A new soil matrix and its preparation method and application

Abstract

The present invention belongs to the technical field of soil improvement, specifically relating to a newly formed soil matrix, its preparation method, and its application. The newly formed soil matrix, formed by mixing strongly weathered rock soil, degraveled sandy soil, loess, and organic fertilizer, helps eliminate soil barriers, increase trace elements, improve soil structure, increase soil organic matter, and enhance soil moisture retention, further contributing to improving the inefficient arable layer of farmland in central and northern my country.

Description

Technical Field

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

[0002] Low-yield farmland in central and northern my country suffers from a thin soil layer, poor soil fertility, low nutrient content, poor soil structure and water and fertilizer retention capacity, and an unbalanced water, fertilizer, air, and heat environment, which seriously impacts the growth and development of local crops. Although existing technologies have proven that conservation tillage practices such as increased application of organic fertilizers, combined application of organic and inorganic fertilizers, and returning straw to the fields can effectively improve soil fertility, due to the large number of soil barriers in central and northern China, relying solely on existing single-agricultural land improvement techniques such as filling with imported soil and increasing fertilizer application to improve arable land fertility is difficult to completely eliminate the barriers to low-yield fields, and therefore cannot achieve the desired results of increasing yields and incomes.

[0003] Furthermore, as my country strengthens its efforts to protect its ecological environment, the use of highly weathered rock and soil with multiple barriers, gravelly sand, and other materials unsuitable for cultivation, to prepare new soils is becoming an inevitable trend in northern my country's hilly and semi-arid regions. However, current new soil preparation methods are mostly based on laboratory sample preparation techniques, which cannot be prepared on a large scale at low cost, and therefore lack the value for widespread application. Summary of the Invention

[0004] The purpose of the present invention is to provide a new soil matrix and its preparation method and application, which is suitable for low-yield farmland in the central and northern regions of my country and has the characteristics of eliminating soil barrier factors and adapting to industrial production.

[0005] The invention provides a newly formed soil matrix comprising the following components in percentage by mass: 33% to 55% of strongly weathered rock soil, 20% to 30% of gravel-removed sandy soil, 15% to 30% of loess and 4% to 8% of organic fertilizer.

[0006] Preferably, the particle sizes of the strongly weathered rock soil, gravel-removed sandy soil and loess are respectively less than 15 mm.

[0007] Preferably, the strongly weathered rock and soil includes processed strongly weathered rock and soil;

[0008] The processing method comprises: performing soft rubbing and peeling and screening on the strongly weathered rock and soil.

[0009] Preferably, the loess includes processed loess;

[0010] The processing method comprises: sequentially drying and sieving the loess.

[0011] Preferably, after the drying, the moisture content of the loess is ≤8%.

[0012] The present invention also provides a method for preparing the newly formed soil matrix, comprising the following steps: mixing strongly weathered rock soil, gravel-removed sandy soil and loess, and then adding organic fertilizer and stirring to obtain the newly formed soil matrix.

[0013] Preferably, the preparation method further comprises adding water during the mixing process.

[0014] Preferably, the amount of water added is 10% to 12% of the total mass of the strongly weathered rock soil, gravel-removed sandy soil, loess and organic fertilizer.

[0015] In addition, the present invention also provides the use of the newly formed soil matrix in eliminating multiple soil barrier factors and / or improving soil moisture retention and water storage.

[0016] Beneficial effects:

[0017] The present invention provides a newly formed soil matrix comprising the following components in percentage by weight: 33% to 55% of strongly weathered rock and soil, 20% to 30% of de-graveled sand, 15% to 30% of loess, and 4% to 8% of organic fertilizer. The present invention eliminates soil barrier factors in the aforementioned matrix by processing and grading the strongly weathered rock and soil and the gravelly sand, thereby increasing the trace elements in the newly formed soil matrix and effectively improving the soil structure. The addition of loess, utilizing its viscosity, facilitates the formation of soil aggregates and enhances the soil's moisture retention function. The addition of organic fertilizer facilitates the rapid decomposition of the newly formed soil within a single cultivation cycle (12 months), promoting the transformation of the cultivated land to be improved from raw soil to mature soil, significantly increasing soil organic matter, further enhancing soil aggregation, and optimizing soil porosity and air permeability, further contributing to improving the arable layer of inefficient farmland in central and northern my country.

