Soil conditioner, method for preparing the same, and use thereof

Abstract

The application relates to the field of improving severely salinized soil, and discloses a soil improver and a preparation method and application thereof. The method comprises the following steps: mixing agricultural and forestry wastes and bacillus spores, and sequentially carrying out anaerobic composting and aerobic composting, wherein the agricultural and forestry wastes are a mixture of at least one of corncob, mushroom residue, peanut shell and crop straw and sweet sorghum residue. The composition provided by the application not only has the functions of water and fertilizer conservation, soil fertility improvement, soil structure improvement and biological diversity improvement, but also can promote plant growth, reduce the total salt content, pH value, alkalinity, conductivity and sodium ion exchange capacity of the soil.

Description

Technical Field

[0001] This invention relates to the field of improving saline-alkali soils, specifically to soil conditioners, their preparation methods, and applications. Background Technology

[0002] China is a country with a large amount of saline-alkali land, with a total area of ​​99.13 million hectares. 2 Saline-alkali land accounts for approximately 10% of my country's land area and causes economic losses of 3 billion yuan annually. Regarding saline-alkali land improvement, 100 million mu (approximately 6.67 million hectares) of saline-alkali land has agricultural development value and near-term potential for agricultural improvement and utilization. Of this, 35 million mu (approximately 2.3 million hectares) can achieve significant yield increases after improvement, and 65 million mu (approximately 4.3 million hectares) of saline-alkali land not yet used for agriculture can be converted into arable land after improvement.

[0003] Saline-alkali land is essentially formed by the accumulation of salt in the surface layer of soil in salt-collecting areas. Climate, hydrology, topography, geology, and human activities are all important factors in its formation. Saline-alkali soils have high salt (alkali) content, low organic matter and nutrient content, poor soil structure and biodiversity, making it difficult to meet the requirements for crop growth. The improvement of saline-alkali soils aims at cultivating healthy soil. Besides avoiding "secondary pollution" and effectively controlling and suppressing salt concentration, the focus should be on improving soil fertility, structure, and biodiversity, thereby enhancing the soil's water and fertilizer retention capacity and promoting crop production.

[0004] Currently, research in the field of saline-alkali land mainly focuses on hot issues such as plant response to salt stress, farmland water and fertilizer management, soil improvement, and soil microorganisms. In the future, research hotspots may focus on two major aspects: sustainable utilization of agricultural water resources and soil microbial diversity. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the prior art and to provide soil conditioners, their preparation methods, and applications.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a soil conditioner, the method comprising: mixing agricultural and forestry waste and Bacillus subtilis and sequentially performing anaerobic composting and aerobic composting, wherein the agricultural and forestry waste is a mixture of at least one of corn cobs, mushroom residue, peanut shells and crop straw with sweet sorghum residue.

[0007] A second aspect of the present invention provides a soil conditioner prepared by the above-described method.

[0008] The third aspect of the present invention provides the application of the above-mentioned soil conditioner in the improvement of saline soil.

[0009] A fourth aspect of the present invention provides a method for improving saline soil, the method comprising: applying the above-mentioned soil conditioner to the soil.

[0010] Through the above technical solution, the soil conditioner provided by this invention has the effect of improving severely saline-alkali soil. It not only has the functions of water and fertilizer retention, improving soil fertility, soil structure, and biodiversity, but also promotes plant growth and reduces soil salinity and alkalinity (total salt content, pH value, alkalinity, electrical conductivity, and sodium ion exchange capacity). In addition, it can effectively reduce the heavy metal content in crops grown in heavy metal-contaminated soils. Furthermore, the raw materials in the composition are widely available, and the production and use processes do not cause secondary pollution, promoting resource recycling. The production cost is low, and the model is replicable and scalable. The utilization of agricultural and forestry waste in the composition is beneficial to promoting the recycling of agricultural resources. Attached Figure Description

[0011] Figure 1 This is a process flow diagram of the present invention;

[0012] Figure 2 This shows the germination status of Example 1 and the blank control group. Detailed Implementation

[0013] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0014] The first aspect of the present invention provides a method for preparing a soil conditioner, the method comprising: mixing agricultural and forestry waste and Bacillus subtilis and sequentially performing anaerobic composting and aerobic composting, wherein the agricultural and forestry waste is a mixture of at least one of corn cobs, mushroom residue, peanut shells and crop straw with sweet sorghum residue.

