A method for synchronously improving soil acidity and compactness in sugarcane fields

Abstract

A method for synchronously improving the acidity and compactness of sugarcane field soil. After opening the planting ditch for newly planted sugarcane, first sprinkle the soil conditioner at the bottom of the planting ditch, then apply a layer of organic fertilizer on top of the soil conditioner and then plant sugarcane; when earthing up the sugarcane in the middle stage, sprinkle a layer of soil conditioner between the sugarcane rows; the soil conditioner includes modified carbonized sugarcane bagasse, fermented sugarcane bagasse and modified coconut coir. By directionally modifying biochar and coconut coir and directionally fermenting sugarcane bagasse, the present invention makes a soil conditioner with high organic matter content, good effect on improving soil aggregation, ability to solve aluminum and manganese toxicity and long-lasting acid modification effect. Using the soil conditioner of the present invention during the newly planted sugarcane and the middle growth stage of sugarcane can effectively improve soil acidification and compaction in the sugarcane field at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of acid soil improvement, and particularly relates to a method for simultaneously improving the soil acidity and compactness of sugarcane fields. Background Art

[0002] Sugarcane is widely planted in regions such as Guangxi, Guangdong, and Fujian in China and is an important sugar crop in southern China. The cultivated land in the main sugarcane-growing areas of China has a poor soil fertility foundation. Due to long-term continuous cropping, excessive application of chemical fertilizers, repeated shallow tillage, and seasonal rainstorm leaching in the south, the soil in sugarcane fields has become severely acidified. Acidic soil is prone to hardening, leakage, and poor water retention, which affects the growth of sugarcane. The main manifestations are as follows: The soil is hard and compact, lacking organic matter, which affects the growth of sugarcane roots, with fewer new roots promoted, and the root's ability to absorb nutrients decreases, resulting in slower growth of the above-ground part of sugarcane; The suitable soil pH for sugarcane is 6.5 - 7.5. Soil acidification can damage the physiological functions of sugarcane roots and hinder sugarcane growth; Soil acidification also leads to a sharp decrease in the content of available potassium, calcium, and magnesium in the soil, a reduction in the availability of nutrient elements, and nutrient deficiency; Ions such as aluminum and manganese in acidified soil will be released and be toxic to sugarcane; Soil acidification causes the continuous deterioration of land quality, affecting the quality and yield of sugarcane.

[0003] The conditions for mechanized operation of sugarcane in China are becoming increasingly mature. Mechanized harvesting can greatly improve work efficiency, reduce labor intensity, and lower production costs, which is a key measure to enhance the competitiveness of the sugarcane industry. During mechanical harvesting, the tires roll over the soil, resulting in an increase in soil compactness, a change in the physical structure of the soil, a decrease in porosity, an increase in soil bulk density, and a decline in soil permeability and water infiltration ability. It has an adverse impact on sugarcane growth, such as directly affecting the root morphology, distribution, and physiological metabolism of sugarcane, and then affecting the growth of the above-ground part, resulting in a decrease in yield and quality.

[0004] At present, the main methods for improving soil acidity are to treat with single or multiple soil conditioners. Common soil conditioners include lime, minerals and industrial by-products, biochar, organic materials, and microbial fertilizers, etc. However, these soil conditioners have various problems: lime is likely to cause soil compaction and it is difficult to relieve the toxicity of free aluminum and manganese ions in acidic soil to sugarcane; minerals and industrial by-products are prone to heavy metal pollution risks and have low organic matter content; biochar is likely to cause nutrient leaching loss and the improvement effect of aggregation is not good; the acid improvement effect of organic materials and microbial fertilizers is not persistent, the acid reflux effect is strong, they need to be used frequently, and the cost is high. At present, the main methods for improving soil compaction are to reduce the number of mechanical operations, optimize the mechanical operation routes, reduce direct rolling and deep plowing, etc., but the solution effects are not ideal. Patent No. 202210033653.4 discloses a method for synchronously improving the soil acidity and compactness of apple orchards, which combines animal manure with the planting of vetch, and can well reduce soil acidity, but it is difficult to guarantee the effect of relieving aluminum and manganese toxicity in acidic soil, and the acid improvement effect is not persistent, the acid reflux effect is strong, and repeated use is required to achieve better results. Therefore, finding a method that can synchronously improve the soil acidity and compaction of sugarcane fields has become an urgent problem to be solved currently. Summary of the Invention

[0005] Aiming at the above deficiencies, the technical problem to be solved by the present invention is to provide a method for synchronously improving the soil acidity and compactness of sugarcane fields, which can synchronously improve the soil acidity and compaction of sugarcane fields, can well relieve the aluminum and manganese toxicity in acidic soil, and has a persistent acid improvement effect. The specific technical solutions are as follows:

[0006] A method for synchronously improving the soil acidity and compactness of sugarcane fields, after opening planting grooves for newly planted sugarcane, first sprinkle the soil conditioner at the bottom of the planting groove, then apply a layer of organic fertilizer on the soil conditioner and then plant sugarcane; when earthing up sugarcane in the middle stage, sprinkle a layer of soil conditioner between the sugarcane rows; after the ratoon sugarcane is newly planted, every year hereafter, the above method can be followed to open deep grooves between the sugarcane rows in the middle stage of sugarcane planting and turn the soil conditioner into the soil by burying it, which can relieve the soil compaction after mechanical pressing and harvesting of the sugarcane rows.

[0007] The soil conditioner comprises the following raw materials in parts by weight: 20 - 30 parts of modified carbonized sugarcane bagasse, 50 - 80 parts of fermented sugarcane bagasse, and 10 - 20 parts of modified coconut coir.

[0008] The preparation method of the modified carbonized sugarcane bagasse is as follows: crush and dry the sugarcane bagasse, then carry out carbonization treatment at 300 - 400 °C to obtain carbonized sugarcane bagasse; put the carbonized sugarcane bagasse into a magnesium chloride solution and impregnate it for 20 - 24 h, then dry it to obtain the modified carbonized sugarcane bagasse.

[0009] The preparation method of the fermented bagasse is as follows: crush the bagasse, add water and stir until the humidity is 60 - 70%, obtaining wet material; add 0.5 - 1.0% of glutamic acid and 1 - 6% of urea based on the weight of the wet material to the wet material, mix evenly, then add 2 - 5% of Bacillus licheniformis based on the weight of the wet material, ferment at 30 - 40°C for 3 - 5 days, then spread out and cool to obtain the first fermented material; add 5 - 10% of soybean powder, 0.1 - 0.5% of calcium chloride and 0.01 - 0.05% of casein to the first fermented material, mix evenly, inoculate Mucor racemosus, with the inoculation amount being 1 - 5% of the weight of the first fermented material, ferment at 20 - 30°C for 5 - 8 days to obtain the second fermented material; add 5 - 10% of chitosan and 0.5 - 1.0% of glycine to the second fermented material, mix evenly, inoculate Pseudonocardia thermophila, with the inoculation amount being 0.2 - 0.8% of the weight of the second fermented material, ferment at 40 - 50°C for 1 - 5 days, then spread out and cool to obtain the third fermented material; add 0.05 - 0.1% of glutathione, 5 - 10% of corn flour, 0.05 - 0.08% of ferric chloride and 0.01 - 0.05% of manganese chloride to the third fermented material, mix evenly, inoculate actinomycetes, with the inoculation amount being 0.5 - 1.0% of the weight of the third fermented material, ferment at 25 - 30°C for 8 - 10 days, thus obtaining the fermented bagasse.

[0010] The preparation method of the modified coco coir is as follows: put the coco coir into an aqueous potassium hydroxide solution, soak at 40 - 50°C for 1 - 2 h to obtain the first reactant, add the first reactant to an ethanol solution of chloroacetic acid, soak and react at 70 - 80°C for 40 - 50 min to obtain the second reactant, put the second reactant into an aqueous potassium hydroxide solution, soak at 80 - 100°C for 20 - 30 min, then dry to obtain the modified coco coir.

[0011] Preferably, the addition amount of the soil conditioner in the planting trench is 50 - 100 kg / mu; the addition amount of the soil conditioner between the sugarcane rows is 80 - 150 kg / mu.

[0012] Preferably, the soil conditioner comprises the following raw materials in parts by weight: 25 parts of modified carbonized bagasse, 68 parts of fermented bagasse and 12 parts of modified coco coir.

[0013] Preferably, the preparation method of the soil conditioner is: weigh each raw material according to the parts by weight, mix the modified carbonized bagasse and the fermented bagasse evenly, age at 20 - 35°C for 7 - 10 days, then mix evenly with the modified coco coir and granulate to obtain the soil conditioner.

[0014] Preferably, the concentration of the magnesium chloride solution is 60 - 75 mmol / L.

[0015] Preferably, during the fermentation process of the third fermentation material, the material is turned over for heat dissipation 1-2 times a day.

[0016] Preferably, the mass percentage concentration of the potassium hydroxide is 40-50%.

[0017] Preferably, the mass percentage concentration of the ethanol solution of chloroacetic acid is 50-80%.

