Method for improving arable layer of acidic clayey soil

Abstract

The invention discloses a method for improving an acidic clayey soil plough layer, which comprises the following steps of: 1, after autumn rice is harvested, draining water in a rice field, and carrying out conventional tillage, soil turning and leveling on the rice field for later use; 2, green manure planting is conducted in the suitable green manure sowing period from October to November; 3, in the full-bloom stage, green manure is smashed, turned, pressed and returned to the field, lime and organic fertilizer are spread, the rice field is deeply ploughed at a time, and the green manure, the lime and the organic fertilizer are deeply buried in soil of the rice field; 4, the rice field is irrigated and soaked in water for a period of time, and then rice is planted. The method can inhibit and stabilize acid, improve the buffer performance of the soil, effectively expand a deep ploughing layer, improve the physical structure of the soil and improve the utilization rate of rainfall resources by the soil, so that the purposes of minimal ploughing, high yield and farmland protection are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of acidic clay soil improvement, and in particular to a method for improving an acidic clay soil plough layer. Background Art

[0002] Healthy soil is the foundation for ensuring food security, improving arable land productivity and high-quality agricultural development. In recent decades, soil degradation has become increasingly serious due to human activities such as unreasonable fertilization, extensive farmland management, and mechanized rotary tillage. Among them, the degradation of soil tillage structure is prominent, and its significant characteristics are shallow soil tillage, poor soil structure and decreased stability of aggregates. Soil aggregates are the basic units of soil structure. They are porous media structures formed by the coagulation and cementation of mineral particles and colloidal substances. As the transformation site of soil nutrients and the living environment of soil microorganisms, soil aggregates are of great significance for regulating soil fertility and vegetation growth. Soil organic-inorganic complexes are an important mechanism and material basis for the formation of stable aggregates and soil fertility. They are the main form of soil colloids and play an important role in the formation of good soil structure. The surface of soil clay minerals is mostly negatively charged, and they are easily combined with negatively charged organic matter under the action of cationic bridging to form organic-inorganic complexes. However, the soil in southern my country is heavy in texture, low in organic matter, and suffers from severe leaching of base ions, which is not conducive to the formation of a good structure and seriously affects the quality of the soil plough layer structure. Poor soil plough layer structure will lead to a decrease in soil fertility, restrict the downward growth of crop roots, cause poor crop growth and development, seriously affect crop yield and quality, restrict soil productivity, and restrict the sustainable development of agriculture and the improvement of economic benefits. Therefore, taking effective measures to improve the quality of the soil plough layer is of great significance for stabilizing food safety production.

[0003] In the past, in order to improve the soil structure of the cultivated layer, organic materials such as returning straw to the field and applying organic manure were generally used to increase the soil organic matter content, promote the formation of organic-inorganic complexes, and facilitate the transformation of soil microaggregates into macroaggregates, thereby improving the stability of soil structure. However, for acidic clay soils in the south, due to the compact and sticky soil structure and poor soil ventilation and water permeability, the microbial activity is reduced, the microbial-mediated soil organic carbon formation, transformation and stabilization process is hindered, and the nutrient turnover activation is affected. At the same time, due to the strong soil leaching effect, the increase in the number of protons in the soil, and the leaching of base ions, even if organic matter is unilaterally added, the lack of base ions limits the cation bridging effect, which seriously affects the formation of organic-inorganic complexes. Organic-inorganic complexes are the material basis for the formation of stable aggregates and play an important role in the formation of good soil structure. At present, this acidic and clayey poor soil structure has seriously affected the sustainable development of the soil.

[0004] Therefore, proposing a technical method for improving the tillage layer of acidic clay soil is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of the technical problems existing in the above-mentioned prior art, the purpose of the present invention is to propose a method for improving the tillage layer of acidic clay soil. The method can suppress and stabilize acidity, improve soil buffering performance, effectively deepen the tillage layer, improve soil physical structure, and increase the utilization rate of soil for precipitation resources, thereby achieving the purpose of less tillage, high yield, and protective farmland.