[0015] In this invention, the sweet sorghum residue is mainly the stalk residue remaining after pressing fresh sweet sorghum stalks to separate the juice and residue.

[0016] In this invention, the corn stalks consist of the leaves, stems, and cobs of the corn plant left in the field after harvest.

[0017] In this invention, the rice straw refers to the rice ears left after rice harvesting, excluding grains, stems, and leaves.

[0018] In this invention, the mushroom residue is the post-growth culture medium left after mushrooms have grown and been harvested on a culture medium. The culture medium contains pesticide residues, sawdust, and water, with a pesticide residue to sawdust weight ratio of 3-5:1 and a water content of 50-60% by weight. The pesticide residues are selected from at least one of rice straw, wheat straw, and corn cobs. In practical use, the pesticide residues can be pulverized. The mushrooms are not limited and can be at least one of conventional fungi in the art, such as oyster mushrooms, shiitake mushrooms, enoki mushrooms, tea tree mushrooms, king oyster mushrooms, and lion's mane mushrooms. The growth conditions include a temperature of 20-30℃, humidity of 85-95%, and a growth period of 4-5 harvests.

[0019] In this invention, to further improve the fertility and reduce the salinity of saline-alkali soils, the obtained soil conditioner contains 10 viable Bacillus bacteria relative to 1g of agricultural and forestry waste. 3 -10 5 The weight of the agricultural and forestry waste is calculated as dry weight.

[0020] In this invention, to further improve the fertility of saline-alkali soil, reduce its salinity and alkalinity, and decrease the heavy metal content in crops grown in heavy metal-contaminated soil, the anaerobic composting conditions include: a temperature of 50-70°C (any two values ​​from 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, 62°C, 64°C, 66°C, 68°C, 70°C, or higher), and a time of 2-4 days (any two values ​​from 2 days, 3 days, 4 days, or higher). Preferably, the oxygen content in the anaerobic compost is less than 10% by weight.

[0021] In this invention, to further improve the fertility of saline-alkali soil, reduce its salinity and alkalinity, and decrease the heavy metal content in crops grown in heavy metal-contaminated soil, the aerobic composting conditions include: a temperature of 50-70℃ (any two values ​​from 50℃, 52℃, 54℃, 56℃, 58℃, 60℃, 62℃, 64℃, 66℃, 68℃, 70℃, or higher), and a time of 7-10 days (any two values ​​from 7 days, 8 days, 9 days, or higher). The oxygen content in the aerobic compost is higher than 20% by weight. The temperature of the anaerobic compost may be the same as or different from that of the aerobic compost.

[0022] In this invention, in order to enable better fermentation of Bacillus, the water content of the mixed system is 50-60% by weight; preferably, the particle size of the agricultural and forestry waste is less than 5 mm; more preferably, the thickness of the compost is 30-50 cm.

[0023] Preferably, the crop straw includes at least one of corn straw, rice straw, wheat straw, rapeseed straw, and soybean straw.

[0024] The inventors of this invention have discovered that when the agricultural and forestry waste is a mixture of at least one of corn cobs and mushroom residue with sweet sorghum residue, the resulting soil conditioner can further improve the fertility of saline-alkali soils and reduce their salinity. Preferably, the sweet sorghum residue accounts for 30-70% by weight of the total agricultural and forestry waste, and can be any two of the following values ​​within the range: 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or more.

[0025] The inventors of this invention have discovered that the Bacillus is Bacillus subtilis and / or Bacillus licheniformis; preferably, the Bacillus is Bacillus subtilis and Bacillus licheniformis; more preferably, the viable count ratio of Bacillus subtilis and Bacillus licheniformis is 1:0.05-0.1, which can be 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1 or any two of the above values ​​within a range; the obtained soil conditioner can further improve the fertility of saline soil and reduce the salinity of saline soil.

