Soda saline-alkali land paddy field desalination fertile plough layer construction method

Abstract

The invention belongs to the technical field of saline-alkali soil improvement, and particularly relates to a soda saline-alkali soil paddy field desalination fertile plough layer construction method. A soil conditioner is used in the process of constructing a fertile plough layer, and the soil conditioner comprises the following components in parts by mass: 15-20 parts of cow dung granules, 35-45 parts of humic acid, 20-25 parts of humic acid production residues, 15-20 parts of corn straw powder, 10-15 parts of urea, 8-13 parts of bacillus subtilis and 3-5 parts of monocalcium phosphate. Meanwhile, tillering promoting fertilizer is applied 10-12 days after rice transplanting of the water-salt-fertilizer regulation seed rice, and a second complex microbial inoculant is applied in a matched mode, so that the yield of the soda saline-alkali soil rice in the Songnen plain can be increased, and the salt content of soil is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of saline-alkali land improvement, and particularly relates to a method for constructing a desalinated fertile tillage layer in a soda saline-alkali paddy field. Background Art

[0002] The soda-alkali lands of the Songnen Plain suffer from high soil pH and the presence of highly exchangeable sodium ions, leading to deficiencies or ineffectiveness of plant nutrients. This, combined with deteriorating soil properties and extremely low organic matter content, inhibits crop growth and reduces nutrient utilization efficiency. Specifically, excessive metal ions and anions in the soil contribute to high salinity, further hindering effective nutrient absorption by crop roots.

[0003] Traditional methods for improving saline-alkali land include washing salt, increasing the application of organic fertilizers, rationally applying chemical fertilizers, draining salt, deep plowing, and land leveling. However, these methods are costly, ineffective, and time-consuming, and are also limited in their effectiveness in lowering soil pH and reducing harmful anions and cations.

[0004] Chinese patent publication number CN 113711876 B discloses a method for using favorable flow to desalinate and fertilize coastal saline-alkali land to establish a fertile arable layer for rice cultivation. The method includes constructing a salt washing plant, creating a fertile arable layer, soil testing and fertilization, desalinating the soil with favorable flow, and regulating rice cultivation with water, salt, and fertilizer. Based on the buried pipes (ditches), the construction of sand trenches, and the salt leaching layer, straw return is implemented in conjunction with the application of soil conditioners, plowing, deep loosening, and flooding irrigation. This creates favorable flow to wash away soil salt, enrich the arable layer, desalinate the soil, and establish a fertile arable layer. Soil testing and fertilization, as well as water, salt, and fertilizer, are then used to optimize and regulate rice cultivation, thereby increasing rice yield.

[0005] The above methods have shown remarkable effects in improving coastal saline-alkali land, but in actual application, it was found that the application effect of the above methods on the soda saline-alkali land in the Songnen Plain was not ideal, and it was difficult to try: First, the above methods rely on frequent flooding of fields to quickly wash away salts through dominant flow. However, the Songnen Plain belongs to the inland arid and semi-arid climate zone with low average annual precipitation, evaporation much higher than precipitation, and scarce fresh water resources. Frequent irrigation is difficult to achieve in the Songnen Plain, which may lead to excessive consumption of water resources and even increase ecological pressure in arid areas. Secondly, the soda saline-alkali land in the Songnen Plain is characterized by high pH and high exchangeable sodium. Sodium ions will destroy soil aggregates, resulting in soil compaction, poor aeration, and hindered root development, which is different from the soil conditions of coastal saline-alkali land.

[0006] Therefore, there is an urgent need for a method for constructing a fertile arable layer for paddy field desalination in the soda saline-alkali land of the Songnen Plain. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for constructing a desalinated fertile tillage layer in a soda saline-alkali paddy field.

[0008] In order to achieve the above object, the present invention provides the following technical solutions: A method for constructing a desalinated fertile arable layer in a soda saline-alkali paddy field comprises the following steps: constructing a salt washing project, constructing a fertile arable layer, and regulating water, salt, and fertilizer for rice planting; a soil conditioner used in the process of constructing the fertile arable layer comprises the following components in parts by weight: 15-20 parts of cow dung pellets, 35-45 parts of humic acid, 20-25 parts of humic acid production residue, 15-20 parts of corn straw powder, 10-15 parts of urea, 8-13 parts of Bacillus subtilis, and 3-5 parts of calcium dihydrogen phosphate.