[0018] Preferably, in the preparation of the modified coco coir, the drying is carried out until the water content is 20-40%.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. By directionally modifying biochar and coco coir and directionally fermenting bagasse, the present invention prepares a soil conditioner with high organic matter content, good improvement effect on soil aggregation, ability to solve aluminum toxicity and manganese toxicity, and long-lasting acid modification effect. Using the soil conditioner of the present invention in newly planted sugarcane and during the mid-growth stage of sugarcane can effectively improve soil acidification and compaction in sugarcane fields simultaneously.

[0021] 2. The modified carbonized bagasse, fermented bagasse and modified coco coir in the soil conditioner of the present invention are used in combination. The modified carbonized bagasse contains a large amount of alkaline metal ions, magnesium ions; the fermented bagasse contains a large amount of adsorbed enzymes; and the modified coco coir contains a large amount of alkaline metal ions, potassium ions. The magnesium ions in the modified carbonized bagasse and the potassium ions in the modified coco coir can displace high-concentration Al 3+ , Mn 2+ and Fe 2+ in acidic soil. The displaced Al 3+ , Mn 2+ and Fe 2+ and other harmful substances are polymerized and precipitated by the adsorbed enzymes in the fermented bagasse, thereby increasing the soil pH value and reducing the toxicity of Al 3+ , Mn 2+ to sugarcane. At the same time, the modified coco coir has good water retention and heat preservation effects. After being applied, it moisturizes and warms the soil, and can maintain the activity of the enzymes in the fermented bagasse for a long time. In addition, the enzymes in the fermented bagasse can be adsorbed in the pores of the modified carbonized bagasse in large quantities, having a slow-release effect, effectively prolonging the acid modification effect and preventing the soil from becoming acidic again. Therefore, the combined use of the modified carbonized bagasse, fermented bagasse and modified coco coir in the soil conditioner of the present invention can effectively increase the soil pH value, solve the aluminum toxicity and manganese toxicity in the soil, and prevent the soil from becoming acidic again.

[0022] 3. The present invention ferments bagasse with different strains in four times. During the first fermentation, glutamic acid and urea can inductively produce more urease by Bacillus licheniformis, so that a large amount of urease is contained in the first fermentation material; during the second fermentation, soybean powder, calcium chloride and casein can inductively produce more protease by Mucor racemosus, so that a large amount of protease is contained in the second fermentation material; during the third fermentation, chitosan and glycine can inductively produce more aromatic aminase and chitinase by Pseudonocardia thermophila, so that a large amount of aromatic aminase and chitinase are contained in the third fermentation material; during the fourth fermentation, glutathione, corn flour, ferric chloride and manganese chloride can inductively produce more iron-manganese reductase by actinomycetes, so that the fermented bagasse is rich in iron-manganese reductase. Through multiple different fermentations, fermented bagasse rich in urease, protease, aromatic aminase, chitinase and iron-manganese reductase can be obtained.

[0023] 4. The adsorbed soil enzymes in the fermented bagasse of the present invention are mainly urease, protease, aromatic aminase, chitinase and iron-manganese reductase; urease can ammonify soil organic nitrogen to produce OH-, reducing the H+ and Al 3+ concentrations in the soil; protease can hydrolyze soil proteins and peptides into amino acids, and under the further action of urease, ammonification occurs to produce OH-, reducing the H+ and Al 3+ concentrations in the soil; aromatic aminase and chitinase can catalyze the hydrolysis of amino compounds and aromatic amino compounds in the soil, releasing NH 4+ , thereby reducing the H+ concentration in the soil; iron-manganese reductase can enzymatically passivate Mn 2+ and Fe 2+ in the soil, forming non-toxic compounds that cannot enter the roots and reducing their toxic effects.

[0024] 5. The soil enzymes of the present invention can also promote the formation of humus and organic-inorganic colloids in the soil, form aggregate structures, improve soil compaction, make the soil loose and reduce the bulk density. Detailed implementation manners

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0026] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0027] In the description of the present invention, the meaning of "several" is one or more, the meaning of "multiple" is more than two, and understandings such as "greater than", "less than", "exceeding", etc. do not include the base number, and understandings such as "above", "below", "within", etc. include the base number. If there are descriptions of the terms "first", "second", "third", etc., they are only for descriptive purposes and for distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0028] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations. In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] Example 1

[0030] A method for synchronously improving the soil acidity and compactness of a sugarcane field, which includes that after a new sugarcane is planted and a planting ditch is opened, first spread a soil conditioner on the bottom of the planting ditch, the addition amount of the soil conditioner in the planting ditch is 50 kg / mu, then apply a layer of organic fertilizer on the soil conditioner and then plant sugarcane; when earthing up the sugarcane in the middle stage, spread a layer of soil conditioner between the sugarcane rows, and the addition amount of the soil conditioner between the sugarcane rows is 80 kg / mu.