[0026] More preferably, the Bacillus subtilis has the accession number ACCC 19373 (purchased from the China Agricultural Microbiological Culture Collection Center). More preferably, the Bacillus licheniformis has the accession number CGMCC No. 20977 (disclosed in CN112522155A).

[0027] In this invention, to further improve the fertility of saline-alkali soil, reduce the salinity and alkalinity of saline-alkali soil, and reduce the heavy metal content in crops grown in heavy metal soil, the mixed system also includes amino acid fertilizer. Preferably, the weight ratio of agricultural and forestry waste to amino acid fertilizer is 100:0.002-0.01, which can be 100:0.002, 100:0.003, 100:0.004, 100:0.005, 100:0.006, 100:0.007, 100:0.008, 100:0.009, 100:0.01, or any two of the above values ​​within a range. The weights of the agricultural and forestry waste and fertilizer are all based on dry weight. More preferably, the pH of the amino acid fertilizer is 3-6, and it can be diluted 100-1500 times before actual use.

[0028] In this invention, in order to further improve the fertility of saline soil, reduce the salinity and alkalinity of saline soil, and reduce the heavy metal content in crops grown in heavy metal soil, the amino acid fertilizer is obtained by hydrolyzing animal protein from livestock and poultry processing waste, slaughter waste, or dead livestock and poultry. Preferably, the free amino acid content in the amino acid fertilizer is not less than 100 g / L, and the trace element content is not less than 20 g / L. The trace element is at least one of Fe, Mn, Zn, and B.

[0029] In this invention, in order to further improve the fertility of saline soil, reduce the salinity and alkalinity of saline soil, and reduce the heavy metal content in crops grown in heavy metal soil, the mixed system also includes urea; preferably, the weight ratio of agricultural and forestry waste to urea is 100:0.3-0.8, which can be 100:0.3, 100:0.4, 100:0.5, 100:0.6, 100:0.7, 100:0.8 or any two of the above values ​​and values ​​within the range, and the weight of the agricultural and forestry waste is based on dry weight.

[0030] In this invention, in order to further improve the fertility of saline soil, reduce the salinity and alkalinity of saline soil, and reduce the heavy metal content in crops grown in heavy metal soil, the mixed system also includes fulvic acid; preferably, the weight ratio of agricultural and forestry waste to fulvic acid is 100:0.3-0.5, which can be any two of the following values: 100:0.3, 100:0.4, 100:0.5, or values ​​within the range of these values, and the weight of the agricultural and forestry waste is based on dry weight.

[0031] In this invention, in order to enable Bacillus to ferment better, agricultural and forestry waste can be mixed evenly with urea and humic acid, the moisture content can be adjusted, the weight ratio of carbon to nitrogen can be adjusted to 25-35:1, and then mixed with Bacillus.

[0032] In this invention, in order to further improve the fertility of saline soil, reduce the salinity and alkalinity of saline soil, and reduce the heavy metal content in crops grown in heavy metal soil, the mixed system also includes sulfate; preferably, the weight ratio of agricultural and forestry waste to sulfate is 100:1-2, which can be 100:1.1, 100:1.2, 100:1.3, 100:1.4, 100:1.5, 100:1.6, 100:1.7, 100:1.8, 100:1.9, 100:2 or any two of the above values ​​and values ​​within the range. The weight of the agricultural and forestry waste is based on dry weight. Preferably, the sulfate is aluminum sulfate and / or calcium sulfate.

[0033] In this invention, sulfate can be added during composting or after composting, preferably after composting.

[0034] In this invention, in order to further improve the fertility of saline soil, reduce the salinity and alkalinity of saline soil, and reduce the heavy metal content in crops grown in heavy metal soil, the mixed system also includes urea phosphate; more preferably, the weight ratio of agricultural and forestry waste to urea phosphate is 100:0.5-1, which can be 100:0.5, 100:0.6, 100:0.7, 100:0.8, 100:0.9, 100:1 or any two of the above values ​​and values ​​within the range, and the weight of the agricultural and forestry waste is based on dry weight.