[0006] To achieve the above object, the present invention is implemented by the following technical solutions:

[0007] A method for improving the plough layer of acidic clay soil, the method comprising the following steps:

[0008] Step 1: After the rice is harvested in autumn, drain the water from the paddy field, till the paddy field with conventional tillage, and level the soil for later use;

[0009] Step 2: Plant green manure during the appropriate planting period from October to November;

[0010] Step 3: During the flowering period, crush the green manure, turn it over and return it to the field, spread lime and organic fertilizer, and deep-plow the rice field once, so that the green manure, lime and organic fertilizer are deeply buried in the rice field soil;

[0011] Step 4: Irrigate the rice fields, keep them soaked for a period of time, and then plant rice.

[0012] The above scheme involves a soil fertility improvement process and a land preparation method after autumn harvest and before sowing. The soil fertility improvement process includes improving and fertilizing the acidic clay soil plow layer. The present invention can effectively provide calcium base ions and organic matter by applying organic fertilizer and lime. Under the bridging effect of calcium base ions, soil clay minerals with negative charges on the surface are easily combined with negatively charged organic matter to form organic-inorganic complexes, thereby improving the stability of soil aggregates and promoting the formation of good soil structure. Green manure plants are planted in winter to nourish the land, and the green manure plants are crushed and buried deep in the soil together with organic and inorganic materials during the peak flowering period of green manure. The application of these exogenous organic substances can effectively increase the soil porosity and organic carbon content, promote the absorption and utilization of nitrogen, phosphorus and potassium nutrients by crops, and the alkaline substances rich in organic carbon have the potential to improve soil acidity. The deep plowing part breaks the plow bottom layer, which helps the crop roots to grow deep and elongate to absorb water and nutrients, thereby promoting crop growth and development, and increasing crop yields. While realizing the process of improving the soil fertility of acidic clay soil, it can effectively improve crop production capacity, thereby promoting the efficient development and utilization of acidic clay soil in the south.

[0013] As a further optimization scheme of the present invention, the green manure includes at least one of astragalus, rapeseed and ryegrass.

[0014] In the above scheme, astragalus - a legume plant, has a strong nitrogen fixing ability. It can coexist with rhizobia, fix nitrogen in the air into the soil, increase the nitrogen content of the soil, and provide sufficient nitrogen fertilizer for subsequent crops. Rapeseed - can accumulate a large amount of biomass during growth, and its root system has good penetration into the soil, which helps to improve the structure of the soil and increase the aeration and permeability of the soil. In addition, the residual plants of rapeseed decompose in the soil, which can increase the organic matter content of the soil and improve soil fertility. Ryegrass - has a strong growth potential and a high biomass, and its well-developed root system helps to stabilize the soil structure and prevent soil erosion. At the same time, the residue of ryegrass is easy to decompose, can quickly provide organic matter to the soil, and promote the nutrient cycle of the soil. These three green manure plants all have a short growth cycle and can grow rapidly and form a large amount of biomass in a crop growing season. This makes them very suitable for planting as green manure crops and can effectively improve the soil in a short time. In addition, these plants have a wide adaptability and can grow under a variety of soil types and climatic conditions, and are suitable for agricultural production in different regions.

[0015] As a further optimization scheme of the present invention, the transplanting planting density of the green manure is 8000-15000 plants / mu, and the direct seeding planting density is 20-30 kg / ha or 25000-35000 plants / mu.

[0016] In the above scheme, reasonable transplanting row spacing and direct seeding density can ensure that green manure crops can fully utilize light energy, water and nutrients during the growth process to achieve the best growth effect, thereby providing more organic matter and nutrients to the soil.

[0017] As a further optimization scheme of the present invention, the lime includes one or more of quicklime, slaked lime, and limestone powder.

