cost of preparing improvers using bulk solid wastes such as phosphogypsum is high, resulting in unacceptable treatment costs.

[0009] (3) Currently, no economic crop varieties have been cultivated that are tolerant to extremely severe saline-alkali soils. The existing salt-alkali-tolerant crops have a low germination rate in extremely severe saline-alkali soils and their growth in the later stages is poor. Summary of the invention

[0010] The purpose of the present invention is to provide a method for improving extremely severe saline-alkali land, which can not only better improve the soil salinity, but also create a good soil environment for seed germination and emergence, and improve the seed emergence rate.

[0011] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0012] The present invention provides a method for improving extremely severe saline-alkali land soil, comprising the following steps:

[0013] (1) Plowing the soil to be improved, digging trenches, and spreading material A into the trenches;

[0014] (2) Irrigation after sowing crops in the furrow and field management during the crop growth cycle;

[0015] (3) After the crops are harvested, the crop straw is crushed and rotary tilled into the soil;

[0016] (4) Repeat steps (1) to (3) to carry out continuous soil improvement treatment.

[0017] Preferably, the material A includes organic fertilizer, microbial agent and soil conditioner.

[0018] Preferably, the tillage depth in step (1) is 20-35 cm; the furrowing depth is 15-25 cm, the furrowing width is 30-45 cm, and the distance between furrows is 40-65 cm.

[0019] Preferably, the mass ratio of the organic fertilizer, the microbial agent and the soil conditioner is (1000-2500):(50-100):(50-150).

[0020] Preferably, the organic fertilizer is decomposed and fermented sheep manure; the effective viable bacteria count of the microbial agent is ≥5.0×10 8 CFU / g; the soil conditioner is a mineral soil conditioner with a pH value of 7.0-12.

[0021] Preferably, the crops sown in step (2) include sunflower, sugar beet, sorghum and millet, the sowing rate of sunflower is 1-2.5 kg / mu, the sowing rate of sugar beet is 0.5-1.5 kg / mu, the sowing rate of sorghum is 0.5-1.5 kg / mu, and the sowing rate of millet is 0.5-1.5 kg / mu.

[0022] Preferably, the sowing spacing in step (2) is 15-25 cm, and the sowing row spacing is 50-60 cm.

[0023] Preferably, during the irrigation process of step (2), a salt reducing agent is used, and the amount of the salt reducing agent and the amount of irrigation water per mu is (4-8) kg: (3-6) m 3 .

[0024] Preferably, the salt-reducing agent includes any one or two of salt-loving / halotolerant microbial agents, moisture retainers, wood vinegar, and soil loosening agents.

[0025] Preferably, the depth of the rotary tillage in step (3) is 20-30 cm.

[0026] The invention also provides application of the improved method in comprehensive management of semi-arid areas or saline-alkali land.

[0027] By adopting the above technical solution, the present invention has the following beneficial effects:

[0028] 1. The technical solution of the present invention improves soil organic matter and nutrient content, improves soil structure and microbial environment, and increases soil permeability by land preparation and fertilization before sowing; reduces soil salt content and soil osmotic pressure by salt reduction measures; and continuously reduces soil salt content by crop planting measures. It effectively inhibits the stress of soil salt on crops, creates a good soil environment for seed germination and emergence, and improves seed emergence rate.

[0029] 2. Drip irrigation can save more than 80% of water compared to traditional flooding. It also makes topdressing and salt-reducing agents more even and requires less work.

[0030] 3. The technical solution of the present invention reduces the cost of achieving saline-alkali soil improvement while ensuring a certain soil improvement effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The changes of total soil salt content and pH during the saline-alkali soil improvement process described in Experimental Example 1;

[0032] Figure 2This is the situation of crops at various growth stages during the saline-alkali soil improvement process described in Experimental Example 1. DETAILED DESCRIPTION

[0033] The present invention provides a method for improving extremely severe saline-alkali land soil, comprising the following steps:

[0034] (1) Plowing the soil to be improved, digging trenches, and spreading material A into the trenches;

[0035] (2) Irrigation after sowing crops in the furrow and field management during the crop growth cycle;

[0036] (3) After the crops are harvested, the crop straw is crushed and rotary tilled into the soil;

[0037] (4) Repeat steps (1) to (3) to carry out continuous soil improvement treatment.

[0038] In the present invention, the average salt content of the soil to be improved is preferably 102-226 g / kg, and the average pH value is preferably 8.65-9.10.

[0039] The soil to be improved is plowed and then furrowed. The plowing depth of the present invention is preferably 20-35 cm, more preferably 25-32 cm, and more preferably 30 cm; the furrowing depth is preferably 15-25 cm, more preferably 18-23 cm, and more preferably 20 cm; the furrowing width is preferably 30-45 cm, more preferably 35-42 cm, and more preferably 40 cm; the spacing between the furrows is preferably 40-60 cm, more preferably 45-55 cm, and more preferably 50 cm.