[0031] The soil conditioner includes the following raw materials in parts by weight: 20 parts of modified carbonized sugarcane bagasse, 50 parts of fermented sugarcane bagasse, and 10 parts of modified coconut coir. The preparation method of the soil conditioner is: weigh each raw material according to the parts by weight, mix the modified carbonized sugarcane bagasse and the fermented sugarcane bagasse, age at 20 °C for 7 days, and then mix with the modified coconut coir to make particles with a particle size of 3 mm, thus obtaining the soil conditioner.

[0032] The preparation method of the modified carbonized sugarcane bagasse is: crush and dry the sugarcane bagasse, then carry out carbonization treatment at 300 °C to obtain carbonized sugarcane bagasse; put the carbonized sugarcane bagasse into a magnesium chloride solution with a concentration of 60 mmol / L and soak for 20 h, and then dry to obtain the modified carbonized sugarcane bagasse;

[0033] The preparation method of the fermented bagasse is as follows: crushing the bagasse, adding water and stirring until the humidity is 60% to obtain a wet material, adding 0.5% of glutamic acid and 1% of urea by weight of the wet material to the wet material, mixing well, adding 2% of licheniformis by weight of the wet material, fermenting at 30°C for 3 days, spreading and cooling to obtain a first fermentation material; adding 5% of soybean powder, 0.1% of calcium chloride and 0.01% of casein by weight of the first fermentation material to the first fermentation material, mixing well, inoculating Mucor racemosus in an inoculation amount of 1% of the weight of the first fermentation material, fermenting at 20°C for 5 days to obtain a second fermentation material; adding 0.5% of glutamic acid and 1% of urea by weight of the wet material to the wet material, fermenting at 30°C for 3 days to obtain a first fermentation material. Add 5% chitosan and 0.5% glycine by weight of the second fermentation material to the fermentation material, mix well, inoculate thermophilic Pseudonocardia in an amount of 0.2% by weight of the second fermentation material, ferment at 40°C for 1 day, spread out to cool, and obtain a third fermentation material; add 0.05% glutathione, 5% corn flour, 0.05% ferric chloride and 0.01% manganese chloride by weight of the third fermentation material to the third fermentation material, mix well, inoculate actinomycetes in an amount of 0.5% by weight of the third fermentation material, ferment at 25°C for 8 days, turn the material over once a day to dissipate heat during the fermentation process, and obtain the fermented bagasse;

[0034] The preparation method of the modified coconut bran is as follows: putting coconut bran into a potassium hydroxide aqueous solution with a mass percentage concentration of 40%, soaking it at 40°C for 1 hour to obtain a first reactant, adding the first reactant into an ethanol solution of chloroacetic acid with a mass percentage concentration of 50%, soaking it at 70°C for reaction for 40 minutes to obtain a second reactant, putting the second reactant into a potassium hydroxide aqueous solution with a mass percentage concentration of 40%, soaking it at 80°C for 20 minutes, and drying it to a water content of 20%, thereby obtaining the modified coconut bran.

[0035] Example 2

[0036] A method for synchronously improving the acidity and compactness of soil in a sugarcane field comprises: after digging a planting ditch for newly planted sugarcane, firstly spreading a soil conditioner into the bottom of the planting ditch, the amount of soil conditioner added in the planting ditch is 100 kg / mu, then applying a layer of organic fertilizer on the soil conditioner before planting sugarcane; when soil is cultivated in the middle stage of sugarcane, spreading a layer of soil conditioner between sugarcane rows, the amount of soil conditioner added between sugarcane rows is 150 kg / mu.

[0037] The soil conditioner comprises the following raw materials in parts by weight: 30 parts of modified carbonized bagasse, 80 parts of fermented bagasse and 20 parts of modified coconut bran; the preparation method of the soil conditioner comprises the following steps: weighing the raw materials in parts by weight, uniformly mixing the modified carbonized bagasse and the fermented bagasse, aging them at 35° C. for 10 days, and then uniformly mixing them with the modified coconut bran to prepare particles with a particle size of 4 mm, thereby obtaining the soil conditioner.