[0018] Based on the aforementioned technical advantages, the present invention also provides the use of the aforementioned newly formed soil matrix to eliminate multiple soil barrier factors and / or improve soil moisture retention. Experiments have shown that, compared to unremediated farmland, using the newly formed soil matrix provided by this application to remediate gravelly sandy farmland, the nitrogen, phosphorus, and potassium contents in the remediated farmland increased by 138%, 120.5%, and 38.65%, respectively, 12 months after the completion of land reclamation. The saturated water holding capacity also increased by 87.4% to 101.2%. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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 are briefly introduced below.

[0020] Figure 1 This is Photo 1 of Example 2, in which newly formed soil is returned to the field for paving;

[0021] Figure 2Photo 2 shows the newly formed soil being returned to the field and spread in Example 2;

[0022] Figure 3 This is a photo of the farmland 12 months after the new soil was restored in Example 2;

[0023] Figure 4 Photo 3 shows the newly formed soil being returned to the field and spread in Example 2;

[0024] Figure 5 This is a photo of crops planted on fresh soil in Example 2;

[0025] Figure 6 The physical and chemical index test result 1 of the newly formed soil matrix in Example 1;

[0026] Figure 7 The physical and chemical index test result 2 of the newly formed soil matrix in Example 1;

[0027] Figure 8 This is the physical and chemical index test result 3 of the newly formed soil matrix in Example 1. DETAILED DESCRIPTION

[0028] The invention provides a newly formed soil matrix, which preferably comprises the following components in percentage by mass: 33% to 55% of strongly weathered rock soil, 20% to 30% of de-graveled sandy soil, 15% to 30% of loess and 4% to 8% of organic fertilizer.

[0029] In the present invention, the mass percentage of highly weathered rock and soil in the newly formed soil matrix is further preferably 33% to 40%, 40% to 48%, or 48% to 55%. The highly weathered rock and soil described in the present invention preferably includes processed highly weathered rock and soil; the processing method preferably includes: softly rubbing and peeling the highly weathered rock and soil and screening it. Processing the highly weathered rock and soil eliminates soil barrier factors in the highly weathered rock and soil, further facilitating the improvement of trace elements in the newly formed soil matrix.

[0030] The present invention preferably obtains highly weathered rock and soil raw materials. The location for taking the highly weathered rock and soil raw materials of the present invention is preferably a location approved by the relevant government departments, and the raw materials of the highly weathered rock and soil preferably include one or more of rock and soil with completely weathered surfaces, highly weathered loose stones, soft stones partially containing medium-weathered debris, and highly weathered surface soil and stone materials stripped before open-pit mining. The present invention preferably pre-treats the highly weathered rock and soil raw materials, and the pre-treatment preferably includes removing surface plants of the highly weathered rock and soil. The present invention has no special requirements for the method of taking and pre-treating the highly weathered rock and soil raw materials, and can adopt the techniques well known to those skilled in the art.

[0031] In the present invention, the flexible rubbing and stripping preferably includes mechanical stripping by a non-crushing method to achieve soil-rock separation. After the screening, the present invention preferably obtains highly weathered rock and soil with a particle size of less than 15 mm. The present invention has no special requirements for the mechanical stripping and screening devices, and can adopt technologies well known in the art. Flexible rubbing and stripping and screening can efficiently remove moderately weathered and weakly weathered rocks in the highly weathered rock and soil, while reducing the impact of hard rock crushing powder on the soil during the removal process.