[0035] In this invention, urea phosphate can be added during composting or after composting, preferably after composting.

[0036] According to a more preferred embodiment of the present invention, the weight ratio of the agricultural and forestry waste, amino acid fertilizer, urea, humic acid, sulfate, and urea phosphate is 100:0.002-0.01:0.5-0.65:0.35-0.45:1.3-1.7:0.7-0.9, the content of sweet sorghum residue in the agricultural and forestry waste is 45-55% by weight, and the sulfate is calcium sulfate.

[0037] A second aspect of the present invention provides a soil conditioner prepared by the above-described method.

[0038] The third aspect of the present invention provides the application of the above-mentioned soil conditioner in the improvement of saline soil.

[0039] A fourth aspect of the present invention provides a method for improving saline soil, the method comprising: applying the above-mentioned soil conditioner to the soil.

[0040] In this invention, if applied to land, the application rate of the soil conditioner is 1000-3000 kg / mu; if applied to potted plants, the application rate of the soil conditioner is 1-3 times the total weight of the soil.

[0041] In this invention, the soil conditioner is more suitable for severely saline soils with a pH of 10.42-10.79, a total salt content of 11.25-55.7 g / kg, an alkalinity of 49.18-73.45%, an electrical conductivity of 756-3010 μS / cm, and a sodium ion exchange capacity of 6.9-11.76 cmol / kg.

[0042] In this invention, in order to ensure that the soil and the soil conditioner are fully mixed, the method further includes: applying the soil conditioner to the soil and then tilling the soil; preferably, the tilling depth is not less than 15-25cm.

[0043] In this invention, the soil conditioner is used to improve plant germination rate. The plants include at least one of corn, sweet sorghum, rice, peanut, wheat, and soybean.

[0044] In this invention, the soil conditioner is used to reduce the heavy metal content in plants. The plants include at least one of corn, sweet sorghum, rice, peanut, wheat, and soybean.

[0045] The present invention will be described in detail below through examples. In the following examples, the mushroom residue is the culture medium remaining after harvesting oyster mushrooms after five harvests of oyster mushrooms grown in a culture medium (the weight ratio of crushed corn cob and sawdust is 4:1, and the moisture content is 55% by weight) at a temperature of 25°C and a humidity of 90%.

[0046] Urea source: Purchased from Henan Xinlianxin Chemical Industry Group Co., Ltd., and the urea conforms to GB / T2440-2017;

[0047] Source of fulvic acid: Purchased from Shandong Zhongke Cuiwei Power Technology Co., Ltd. Potassium fulvic acid conforms to GB / T 33804-2017 "Potassium Humate for Agricultural Use";

[0048] Source of amino acid fertilizer: Purchased from Jiangyin Pengyao Lianye Biotechnology Co., Ltd., the animal protein amino acid fertilizer is mainly made from the hydrolysis of animal protein from livestock and poultry processing waste, slaughter waste or dead livestock and poultry. Its free amino acid content is ≥100g / L and trace elements (Fe+Mn+Zn+B) are ≥20g / L.

[0049] Foliar fertilizer source and composition: Purchased from Shandong Mairuis Biotechnology Co., Ltd., the foliar fertilizer product complies with GB / T17419-2018;

[0050] Source of Bacillus subtilis: Bacillus subtilis is deposited at the China Agricultural Microbial Culture Collection Center, strain number ACCC19373, with a viable count of ≥0.2 billion CFU / g;

[0051] Source of Bacillus licheniformis: Bacillus licheniformis is deposited at the China General Microbiological Culture Collection Center, with accession number CGMCC No. 20977, and the viable count is greater than or equal to 0.2 billion CFU / g;

[0052] Source of Bacillus cereus: Selected from strain number ACCC10604;

[0053] Bacillus megaterium source: selected from strain number ACCC10010;

[0054] Urea phosphate source: purchased from Shifang Kanglong Chemical Co., Ltd., and urea phosphate conforms to GB / T27805-2011.