[0009] The preparation method of humic acid and humic acid production residue comprises the following steps: (1) Grinding and screening the mineral source to obtain mineral source powder; (2) mixing weathered coal powder, dilute nitric acid, acetic acid and hydrogen peroxide in a mass ratio of (15-17): (1-2): (2-3): (3-5), continuously stirring, pressurizing and heat-insulating to react, and obtaining a reaction product; (3) The reaction product is filtered to separate the solid and liquid to obtain humic acid production residue and extract; (4) The pH of the extract is adjusted, and the extract is allowed to stand to separate out a precipitate. The precipitate is collected and dried to obtain humic acid.

[0010] Furthermore, the preparation method comprises: (1) Grinding and crushing the ore source, and screening (e.g., 120-160 mesh) to obtain weathered coal powder; (2) Mixing the mineral source powder in a mass ratio of (15-17): (1-2): (2-3): (3-5), diluted nitric acid at a concentration of 12 wt%, acetic acid, and hydrogen peroxide, in a reactor, maintaining the temperature at 78-82°C, and reacting for 2-3 hours to obtain a reaction product; (3) The reaction product is filtered to separate the solid and liquid to obtain humic acid production residue and extract; (4) The extract is treated with 6-8 wt% sulfuric acid to adjust the pH to 3.0-3.3, and the extract is allowed to stand to separate out a precipitate. The precipitate is collected and dried to obtain humic acid.

[0011] The mineral source is selected from at least one of peat, lignite and weathered coal.

[0012] Humic acid has strong cation exchange capacity and water absorption, and can significantly improve the water holding capacity and nutrient retention capacity of the soil. During the production of mineral-source humic acid, a large amount of waste liquid is also generated. If it is discarded, it wastes manpower and material resources, and the humic acid production waste liquid is not recycled. The present invention uses weathered coal to prepare humic acid, and at the same time, the humic acid production residue is added to the soil conditioner. At the same time, by compounding with other components, it has a good improvement effect on the soda saline-alkali land in the Songnen Plain, thereby increasing rice yield.

[0013] The preparation method of the soil conditioner comprises the following steps: uniformly mixing cow dung pellets, humic acid, humic acid production residue, corn straw powder, urea, Bacillus subtilis and calcium dihydrogen phosphate to obtain the soil conditioner.

[0014] Preferably, water-salt fertilizer is used to regulate the tillering of rice 10 days after transplanting, and a second composite bacterial agent is applied in an amount of 4-6 kg / mu. The second composite bacterial agent includes Bacillus subtilis, Bacillus megaterium and Sphingomonas.

[0015] The ratio of the live bacteria of Bacillus subtilis, Bacillus megaterium and Sphingomonas in the second composite bacterial agent is (1.3-1.5):1:(0.4-0.6).

[0016] Sphingomonas sp., product number HZB112053, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0017] Bacillus subtilis, strain number: HZB200182, Zhengzhou Fangjue Biotechnology Co., Ltd.

[0018] Bacillus megaterium, strain number: HZB121018, Zhengzhou Fangjue Biotechnology Co., Ltd.

[0019] The three bacteria selected in the present invention have no antagonistic effect, and after being compounded in a specific ratio, they have a synergistic effect on rice development.

[0020] Preferably, the specific steps of constructing the fertile arable layer are: Straw salt pressing: When the crops are mature, use a combine harvester with a straw chopping device to harvest the crops. The straw cutting height is less than 15 cm, the chopped length is less than 15 mm, and the crops are evenly spread on the field surface. Apply soil conditioner: Apply soil conditioner before plowing at a rate of 2000-2500kg / hm², evenly spread on the field surface where straw is spread; Tillage and deep loosening: The first tillage depth should be ≥22 cm, with an angle of 80-100°, and straw and soil conditioners should be turned into the 0-20 cm soil layer; the first deep loosening depth should be ≥30 cm to create large pores.

