Soil conditioner and preparation method thereof

Abstract

The invention discloses a soil amendment and a preparation method thereof, and belongs to the technical field of soil amendment formulas, the soil amendment provided by the invention comprises 0-10 parts of a pH conditioner, 20-40 parts of a nutrient conditioner and 0-10 parts of a moisture conditioner, and no more than 0 part of the pH conditioner and no more than 0 part of the moisture conditioner, the composition obviously improves the characteristic that the saline-alkali soil is difficult to form a water-stable aggregate, and enhances the water binding capacity and air permeability of the soil, so that the emergence rate of crops is obviously increased, and the growth of the crops is promoted. Experimental results show that the soil conditioner can significantly reduce the pH of soil, improve the emergence rate of soybeans and accumulation of dry matter mass, and create a more suitable environment for soybean growth.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil improvement agent formulation, and in particular relates to a soil improvement agent and a preparation method thereof. Background Art

[0002] According to the soil classification and grading standards for agricultural use of saline-alkali land, when the alkalinity of the soil is greater than 45%, the soil is identified as saline-alkali wasteland, that is, extremely severe saline-alkali soil. This kind of soil is extremely unfavorable for crop growth, and only a few highly salt-tolerant crops can obtain relatively ideal yields in this environment. Therefore, this kind of land is usually difficult to use directly for agricultural production and requires soil improvement measures.

[0003] Soil conditioners are preparations that can improve soil structure and physical and chemical indicators. After being applied to the soil, they can improve soil structure, increase soil nutrients and maintain soil moisture. They are increasingly widely used in curbing soil degradation, improving medium and low-yield fields, increasing capacity and storage, etc. At the same time, soil conditioners have been widely used in crop production, forest protection planting, grassland production, urban greening, highway greening and flower production.

[0004] At present, there are four methods and technologies for improving and utilizing saline-alkali land in China: physical improvement, hydraulic improvement, chemical improvement and biological improvement. The use of these methods has brought great benefits to agricultural production in saline-alkali land. However, the above improvement methods have their own advantages and disadvantages. For example, the investment in physical methods such as bottom-sealed soil raising the ground is too large; hydraulic improvement methods such as large water washing cause waste of water resources; although biological improvement such as microbial fertilizer is a sustainable utilization measure, there are problems such as single strain and low survival rate; the current chemical improvement method has a single performance, and it must be mixed with other substances to form a multifunctional soil conditioner. Patent CN101514290A discloses the use of artificially synthesized organic polymer polyacrylamide (Polyacrylamide, PAM) as an efficient water and fertilizer retention material, and patent CN102517030A discloses the use of PAM as a sodium ion adsorbent to improve soil, but the intermediate product of PAM degradation is acryloyl, which is toxic. In the long run, whether the use of PAM as a soil conditioner will cause soil pollution deserves further attention and in-depth research. Patent CN1317539A discloses a soil conditioner composed of polysuccinic acid, sodium alkylbenzene sulfonate and water, which has the advantages of simple preparation process, low cost and convenient operation. Its principle is to use a single acid to reduce pH value to reduce alkali and desalination, but the improvement of soil fertility and soil structure needs further improvement. In the prior art, there is no effective soil conditioner for the extremely severe soda saline-alkali soil stress environment in the Songnen Plain. Summary of the invention

[0005] The purpose of the present invention is to provide a soil conditioner and a preparation method thereof to solve the problems existing in the above-mentioned prior art. The present invention develops a soil conditioner for extremely severe soda saline-alkali soil, aiming to improve the soil properties of saline-alkali soil and promote the growth and development of soybeans. At present, there is a lack of conditioners that can effectively improve extremely severe soda saline-alkali soil on the market. The present invention proposes an innovative conditioner combination: pyrolyzed straw biochar, anhydrous aluminum sulfate and a viscosity of 20×10 4 mPa.s of hydroxypropyl methylcellulose.

[0006] One of the technical solutions provided by the present invention:

[0007] A soil conditioner comprises the following components, measured by weight: 0-10 parts of a pH conditioner, 20-40 parts of a nutrient conditioner and 0-10 parts of a moisture conditioner, wherein the pH conditioner and the moisture conditioner are not 0 parts.

[0008] Preferably, the soil conditioner comprises the following components in parts by mass: 6.8 parts of pH conditioner, 20 parts of nutrient conditioner and 4 parts of moisture conditioner.