[0038] The preparation method of the modified carbonized sugarcane bagasse is as follows: After crushing and drying the sugarcane bagasse, it is carbonized at 400 °C to obtain carbonized sugarcane bagasse; the carbonized sugarcane bagasse is immersed in a magnesium chloride solution with a concentration of 75 mmol / L for 24 h and then dried to obtain the modified carbonized sugarcane bagasse;

[0039] The preparation method of the fermented sugarcane bagasse is as follows: The sugarcane bagasse is crushed and stirred with water until the humidity reaches 70% to obtain a wet material. Glutamic acid accounting for 1.0% of the weight of the wet material and urea accounting for 6% of the weight of the wet material are added to the wet material. After mixing evenly, Bacillus licheniformis accounting for 5% of the weight of the wet material is added, and fermentation is carried out at 40 °C for 5 days. Then it is spread out and cooled to obtain the first fermented material; soybean powder accounting for 10% of the weight of the first fermented material, calcium chloride accounting for 0.5% of the weight of the first fermented material, and casein accounting for 0.05% of the weight of the first fermented material are added to the first fermented material. After mixing evenly, Rhizopus racemosus is inoculated, and the inoculation amount is 5% of the weight of the first fermented material. Fermentation is carried out at 30 °C for 8 days to obtain the second fermented material; chitosan accounting for 10% of the weight of the second fermented material and glycine accounting for 1.0% of the weight of the second fermented material are added to the second fermented material. After mixing evenly, Pseudonocardia thermophila is inoculated, and the inoculation amount is 0.8% of the weight of the second fermented material. Fermentation is carried out at 50 °C for 5 days. Then it is spread out and cooled to obtain the third fermented material; glutathione accounting for 0.1% of the weight of the third fermented material, corn flour accounting for 10% of the weight of the third fermented material, ferric chloride accounting for 0.08% of the weight of the third fermented material, and manganese chloride accounting for 0.05% of the weight of the third fermented material are added to the third fermented material. After mixing evenly, actinomycetes are inoculated, and the inoculation amount is 1.0% of the weight of the third fermented material. Fermentation is carried out at 30 °C for 10 days. During the fermentation process, the material is turned over and cooled 2 times a day to obtain the fermented sugarcane bagasse;

[0040] The preparation method of the modified coco coir is as follows: The coco coir is put into an aqueous potassium hydroxide solution with a mass percentage concentration of 50% and soaked at 50 °C for 2 h to obtain a first reactant. The first reactant is added to an ethanol solution of chloroacetic acid with a mass percentage concentration of 80% and soaked and reacted at 80 °C for 50 min to obtain a second reactant. The second reactant is put into an aqueous potassium hydroxide solution with a mass percentage concentration of 50% and soaked at 100 °C for 30 min, and then dried to a water content of 40% to obtain the modified coco coir.

[0041] Example 3

[0042] A method for synchronously improving the soil acidity and compactness of a sugarcane field includes, after opening a planting ditch for newly planted sugarcane, first spreading a soil conditioner at the bottom of the planting ditch, and the addition amount of the soil conditioner in the planting ditch is 90 kg / mu. Then, a layer of organic fertilizer is applied on the soil conditioner and then sugarcane is planted; when earthing up the sugarcane in the middle stage, a layer of soil conditioner is applied between the sugarcane rows, and the addition amount of the soil conditioner between the sugarcane rows is 130 kg / mu.

[0043] The soil conditioner comprises the following raw materials in parts by weight: 25 parts of modified carbonized sugarcane bagasse, 68 parts of fermented sugarcane bagasse, and 12 parts of modified coconut coir. The preparation method of the soil conditioner is as follows: Weigh each raw material according to the parts by weight, mix the modified carbonized sugarcane bagasse and the fermented sugarcane bagasse, age at 30 °C for 8 days, then mix with the modified coconut coir, and make into particles with a particle size of 2 mm, thus obtaining the soil conditioner.

[0044] The preparation method of the modified carbonized sugarcane bagasse is as follows: Crush and dry the sugarcane bagasse, then perform carbonization treatment at 350 °C to obtain carbonized sugarcane bagasse; Immerse the carbonized sugarcane bagasse in a magnesium chloride solution with a concentration of 70 mmol / L for 22 h, and then dry it to obtain the modified carbonized sugarcane bagasse.

[0045] The preparation method of the fermented sugarcane bagasse is as follows: Crush the sugarcane bagasse, add water and stir until the humidity reaches 65% to obtain wet material. Add 0.8% of glutamic acid and 4% of urea based on the weight of the wet material to the wet material, mix well, then add 3% of Bacillus licheniformis based on the weight of the wet material, ferment at 35 °C for 4 days, then spread out and cool to obtain the first fermented material; Add 8% of soybean powder, 0.3% of calcium chloride, and 0.03% of casein based on the weight of the first fermented material to the first fermented material, mix well, inoculate with Mucor racemosus, and the inoculation amount is 3% of the weight of the first fermented material, ferment at 25 °C for 6 days to obtain the second fermented material; Add 7% of chitosan and 0.8% of glycine based on the weight of the second fermented material to the second fermented material, mix well, inoculate with Pseudonocardia thermophila, and the inoculation amount is 0.6% of the weight of the second fermented material, ferment at 45 °C for 4 days, then spread out and cool to obtain the third fermented material; Add 0.07% of glutathione, 9% of corn flour, 0.06% of ferric chloride, and 0.02% of manganese chloride based on the weight of the third fermented material to the third fermented material, mix well, inoculate with actinomycetes, and the inoculation amount is 0.6% of the weight of the third fermented material, ferment at 28 °C for 9 days. During the fermentation process, turn the material and dissipate heat 2 times a day, thus obtaining the fermented sugarcane bagasse.