[0018] In the above scheme, the application of lime (including quicklime, slaked lime, and limestone powder) can effectively neutralize soil acidity and increase soil pH. At the same time, the calcium ions in the lime can also combine with organic matter in the soil to promote the formation of organic-inorganic complexes and enhance the stability of soil aggregates.

[0019] As a further optimization scheme of the present invention, the application amount of the lime is 750-2500 kg / ha.

[0020] In the above scheme, a reasonable amount of lime application can ensure that the soil pH value reaches an appropriate range, neither too acidic nor too alkaline, which is conducive to the activity of soil microorganisms and the conversion and absorption of nutrients.

[0021] As a further optimization scheme of the present invention, the organic fertilizer includes one or more of earthworm manure, pig manure, cow manure, and commercial organic fertilizer.

[0022] In the above scheme, the application of organic fertilizers (such as earthworm manure, pig manure, cow manure, and commercial organic fertilizers) can increase the organic matter content of the soil, improve the physical structure of the soil, and enhance the soil's ability to retain water and fertilizer. At the same time, the microorganisms in the organic fertilizer can also promote the circulation and transformation of soil nutrients.

[0023] As a further optimization scheme of the present invention, the application amount of the organic fertilizer is 5000kg / ha to 40000kg / ha.

[0024] In the above scheme, the reasonable application amount of organic fertilizer can ensure the continuous increase of soil organic matter, provide a good living environment for soil organisms, and promote the healthy and sustainable development of soil.

[0025] As a further optimization scheme of the present invention, the lime and organic fertilizer are both solid fertilizers.

[0026] In the above scheme, lime and organic fertilizer are both solid fertilizers, which are easy to store, transport and apply. At the same time, they can slowly release nutrients in the soil, prolong fertilizer effect and reduce nutrient loss.

[0027] As a further optimization scheme of the present invention, the depth of deep plowing is 20 to 30 cm.

[0028] In the above scheme, the plow bottom layer of the soil in the south is 20-40cm. Deep plowing at this depth can break the plow bottom layer formed by long-term shallow plowing, promote soil maturation, and improve soil fertility. Appropriately expand the plow layer to retain water and fertilizer. Within this depth range, the soil structure is relatively suitable for the growth of crop roots, which can not only ensure the permeability of the soil, but also maintain a certain ability to retain water and fertilizer. It is conducive to the root system to go down. The roots of most crops are mainly distributed in this soil layer. Deep plowing is conducive to the deep rooting of the root system, improving the stress resistance and yield of crops. Deep plowing less than 20cm: The plowing layer is too shallow to effectively break the plow bottom layer, and the problem of soil compaction cannot be fundamentally solved. It is difficult for crop roots to go deep, affecting the growth and yield of crops. The soil's ability to retain water and fertilizer is weakened, which is easy to cause nutrient loss and water evaporation. Deep plowing greater than 30cm: The plowing layer is too deep, which may destroy the natural structure of the soil and lead to a decrease in soil fertility. Too deep plowing will increase mechanical energy consumption and cost and reduce farming efficiency.

[0029] As a further optimization scheme of the present invention, the time for retaining water and soaking the field is 15-20 days.

[0030] In the above scheme, the water retention and soaking time is designed to be 15-20 days, which can create a reducing environment, and the eggs of pests and diseases can be suppressed / eliminated under reducing conditions, ensuring the full softening and improvement of the paddy field soil, while promoting the decomposition of organic matter in the soil and reducing the growth of weeds. If the water retention time is less than 15 days, the soil may not be fully softened, affecting the growth of rice roots, and may also lead to insufficient decomposition of organic matter in the soil, affecting the nutrient supply of rice. If the water retention time is longer than 20 days, the soil may become too saturated, resulting in poor ventilation, which may inhibit the normal respiration and growth of rice roots and may cause the loss of certain nutrients in the soil.