[0009] Preferably, the pH regulator is anhydrous aluminum sulfate, the nutrient regulator is straw biochar, and the moisture regulator is hydroxypropyl methylcellulose.

[0010] Preferably, the viscosity of the hydroxypropyl methyl fiber is 6×10 4 -20×10 4 mPa.s, more preferably, the viscosity of the hydroxypropyl methyl fiber is 20×10 4 mPa.s.

[0011] The second technical solution provided by the present invention is:

[0012] A method for preparing the soil conditioner comprises weighing raw materials according to parts by mass and mixing the raw materials to obtain the soil conditioner.

[0013] The third technical solution provided by the present invention is:

[0014] Application of the soil conditioner in improving extremely heavy soda saline-alkali soil.

[0015] Preferably, the soil conditioner is added into extremely heavy soda saline-alkali soil, and the soil conditioner accounts for 3.08% of the soil weight.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects:

[0017] The soil conditioner provided by the present invention includes 20 parts of corn straw pyrolysis biochar, 6.8 parts of anhydrous aluminum sulfate and 4 parts of hydroxypropyl methylcellulose. The combination significantly improves the property of saline-alkali soil that is difficult to form water-stable aggregates, enhances the water holding capacity and air permeability of the soil, thereby significantly improving the emergence rate of crops and promoting their growth. Experimental results show that the soil conditioner can significantly reduce soil pH, increase the emergence rate of soybeans and the accumulation of dry matter, and create a more suitable environment for soybean growth. The present invention provides effective guidance for soybean planting in saline-alkali land in Songnen Plain, and also provides a recommended ratio of each conditioner in the soil conditioner for the improvement of saline-alkali soil and crop production in the region. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 The effects of different soil conditioners on soybean emergence rate;

[0020] Figure 2 The effects of different concentrations of pH regulator B on pH and conductivity of saline-alkali soil;

[0021] Figure 3 The effect of different concentrations of nutrient conditioner A on available nutrients in saline-alkali soil;

[0022] Figure 4 The effects of different concentrations of water conditioner A on soybean emergence rate and soil water content;

[0023] Figure 5 The effect of the interaction between nutrient conditioner A and pH conditioner B on pH;

[0024] Figure 6 The effect of the interaction between pH conditioner B and moisture conditioner A on pH;

[0025] Figure 7 The effect of the interaction between nutrient conditioner A and water conditioner A on pH;

[0026] Figure 8 The effect of the interaction between nutrient conditioner A and water conditioner A on electrical conductivity;

[0027] Fig. 9 The effect of the interaction between nutrient conditioner A and pH conditioner B on conductivity;

[0028] Fig.10 The effect of the interaction between pH conditioner B and moisture conditioner A on conductivity;

[0029] Fig.11 The effect of the interaction between nutrient conditioner A and water conditioner A on the emergence rate;

[0030] Fig.12 The effect of the interaction between nutrient conditioner A and pH conditioner B on the emergence rate;

[0031] Fig.13 The effect of the interaction between pH regulator B and water regulator A on the emergence rate;

[0032] Fig.14 The effect of the interaction between nutrient conditioner A and water conditioner A on dry matter quality;

[0033] Fig.15 The effect of the interaction between nutrient conditioner A and pH conditioner B on dry matter content;

[0034] Fig.16 The effect of the interaction between pH regulator B and moisture regulator A on dry matter quality;

[0035] Fig.17 is the effect of HPMC viscosity on the cumulative infiltration amount;

[0036] Fig.18 The effect of HPMC viscosity on soil infiltration rate;

[0037] Fig.19 This is the solute penetration curve under different HPMC viscosity conditions. DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0039] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0040] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0041] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0042] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0043] The normal temperature of the present invention refers to 25±2°C.

[0044] The purpose of the present invention is to provide a soil conditioner and a preparation method thereof. The formula of the soil conditioner provided by the present invention can solve the damage of extremely heavy soda saline-alkali soil to the soil, play a role in comprehensively improving the soil and promoting plant growth.

