An amendment of soil conditioner for acid soil and its preparation method

Abstract

The application discloses an improved soil conditioner for acid soil and a preparation method thereof, and the soil conditioner is prepared by mixing dolomite, bentonite and a sodium alginate solution in a certain proportion, using acidified dolomite as a crosslinking agent, forming small balls, washing the small balls with deionized water, and drying the small balls. 2+ In the application, the natural dolomite is used as the main raw material for improving the acid soil and as the raw material for the crosslinking agent, so that Ca The soil conditioner can improve the acid environment of the soil, double-regulate the pH of the soil, and increase the nutritional elements such as Ca and Mg in the soil, and the preparation method is simple, green and safe.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soil improvement, and particularly relates to a conditioner for improving acid soil and a preparation method thereof. BACKGROUND

[0002] The essence of soil acidification is the change of the chemical properties of the soil itself, and the most direct manifestation of soil acidification is the decrease of soil pH. With the decrease of soil pH, the release of different forms of aluminum ions in the soil will increase the toxicity to plants, and at the same time, will promote the leaching of calcium, magnesium and other alkali ions, resulting in the decrease of soil fertility and seriously affecting the yield and quality of crops.

[0003] The soil conditioner has been widely concerned and applied due to its simple operation and remarkable effect. In the existing conditioner for improving acid soil, the organic material type conditioner can adjust the soil microbial community and quantity, but the harmful microorganisms such as pathogenic microorganisms and parasite eggs increase, which makes it difficult to promote the use. The industrial waste and by-product type conditioner is easy to cause soil heavy metal pollution, resulting in secondary pollution. The production cost of part of the new type conditioner is high, which limits its large-scale application. At present, the most common method for improving acid soil is to directly spread lime, but improper amount will cause soil acidification.

[0004] Sodium alginate is widely available, low in price, high in safety, biodegradable, easy to handle and easy to mass-produce, and has the properties of being used as an embedding material for protecting and transporting agricultural beneficial substances. Bentonite has the advantages of electronegativity, good water absorption and expansion, cohesiveness, environmental friendliness and the like, and is rich in constant and trace elements required by animals and plants, and can effectively adjust the soil structure, increase the soil water storage capacity and the content and stability of large aggregates. Dolomite is a carbonate mineral with magnesium carbonate and calcium carbonate, which can effectively increase the soil pH and increase the availability of soil Ca, Mg and other nutrient elements. In addition, after acidification treatment, Ca 2+ The acidified dolomite can be used as a crosslinking agent to crosslink with sodium alginate, so as to obtain a soil conditioner with a three-dimensional crosslinked network and pore structure.

[0005] At present, there is no report on the use of sodium alginate to embed inorganic minerals and acidified dolomite as a crosslinking agent for improving acid soil. SUMMARY

[0006] In view of the deficiencies of the prior art, the application provides a conditioner for improving acid soil and a preparation method thereof. The application uses sodium alginate to embed dolomite and bentonite, and uses acidified dolomite as a crosslinking agent, so as to obtain a composite stable, green and safe conditioner for improving acid soil.

[0007] The technical scheme of the application is as follows:

[0008] An improved soil conditioner for improving acid soil is prepared by the following method:

[0009] (1) grinding and sieving (200 mesh) natural dolomite, and putting it into a muffle furnace, and heating it to 800-1000℃ for 3-5h to obtain calcined dolomite; and dissolving the obtained calcined dolomite in deionized water to obtain dolomite milk;

[0010] Preferably, the heating rate during calcination is 5℃ / min;

[0011] Preferably, the mass ratio of calcined dolomite to deionized water is 2.5:12.5-75;

[0012] (2) adding natural dolomite into hydrochloric acid solution, stirring (1h), filtering (to remove dolomite residue), adding the dolomite milk obtained in step (1) into the filtrate to adjust the pH to neutral, filtering, and diluting the filtrate with deionized water to obtain acidified dolomite crosslinking agent;

[0013] Preferably, the mass fraction of the hydrochloric acid solution is 37%;

[0014] Preferably, the molar ratio of natural dolomite to hydrochloric acid is 1:4;

[0015] The dolomite milk is used as a pH adjusting agent to adjust the pH of the filtrate obtained in the first filtration to neutral, and to convert Al 3+ , Fe 3+ in the filtrate into Al(OH)3, Fe(OH)3, which are removed in the second filtration;

[0016] Preferably, the feeding ratio of natural dolomite to deionized water (for dilution) is 20:50-200, g / mL;