[0032] In the present invention, the mass percentage of the de-graveled sand in the newly formed soil matrix is further preferably 20% to 24%, 24% to 27%, or 27% to 30%. The de-graveled sand of the present invention is preferably obtained through sieving, and the particle size of the de-graveled sand is preferably less than 15 mm. The present invention does not require any special screening equipment, and techniques well known in the art can be used. The de-graveled sand obtained through sieving has a significantly reduced soil barrier factor, which is more conducive to increasing the trace elements in the newly formed soil matrix and improving the soil structure to be repaired.

[0033] The present invention preferably obtains de-graveled sandy soil as raw material. The de-graveled sandy soil is preferably obtained from a site where farmland remediation is planned. The de-graveled sandy soil preferably comprises gravelly-containing sandy soil on the surface of the barren sandy soil of the farmland. The present invention has no special requirements for the extraction process of the de-graveled sandy soil, and techniques well known in the art can be employed.

[0034] In the present invention, the mass percentage of loess in the newly formed soil matrix is further preferably 25% to 30%, 20% to 25%, or 15% to 20%. The loess described in the present invention preferably includes processed loess; the processing method of the loess preferably includes airing and sieving the loess in sequence. In the present invention, the moisture content of the loess raw material after the airing is preferably ≤8%. The particle size of the loess described in the present invention is preferably <15mm. By effectively controlling the moisture content in the loess raw material and sieving it, it is beneficial to screen out the effective components in the loess and significantly improve the viscosity characteristics of the loess. The present invention has no special requirements for the airing method and screening device, and can adopt the technology well known in the art.

[0035] The present invention preferably obtains loess raw material. The loess raw material is preferably obtained from virgin (secondary) loess generated by urban engineering foundation construction or from government-designated virgin (secondary) loess sources. The present invention has no special requirements for the loess raw material extraction process; techniques well known in the art can be used.

[0036] The newly formed soil matrix described herein is preferably suitable for remediating barren yellow soil farmland, more preferably barren farmland in the central, western, and northern regions north of the Yangtze River and south of the three northeastern provinces, and even more preferably barren farmland in the hilly and semi-arid regions of northern China. In specific embodiments of the present invention, the newly formed soil matrix is remediated in Shandong and / or Hebei.

[0037] The present invention also provides a method for preparing the newly formed soil matrix, comprising the steps of mixing highly weathered rock and soil, de-graveled sandy soil, and loess, and then adding organic fertilizer and stirring to obtain the newly formed soil matrix. The initial mixing of the highly weathered rock and soil, de-graveled sandy soil, and loess further eliminates soil barrier factors in the highly weathered rock and soil, de-graveled sandy soil, and loess, thereby optimizing the structure of the newly formed soil matrix. The subsequent addition of organic fertilizer further promotes soil decomposition, significantly increases soil organic matter, and enhances soil cohesion. Furthermore, due to its simplicity, the preparation method is more suitable for industrial production and has the potential for widespread application.

[0038] The present invention preferably adds water to the mixture of the highly weathered rock soil, the gravel-free sandy soil, and the loess, and then adds the organic fertilizer for stirring. The amount of water added in the present invention is preferably 10% to 12% of the total mass of the highly weathered rock soil, the gravel-free sandy soil, the loess, and the organic fertilizer, and more preferably 8%. Adding water during the mixing process helps to suppress the release of dust from the newly formed soil matrix and reduce environmental pollution. The present invention has no special requirements for the source of the organic fertilizer.

[0039] After obtaining the newly formed soil matrix, the present invention preferably performs soil remediation on the farmland to be remediated. In the present invention, the soil remediation method preferably includes directly returning the newly formed soil matrix to the field for paving and use as soil; the paving thickness is ≥ 30 cm; and the soil remediation period is preferably 12 months or longer. The present invention does not require any specific tools for paving the field; tools well known in the art can be used.

[0040] Based on the above technical advantages, the present invention also provides the application of the above-mentioned new soil matrix in eliminating multiple soil barrier factors and / or improving soil moisture retention and water storage. Experiments have shown that when the artificial new soil matrix provided by this application is used to repair gravelly sandy arable land, compared with unremediated arable land, the nitrogen, phosphorus and potassium contents in the new soil increased by 138%, 120.5% and 38.65% respectively 12 months after the completion of land reclamation; the saturated water holding capacity of the new soil increased by 87.4% to 101.2%. Therefore, the new soil matrix provided by this application is beneficial for eliminating multiple soil barrier factors and / or improving soil moisture retention and water storage.