[0021] Preferably, the steps of constructing the salt washing project are: Dig several furrows in the field, each 22 cm wide and 65-70 cm deep, with a distance of 7-9 m between adjacent furrows; Lay a non-woven fabric-wrapped perforated PVC corrugated pipe or a culvert filled with permeable gravel at the bottom of the ditch. The burial depth of the culvert / culvert is 50-60 cm, with a slope of 1-2‰, and the surrounding area is filled with 22 cm thick permeable gravel. Lay a 1-2 cm diameter gravel layer (12 cm thick, 18 cm wide) over the underground pipe / ditch and cover it with straw or grass to prevent clogging; Fill the trench with 35-40 cm high sand above the gravel layer; Backfill the soil and level it.

[0022] Compared with the prior art, the advantages and beneficial effects of the present invention are: 1. The present invention provides a method for constructing a fertile arable layer of desalinated paddy fields in soda saline-alkali land, which is specifically designed for the soda saline-alkali land in the Songnen Plain. It does not require frequent irrigation and soaking of the fields. Through the synergistic effect of scientifically proportioned soil conditioners and composite bacterial agents, it can effectively reduce the soluble salt content in the arable layer of soil, alleviate the toxic effects of salt damage on crop roots, improve the soil aggregate structure, and enhance the soil permeability and water and fertilizer retention capacity.

[0023] 2. The second composite bacterial agent with a specific ratio used in the present invention can promote the development of rice roots, enhance nutrient absorption capacity, increase the number of effective rice panicles, fruit set rate and 1,000-grain weight, thereby significantly increasing the yield per unit area. Under the continuous action of microorganisms and organic materials, the soil organic matter content increases year by year, providing good basic conditions for subsequent continuous planting, which is conducive to achieving long-term management of saline-alkali land and stable and high yields.

[0024] 3. The present invention provides a method for constructing a fertile arable layer for desalinated paddy fields specifically for the soda saline-alkali land in the Songnen Plain, which can effectively solve the problems of severe soil salinization, poor arable layer structure, and low fertility in the region. This method combines the local soil physical and chemical properties with agricultural ecological conditions to significantly increase soil organic matter content, improve soil structure, enhance cation exchange capacity, and promote the reconstruction of beneficial microbial communities, thereby forming a deep, loose, and fertile paddy field arable layer. This technology is not only suitable for the management and improvement of typical soda saline-alkali land in the Songnen Plain, but also provides a replicable and popularizable technical path for improving the quality of cultivated land and sustainable agricultural development in saline-alkali paddy fields in northern my country. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0026] The raw materials used in the following examples of the present invention are all commercially available commodities: Sphingomonas sp., product number HZB112053, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0027] Bacillus subtilis, strain number: HZB200182, Zhengzhou Fangjue Biotechnology Co., Ltd.

[0028] Bacillus megaterium, strain number: HZB121018, Zhengzhou Fangjue Biotechnology Co., Ltd.

[0029] Bacillus mucilaginosus, product number HZB169171, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch.

[0030] Bacillus amyloliquefaciens, product number HZB115616, Wuhan Huizao Biotechnology Co., Ltd. Hangzhou Branch Example 1 This embodiment provides a method for constructing a fertile arable layer in a soda saline-alkali paddy field by desalination, including constructing a salt washing project, constructing a fertile arable layer, and regulating water, salt, and fertilizer for rice planting. The steps to build a salt washing project are: Several trenches were dug in the field, each trench was 22 cm wide and 70 cm deep, and the distance between adjacent trenches was 8 m; Fill the bottom of the ditch with permeable gravel, with a depth of 55 cm and a slope of 1.5‰, and fill the surrounding area with 22 cm thick permeable gravel; Lay a 2 cm diameter gravel layer (12 cm thick, 18 cm wide) over the culvert and cover it with straw or grass to prevent clogging; Fill the ditch with sand 35 cm high above the gravel layer; Backfill the soil and level it.