[0017] (3) mixing sodium alginate with deionized water, and stirring to disperse uniformly to obtain sodium alginate solution;

[0018] Preferably, the mass fraction of the sodium alginate solution is 1%;

[0019] (4) adding natural dolomite and bentonite into the sodium alginate solution obtained in step (3) in turn, and mixing uniformly to obtain mixed slurry;

[0020] Preferably, the mass ratio of natural dolomite to bentonite is 0-4:2-6;

[0021] Preferably, the mass ratio of the total mass of natural dolomite and bentonite to sodium alginate is 6:1;

[0022] (5) pumping the mixed slurry obtained in step (4) into the acidified dolomite crosslinking agent obtained in step (2) by using a peristaltic pump, and soaking and forming, washing (with deionized water), and drying to obtain the improved soil conditioner for improving acid soil;

[0023] The volume ratio of the mixed slurry to the acidified dolomite crosslinking agent is preferably 100:50-200.

[0024] The soaking forming time is preferably 3-24h.

[0025] Compared with the prior art, the application has the following beneficial effects:

[0026] In the application, the natural dolomite and bentonite are embedded by sodium alginate, which increases the stability of sodium alginate and enables the slow release of the natural dolomite and bentonite, thereby improving the acidic environment of the soil. The natural dolomite not only serves as the main raw material for improving the acidic soil conditioner, but also serves as the raw material for the crosslinking agent, so that the Ca 2+ The soil conditioner is fully crosslinked with the sodium alginate, has a three-dimensional crosslinked network and a pore structure, and can double-regulate the pH of the soil and increase the content of Ca, Mg and other nutrient elements in the soil. The soil conditioner is complex-stable, green and safe, and simple to prepare. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The soil conditioner of Example 2. DETAILED DESCRIPTION

[0028] The application will be further described in conjunction with specific examples, and the advantages and characteristics of the application will be more apparent as the description proceeds. However, these examples are only exemplary and do not constitute any limitation on the scope of the application. Those skilled in the art should understand that the details and forms of the technical solutions of the application can be modified or replaced without departing from the spirit and scope of the application described before and after, and such modifications and replacements all fall within the protection scope of the application.

[0029] In the examples of the application:

[0030] The pH value of the soil is detected according to HJ 962-2018 'Determination of pH value of soil by potentiometric method'.

[0031] The content of Ca and Mg in the soil is detected according to NY / T1121.13-2006 'Soil Testing Part 13: Determination of Soil Exchangeable Calcium and Magnesium'.

[0032] The acidic red soil is taken from farmland in Jiuchang Village, Suixi County, Zhanjiang City, Guangdong Province.

[0033] Example 1

[0034] (1) 2.5g of natural dolomite was placed in a muffle furnace and heated to 800℃ at a heating rate of 5℃ / min and calcined for 4h to obtain calcined dolomite. Then the calcined dolomite was dissolved in 12.5g of deionized water to obtain a dolomite milk;

[0035] (2) 20 g of natural dolomite was added into 36.27 ml of 37% hydrochloric acid solution, stirred for 1 h, filtered, then the dolomite milk obtained in step (1) was added into the solution, the pH was adjusted to neutral, filtered, a mixed solution was obtained, and then 50 ml of deionized water was added into the mixed solution to obtain an acidified dolomite crosslinking agent;

[0036] (3) 1 g of sodium alginate was mixed with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0037] (4) 2 g of natural dolomite and 4 g of bentonite were sequentially added into the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0038] (5) The mixed slurry obtained in step (4) was pumped into the acidified dolomite crosslinking agent by using a YZ15-13A peristaltic pump with a 16# silica gel hose, and the rotation speed was set to 15.0 rmp; the mixed slurry was soaked in the acidified dolomite crosslinking agent for 3 h, washed, dried, and a soil conditioner was obtained;

[0039] (6) 5 g of the soil conditioner was put into 500 g of acidic red soil to perform an indoor simulation experiment, and the sample was taken after 2 months, and it was measured that the soil pH was 6.45, the exchangeable calcium was 1257 mg / kg, and the exchangeable magnesium was 198 mg / kg.