[0040] In the present invention, material A is then spread into the ditch, and the material A preferably includes organic fertilizer, microbial agent and soil conditioner. The organic fertilizer of the present invention is preferably decomposed and fermented sheep manure; the microbial agent is preferably purchased from Beijing Zhongnong Fuyuan Group Co., Ltd., and the microbial agent preferably contains Bacillus amyloliquefaciens, Bacillus licheniformis and Bacillus subtilis, and the effective viable count of the microbial agent is ≥5.0×10 8CFU / g. The soil conditioner of the present invention is preferably a mineral soil conditioner, which is purchased from Liaoning Lianshi Ecological Technology Co., Ltd., and the mineral soil conditioner contains SiO2≥10%, CaO≥20%, K2O≥3%, and MgO≥3.5%. The pH value of the mineral soil conditioner is preferably 7.0-12. The mass ratio of the organic fertilizer, microbial agent and soil conditioner is preferably (1000-2500): (50-100): (50-150), further preferably (1500-2200): (70-90): (80-120), and further preferably 2000: 80: 100. In the present invention, after spreading material A, rotary tillage is performed in the ditch to fully and evenly mix material A with the soil.

[0041] In the present invention, crops are then sown in the furrow, and the sown crops preferably include oil sunflower, sugar beet, sorghum and millet, and the four crops are planted in different areas. The sowing amount of the oil sunflower of the present invention is preferably 1-2.5 kg / mu, further preferably 1.5-2.2 kg / mu, and further preferably 2 kg / mu; the sowing amount of sugar beet is preferably 0.5-1.5 kg / mu, further preferably 0.8-1.2 kg / mu, and further preferably 1 kg / mu; the sowing amount of sorghum is preferably 0.5-1.5 kg / mu, further preferably 0.7-1.2 kg / mu, and further preferably 1 kg / mu; the sowing amount of millet is preferably 0.5-1.5 kg / mu, further preferably 0.8-1.3 kg / mu, and further preferably 1 kg / mu. The sowing spacing of the present invention is preferably 15-25 cm, further preferably 18-23 cm, and further preferably 20 cm; the sowing row spacing is preferably 50-65 cm, further preferably 55-62 cm, and further preferably 60 cm.

[0042] In the present invention, irrigation is performed after sowing is completed, and the irrigation method is preferably drip irrigation. In the irrigation process of the present invention, a salt-reducing agent is preferably used in combination, and the salt-reducing agent is added to the irrigation water. The salt-reducing agent preferably includes any one or two of salt-loving / halophilic microbial agents, moisture-retaining agents, wood vinegar, and soil loosening agents. The dosage of the salt-reducing agent and the irrigation water per mu of the present invention is preferably (4-8) kg: (3-6) m 3 , further preferably (4.5-6) ​​kg: (4-5) m 3 , further preferably 5kg:4m 3 .

[0043] In the present invention, field management is performed throughout the entire growth cycle of the crop, and the field management preferably includes topdressing, irrigation, and the use of salt-reducing agents. The specific operations are determined based on actual conditions and agronomic experience.

[0044] In the present invention, after the crops are harvested, the crop straw is crushed and rotary tilled into the soil, and the depth of the rotary tillage is preferably 20-30 cm, more preferably 22-28 cm, and even more preferably 25 cm.

[0045] In the present invention, it is preferred to sample and test the saline-alkali land soil during the crop growth period and after harvest, analyze the changing patterns of physical and chemical properties, and observe the improvement of the saline-alkali land.

[0046] The invention also provides application of the improved method in comprehensive management of semi-arid areas or saline-alkali land.

[0047] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0048] The salt-loving / halotolerant microbial agent in the present invention was purchased from Fengda Saltwater Technology Development (Shandong) Co., Ltd., and the moisture retaining agent was purchased from the Operation Center of Fengda Salt-alkali Land Improvement Agricultural Research Institute in Dongying City.