[0031] The specific steps to build a fertile arable layer are: Straw salt pressing: When the crops are mature, use a combine harvester with a straw chopping device to harvest the crops. The straw is cut to a height of 13 cm and chopped to a length of 10 mm, and then evenly spread on the field surface. Applying a soil conditioner: Before plowing, apply a soil conditioner at a rate of 2,000 kg / hm², evenly spreading it on the straw-covered field surface. The soil conditioner comprises the following components by weight: 17 parts cow dung pellets, 40 parts humic acid, 22 parts humic acid production residue, 18 parts corn straw powder, 13 parts urea, 10 parts Bacillus subtilis, and 4 parts monocalcium phosphate. The viable bacterial count per gram of Bacillus subtilis is 200 million CFU. The preparation method of the soil conditioner comprises the following steps: uniformly mixing the cow dung pellets, humic acid, humic acid production residue, corn straw powder, urea, Bacillus subtilis, and monocalcium phosphate to obtain the soil conditioner. The preparation method of humic acid and humic acid production residue comprises the following steps: (1) grinding and crushing weathered coal, screening particles between 120-160 meshes, and obtaining weathered coal powder; (2) mixing weathered coal powder with a mass ratio of 16:1.5:2.4:4, diluted nitric acid with a concentration of 12wt%, acetic acid, and 27.5wt% hydrogen peroxide, and stirring in a reactor at a pressure of 0.3MPa, maintaining a speed of 620 r / min, maintaining a temperature of 80°C, and reacting for 2.5h to obtain a reaction product; (3) filtering the reaction product for solid-liquid separation to obtain humic acid production residue and an extract; (4) adjusting the extract to a pH of 3.0 using 7wt% sulfuric acid, allowing the extract to stand to precipitate, collecting the precipitate, and drying to obtain humic acid.

[0032] Tillage and deep loosening: The first tillage depth is 22 cm, the turning angle is 100°, and the straw and soil conditioner are turned into the soil layer between 0-20 cm; the first deep loosening depth is 30 cm to create large pores.

[0033] Water, salt and fertilizer regulation of rice planting specifically includes the following steps: 1) Apply basal fertilizer before transplanting. Apply basal fertilizer (120 kg / mu, JX04, from Shijiazhuang Jinxin Fertilizer Co., Ltd.) before irrigation. Plow and mix thoroughly to a depth of 20 cm. Use a conductivity sensor for real-time monitoring. When the salinity is ≤ 0.8 g / L, plow the field, harrow the field, and transplant the rice seedlings. 2) During the greening and tillering period, after transplanting, when the salinity of field water exceeds 0.8 g·L -1 When the rice turns green, drain the water and add fresh water to maintain a 5cm water layer on the surface of the field. When the rice turns green, drain the water and add fresh water to regulate the salinity of the surface water at 0.8g·L -1Ten days after transplanting, apply tillering-promoting fertilizer (Henan Shuanghui Agricultural Science and Technology Development Co., Ltd., special fertilizer for high-yield wheat and rice, 40 mL per mu + 30 kg of water, sprayed on the leaves) and a second compound microbial agent at a rate of 5 kg per mu. The second compound microbial agent contains 250 million CFU of viable bacteria per gram, and the ratio of viable bacteria of Bacillus subtilis, Bacillus megaterium, and Sphingomonas is 1.4:1:0.5. At the end of the rice tillering stage, dig vertical, waist, and surrounding trenches in the field. The trenches are 25 cm wide and 38 cm deep to divert water for irrigation and remove surface water and soil salinity. 3) During the jointing and booting stage, 20 days before heading, when the salinity of the field water exceeds 0.8 g·L -1 When the water is drained and fresh water is added, the salinity of the surface water is regulated to 0.8 g·L -1 Below that, maintain a 2-4cm water layer on the field surface and apply the first ear fertilizer (200 catties potassium chloride and 120 catties urea per hectare) to promote spikelet differentiation and increase the number of spikelets. 17 days before ear emergence, drain the field and supplement with fresh water. Apply the second ear fertilizer (200 catties potassium chloride and 100 catties urea per hectare) to increase the number of filled grains and grain weight. 4) During the heading and flowering period, apply granular fertilizer during the breaking stage to maintain a 4cm water layer on the field surface. When the salinity of the field surface water exceeds 0.8 g·L -1 When the water is drained and fresh water is added, the salinity of the field surface water is regulated to 0.8 g·L -1 Below, apply urea 40kg·hm -2 ; 5) During the grain filling and fruiting period, when the salinity of the field water exceeds 0.8 g·L -1 When the water is drained and fresh water is added, the salinity of the surface water is regulated to 0.8 g·L -1 Keep the water layer on the field surface below 3 cm, drain the water 10 days before the rice is fully mature, dry the field surface, and harvest when the rice reaches 90% maturity.