[0045] In the embodiment of the present invention, a variety of substances that can improve soda saline-alkali soil are screened to obtain pyrolysis straw biochar, anhydrous aluminum sulfate and a viscosity of 20×10 4 mPa.s of hydroxypropyl methylcellulose. The present invention selects the pyrolysis straw biochar, anhydrous aluminum sulfate and a viscosity of 20×10 4 The application effect of hydroxypropyl methylcellulose at mPa.s was tested by concentration gradient to determine the optimal application concentration. The results showed that too high a concentration of hydroxypropyl methylcellulose may cause difficulty in crop emergence, and too high a concentration of aluminum sulfate may cause changes in soil salt composition and increase in conductivity. Corn straw pyrolysis biochar is expensive, and large-scale application will increase costs.

[0046] In order to solve the above problems, the present invention conducts a combination formula test through the response surface method, and obtains a soil conditioner suitable for extremely severe soda saline-alkali soil, including 20 parts of corn straw pyrolysis biochar, 6.8 parts of aluminum sulfate and 4 parts of hydroxypropyl methylcellulose, which effectively solves the above problems and solves the damage of extremely severe soda saline-alkali soil to the soil, and plays a role in comprehensively improving the soil and promoting plant growth. The pyrolysis straw biochar is a product obtained by high-temperature pyrolysis of corn straw; the anhydrous aluminum sulfate refers to aluminum sulfate without water, which is an insoluble inorganic compound composed of metal aluminum and sulfate; the hydroxypropyl methylcellulose is a kind of non-ionic cellulose mixed ether, which is a semi-synthetic, inactive, viscoelastic polymer.

[0047] The present invention adopts the response surface method to optimize the ratio of the conditioning agent, which can provide more accurate and clear results compared with the traditional ratio method. By reducing the application amount of biochar and aluminum sulfate, and innovatively introducing a viscosity of 20×10 4 mPa.s of hydroxypropyl methylcellulose, the present invention effectively solves the problems of excessive biochar application, high cost, and increased conductivity after aluminum sulfate changes the soil salt composition in previous studies, and clarifies the appropriate concentration of hydroxypropyl methylcellulose, thereby avoiding the problem of excessive concentration inhibiting crop growth. By adjusting the application concentration range of pyrolyzed straw biochar, anhydrous aluminum sulfate and hydroxypropyl methylcellulose in soda saline-alkali soil, and through combined experiments, the problems of increased soil improvement costs, increased soil salinity and hindered crop emergence that may be caused by inappropriate application of the three conditioners are solved.

[0048] The embodiment of the present invention also provides a method for preparing the above-mentioned soil conditioner: corn straw pyrolysis biochar, aluminum sulfate and hydroxypropyl methylcellulose are weighed according to weight proportion, and mixed evenly in a blender to obtain the soil conditioner, wherein the stirring speed is 300-400r / min.

[0049] In the embodiments of the present invention, citric acid was purchased from Henan Chuanghua Chemical Products Co., Ltd., anhydrous aluminum sulfate was purchased from Tianjin Zhiyuan Chemical Reagent Co., Ltd., wood vinegar was purchased from Qingdao Yousuo Chemical Technology Co., Ltd., hydroxypropyl methylcellulose was purchased from Hengke Biotechnology Co., Ltd., attapulgite was purchased from Lingshou County Dehang Mineral Products Co., Ltd., sodium polyacrylate was purchased from Henan Feishi Biotechnology Co., Ltd., microbial agents were purchased from Tai'an Chenhui Biotechnology Co., Ltd., and fulvic acid was purchased from Tai'an Chenhui Biotechnology Co., Ltd.

[0050] The present invention selects samples from the Sartu area of ​​Daqing City, Heilongjiang Province. The soil pH value of the area is 10.05, the conductivity is 96.77us / cm, and the alkalinity is 60%. Experiments are conducted by screening and combining different soil conditioners.

[0051] Example 1

[0052] The crushed corn straw was pyrolyzed at 500°C for 60 min to prepare pyrolyzed corn straw biochar.

[0053] Example 2 Screening of soil conditioners

[0054] In this example, citric acid, anhydrous aluminum sulfate and wood vinegar are used as pH conditioners, hydroxypropyl methylcellulose, attapulgite and sodium polyacrylate are used as moisture conditioners, pyrolyzed straw biochar, fulvic acid and microbial agents are used as nutrient conditioners, and the amount of soil conditioner added in the 0-5 cm soil layer is used as the experimental factor. The test is repeated three times, and the recommended amount of each conditioner is added (as a percentage of soil weight). The effects of each conditioner are compared and analyzed, that is, the above-mentioned separate pH conditioners, moisture conditioners and nutrient conditioners are added to the soil according to the mass ratio in Table 1 and mixed, and the emergence rate is determined after the soybean seedlings emerge.