[0046] The preparation method of the modified coconut coir is as follows: Put the coconut coir into an aqueous potassium hydroxide solution with a mass percentage concentration of 45%, soak at 45 °C for 1.5 h to obtain the first reactant, add the first reactant into an ethanol solution of chloroacetic acid with a mass percentage concentration of 60%, soak and react at 75 °C for 45 min to obtain the second reactant, put the second reactant into an aqueous potassium hydroxide solution with a mass percentage concentration of 45%, soak at 90 °C for 25 min, and then dry to a water content of 30%, thus obtaining the modified coconut coir.

[0047] Comparative Example 1

[0048] The soil conditioner used does not contain modified carbonized sugarcane bagasse, that is, the soil conditioner is: fermented sugarcane bagasse + modified coconut coir, and other methods are the same as those in Example 3.

[0049] Comparative Example 2

[0050] The soil conditioner used does not contain fermented sugarcane bagasse, that is, the soil conditioner is: modified carbonized sugarcane bagasse + modified coco coir, and other methods are the same as those in Example 3.

[0051] Comparative Example 3

[0052] The soil conditioner used does not contain modified coco coir, that is, the soil conditioner is: fermented sugarcane bagasse + modified carbonized sugarcane bagasse, and other methods are the same as those in Example 3.

[0053] Comparative Example 4

[0054] In the soil conditioner used, biochar is used to replace modified carbonized sugarcane bagasse, and other raw materials remain unchanged, that is, the soil conditioner is: biochar + fermented sugarcane bagasse + modified coco coir, and other methods are the same as those in Example 3.

[0055] Comparative Example 5

[0056] In the soil conditioner used, the fermented sugarcane bagasse obtained by the conventional composting method (the conventional composting method is to directly stack the sugarcane bagasse at room temperature for 2 - 3 months) is used to replace the fermented sugarcane bagasse in Example 3, and other raw materials remain unchanged, that is, the soil conditioner is: modified carbonized sugarcane bagasse + conventionally fermented sugarcane bagasse + modified coco coir, and other methods are the same as those in Example 3.

[0057] Comparative Example 6

[0058] In the soil conditioner used, coco coir is used to replace the modified coco coir in Example 3, and other raw materials remain unchanged, that is, the soil conditioner is: modified carbonized sugarcane bagasse + fermented sugarcane bagasse + coco coir, and other methods are the same as those in Example 3.

[0059] Comparative Example 7

[0060] Biochar + conventionally fermented sugarcane bagasse + coco coir is used as the No. 1 soil conditioner, and the same amount of the No. 1 soil conditioner as in Example 3 is applied to the planting furrows of newly planted sugarcane and the furrows of sugarcane in the middle growth stage in 2020, and it is not continued to be used in 2021. Other field management is the same as that in Comparative Example 8.

[0061] Comparative Example 8

[0062] The soil conditioner of the present invention is used, and the same amount of the soil conditioner of the present invention (the soil conditioner prepared in Example 3) as in Example 3 is applied to the planting furrows of newly planted sugarcane and the furrows of sugarcane in the middle growth stage in 2020, and it is not continued to be used in 2021. Other field management is the same as that in Comparative Example 7.

[0063] In the above-mentioned examples and comparative examples, the Bacillus licheniformis was purchased from Shandong Bilan Biotechnology Co., Ltd., the Mucor racemosus was purchased from Shanghai Xuanya Biotechnology Co., Ltd., the Pseudonocardia thermophila was purchased from the Institute of Microbiology, Chinese Academy of Sciences, and the Actinomycetes was purchased from Shandong Nuojie Biotechnology Co., Ltd.