[0040] Example 2

[0041] (1) 2.5 g of natural dolomite was put into a muffle furnace and calcined at a temperature increasing rate of 5 ℃ / min to 800 ℃ for 4 h to obtain calcined dolomite. Then the calcined dolomite was dissolved in 12.5 g of deionized water to obtain a dolomite milk;

[0042] (2) 20 g of natural dolomite was added into 36.27 ml of 37% hydrochloric acid solution, stirred for 1 h, filtered, then the dolomite milk obtained in step (1) was added into the solution, the pH was adjusted to neutral, filtered, a mixed solution was obtained, and then 50 ml of deionized water was added into the mixed solution to obtain an acidified dolomite crosslinking agent;

[0043] (3) 1 g of sodium alginate was mixed with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0044] (4) 3 g of natural dolomite and 3 g of bentonite were sequentially added into the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0045] (5) The mixed slurry obtained in step (4) was pumped into the acidified dolomite crosslinking agent by using a YZ15-13A peristaltic pump with a 16# silica gel hose, and the rotation speed was set to 15.0 rmp; the mixed slurry was soaked in the acidified dolomite crosslinking agent for 3 h, washed, dried, and a soil conditioner was obtained;

[0046] (6) Put 5 g of the soil conditioner into 500 g of acidic red soil, and carry out indoor simulation experiment, and sample after 2 months, and it is measured that the soil pH is 6.65, the exchangeable calcium is 1497 mg / kg, and the exchangeable magnesium is 349 mg / kg.

[0047] Example 3

[0048] (1) Put 2.5 g of natural dolomite into a muffle furnace, and heat to 800 DEG C at a heating rate of 5 DEG C / min and calcine for 4 h to obtain calcined dolomite. Then, the calcined dolomite is dissolved in 12.5 g of deionized water to obtain a dolomite milk;

[0049] (2) Put 20 g of natural dolomite into 36.27 ml of a 37% hydrochloric acid solution, stir for 1 h, filter, then add the dolomite milk obtained in step (1) to it, adjust the pH to neutral, filter, obtain a mixed solution, and then add 50 ml of deionized water to the mixed solution to obtain an acidified dolomite crosslinking agent;

[0050] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0051] (4) Weigh 3.6 g of natural dolomite and 2.4 g of bentonite, and add the sodium alginate solution obtained in step (3) to them in sequence to obtain a mixed slurry;

[0052] (5) The mixed slurry obtained in step (4) is pumped into the acidified dolomite crosslinking agent by using a YZ15-13A peristaltic pump, the peristaltic pump silica gel hose is 16#, and the rotation speed is set to 15.0 rmp; soak for 3 h, wash, and dry to obtain a soil conditioner;

[0053] (6) Put 5 g of the soil conditioner into 500 g of acidic red soil, and carry out indoor simulation experiment, and sample after 2 months, and it is measured that the soil pH is 6.65, the exchangeable calcium is 1497 mg / kg, and the exchangeable magnesium is 349 mg / kg.

[0054] Example 4

[0055] (1) Put 2.5 g of natural dolomite into a muffle furnace, and heat to 800 DEG C at a heating rate of 5 DEG C / min and calcine for 4 h to obtain calcined dolomite. Then, the calcined dolomite is dissolved in 12.5 g of deionized water to obtain a dolomite milk;

[0056] (2) Put 20 g of natural dolomite into 36.27 ml of a 37% hydrochloric acid solution, stir for 1 h, filter, then add the dolomite milk obtained in step (1) to it, adjust the pH to neutral, filter, obtain a mixed solution, and then add 50 ml of deionized water to the mixed solution to obtain an acidified dolomite crosslinking agent;

[0057] (3) 1 g of sodium alginate was weighed and mixed with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0058] (4) 4 g of natural dolomite and 2 g of bentonite were weighed and sequentially added to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0059] (5) The mixed slurry obtained in step (4) was pumped into the acidified dolomite crosslinking agent using a YZ15-13A peristaltic pump with a 16# peristaltic pump silica gel hose, and the rotation speed was set to 15.0 rpm; the mixed slurry was soaked in the acidified dolomite crosslinking agent for 3 h, washed, dried, and soil conditioner was obtained;

[0060] (6) 5 g of the soil conditioner was placed in 500 g of acidic red soil for indoor simulation experiment, and samples were taken after 2 months, and the soil pH was measured to be 6.65, the exchangeable calcium was 1293 mg / kg, and the exchangeable magnesium was 238 mg / kg.