[0031] Compared with the prior art, the technical solution provided by the present invention has the following advantages and beneficial effects:

[0032] Organic fertilizers are rich in alkaline substances and have long-term acid-suppressing potential, and are beneficial to increasing the total organic carbon content and soil aggregate stability in the soil. Lime can provide metal cations Ca 2+ , which can play a bridging role between minerals and organic matter, thereby promoting the formation of organic-inorganic complexes. This mechanism is also more conducive to soil carbon sequestration, increasing the content of stable carbon in the soil, indirectly promoting the formation of humus, improving soil nutrients, and meeting the nutrient needs of crops during growth. The combination of the two can enhance the soil buffering capacity, promote the formation of organic-inorganic complexes, effectively improve soil acidity, promote the formation of good soil structures, increase the number and activity of soil microorganisms, and promote the transformation of organic materials, thereby increasing the total organic carbon content in the soil, effectively improving soil quality, and increasing crop yields, which is of great significance for stabilizing food production safety.

[0033] The method for improving the tillage layer of acidic clay soil in the present invention realizes the rational utilization of fallow fields in winter. Planting green manure in fallow fields in winter fully utilizes winter water, heat, land and other resources. After the green manure is turned over and returned to the field, the abundance of aerobic bacteria increases, the aeration of the soil is enhanced, the soil microecological environment is improved, and microorganisms and their metabolites promote the formation of large aggregates. At the same time, after returning the green manure to the field, it can promote the mineralization and decomposition of soil organic matter and enrich the soil phosphorus and potassium, provide the necessary nutrients for the growth of subsequent crops, increase soil mineral nutrients, and thus increase the yield of the next crop season; it can also provide a large amount of carbon source and nutrients for the soil, which has a good effect on reducing the amount of chemical fertilizers applied, saving the cost of chemical fertilizer inputs and reducing agricultural environmental pollution.

[0034] Reasonable deep tillage combined with green manure and organic and inorganic material addition can give full play to their respective advantages, complement each other, and promote each other. It can not only effectively increase the thickness of the tillage layer, improve soil permeability, and improve soil acidity, but also promote the formation of a good soil structure, thereby improving the quality of the soil tillage layer. The soil tillage layer improvement technology proposed in the present invention can simultaneously improve multiple obstacle factors in the soil, improve soil quality and crop yield, reduce environmental pollution, and improve resource utilization efficiency. It meets the requirements of my country's green agricultural development and has important guiding significance for achieving sustainable development of agricultural production and environmental protection. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the preferred implementation scheme of the present invention is described below in conjunction with specific embodiments, but it should not be understood as limiting the present invention and is only used as an example.

[0036] The experimental methods or test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials are obtained from conventional commercial channels or prepared by conventional methods unless otherwise specified.

[0037] The present invention provides a comprehensive improvement model for multiple obstacle factors in acidic clay soil. Specifically, a reasonable farming method combined with appropriate fertilization measures is applied to barren farmland soil. Under this model, the quality of the soil plow layer is improved and crop yields are increased.

[0038] The farming and fertilizing method provided by the present invention comprises the following steps: before planting rice, green manure is crushed and turned over and returned to the field, lime and organic fertilizer are spread at a dosage of 1.5 t / ha and 5-40 t / ha respectively, and the rice field is deep-ploughed once, with a deep-ploughing depth of 20-30 cm.

[0039] The sowing amount of the astragalus green manure provided by the invention is 20-30 kg / ha, and the astragalus green manure is sown when the field soil is kept moist in mid-to-late October, and the astragalus green manure is crushed, turned over and returned to the field in the blooming period.

[0040] The rapeseed green manure transplanting density provided by the present invention is 8000-15000 plants / mu, and the direct seeding cultivation density is preferably 25000-35000 plants / mu. Rapeseed seeding and seedling raising are carried out in mid-to-late September, and rapeseed transplanting is completed in early November. 50kg of Danxing rapeseed fertilizer (15-7-8) is applied per mu as base fertilizer, and 6kg of urea is applied as topdressing during the wintering period. Picking rapeseed stalks in the stalk stage increases economic benefits, and crushing and turning them back to the field in the blooming period.