[0049] Example 1

[0050] A method for improving extremely heavy saline-alkali soil, comprising the following steps:

[0051] (1) The soil to be improved with an average salt content of 154 g / kg and an average pH of 8.86 was plowed for 30 cm, and then furrowed with a depth of 20 cm, a width of 40 cm, and a spacing of 50 cm;

[0052] (2) applying 2000 kg / mu of fermented sheep manure, 80 kg / mu of microbial agents, and 100 kg / mu of mineral soil conditioners to the ditch, and then rotary tilling the ditch to fully mix the above-mentioned components with the soil;

[0053] (3) Sunflower seeds were sown in the furrow at a sowing rate of 2 kg / mu, sugar beets 1 kg / mu, sorghum 1 kg / mu, and millet 1 kg / mu. The four crops were planted in different areas, with a sowing spacing of 20 cm and a row spacing of 60 cm. After sowing, drip irrigation belts were laid for irrigation. Salt-loving / tolerant microbial agents and moisture retainers were used during the irrigation process. Salt-loving / tolerant microbial agents and moisture retainers were added to the irrigation water for application. The irrigation water volume per mu was 4m 3 , the application rate of salt-loving / tolerant microbial agents is 3kg / mu, and the application rate of moisture retaining agents is 2kg / mu;

[0054] (4) Carry out field management according to actual conditions and agronomic experience throughout the crop growth cycle to ensure normal growth of crops;

[0055] (5) After the crops are harvested, the crop straw is crushed and rotary tilled into the soil to a depth of 25 cm;

[0056] (6) After the crops are harvested, the process of steps (1) to (5) is repeated to carry out continuous soil improvement treatment.

[0057] Example 2

[0058] A method for improving extremely heavy saline-alkali soil, comprising the following steps:

[0059] (1) The soil to be improved with an average salt content of 226 g / kg and an average pH of 9.05 was plowed for 30 cm, and then furrowed with a depth of 15 cm, a width of 45 cm, and a spacing of 40 cm;

[0060] (2) applying 1000 kg / mu of decomposed and fermented sheep manure, 100 kg / mu of microbial agents, and 150 kg / mu of mineral soil conditioners to the ditch, and then rotary tilling the ditch to fully mix the above-mentioned components with the soil;

[0061] (3) Sunflowers were sown at a sowing rate of 1 kg / mu, sugar beets at 1.5 kg / mu, sorghum at 1.5 kg / mu, and millet at 0.5 kg / mu in the furrows. The four crops were planted in different areas, with a sowing spacing of 15 cm and a row spacing of 65 cm. After sowing, drip irrigation belts were laid for irrigation. Wood vinegar and moisture retaining agents were used during the irrigation process. The wood vinegar and moisture retaining agents were added to the irrigation water for application. The irrigation water volume per mu was 6m 3 , the application rate of wood vinegar is 3kg / mu, and the application rate of moisture retainer is 4kg / mu;

[0062] (4) Carry out field management according to actual conditions and agronomic experience throughout the crop growth cycle to ensure normal growth of crops;

[0063] (5) After the crops are harvested, the crop straw is crushed and rotary tilled into the soil to a depth of 20 cm;

[0064] (6) After the crops are harvested, the process of steps (1) to (5) is repeated to carry out continuous soil improvement treatment.

[0065] Example 3

[0066] A method for improving extremely heavy saline-alkali soil, comprising the following steps:

[0067] (1) The soil to be improved with an average salt content of 102 g / kg and an average pH of 8.65 was plowed for 30 cm, and then furrowed with a depth of 25 cm, a width of 30 cm, and a spacing of 50 cm;

[0068] (2) applying 2500 kg / mu of fermented sheep manure, 50 kg / mu of microbial agents, and 50 kg / mu of mineral soil conditioners to the ditch, and then rotary tilling the ditch to fully mix the above-mentioned components with the soil;

[0069] (3) Sunflower seeds were sown in the furrow at a sowing rate of 2.5 kg / mu, sugar beets at 0.5 kg / mu, sorghum at 0.5 kg / mu, and millet at 1.5 kg / mu. The four crops were planted in different areas, with a sowing spacing of 25 cm and a row spacing of 50 cm. After sowing, drip irrigation belts were laid for irrigation. Wood vinegar and moisture retaining agents were used during the irrigation process. Wood vinegar and soil loosening agent were added to the irrigation water for application. The irrigation water volume per mu was 5m 3 , the application rate of wood vinegar is 2.5kg / mu, and the application rate of soil loosening agent is 2.5kg / mu;

[0070] (4) Carry out field management according to actual conditions and agronomic experience throughout the crop growth cycle to ensure normal growth of crops;

[0071] (5) After the crops are harvested, the crop straw is crushed and rotary tilled into the soil to a depth of 20 cm;

[0072] (6) After the crops are harvested, the process of steps (1) to (5) is repeated to carry out continuous soil improvement treatment.