[0061] Example 5

[0062] (1) 2.5 g of natural dolomite was placed in a muffle furnace and heated to 800℃ at a heating rate of 5℃ / min and calcined for 4 h to obtain calcined dolomite. Then the calcined dolomite was dissolved in 12.5 g of deionized water to obtain a dolomitic lime milk;

[0063] (2) 20 g of natural dolomite was added to 36.27 ml of 37% hydrochloric acid solution, stirred for 1 h, filtered, then the dolomitic lime milk obtained in step (1) was added to adjust the pH to neutral, filtered to obtain a mixed solution, and then 50 ml of deionized water was added to obtain an acidified dolomite crosslinking agent;

[0064] (3) 1 g of sodium alginate was weighed and mixed with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0065] (4) 6 g of bentonite was weighed and sequentially added to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0066] (5) The mixed slurry obtained in step (4) was pumped into the acidified dolomite crosslinking agent using a YZ15-13A peristaltic pump with a 16# peristaltic pump silica gel hose, and the rotation speed was set to 15.0 rpm; the mixed slurry was soaked in the acidified dolomite crosslinking agent for 3 h, washed, dried, and soil conditioner was obtained;

[0067] (6) 5 g of the soil conditioner was placed in 500 g of acidic red soil for indoor simulation experiment, and samples were taken after 2 months, and the soil pH was measured to be 6.55, the exchangeable calcium was 1267 mg / kg, and the exchangeable magnesium was 224 mg / kg.

[0068] Example 6

[0069] (1) Put 2.5 g of natural dolomite into a muffle furnace and heat to 900℃ at a heating rate of 5℃ / min and calcine for 4 h to obtain calcined dolomite. Then dissolve the calcined dolomite in 25 g of deionized water to obtain a dolomite milk;

[0070] (2) Add 20 g of natural dolomite to 36.27 ml of 37% hydrochloric acid solution, stir for 1 h, filter, then add the dolomite milk obtained in step (1) to it, adjust the pH to neutral, filter to obtain a mixed solution, and then add 100 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0071] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0072] (4) Weigh 3 g of natural dolomite and 3 g of bentonite, and add the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0073] (5) Use a YZ15-13A peristaltic pump with a 16# silicone rubber hose to pump the mixed slurry into the acidified dolomite crosslinking agent at a speed of 15.0 rmp, soak for 3 h, wash, and dry to obtain a soil conditioner;

[0074] (6) Put 5 g of the soil conditioner into 500 g of acidic red soil and conduct an indoor simulation experiment. After 2 months, sample and measure the soil pH to be 6.55, the exchangeable calcium to be 1417 mg / kg, and the exchangeable magnesium to be 303 mg / kg.

[0075] Example 7

[0076] (1) Put 2.5 g of natural dolomite into a muffle furnace and heat to 900℃ at a heating rate of 5℃ / min and calcine for 3 h to obtain calcined dolomite. Then dissolve the calcined dolomite in 25 g of deionized water to obtain a dolomite milk;

[0077] (2) Add 20 g of natural dolomite to 36.27 ml of 37% hydrochloric acid solution, stir for 1 h, filter, then add the dolomite milk obtained in step (1) to it, adjust the pH to neutral, filter to obtain a mixed solution, and then add 150 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0078] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0079] (4) Weigh 3 g of natural dolomite and 3 g of bentonite, and add the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0080] (5) The mixed slurry obtained in step (4) is pumped into the acidified dolomite crosslinking agent using a YZ15-13A peristaltic pump with a 16# silicone rubber hose, and the rotation speed is set to 15.0 rpm; the mixed slurry is soaked in the acidified dolomite crosslinking agent for 3 h, washed, dried, and soil conditioner is obtained;

[0081] (6) 5 g of the soil conditioner is put into 500 g of acidic red soil for indoor simulation experiment, and the sample is taken after 2 months, and the soil pH is measured to be 6.55, the exchangeable calcium is 1421 mg / kg, and the exchangeable magnesium is 288 mg / kg.

[0082] Example 8

[0083] (1) 2.5 g of natural dolomite is put into a muffle furnace and calcined at a temperature increasing rate of 5 ℃ / min to 900 ℃ for 4 h to obtain calcined dolomite. Then the calcined dolomite is dissolved in 50 g of deionized water to obtain dolomite milk;

[0084] (2) 20 g of natural dolomite is added into 36.27 ml of 37% hydrochloric acid solution, stirred for 1 h, filtered, then the dolomite milk obtained in step (1) is added to adjust the pH to neutral, filtered, and 200 ml of deionized water is added to obtain an acidified dolomite crosslinking agent;