[0041] Example 1

[0042] After the rice is harvested in autumn, the paddy fields are drained, the paddy fields are tilled and leveled for use; in winter, astragalus green manure is planted at a sowing rate of 20kg / ha. Before planting rice again, the astragalus is crushed and turned over and returned to the field during its peak flowering period, and quicklime and earthworm manure are spread at a rate of 1.5t / ha and 5t / ha respectively. The paddy fields are deep plowed once, with a deep plowing depth of 30cm, so that the astragalus green manure and organic and inorganic materials are deeply buried in the paddy field soil; the paddy fields are irrigated, the fields are kept water-soaked for 20 days, and then rice is planted.

[0043] Example 2

[0044] After the rice is harvested in autumn, the paddy fields are drained, the paddy fields are tilled and leveled for use; in winter, astragalus sinensis green manure is planted at a sowing rate of 20kg / ha. Before planting rice again, the astragalus sinensis is crushed and turned over and returned to the field during its peak flowering period, and quicklime and earthworm manure are spread at a rate of 1.5t / ha and 10t / ha respectively. The paddy fields are deep plowed once, with a deep plowing depth of 30cm, so that the astragalus sinensis green manure and organic and inorganic materials are deeply buried in the paddy field soil; the paddy fields are irrigated, the fields are kept water-soaked for 20 days, and then rice is planted.

[0045] Example 3

[0046] After the rice is harvested in autumn, the paddy fields are drained, the paddy fields are tilled and leveled for use; in winter, astragalus sinensis green manure is planted at a sowing rate of 20kg / ha. Before planting rice again, the astragalus sinensis is crushed and turned over and returned to the field during its peak flowering period, and quicklime and earthworm manure are spread at a rate of 1.5t / ha and 20t / ha respectively. The paddy fields are deep plowed once, with a deep plowing depth of 30cm, so that the astragalus sinensis green manure and organic and inorganic materials are deeply buried in the paddy field soil; the paddy fields are irrigated, the fields are kept water-soaked for 20 days, and then rice is planted.

[0047] Example 4

[0048] After the rice is harvested in autumn, the paddy fields are drained, the paddy fields are tilled and leveled for use; in winter, astragalus sinensis green manure is planted at a sowing rate of 20kg / ha. Before planting rice again, the astragalus sinensis is crushed and turned over and returned to the field during its peak flowering period, and quicklime and earthworm manure are spread at a rate of 1.5t / ha and 40t / ha respectively. The paddy fields are deep plowed once, with a deep plowing depth of 30cm, so that the astragalus sinensis green manure and organic and inorganic materials are deeply buried in the paddy field soil; the paddy fields are irrigated, the fields are kept water-soaked for 20 days, and then rice is planted.

[0049] Example 5

[0050] After the rice is harvested in autumn, the paddy fields are drained, the fields are tilled and leveled for later use; rapeseed green manure is planted in winter at a transplanting density of 11,000 plants / mu. Before planting rice again, the rapeseed is crushed and turned over and returned to the field during its peak flowering period, and quicklime and earthworm manure are spread at a rate of 1.5t / ha and 40t / ha respectively. The paddy fields are deep plowed once, with a plowing depth of 30cm, so that the rapeseed green manure and organic and inorganic materials are deeply buried in the paddy field soil; the paddy fields are irrigated, the fields are kept water-soaked for 20 days, and then rice is planted.

[0051] Comparative Example 1

[0052] After the rice is harvested in autumn, the water in the rice fields is drained; before planting rice again, the soil is plowed to a depth of 10 cm, and then the rice fields are irrigated, keeping the fields water-logged for 20 days before planting rice.