[0055] Table 1

[0056]

[0057] Different types of soil conditioners were selected to analyze the soybean emergence rate under saline-alkali stress. The results are shown in Figure 1 The effects of different soil conditioners on soybean emergence rate are shown in the figure, where different lowercase letters indicate significant differences (P < 0.05). Among pH conditioners, pH conditioner B has a significant effect on soybean emergence rate compared with CK, among water conditioners, water conditioner A has a significant effect on soybean emergence rate compared with CK, and among nutrient conditioners, nutrient conditioner A has a significant effect on soybean emergence rate compared with CK. Therefore, pH conditioner B, water conditioner A, and nutrient conditioner A were selected as the subsequent saline-alkali land soil conditioner compound test materials.

[0058] Example 3 Single Factor Concentration Test

[0059] According to the results of Example 1, pH conditioner B (anhydrous aluminum sulfate) and moisture conditioner A (viscosity 20×10 4 mPa.s of hydroxypropyl methylcellulose), nutrient conditioner A (pyrolysis straw biochar) was the best conditioner. After comparing and analyzing the effects of single conditioners at different concentrations, a single factor concentration gradient test was carried out on the screened soil conditioners to explore the optimal concentration of the single conditioner. The design scheme of the concentration gradient test is shown in Table 2 Single factor test concentration gradient table.

[0060] Table 2

[0061]

[0062] The pH regulator B (anhydrous aluminum sulfate) with different concentrations as shown in Table 2 was selected to analyze the soil pH and conductivity under saline-alkali stress. The results are as follows: Figure 2 The effects of different concentrations of pH conditioner B on the pH and conductivity of saline-alkali soil are shown in the figure, where different lowercase letters indicate significant differences (P < 0.05). Compared with CK, the application of pH conditioner B concentration (1) (2) (3) (4) had a significant effect on soil pH. As the concentration of pH conditioner B increased, the soil pH showed a downward trend. Compared with CK, the application of pH conditioner B concentration (2) (3) (4) had a significant effect on soil conductivity. As the concentration of pH conditioner B increased, the soil conductivity showed an upward trend. After comprehensive consideration, the pH conditioner B concentration range of 0-1% was selected.

[0063] The available nutrients of soil under saline-alkali stress were analyzed by selecting nutrient conditioner A (pyrolysis straw biochar) with different concentrations as shown in Table 2. Figure 3 The effects of different concentrations of nutrient conditioner A on available nutrients in saline-alkali soil are shown in the figure, where different lowercase letters indicate significant differences (P < 0.05). Compared with CK, the application of nutrient conditioner A concentration (1) (2) (3) (4) had no significant effect on soil available N; compared with CK, the application of nutrient conditioner A concentration (4) had a significant effect on soil available K. As the concentration of nutrient conditioner A increased, soil available K showed an upward trend. Compared with CK, the application of nutrient conditioner A concentration (2) (3) (4) had a significant effect on soil available P. Taking all factors into consideration, the nutrient conditioner A concentration range of 2-4% was selected.

[0064] Select different concentrations of moisture conditioner A (viscosity 20×10 4 The effects of hydroxypropyl methylcellulose (mPa.s) on soybean emergence rate and soil moisture content were analyzed. The results are as follows Figure 4 The effects of different concentrations of water conditioner A on soybean emergence rate and soil water content are shown in the figure, where different lowercase letters indicate significant differences (P < 0.05). Compared with CK, the application of water conditioner A concentration (1) (2) (3) (4) had a significant effect on soil water content. As the concentration of water conditioner A increased, the soil water content increased. Compared with CK, the application of water conditioner A concentration (2) (3) had a significant effect on soybean emergence rate. As the concentration of water conditioner A increased, the soybean emergence rate increased first and then decreased, reaching a peak at water conditioner A concentration (2). After comprehensive consideration, the concentration range of water conditioner A was selected to be 0-1%.

[0065] Example 4 Soil Conditioner Formulation Test

[0066] On the basis of Example 3, this example uses the response surface methodology to conduct compounding tests to screen out the best compounding combination. The response surface test factors and levels are shown in Table 3.