[0085] (3) 1 g of sodium alginate is weighed and mixed with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0086] (4) 3 g of natural dolomite and 3 g of bentonite are weighed and added into the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0087] (5) The mixed slurry obtained in step (4) is pumped into the acidified dolomite crosslinking agent using a YZ15-13A peristaltic pump with a 16# silicone rubber hose, and the rotation speed is set to 15.0 rpm; the mixed slurry is soaked in the acidified dolomite crosslinking agent for 3 h, washed, dried, and soil conditioner is obtained;

[0088] (6) 5 g of the soil conditioner is put into 500 g of acidic red soil for indoor simulation experiment, and the sample is taken after 2 months, and the soil pH is measured to be 6.55, the exchangeable calcium is 1421 mg / kg, and the exchangeable magnesium is 288 mg / kg.

[0089] Example 9

[0090] (1) 2.5 g of natural dolomite is put into a muffle furnace and calcined at a temperature increasing rate of 5 ℃ / min to 1000 ℃ for 4 h to obtain calcined dolomite. Then the calcined dolomite is dissolved in 75 g of deionized water to obtain dolomite milk;

[0091] (2) 20 g of natural dolomite was added into 36.27 ml of 37% hydrochloric acid solution, stirred for 1 h, filtered, then the dolomite milk obtained in step (1) was added into the mixture, the pH was adjusted to neutral, filtered, a mixed solution was obtained, and then 150 ml of deionized water was added into the mixed solution to obtain an acidified dolomite crosslinking agent;

[0092] (3) 1 g of sodium alginate was mixed with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0093] (4) 3 g of natural dolomite and 3 g of bentonite were sequentially added into the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0094] (5) The mixed slurry obtained in step (4) was pumped into the acidified dolomite crosslinking agent by using a YZ15-13A peristaltic pump with a 16# silica gel hose, and the rotation speed was set to 15.0 rpm; the mixed slurry was soaked in the acidified dolomite crosslinking agent for 3 h, washed, dried, and a soil conditioner was obtained;

[0095] (6) 5 g of the soil conditioner was put into 500 g of acidic red soil to perform an indoor simulation experiment, and the sample was taken after 2 months, and it was measured that the soil pH was 6.55, the exchangeable calcium was 1403 mg / kg, and the exchangeable magnesium was 278 mg / kg.

[0096] Example 10

[0097] (1) 2.5 g of natural dolomite was put into a muffle furnace and calcined at a temperature increasing rate of 5 ℃ / min to 1000 ℃ for 4 h to obtain calcined dolomite. Then the calcined dolomite was dissolved in 75 g of deionized water to obtain a dolomite milk;

[0098] (2) 20 g of natural dolomite was added into 36.27 ml of 37% hydrochloric acid solution, stirred for 1 h, filtered, then the dolomite milk obtained in step (1) was added into the mixture, the pH was adjusted to neutral, filtered, a mixed solution was obtained, and then 150 ml of deionized water was added into the mixed solution to obtain an acidified dolomite crosslinking agent;

[0099] (3) 1 g of sodium alginate was mixed with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0100] (4) 3 g of natural dolomite and 3 g of bentonite were sequentially added into the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0101] (5) The mixed slurry obtained in step (4) was pumped into the acidified dolomite crosslinking agent by using a YZ15-13A peristaltic pump with a 16# silica gel hose, and the rotation speed was set to 15.0 rpm; the mixed slurry was soaked in the acidified dolomite crosslinking agent for 6 h, washed, dried, and a soil conditioner was obtained;

[0102] (6) Put 5 g of the soil conditioner into 500 g of acidic red soil for indoor simulation experiment, and take samples after 2 months. The measured soil pH is 6.55, the exchangeable calcium is 1417 g / kg, and the exchangeable magnesium is 292 mg / kg.

[0103] Example 11

[0104] (1) Put 2.5 g of natural dolomite into a muffle furnace and heat to 1000℃ at a heating rate of 5℃ / min and calcine for 4 h to obtain calcined dolomite. Then dissolve the calcined dolomite in 75 g of deionized water to obtain a dolomite milk;

[0105] (2) Add 20 g of natural dolomite to 36.27 ml of 37% hydrochloric acid solution, stir for 1 h, filter, then add the dolomite milk obtained in step (1) to it, adjust the pH to neutral, filter to obtain a mixed solution, and then add 150 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0106] (3) Weigh 1 g of sodium alginate and mix with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0107] (4) Weigh 3 g of natural dolomite and 3 g of bentonite, and add the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0108] (5) Use a YZ15-13A peristaltic pump with a 16# silicone rubber hose to pump the mixed slurry into the acidified dolomite crosslinking agent at a speed of 15.0 rmp, soak for 12 h, wash, and dry to obtain a soil conditioner;

[0109] (6) Put 5 g of the soil conditioner into 500 g of acidic red soil for indoor simulation experiment, and take samples after 2 months. The measured soil pH is 6.55, the exchangeable calcium is 1417 g / kg, and the exchangeable magnesium is 292 mg / kg.