[0073] Example 4

[0074] A method for improving extremely heavy saline-alkali soil, comprising the following steps:

[0075] (1) The soil to be improved with an average salt content of 154 g / kg and an average pH of 8.86 was plowed for 30 cm, and then furrowed with a depth of 20 cm, a width of 40 cm, and a spacing of 50 cm;

[0076] (2) applying 2000 kg / mu of fermented sheep manure, 80 kg / mu of microbial agents, and 100 kg / mu of mineral soil conditioners to the ditch, and then rotary tilling the ditch to fully mix the above-mentioned components with the soil;

[0077] (3) Sunflower seeds were sown in the furrow at a sowing rate of 2 kg / mu for oilseed, 1 kg / mu for sugar beet, 1 kg / mu for sorghum and 1 kg / mu for millet. The four crops were planted in different areas with a sowing spacing of 20 cm and a row spacing of 60 cm. After sowing, drip irrigation belts were laid for irrigation. During the irrigation process, salt-loving / tolerant microbial agents and moisture retainers were used. The moisture retainers were added to the irrigation water for application. The irrigation water volume per mu was 4m 3 , the application rate of moisture retainer per mu is 5kg / mu;

[0078] (4) Carry out field management according to actual conditions and agronomic experience throughout the crop growth cycle to ensure normal growth of crops;

[0079] (5) After the crops are harvested, the crop straw is crushed and rotary tilled into the soil to a depth of 25 cm;

[0080] (6) After the crops are harvested, the process of steps (1) to (5) is repeated to carry out continuous soil improvement treatment.

[0081] Test Example 1

[0082] An experimental field was selected in Hongyue Village, Caowotan Town, Jingtai County, Gansu Province, and soil improvement treatment was carried out based on the extremely severe saline-alkali land soil improvement method recorded in Example 1. Before the improvement treatment, the soil was sampled and the total salt content and pH value of the soil were determined. Then, the saline-alkali land soil was sampled and tested during the crop growth period and after harvest, and the changes in physical and chemical properties were analyzed.

[0083] The determination method of soil pH shall refer to NY / T 1121.2-2006, and the determination method of total salt content shall refer to NY / T1121.16-2006.

[0084] The results are as follows Figure 1 As shown in Figure 2, the total salt content in the soil decreased significantly in the late stage of crop growth, and the pH value also decreased to a certain extent; the image records of each growth stage of the crop during the improvement process, such as Figure 2 shown.

[0085] In summary, it can be seen that the technical solution of the present invention improves soil structure and microbial environment by land preparation and fertilization before sowing, reduces the salt content of the cultivated layer soil and reduces soil osmotic pressure through salt reduction measures, and achieves continuous reduction of soil salt content through crop planting measures.

[0086] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving extremely severe saline-alkali soil, characterized in that: The steps include: (1) Plowing the soil to be improved, digging trenches, and spreading material A into the trenches; (2) Irrigation after sowing crops in the furrow and field management during the crop growth cycle; (3) After the crops are harvested, the crop straw is crushed and rotary tilled into the soil; (4) Repeat steps (1) to (3) to perform continuous soil improvement treatment; The material A includes organic fertilizer, microbial agent and soil conditioner.

2. The method for improving extremely severe saline-alkali land according to claim 1, characterized in that: The tillage depth in step (1) is 20-35 cm; The depth of the trench is 15-25 cm, the width of the trench is 30-45 cm, and the spacing between trenches is 40-60 cm.

3. The method for improving extremely severe saline-alkali land according to claim 1, characterized in that: The mass ratio of the organic fertilizer, the microbial agent and the soil conditioner is (1000-2500): (50-100): (50-150).

4. The method for improving extremely severe saline-alkali land according to claim 3, characterized in that: The organic fertilizer is decomposed and fermented sheep manure; the effective viable bacteria count of the microbial agent is ≥5.0×10 8 CFU / g; the soil conditioner is a mineral soil conditioner with a pH value of 7.0-12.

5. The method for improving extremely severe saline-alkali land according to claim 1, characterized in that: The crops sown in step (2) include oil sunflower, sugar beet, sorghum and millet. The sowing rate of oil sunflower is 1-2.5 kg / mu, the sowing rate of sugar beet is 0.5-1.5 kg / mu, the sowing rate of sorghum is 0.5-1.5 kg / mu, and the sowing rate of millet is 0.5-1.5 kg / mu.

6. The method for improving extremely severe saline-alkali land according to claim 1, characterized in that: The sowing spacing in step (2) is 15-25 cm, and the sowing row spacing is 50-65 cm.

7. The method for improving extremely severe saline-alkali land according to claim 1, characterized in that: In step (2), during the irrigation process, a salt reducing agent is used. The dosage of the salt reducing agent and the amount of irrigation water per mu is (4-8) kg: (3-6) m 3 .

8. The method for improving extremely severe saline-alkali land according to claim 7, characterized in that: The salt-reducing agent includes any one or two of salt-loving / halotolerant microbial agents, moisture retaining agents, wood vinegar, and soil loosening agents.

9. The method for improving extremely severe saline-alkali land according to claim 1, characterized in that: The depth of the rotary tillage in step (3) is 20-30 cm.

10. Use of the improved method according to any one of claims 1 to 9 in the comprehensive management of semi-arid areas or saline-alkali land.

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