[0055] The test method for organic matter content is: NY / T 1121.6-2006, "Soil Testing Part 6: Determination of Soil Organic Matter";

[0056] The method for testing total nitrogen content is: NY / T1121.24-2012 Soil Total Nitrogen Determination Method;

[0057] The test method for available phosphorus content is: NY / T 1121.7-2014 Soil Testing Part 7: Determination of Available Phosphorus in Soil;

[0058] The method for testing total phosphorus content is GB / T9837-1988, Soil Total Phosphorus Determination Method.

[0059] The test method for available potassium is: NY / T 889-2004 Determination of available and slow-release potassium content in soil;

[0060] The pH test method is as follows: NY / T1121.2-2006 Soil Testing Part 2: Determination of Soil pH;

[0061] The method for testing soil alkalinity is as follows: LY / T 1249-1999 Calculation of Soil Alkalinity;

[0062] The conductivity test method is: HJ 802-2016 Determination of Soil Conductivity - Electrode Method;

[0063] The test method for total salt content is: NY / T 1121.16-2006 Soil Testing Part 16: Determination of Total Water-Soluble Salts in Soil;

[0064] The method for testing phosphatase activity is: T / NAIA 012-2020 Determination of Soil Phosphatase Activity - Sodium Phosphate Colorimetric Method;

[0065] The method for testing urease activity is: T / NAIA 011-2020 Determination of Soil Urease Activity - Sodium Phenolate-Sodium Hypochlorite Colorimetric Method.

[0066] Examples and Comparative Examples

[0067] Corn cobs and sweet sorghum residue, agricultural and forestry waste, were crushed (particle size less than 5mm) and mixed evenly. The moisture content of the mixture was adjusted to 55% by weight, and urea and humic acid were added. An acidic amino acid fertilizer (pH 4) was used for further adjustment; the purchased amino acid fertilizer was diluted 100 times and added. Under conditions of 60℃ and Bacillus subtilis and Bacillus licheniformis, the material layer thickness was controlled to be approximately 40cm. A plastic film was laid on top, and the mixture was kept warm (45-65℃) and moist for 3 days of anaerobic composting (oxygen content less than 10% by volume). The plastic film was then removed, and the mixture was turned and piled up every other day for aerobic composting (oxygen content greater than 20-23% by volume). After 9 days, calcium sulfate (desulfurized gypsum) and urea phosphate were added and mixed evenly to obtain a soil conditioner for severely saline soil. The dosage of each raw material (by weight) is shown in Table 1.

[0068] Table 1

[0069]

[0070]

[0071] Example 17

[0072] The method is the same as in Example 1, except that the corn cob is replaced with mushroom residue.

[0073] Example 18

[0074] The method is the same as in Example 1, except that the corn cob is replaced with corn stalk.

[0075] Example 19

[0076] The method is the same as in Example 1, except that the corn cob is replaced with rice straw.

[0077] Example 20

[0078] The method is the same as in Example 1, except that Bacillus subtilis is replaced with Bacillus cereus.

[0079] Example 21

[0080] The method is the same as in Example 1, except that Bacillus licheniformis is replaced with Bacillus megaterium.

[0081] Example 22

[0082] The method is the same as in Example 1, except that 3 days are replaced with 9 days.

[0083] Example 23

[0084] The method is the same as in Example 1, except that 9 days are replaced with 12 days.

[0085] Example 24

[0086] The method is the same as in Example 1, except that the amino acid fertilizer is replaced with foliar fertilizer.

[0087] Example 25

[0088] The method is the same as in Example 1, except that fulvic acid is replaced with humic acid.

[0089] Example 26

[0090] The method is the same as in Example 1, except that calcium sulfate is replaced with aluminum sulfate.

[0091] Example 27

[0092] The method is the same as in Example 1, except that urea phosphate is replaced with monoammonium phosphate.