[0067] Table 3

[0068]

[0069]

[0070] On the 15th day after soybean seedlings emerged, the plants and soil were sampled and analyzed to measure the agronomic traits of soybean plant height, stem diameter, fresh weight and dry weight. The soil was sampled to measure pH, conductivity, etc. The response surface experimental design and experimental results are shown in Table 4.

[0071] Table 4

[0072]

[0073] Germination rate = number of germinations / number of seeds sown × 100%.

[0074] Example 5

[0075] In order to analyze the effects of nutrient conditioner A, pH conditioner B and moisture conditioner A on soybean, the present embodiment used Design-Expert 8.0.6 software, combined with the experimental data in Table 4, to establish quadratic regression fitting surfaces for the effects of the above different conditioner ratios on soil pH, electrical conductivity, germination rate and dry matter accumulation, and performed significance analysis.

[0076] pH response surface analysis and significance test: The pH was subjected to secondary regression analysis as shown in Table 5. The pH regression model significance analysis, the fitting surface equation is: pH = 8.17-0.01204A-0.5213B-0.0175C+0.0492AB-0.0850AC+0.0761A 2 +0.2227B 2 +0.0253C 2 Model P = 0.0001 < 0.01, lack of fit P = 0.6526 > 0.05, indicating that the model fits the actual situation well. pH conditioner B has a very significant effect on soil pH, while water conditioner B and nutrient conditioner A have no significant effect on plant height; the response surface and contour lines of the interaction of factors on pH, such as Figure 5-7 The effect of the interaction of various factors on pH is shown in Figure 2. The contour lines can intuitively reflect whether the interaction of various factors is significant. The more elliptical the contour lines are, the more significant the interaction is, and the more circular the contour lines are, the less significant the interaction is. Figure 5 is the effect of the interaction between nutrient conditioner A and pH conditioner B on pH, Figure 6 is the effect of the interaction between pH conditioner B and moisture conditioner A on pH, Figure 7 The effect of the interaction between nutrient conditioner A and water conditioner A on pH. Figure 5-7The P values ​​in the results are all relatively large, and the contour lines are almost circles with a large radius, indicating that the interaction between the factors on soil pH is not significant.

[0077] Table 5

[0078]

[0079]

[0080] Conductivity response surface analysis and significance test: The secondary regression analysis of soil conductivity Ec is shown in Table 6. The conductivity regression model significance analysis, the fitting surface equation is: Ec = 158.24 + 18.90A + 60.24B-10.44C model P = 0.0001 < 0.01, lack of fit term P = 0.7729 > 0.05, indicating that the model fits the actual situation well, pH conditioner B has a very significant effect on soil conductivity, nutrient conditioner A has a significant effect on soil conductivity, and water conditioner A has no significant effect; the response surface and contour lines of the interaction of various factors on conductivity are as follows: Figure 8-10 The influence of the interaction of various factors on conductivity is shown in Figure 2. Figure 8 The effect of the interaction between nutrient conditioner A and water conditioner A on conductivity, Fig. 9 The effect of the interaction between nutrient conditioner A and pH conditioner B on conductivity. Fig.10 The effect of the interaction between pH conditioner B and moisture conditioner A on conductivity; Figure 8-10 The contour lines in the figure are almost circles with a large radius, and the interactions are not significant.

[0081] Table 6

[0082]

[0083]

[0084] Response surface analysis and significance test of germination rate: The quadratic regression of germination rate is shown in Table 7. The significance analysis of germination rate regression model, the fitting surface equation is: germination rate = 0.6839-0.0157A + 0.0417B + 0.0715C. Model P = 0.0294 < 0.05, lack of fit term P = 0.7814 > 0.05, indicating that the model fits the actual situation well. Water conditioner A has a significant effect on germination rate, while nutrient conditioner A and pH conditioner B have no significant effect. The response surface and contour lines of the interaction of factors on germination rate are as follows: Figure 11-13 The interaction effect of each factor on the germination rate is shown in Figure 2. Fig.11 The effect of the interaction between nutrient conditioner A and water conditioner A on the germination rate. Fig.12The effect of the interaction between nutrient conditioner A and pH conditioner B on the emergence rate. Fig.13 The effect of the interaction between pH regulator B and water regulator A on the germination rate. Figure 11-13 The medium-high lines are almost parallel, and the interactions are not significant.