[0110] Example 12

[0111] (1) Put 2.5 g of natural dolomite into a muffle furnace and heat to 1000℃ at a heating rate of 5℃ / min and calcine for 4 h to obtain calcined dolomite. Then dissolve the calcined dolomite in 75 g of deionized water to obtain a dolomite milk;

[0112] (2) Add 20 g of natural dolomite to 36.27 ml of 37% hydrochloric acid solution, stir for 1 h, filter, then add the dolomite milk obtained in step (1) to it, adjust the pH to neutral, filter to obtain a mixed solution, and then add 150 ml of deionized water to obtain an acidified dolomite crosslinking agent;

[0113] (3) 1 g of sodium alginate was weighed and mixed with 99 g of deionized water to obtain a 1 wt% sodium alginate solution;

[0114] (4) 3 g of natural dolomite and 3 g of bentonite were weighed and sequentially added to the sodium alginate solution obtained in step (3) to obtain a mixed slurry;

[0115] (5) The mixed slurry obtained in step (4) was pumped into the acidified dolomite crosslinking agent using a YZ15-13A peristaltic pump with a 16# silicone rubber hose, and the rotation speed was set to 15.0 rmp; the mixed slurry was soaked in the acidified dolomite crosslinking agent for 24 h, washed, and dried to obtain a soil conditioner;

[0116] (6) 5 g of the soil conditioner was placed in 500 g of acidic red soil for indoor simulation experiment, and samples were taken after 2 months; the measured soil pH was 6.60, the exchangeable calcium was 1468 g / kg, and the exchangeable magnesium was 294 mg / kg.

Claims

1. A conditioner for ameliorating acid soils, characterised in that, The method is as follows: (1) grind and sieve natural dolomite, put it into a muffle furnace, heat to 800-1000℃ and keep for 3-5h to obtain calcined dolomite; dissolve the obtained calcined dolomite in deionized water to obtain dolomite milk; (2) add natural dolomite into hydrochloric acid solution, stir, filter, add the dolomite milk obtained in step (1) to the filtrate to adjust pH to neutral, filter, dilute the filtrate with deionized water to obtain acidified dolomite crosslinking agent; (3) mix sodium alginate with deionized water, stir to disperse uniformly to obtain sodium alginate solution; (4) add natural dolomite and bentonite into the sodium alginate solution obtained in step (3) in turn, mix to obtain mixed slurry; (5) pump the mixed slurry obtained in step (4) into the acidified dolomite crosslinking agent obtained in step (2) by peristaltic pump, soak and shape, wash, dry to obtain the improved acid soil conditioner.

2. The soil amendment for improving acid soil according to claim 1, wherein In step (1), the heating rate during calcination is 5℃ / min.

3. The soil amendment for ameliorating acid soils of claim 1, wherein, In step (1), the mass ratio of calcined dolomite to deionized water is 2.5:12.5-75.

4. The soil amendment for improving acid soil according to claim 1, wherein In step (2), the mass fraction of hydrochloric acid solution is 37%; the molar ratio of natural dolomite to hydrochloric acid is 1:

4.

5. The soil amendment for ameliorating acid soils of claim 1, wherein, In step (2), the feeding ratio of natural dolomite to deionized water is 20:50-200, g / mL.

6. The soil amendment for ameliorating acid soils of claim 1, wherein, In step (3), the mass fraction of sodium alginate solution is 1%.

7. The soil amendment for ameliorating acid soils of claim 1, wherein In step (4), the mass ratio of natural dolomite to bentonite is 0-4:2-6.

8. The soil amendment for ameliorating acid soils of claim 1, wherein, In step (4), the mass ratio of the total mass of natural dolomite and bentonite to sodium alginate is 6:

1.

9. The soil amendment for ameliorating acid soils of claim 1, wherein, In step (5), the volume ratio of mixed slurry to acidified dolomite crosslinking agent is 100:50-200.

10. The soil amendment for ameliorating acid soils of claim 1, wherein, In step (5), the soaking and shaping time is 3-24h.

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