[0093] Comparative Example 3

[0094] The method is the same as in Example 1, except that sweet sorghum residue is replaced with mushroom residue.

[0095] Comparative Example 4

[0096] The method is the same as in Example 1, except that aerobic fermentation is replaced with anaerobic fermentation, that is, the plastic film is always covered before adding calcium sulfate and urea phosphate, so that the oxygen content is always kept below 10%.

[0097] Comparative Example 5

[0098] The method is the same as in Example 1, except that anaerobic fermentation is replaced with aerobic fermentation, that is, the plastic film is not covered and the oxygen content is always kept above 20%.

[0099] Comparative Example 6

[0100] The method is the same as in Example 1, except that aerobic fermentation is carried out first, followed by anaerobic fermentation. That is, fermentation is carried out for 9 days without covering the plastic film, and then fermentation is carried out for 3 days with the plastic film on.

[0101] Test Example 1

[0102] A pot experiment was conducted in the Longhai Irrigation District of Da'an County, Jilin Province, to improve the cultivation of sweet sorghum in saline-alkali land using the soil conditioner obtained above for severely saline-alkali soil. According to the salinization classification standard (HJ964-2018), the soil was severely saline-alkali, which is unfavorable for crop growth. The pot experiment included one blank control group (CKS), one normal group (non-saline-alkali soil, pH 6.95, total soil salt content 0.73 g / kg), and three treatment groups treated with the conditioners obtained in the different examples and comparative proportions described above. Each treatment consisted of three pots, with pot dimensions of 42cm × 31.5cm × 22.5cm. Each pot contained 20kg of soil, and the treatment groups received 2% (by weight) of the conditioner. The pot experiment management followed the principles of optimality and consistency. After the conditioner was added, mixed thoroughly, and the soil moisture content was maintained at 35% (by weight) for one day, sowing was carried out on August 25th, with 20 sweet sorghum seeds sown per pot. The potted plant experiment was conducted in the greenhouse of Sinochem Agriculture (Linyi) R&D Center Co., Ltd., and the soil samples were tested by Sinochem Agriculture (Linyi) R&D Center Co., Ltd.

[0103] (1) Effect of applying amendments on the emergence rate of sweet sorghum seedlings

[0104] Two weeks after sowing, the sweet sorghum CKS group failed to emerge. Therefore, the seedlings were cultivated in a constant temperature and humidity chamber (26℃, 60% humidity) until the 2-3 leaf stage. On September 16th, the seedlings were transplanted to supplement the seedlings. No further replanting or supplementary sowing was carried out. On September 16th, the number of seedlings emerging in each experimental pot was recorded in the greenhouse, and the corresponding emergence rate was calculated: emergence rate of the sweet sorghum group = number of seedlings / 20 × 100%. As shown in Table 2, the sweet sorghum group S, with the added seed conditioner, had a higher emergence rate, while the blank control group CKS failed to emerge. Figure 2 The image shows a comparison of the growth of sweet sorghum in CKS and Example 1 in the later stages.

[0105] Table 2

[0106]

[0107]

[0108] (2) The effect of applying the amendment and curing for 1 day on soil fertility was analyzed by sampling, as shown in Table 3.

[0109] Table 3

[0110]

[0111] (3) The effects of applying the soil conditioner to sweet sorghum pot experiment group on soil alkalinity, pH value, electrical conductivity, total salt content, phosphatase activity and urease activity after 2 months of planting sweet sorghum are shown in Table 4.

[0112] Phosphatases and ureases play crucial roles in the transformation of substances. Soil phosphatases are a class of enzymes that catalyze the conversion of organic phosphorus compounds in soil into inorganic phosphorus. Their activity directly affects the decomposition, transformation, and bioavailability of organic phosphorus in the soil, and serves as an indicator for evaluating the direction and intensity of soil phosphorus biotransformation.

[0113] Urease activity is positively correlated with soil microbial content, organic matter content, total nitrogen and available nitrogen content. High soil urease activity indicates a high degree of organic matter hydrolysis, high organic matter content, and high soil fertility, which is conducive to plant growth and development.