[0085] Table 7

[0086]

[0087]

[0088] Response surface analysis and significance test of dry matter accumulation: The dry matter was regressed quadratically (see Table 8). The significance analysis of the regression model of dry matter accumulation was performed, and the fitting surface equation was: dry matter = 0.2117 + 0.0006A-0.0002B + 0.0082C-0.0134AB + 0.0057AC + 0.0100BC-0.0033A 2 -0.0157B 2 -0.0061C 2 Model P = 0.0325 < 0.05, lack of fit P = 0.5760 > 0.05, indicating that the model fits the actual situation well. Water conditioner A has a significant effect on dry matter, while pH conditioner B and nutrient conditioner A have no significant effect; the response surface and contour lines of the interaction of factors on the surface rate are as follows: Figure 14-16 The interaction effect of each factor on dry matter is shown in Figure 2. Fig.14 )、BC( Fig.16 ) have relatively large P values, the contour lines are almost circular with a large radius, and the interactions are not significant. Fig.15 )P=0.0196<0.05 and the contour lines are elliptical, indicating that the interaction is significant.

[0089] Table 8

[0090]

[0091] Example 6

[0092] According to the results of Example 5, Design-Expert 8.0.6 software was used to maximize the expected soybean emergence rate, minimize the pH, minimize the conductivity, and maximize the dry weight of the model to obtain the optimal application plan of the soil conditioner, as shown in Table 9, which is 2.00% nutrient conditioner A, 0.68% pH conditioner B, and 0.40% water conditioner A. At this time, the soybean emergence rate was 70%, the pH was 8.20, the conductivity was 163.40 us / cm, and the dry weight was 0.21 g. The model was verified by error analysis as shown in Table 9, which basically met the model expectations.

[0093] Table 9

[0094] Nutrient Conditioner A pH Adjuster B Moisture Conditioner A Seedling rate (%) pH Ec Dry weight 2 0.68 0.40 70 8.20 163.40 0.21

[0095] Table 10

[0096]

[0097] It can be seen from Tables 11, 12 and 13 that the soil conditioner formula can effectively improve extremely heavy soda saline-alkali soil, adjust the soil pH to 8.45, reduce the soil alkalinity to 30-20%, and effectively increase soil organic matter.

[0098] Table 11

[0099] soil No improver added Add combination improver pH 10.05 8.45

[0100] Table 12

[0101] Soil alkalinity (%) No improver added Add combination improver 0-5cm 64.76273039 30.66512957 5-10cm 27.61979806 30.26275571 10-15cm 22.59378893 21.04442644 15-20cm 27.23817963 18.69769303

[0102] Table 13

[0103] Soil organic matter (g / kg) No improver added Add combination improver 0-5cm 17.96246143 50.12226576 5-10cm 16.56572698 96.61369609 10-15cm 16.47160703 32.9849411 15-20cm 15.96045537 20.37947896

[0104] Comparative Example 1

[0105] By adding four different viscosities of HPMC (0.4% by weight of soil) into four soils, the effect of HPMC viscosity on cumulative infiltration, soil infiltration rate and solute penetration was investigated.

[0106] The measured curves of the one-dimensional vertical cumulative infiltration of the blank group (CK) and the four different viscosities of HPMC were measured, as shown in Fig.17 The effect of HPMC viscosity on cumulative infiltration is shown in Figure 2. The cumulative infiltration of the five groups of infiltration tests gradually increased with time, and their slopes gradually decreased with time. It can be seen that the viscosity of HPMC added to the soil does not change the trend of cumulative infiltration during one-dimensional vertical infiltration of the soil, and the infiltration rules are generally the same. In the early stage of infiltration, the overlap rate between the five groups of cumulative infiltration curves is high, and after 50 minutes, the differences between the curves gradually become obvious. Fig.17 It is easy to observe that at the same time, the higher the viscosity of HPMC, the smaller the cumulative infiltration amount; for the same cumulative infiltration amount, the higher the viscosity, the longer the time required. During the infiltration process, the cumulative infiltration amount of the CK group was always the highest, 20×10 4 The mPa.s group was always the lowest.