[0064] The above-mentioned examples and comparative examples were carried out by the applicant in the sugarcane fields of Dingdang Town, Long'an County, Guangxi. In 2020, the pH value of the soil in the test plot was 3 - 4, the soil compactness of the soil layer with a depth of 30 - 40 cm was 9000 - 10000 KPa, and the soil bulk density was 2.5 - 3.5 g / cm 3 , the soil organic matter content was 10 - 15 g / kg, the total nitrogen content of the soil was 0.4 - 0.7 g / kg, the available phosphorus content of the soil was 110 - 140 mg / kg, the available potassium content of the soil was 100 - 120 mg / kg. The soil was severely acidified, with high compactness and poor soil fertility. Each example and comparative example was set with 3 replicates and 5 row plots, with a row spacing of 1.2 m, a row length of 10 m, and a plot area of 60 m 2 . The test period was 2 years, and ratoon sugarcane was planted in all cases. The newly planted sugarcane was planted in the spring of 2020. Before planting, the sugarcane field was plowed and the soil was broken up. The whole planting process adopted machine planting, machine management and machine harvesting. The application method of the soil conditioner was as follows: after the planting ditch was opened for the newly planted sugarcane in 2020, the soil conditioner was first spread at the bottom of the planting ditch, and then a layer of organic fertilizer was applied on top of the soil conditioner before planting sugarcane. When the sugarcane was earthed up in the middle stage in 2020 and 2021, a layer of soil conditioner was spread between the sugarcane rows.

[0065] In the mature stage of sugarcane in 2021, 3 sampling points were taken from each plot of Examples 1 - 3 and Comparative Examples 1 - 6. The soil profile was dug, and samples were taken at intervals of 10 cm for each layer. The physical properties of the soil in 4 soil layers were measured, including compactness and bulk density, and the field water holding capacity, soil specific gravity and moisture content were measured. The total porosity was calculated through bulk density, field water holding capacity, soil specific gravity and moisture content, and the average value was obtained. The results are shown in Table 1; 1 kg of soil samples from the 0 - 40 cm plough layer were dug from the soil profile in the plots of Comparative Example 7 and Comparative Example 8 before planting (planted in March 2020), in 2020 and in the mature stage of sugarcane in 2021, air-dried, and the soil pH value, organic matter, total nitrogen, available phosphorus and available potassium of the soil were measured, and the average value was obtained. The results are shown in Table 2.

[0066] Before planting (planted in March 2020), in 2020 and in the mature stage of sugarcane in 2021, 1 kg of soil samples from the 0 - 40 cm plough layer were dug from the soil profile in the plots of Comparative Example 7 and Comparative Example 8, air-dried, and the soil pH value was measured. The results are shown in Table 3.

[0067] Table 1 Physical properties of the soil in each example

[0068] Project Compactness (KPa) <![CDATA[Bulk density (g / cm 3 )]]> Total porosity (%) Example 1 2978 1.58±0.11 62.9±3.78 Example 2 2579 1.31±0.09 66.1±2.18 Example 3 2561 1.29±0.21 68.8±1.77 Comparative Example 1 3413 2.96±0.08 42.1±1.52 Comparative Example 2 3543 2.99±0.11 40.4±1.22 Comparative Example 3 3312 2.87±0.04 41.7±1.27 Comparative Example 4 3011 1.89±0.09 58.4±1.45 Comparative Example 5 3124 1.98±0.23 53.6±1.36 Comparative Example 6 3210 2.03±0.17 50.1±1.21

[0069] Table 2 Chemical properties of the soil in each example

[0070]

[0071]

[0072] Table 3 Comparison of Persistence of Soil Acidification Improvement

[0073] Project Soil pH value before planting Soil pH value in 2020 Soil pH value in 2021 Comparative Example 7 (conventional modifier) 3.45±0.14 6.45±0.79 3.51±0.29 Comparative Example 8 (modifier of the present invention) 3.39±0.22 6.88±0.68 6.19±0.48

[0074] Tables 1, 2 and 3 show that by directionally modifying biochar and coir pith and directionally fermenting bagasse, the present invention prepares a soil conditioner with a high organic matter content, excellent effect on improving soil aggregation, ability to detoxify aluminum and manganese, and long-lasting acidification improvement effect. When the soil conditioner of the present invention is used in newly planted sugarcane and in the middle growth stage of sugarcane, it can effectively improve soil acidification and compaction in sugarcane fields and increase soil fertility at the same time. And during the planting process of each example, no Al 3+ , Mn 2+ toxicity symptoms were found in sugarcane, while in Comparative Example 2 and Comparative Example 5, sugarcane showed aluminum and manganese toxicity symptoms such as short plants, inhibited root growth, and reduced yield during the planting process.

[0075] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claimed rights.