[0114] Table 4

[0115]

[0116] Test Example 2

[0117] Using the soil conditioner obtained in the above examples and comparative examples, a pot experiment was conducted on cadmium-contaminated soil in Yiyang, Hunan Province. The test soil was taken from Shiniujiang Town, Yiyang City, Hunan Province. The average cadmium content in the soil was 9.72 mg / kg (Table 5 shows the test soil data), which is classified as heavily cadmium-contaminated farmland. The pot experiment included one blank control group (CK) and three treatment groups with different addition ratios. Each treatment had three pots, with pot sizes of 28 cm in diameter and 27 cm in height. Each pot contained 10 kg of soil. The treatment groups were treated with 1%, 2%, and 3% (by weight) of the conditioner. The pot experiment management followed the principles of optimality and consistency.

[0118] Table 5

[0119] parameter unit numerical values pH none 5.85 Cr mg / kg 70 Ni mg / kg 42 Cu mg / kg 66.8 Zn mg / kg 175 Cd mg / kg 9.72 Pb mg / kg 32 As mg / kg 14.5 Hg mg / kg 0.222 organic matter g / kg 31.4 Quick-acting potassium mg / kg 120 Available phosphorus mg / kg 16.1 Total nitrogen g / kg 1.70 Effective state Cd mg / kg 5.98

[0120] The rice variety used was Huiliangyou Yuehe Simiao. Three days before transplanting, the soil conditioners obtained in the above examples and comparative examples were mixed evenly with the soil in proportions (1% by weight, 3% by weight, and 5% by weight), and water was added to a depth of 1-2 cm above the soil surface to simulate a flooded field. Manual transplanting was conducted on May 20th, with 6 holes per pot, 2 seedlings per hole, and 12 seedlings per pot. The pot experiment was conducted in the greenhouse of Sinochem Agriculture (Linyi) R&D Center Co., Ltd. Soil and plant samples were tested by Sinochem Agriculture (Linyi) R&D Center Co., Ltd.

[0121] The sampling and testing procedures for each stage of rice growth are as follows:

[0122] Phase 1 sampling (June 22): After the tillering stage, 3-5 rice plants were collected from each pot and sent to the laboratory to test the cadmium content in the roots, stems and leaves;

[0123] Second phase of sampling (July 29): During the young panicle formation stage, 3-5 rice plants were collected from each pot and sent to the laboratory to test the cadmium content in the roots, stems and leaves;

[0124] Third stage sampling (October 17): Grain filling stage. After the rice matures, the roots, stems, leaves and grains of the rice are collected and sent to the laboratory for testing.

[0125] The effects of different addition ratios of the improver on the cadmium content in rice roots, stems, leaves and grains are shown in Table 6.

[0126] Table 6

[0127]

[0128]

[0129] The results above show that the method of this invention can promote plant growth and reduce the total salt content, pH value, alkalinity, electrical conductivity, and sodium ion exchange capacity of the soil.

[0130] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a soil conditioner, characterized in that, The method includes: mixing agricultural and forestry waste with Bacillus subtilis and sequentially performing anaerobic composting and aerobic composting, wherein the agricultural and forestry waste is a mixture of at least one of corn cobs, mushroom residue, peanut shells, and crop straw with sweet sorghum residue. The conditions for anaerobic composting include: a temperature of 50-70℃ and a time of 2-4 days. The conditions for aerobic composting include: a temperature of 50-70℃ and a time of 7-10 days. The sweet sorghum residue accounts for 30-70% of the total weight of agricultural and forestry waste; The Bacillus species are Bacillus subtilis and Bacillus licheniformis; The Bacillus subtilis preservation number is ACCC 19373; The Bacillus licheniformis collection number is CGMCC No. 20977.

2. The method according to claim 1, wherein, The viable count of the Bacillus relative to 1g of agricultural and forestry waste is 10. 3 -10 5 The weight of the agricultural and forestry waste is calculated as dry weight.

3. The method according to claim 1, wherein, The temperature of the anaerobic compost may be the same as or different from the temperature of the aerobic compost.