[0107] The application of HPMC with different viscosities has a significant effect on soil infiltration rate. According to the measured data, the soil infiltration rate of adding different HPMC viscosities is as follows: Fig.18 The effect of HPMC viscosity on soil infiltration rate is shown in Figure 2. Fig.18 It can be seen that after the start of the experiment, the infiltration of the five groups (blank group (CK) and four different viscosity HPMC) was carried out at a faster speed, and the effect of HPMC viscosity on the infiltration rate was not obvious, but in the initial stage of the experiment, the infiltration rate decreased rapidly; when the infiltration was carried out to 25 minutes, the infiltration rate gradually slowed down, and at this time, there was a significant difference between the infiltration rates of HPMC with different viscosities. At the same time, the higher the HPMC viscosity, the lower the infiltration rate. At the same soil column height, the blank group ended infiltration at 60 minutes. Taking 51 minutes as an example, the infiltration rate of the blank group decreased from 0.607 cm / min at the beginning to 0.127 cm / min. At this time, the HPMC viscosity was 2, 4, 10, 20×10 4 The infiltration rates of each group of mPa.s were 0.080, 0.073, 0.069 and 0.065 cm / min, which were 62.99%, 57.48%, 54.33% and 51.18% of the infiltration rates of the blank group at this moment, respectively. After HPMC is dissolved in water, the hydrophilic groups on the molecules can form hydrogen bonds with water molecules, surrounded by water molecules to form a cage-like supramolecular gel network structure, which is relatively stable at room temperature. This gel network structure becomes more complex as the viscosity of HPMC increases, which to a certain extent reduces the large pores in the soil and increases the small pores, thereby slowing down the average pore water flow rate of the soil. Therefore, as the viscosity of HPMC in the soil increases, the soil water infiltration rate decreases, that is, the infiltration rate gradually decreases.

[0108] Fig.19 The solute penetration curves under different HPMC viscosity conditions are shown in Figure 2. Fig.19 It can be obtained that under the same hydraulic gradient, the solute penetration curves of the soil columns with different viscosities of HPMC added are similar to those of the CK group, which are all S-shaped smooth curves. Under different HPMC viscosity conditions, the S-shaped penetration curve has a trend of gradual change, that is, as the viscosity of HPMC increases, the trend of the relative concentration gradually increasing with the increase of the outflow liquid slows down, the tailing characteristics are more obvious, and the pore volume number at complete penetration increases. Therefore, the addition of HPMC has a certain delaying effect on the soil solute migration process, and the higher the viscosity, the more obvious the delay effect.

[0109] Applying HPMC with different viscosities to the soil can significantly reduce the infiltration capacity of the soil and slow down the migration rate of water in the soil; HPMC viscosity ranges from 2-20×10 4 mPa.s, the cumulative infiltration, wetting front migration distance and infiltration rate all decreased significantly with the increase of HPMC viscosity. Applying HPMC with different viscosities to the soil can significantly reduce the infiltration capacity of the soil and slow down the migration speed of water in the soil; therefore, in order to slow down the infiltration of soil water and increase the moisture content of the soil plough layer, the present invention selects 20×10 4Hydroxypropyl methylcellulose with a viscosity of mPa.s is used as a soil moisture retaining agent.

[0110] The above are only preferred specific embodiments 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 a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A soil conditioner, characterized in that: The invention comprises the following components in parts by mass: 0-10 parts of pH conditioner, 20-40 parts of nutrient conditioner and 0-10 parts of moisture conditioner, and the pH conditioner and moisture conditioner are not 0 parts.

2. The soil conditioner according to claim 1, characterized in that The composition comprises the following components in parts by mass: 6.8 parts of pH conditioner, 20 parts of nutrient conditioner and 4 parts of moisture conditioner.

3. The soil conditioner according to claim 1, characterized in that The pH regulator is anhydrous aluminum sulfate, the nutrient regulator is straw biochar, and the moisture regulator is hydroxypropyl methylcellulose.

4. The soil conditioner according to claim 1, characterized in that The viscosity of the hydroxypropyl methyl fiber is 6×10 4 -20×10 4 mPa.s.

5. The soil conditioner according to claim 4, characterized in that The viscosity of the hydroxypropyl methyl fiber is 20×10 4 mPa.s.

6. A method for preparing the soil conditioner according to any one of claims 1 to 5, characterized in that: The raw materials are weighed according to parts by mass and mixed evenly to obtain the soil conditioner.

7. Use of the soil conditioner according to any one of claims 1 to 5 in improving extremely heavy soda saline-alkali soil.

8. The use according to claim 7, characterized in that: The soil conditioner is added into extremely heavy soda saline-alkali soil, and the soil conditioner accounts for 3.08% of the soil weight.

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