[0034] Example 2 The difference between this embodiment and embodiment 1 is that the soil conditioner includes the following components in parts by mass: 15 parts of cow dung pellets, 45 parts of humic acid, 20 parts of humic acid production residue, 20 parts of corn straw powder, 10 parts of urea, 13 parts of Bacillus subtilis and 3 parts of calcium dihydrogen phosphate.

[0035] Example 3 The difference between this embodiment and embodiment 1 is that the soil conditioner includes the following components in parts by mass: 20 parts of cow dung pellets, 35 parts of humic acid, 25 parts of humic acid production residue, 15 parts of corn straw powder, 15 parts of urea, 8 parts of Bacillus subtilis and 5 parts of calcium dihydrogen phosphate.

[0036] Example 4 The difference between this embodiment and embodiment 1 is that the ratio of the live bacteria of Bacillus subtilis, Bacillus megaterium and Sphingomonas in the second composite bacterial agent is 1.3:1:0.6.

[0037] Example 5 The difference between this embodiment and embodiment 1 is that the ratio of the live bacteria of Bacillus subtilis, Bacillus megaterium and Sphingomonas in the second composite bacterial agent is 1.5:1:0.4.

[0038] Comparative Example 1 The difference between this comparative example and Example 1 is that the soil conditioner is a commercially available product, Yingkou Maomei Agricultural Technology Co., Ltd., a special soil conditioner for saline-alkali land.

[0039] Comparative Example 2 The difference between this comparative example and Example 1 is that the soil conditioner is humic acid, and the production method of humic acid is the same as that of Example 1.

[0040] Comparative Example 3 The difference between this comparative example and Example 1 is that the soil conditioner includes the following components in parts by mass: 10 parts of cow dung pellets, 30 parts of humic acid, 30 parts of humic acid production residue, 25 parts of corn straw powder, 20 parts of urea, 5 parts of Bacillus subtilis and 8 parts of calcium dihydrogen phosphate.

[0041] Comparative Example 4 The difference between this comparative example and Example 1 is that the second composite bacterial agent includes Bacillus subtilis and Bacillus megaterium; and the ratio of the live bacteria of Bacillus subtilis and Bacillus megaterium in the second composite bacterial agent is 1.4:1.

[0042] Comparative Example 5 The difference between this comparative example and Example 1 is that the second composite bacterial agent includes Bacillus subtilis, Bacillus megaterium and Bacillus amyloliquefaciens; and the ratio of the live bacteria of Bacillus subtilis, Bacillus megaterium and Bacillus amyloliquefaciens in the second composite bacterial agent is 1.4:1:0.5.

[0043] Comparative Example 6 The difference between this comparative example and Example 1 is that the second composite bacterial agent includes Bacillus subtilis, Bacillus megaterium and Bacillus mucilaginosus; and the ratio of the live bacteria of Bacillus subtilis, Bacillus megaterium and Bacillus mucilaginosus in the second composite bacterial agent is 1.4:1:0.5.

[0044] Performance Testing The experiment started in April 2023 in Zhenlai County, Jilin Province, and the rice variety tested was Dongdao No. 4. The control group used the local conventional planting method, and the experimental group used the soda saline-alkali paddy field desalination fertile layer construction method of the present invention on the basis of the local conventional planting method. The plot area of each group was 0.2hm 2 , 3 parallels were set up in each group.