4. The method according to claim 1, wherein, The oxygen content in the anaerobic compost is less than 10% by weight.

5. The method according to claim 1, wherein, The oxygen content in the aerobic compost is higher than 20% by weight.

6. The method according to claim 1, wherein, The water content of the mixed system is 50-60% by weight.

7. The method according to claim 1, wherein, The particle size of the agricultural and forestry waste is less than 5 mm.

8. The method according to claim 1, wherein, The compost layer should be 30-50cm thick.

9. The method according to claim 1, wherein, The crop straw includes at least one of corn straw, rice straw, wheat straw, rapeseed straw, and soybean straw.

10. The method according to claim 1, wherein, The agricultural and forestry waste is a mixture of at least one of corn cobs and mushroom residue with sweet sorghum residue.

11. The method according to claim 1, wherein, The viable count ratio of Bacillus subtilis to Bacillus licheniformis is 1:0.05-0.

1.

12. The method according to claim 1, wherein, The mixed system also includes amino acid fertilizers.

13. The method according to claim 12, wherein, The weight ratio of the agricultural and forestry waste to the amino acid fertilizer is 100:0.002-0.01, and the weights of the agricultural and forestry waste and the amino acid fertilizer are both based on dry weight.

14. The method according to claim 12, wherein, The amino acid fertilizer is obtained by hydrolyzing animal protein.

15. The method according to claim 12, wherein, The pH of the amino acid fertilizer is 3-6.

16. The method according to claim 12, wherein, The amino acid fertilizer contains no less than 100 g / L of free amino acids and no less than 20 g / L of trace elements, wherein the trace elements are at least one of Fe, Mn, Zn and B.

17. The method according to claim 1, wherein, The mixture also includes urea.

18. The method according to claim 17, wherein, The weight ratio of the agricultural and forestry waste to urea is 100:0.3-0.8, and the weight of the agricultural and forestry waste is based on dry weight.

19. The method according to claim 1, wherein, The mixed system also includes fulvic acid.

20. The method according to claim 19, wherein, The weight ratio of the agricultural and forestry waste to humic acid is 100:0.3-0.5, and the weight of the agricultural and forestry waste is based on dry weight.

21. The method according to claim 1, wherein, The mixture also includes sulfates.

22. The method according to claim 21, wherein, The weight ratio of agricultural and forestry waste to sulfate is 100:1-2, and the weight of the agricultural and forestry waste is based on dry weight.

23. The method according to claim 21, wherein, The sulfate is aluminum sulfate and / or calcium sulfate.

24. The method according to claim 1, wherein, The mixed system also includes urea phosphate.

25. The method according to claim 24, wherein, The weight ratio of the agricultural and forestry waste to urea phosphate is 100:0.5-1, and the weight of the agricultural and forestry waste is based on dry weight.

26. The soil conditioner prepared by the method according to any one of claims 1-25.

27. The application of the soil conditioner according to claim 26 in the improvement of saline-alkali soil.

28. A method for improving saline-alkali soil, characterized in that, The method includes applying the soil conditioner of claim 26 to the soil.

29. The method according to claim 28, wherein, The application rate of the soil conditioner is 1000-3000 kg / mu.

30. The method according to claim 28, wherein, The application rate of the soil conditioner is 1-3% of the total soil weight.

31. The method according to claim 28, wherein, The soil pH was 10.42-10.

79.

32. The method according to claim 28, wherein, The total salt content of the soil is 11.25-55.7 g / kg.

33. The method according to claim 28, wherein, The soil alkalinity ranged from 49.18% to 73.45%.

34. The method according to claim 28, wherein, The soil electrical conductivity is 756-3010 μs / cm.

35. The method according to claim 28, wherein, The sodium ion exchange capacity of the soil is 6.9-11.76 cmol / kg.

36. The method according to claim 28, wherein, The method further includes: applying the soil conditioner to the soil and then tilling the soil.

37. The method of claim 36, wherein, The tillage depth is 15-25cm.

Images