Claims

1. A method for synchronously improving the soil acidity and compactness of a sugarcane field, characterized in that, Including: After the planting furrows are opened for newly planted sugarcane, first sprinkle the soil conditioner into the bottom of the planting furrows, then apply a layer of organic fertilizer on top of the soil conditioner and then plant sugarcane; when earthing up the sugarcane in the middle stage, sprinkle a layer of soil conditioner between the sugarcane rows; The soil conditioner comprises the following raw materials in parts by weight: 20-30 parts of modified carbonized sugarcane bagasse, 50-80 parts of fermented sugarcane bagasse and 10-20 parts of modified coconut coir; The preparation method of the modified carbonized sugarcane bagasse is as follows: crush and dry the sugarcane bagasse, then carry out carbonization treatment at 300-400 °C to obtain carbonized sugarcane bagasse; put the carbonized sugarcane bagasse into a magnesium chloride solution and soak for 20-24 h, then dry to obtain the modified carbonized sugarcane bagasse; The preparation method of the fermented sugarcane bagasse is as follows: crush the sugarcane bagasse, add water and stir until the humidity is 60-70% to obtain a wet material, add 0.5-1.0% of glutamic acid and 1-6% of urea by weight of the wet material to the wet material, mix evenly, then add 2-5% of Bacillus licheniformis by weight of the wet material, ferment at 30-40 °C for 3-5 days, then spread out and cool to obtain a first fermented material; add 5-10% of soybean powder, 0.1-0.5% of calcium chloride and 0.01-0.05% of casein by weight of the first fermented material to the first fermented material, mix evenly, inoculate Mucor racemosus, and the inoculation amount is 1-5% by weight of the first fermented material, ferment at 20-30 °C for 5-8 days to obtain a second fermented material; add 5-10% of chitosan and 0.5-1.0% of glycine by weight of the second fermented material to the second fermented material, mix evenly, inoculate Pseudonocardia thermophila, and the inoculation amount is 0.2-0.8% by weight of the second fermented material, ferment at 40-50 °C for 1-5 days, then spread out and cool to obtain a third fermented material; add 0.05-0.1% of glutathione, 5-10% of corn flour, 0.05-0.08% of ferric chloride and 0.01-0.05% of manganese chloride by weight of the third fermented material to the third fermented material, mix evenly, inoculate actinomycetes, and the inoculation amount is 0.5-1.0% by weight of the third fermented material, ferment at 25-30 °C for 8-10 days to obtain the fermented sugarcane bagasse; The preparation method of the modified coconut coir is as follows: put the coconut coir into an aqueous potassium hydroxide solution, soak at 40-50 °C for 1-2 h to obtain a first reaction product, add the first reaction product to an ethanol solution of chloroacetic acid, soak and react at 70-80 °C for 40-50 min to obtain a second reaction product, put the second reaction product into an aqueous potassium hydroxide solution, soak at 80-100 °C for 20-30 min, then dry to obtain the modified coconut coir; 2. The method for synchronously improving the acidity and compactness of sugarcane field soil according to claim 1, characterized in that, The addition amount of the soil conditioner in the planting furrows is 50-100 kg / mu; the addition amount of the soil conditioner between the sugarcane rows is 80-150 kg / mu.

3. A method for synchronously improving the soil acidity and compactness of a sugarcane field according to claim 1, characterized in that, The soil conditioner comprises the following raw materials in parts by weight: 25 parts of modified carbonized sugarcane bagasse, 68 parts of fermented sugarcane bagasse and 12 parts of modified coconut coir.

4. A method for synchronously improving the acidity and compactness of sugarcane field soil according to claim 1, characterized in that, The preparation method of the soil conditioner comprises the following steps: weighing each raw material by weight, uniformly mixing the modified carbonized bagasse and the fermented bagasse, aging them at 20-35° C. for 7-10 days, uniformly mixing them with the modified coconut bran, and granulating them to obtain the soil conditioner.

5. A method for synchronously improving the soil acidity and compactness of a sugarcane field according to claim 1, characterized in that, The concentration of the magnesium chloride solution is 60-75 mmol / L.

6. A method for synchronously improving the acidity and compactness of sugarcane field soil according to claim 1, characterized in that, During the fermentation process of the third fermentation material, the material is turned over 1-2 times a day to dissipate heat.

7. A method for synchronously improving the acidity and compactness of sugarcane field soil according to claim 1, characterized in that, The mass percentage concentration of the potassium hydroxide is 40-50%.

8. A method for synchronously improving the acidity and compactness of sugarcane field soil according to claim 1, characterized in that, The mass percentage concentration of the chloroacetic acid ethanol solution is 50-80%.

9. A method for synchronously improving the acidity and compactness of sugarcane field soil according to claim 1, characterized in that, In the preparation of the modified coconut bran, the drying is to dry it to a moisture content of 20-40%.

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