[0053] Comparative Example 2

[0054] After the rice is harvested in autumn, the water in the rice fields is drained; before planting rice again, the soil is plowed to a depth of 20 cm, and then the rice fields are irrigated, keeping the fields water-logged for 20 days before planting rice.

[0055] Comparative Example 3

[0056] After the rice is harvested in autumn, the water in the rice fields is drained; before planting rice again, the soil is plowed to a depth of 30 cm, and then the rice fields are irrigated, keeping the fields water-logged for 20 days before planting rice.

[0057] Comparative Example 4

[0058] After the rice is harvested in autumn, the paddy fields are drained, the paddy fields are tilled and leveled for later use; in winter, astragalus sinensis green manure is planted at a sowing rate of 20kg / ha. Before planting rice again, the astragalus sinensis is crushed and turned over and returned to the field during its peak flowering period, and the paddy fields are tilled to a depth of 30cm so that the astragalus sinensis green manure is deeply buried in the paddy field soil. The paddy fields are then irrigated and water is kept in the fields for 20 days before planting rice.

[0059] Comparative Example 5

[0060] After the rice is harvested in autumn, the water in the paddy fields is drained; before planting rice again, quicklime is spread at a rate of 1.5t / ha, and the paddy fields are plowed to a depth of 30cm so that the quicklime is deeply buried in the paddy field soil. The paddy fields are then irrigated and water is kept in the fields for 20 days before planting rice.

[0061] Comparative Example 6

[0062] After the rice is harvested in autumn, the water in the paddy fields is drained; before planting rice again, earthworm manure is spread at a rate of 5t / ha, and the paddy fields are plowed to a depth of 30cm so that the organic fertilizer is deeply buried in the paddy field soil. The paddy fields are then irrigated, and water is kept in the fields for 20 days before planting rice.

[0063] Comparative Example 7

[0064] After the rice is harvested in autumn, the paddy fields are drained, the paddy fields are tilled and leveled for use; in winter, astragalus is planted at a sowing rate of 20 kg / ha. Before planting rice again, the astragalus is crushed and turned over and returned to the field during its peak flowering period, quicklime is spread at a rate of 1.5 t / ha, and the paddy fields are tilled to a depth of 30 cm, so that the astragalus green manure and quicklime are deeply buried in the paddy field soil. The paddy fields are then irrigated, water is kept in the fields for 20 days, and then rice is planted.

[0065] Comparative Example 8

[0066] After the rice is harvested in autumn, the paddy fields are drained, the paddy fields are tilled and leveled for later use; in winter, astragalus sinensis green manure is planted at a sowing rate of 20kg / ha. Before planting rice again, the astragalus sinensis is crushed and turned over and returned to the field during its peak flowering period, and earthworm manure is spread at a rate of 5t / ha. The paddy fields are tilled and the tillage depth is 30cm, so that the astragalus sinensis green manure and organic fertilizer are deeply buried in the paddy field soil. The paddy fields are then irrigated, the fields are kept water-soaked for 20 days, and then rice is planted.

[0067] Comparative Example 9

[0068] After the rice is harvested in autumn, the water in the paddy fields is drained; before planting rice again, quicklime and earthworm manure are spread at a rate of 1.5t / ha and 5t / ha respectively, and the paddy fields are plowed to a depth of 30cm so that the organic fertilizer is deeply buried in the paddy field soil. The paddy fields are then irrigated and water is kept in the fields for 20 days before planting rice.

[0069] Comparative Example 10

[0070] After the rice is harvested in autumn, the water in the paddy fields is drained; before planting rice again, quicklime and earthworm manure are spread at a rate of 1.5t / ha and 40t / ha respectively, and the paddy fields are deep plowed once with a plowing depth of 30cm to bury organic and inorganic materials deeply in the paddy field soil; the paddy fields are irrigated and kept water-soaked for 20 days before planting rice.