[0045] The three factors of rice yield were counted and the soil salt content in the 0-20 cm soil layer was measured. The results are shown in Table 1.

[0046] Table 1 Performance test results As can be seen from Table 1, the rice yields of Examples 1-5 are higher. At the same time, the method of the present invention can reduce the salt content of the soil, which is significantly better than the local conventional planting method.

[0047] Comparative Examples 1-3 show that the composition and ratio of the soil conditioner of the present invention affect rice yield and soil salinity. Comparative Examples 4-6 show that the type and ratio of the second composite bacterial agent also have a significant impact on rice yield and soil salinity.

[0048] The above is 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 principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for constructing a fertile arable layer in a soda saline-alkali paddy field, characterized in that: The method includes constructing a salt washing project, building a fertile arable layer, and regulating rice planting with water, salt, and fertilizer. The soil conditioner used in the process of constructing the fertile arable layer includes the following components in parts by mass: 15-20 parts of cow dung pellets, 35-45 parts of humic acid, 20-25 parts of humic acid production residue, 15-20 parts of corn straw powder, 10-15 parts of urea, 8-13 parts of Bacillus subtilis, and 3-5 parts of calcium dihydrogen phosphate.

2. The method for constructing a fertile arable layer in a soda saline-alkali paddy field desalination according to claim 1, characterized in that: The humic acid is prepared using mineral sources.

3. The method for constructing a fertile arable layer in a desalinated soda saline-alkali paddy field according to claim 2, characterized in that: The humic acid production residue is the production residue obtained when humic acid is prepared using a mineral source.

4. The method for constructing a fertile arable layer in a desalinated soda saline-alkali paddy field according to claim 3, characterized in that: The preparation method of humic acid and humic acid production residue comprises the following steps: (1) Grinding and screening the mineral source to obtain mineral source powder; (2) mixing weathered coal powder, dilute nitric acid, acetic acid and hydrogen peroxide in a mass ratio of (15-17): (1-2): (2-3): (3-5), continuously stirring, pressurizing and heat-insulating to react, and obtaining a reaction product; (3) The reaction product is filtered to separate the solid and liquid to obtain humic acid production residue and extract; (4) The pH of the extract is adjusted, and the extract is allowed to stand to separate out a precipitate. The precipitate is collected and dried to obtain humic acid.

5. The method for constructing a fertile arable layer in a desalinated soda saline-alkali paddy field according to claim 4, characterized in that: The mineral source is selected from at least one of peat, lignite and weathered coal.

6. The method for constructing a fertile arable layer in a desalinated soda saline-alkali paddy field according to claim 1, characterized in that: The dosage of soil conditioner is 2000-2500kg / hm².

7. The method for constructing a fertile arable layer in a desalinated soda saline-alkali paddy field according to claim 1, characterized in that: Water, salt and fertilizer are used to regulate rice planting and tillering fertilizer is applied 10-12 days after transplanting, and a second compound bacterial agent is applied.

8. The method for constructing a fertile arable layer in a desalinated soda saline-alkali paddy field according to claim 7, characterized in that: The dosage of the second composite bacterial agent is 4-6 kg / mu, and the second composite bacterial agent includes Bacillus subtilis, Bacillus megaterium and Sphingomonas.

9. The method for constructing a fertile arable layer in a desalinated soda saline-alkali paddy field according to claim 8, characterized in that: The ratio of the live bacteria of Bacillus subtilis, Bacillus megaterium and Sphingomonas in the second composite bacterial agent is (1.3-1.5):1:(0.4-0.6).

10. The method for constructing a fertile arable layer in a desalinated soda saline-alkali paddy field according to claim 1, characterized in that: The specific steps to build a fertile arable layer are: Straw salt pressing: When the crops are mature, they are harvested using a combine harvester equipped with a straw chopping device and evenly spread on the field surface; Apply soil conditioner: Apply soil conditioner before plowing and spread evenly on the field surface where straw is spread; Ploughing and deep tillage.

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