[0071] Rice and plough soil samples were collected on September 4, 2023 and September 25, 2023, respectively. The collected plants and soil samples were tested and analyzed. The analysis results are shown in Table 1. The basic physical and chemical properties of the rice field soil before planting were pH 5.51 and pH buffer capacity (pHBC) 26.90 mmol kg -1 pH -1 , organic matter 22.2g·kg, alkaline nitrogen 119.1mg·kg, bulk density 1.38g·m -3 .

[0072] Table 1 Effects of the tillage and fertilization measures of the present invention on paddy soil properties

[0073]

[0074] Table 2 Effects of the cultivation and fertilization measures of the present invention on rice traits

[0075]

[0076]

[0077] As can be seen from Tables 1 and 2, by planting green manure plants in winter and deep plowing the soil during the flowering period of green manure, the green manure plants are crushed and buried deep in the soil together with organic and inorganic materials. The green manure is fermented to form biofertilizer to provide fertility for the soil, thereby reducing the use of chemical fertilizers; organic fertilizer can input organic carbon into the soil, and because it is rich in alkaline substances, it has the potential to improve soil acidity and promote the absorption and utilization of nitrogen, phosphorus and potassium nutrients by crops, thereby improving soil structure and increasing soil fertility; lime can provide divalent cations while reducing acidity, promoting the formation of organic-inorganic complexes in the form of ion bond bridges, thereby improving the stability of soil structure; deep plowing helps the elongation and development of rice roots, so that the roots go deep to absorb water and nutrients, the root biomass increases, and the tillering and panicle characteristics are also improved, which is beneficial to the growth and development of crops; deep plowing combined with the addition of green manure and organic and inorganic materials greatly increases the soil pH buffer capacity, organic matter and alkaline nitrogen content, reduces soil bulk density, thereby improving soil fertility and improving the structure of the soil plow layer, improving soil quality, and significantly increasing rice yield.

[0078] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for improving the topsoil of acidic clay soil, characterized in that: The method comprises the following steps: Step 1: After the rice is harvested in autumn, drain the water from the paddy field, till the paddy field with conventional tillage, and level the soil for later use; Step 2: Plant green manure during the appropriate planting period from October to November; Step 3: During the flowering period, crush the green manure, turn it over and return it to the field, spread lime and organic fertilizer, and deep-plow the rice field once, so that the green manure, lime and organic fertilizer are deeply buried in the rice field soil; Step 4: Irrigate the rice fields, keep them soaked for a period of time, and then plant rice.

2. The method for improving the topsoil of acidic clay soil according to claim 1, characterized in that: The green manure includes at least one of astragalus, rapeseed and ryegrass.

3. The method for improving the acidic clay soil topsoil according to claim 1, characterized in that: The transplanting planting density of the green manure is 8000-15000 plants / mu, and the direct seeding planting density is 20-30kg / ha or 25000-35000 plants / mu.

4. The method for improving the acidic clay soil topsoil according to claim 1, characterized in that: The lime includes one or more of quicklime, slaked lime and limestone powder.

5. The method for improving the topsoil of acidic clay soil according to claim 1, characterized in that: The application amount of the lime is 750-2500 kg / ha.

6. The method for improving the acidic clay soil topsoil according to claim 1, characterized in that: The organic fertilizer includes one or more of earthworm manure, pig manure, cow manure, and commercial organic fertilizer.

7. The method for improving the acidic clay soil topsoil according to claim 1, characterized in that: The application amount of the organic fertilizer is 5000kg / ha to 40000kg / ha.

8. The method for improving the topsoil of acidic clay soil according to claim 1, characterized in that: The lime and organic fertilizer are both solid fertilizers.

9. The method for improving the topsoil of acidic clay soil according to claim 1, characterized in that: The depth of deep plowing is 20 to 30 cm.

10. The method for improving the topsoil of acidic clay soil according to claim 1, characterized in that: The time for retaining water and soaking the fields is 15-20 days.

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