[0041] To further illustrate the present invention, a new soil matrix provided by the present invention, its preparation method and application are described in detail below with reference to the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0042] Example 1

[0043] In 2015, we began to partially restore the gravelly sandy farmland in the northwest of Huangjiazhuang Village, Shengshuiyu Town, Sishui County, Jining City, Shandong Province. The restoration area this time was 200 mu. The specific operations are as follows:

[0044] Preliminary Preparation: Separate raw materials were obtained: highly weathered rock and soil, de-graveled sandy soil, and loess. The highly weathered rock and soil were then softly rubbed and sieved, the de-graveled sandy soil was sieved, and the loess was air-dried and sieved, yielding highly weathered rock and soil, de-graveled sandy soil, and loess with particle sizes <15 mm, respectively. The de-graveled sandy soil was sourced from the gravelly sandy farmland to be restored northwest of Huangjiazhuang Village, Shengshuiyu Town, Sishui County, Jining City, Shandong Province. The highly weathered rock and soil were obtained from the subsoil layer of the reclaimed gravelly sandy farmland during leveling, as well as from the surface and subsoil layers of other unused land in the area, such as bare rock and wasteland. Organic fertilizer was purchased from the Hongshan Organic Fertilizer Factory in Sishui County, with a dry organic matter content of ≥47%.

[0045] New soil matrix: composed of the following components in percentage by mass: 33% to 55% of strongly weathered rock soil, 20% to 30% of gravel-removed sandy soil, 15% to 30% of loess and 4% to 8% of organic fertilizer.

[0046] Soil Remediation: Spread the prepared new soil matrix onto the gravelly sandy field to be remediated, at a thickness of at least 80 cm. After spreading, plant grapes, peaches, apples, and other crops, and perform routine field management according to local practices.

[0047] Analysis of physical and chemical properties of newly formed soil: After a cultivation cycle (12 months), Shandong Wuzhou Testing Co., Ltd. was commissioned to take on-site samples of newly formed soil. The physical and chemical test results of the newly formed soil are as follows: Figures 6 to 8 shown.

[0048] Depend on Figures 6 to 8 It can be seen that after 12 months, the pH value of the newly formed soil prepared by the present invention is 6.9, the bulk density is 0.84 g / kg, the organic matter content is 13.7 g / kg, the total salt content is 0.84 g / kg, and the heavy metal content meets the requirements of the "Soil Environmental Quality Standard" (GB15618-1995).

[0049] Example 2

[0050] In 2019, unrestored farmland was selected for restoration. The location was still the gravel sandy farmland to be restored in the northwest of Huangjiazhuang Village, Shengshuiyu Town, Sishui County, Jining City, Shandong Province. The restoration area this time was 300 acres.

[0051] A method for preparing a new soil matrix comprises the following steps:

[0052] Preliminary Preparation: We collected highly weathered rock and soil, de-graveled sandy soil, and loess raw materials. The highly weathered rock and soil were then softly rubbed and sieved, the de-graveled sandy soil was sieved, and the loess was air-dried and sieved, yielding highly weathered rock and soil, de-graveled sandy soil, and loess with particle sizes <15 mm, respectively. The highly weathered rock and de-graveled sandy soil were sourced from arable land in gravelly sandy soil awaiting restoration northwest of Huangjiazhuang Village, Shengshuiyu Town, Sishui County, Jining City, Shandong Province. Organic fertilizer was purchased from the Hongshan Organic Fertilizer Factory in Sishui County, with a dry organic matter content of ≥47%.

[0053] New soil matrix: composed of the following components in percentage by mass: 33% to 55% of strongly weathered rock soil, 20% to 30% of gravel-removed sandy soil, 15% to 30% of loess and 4% to 8% of organic fertilizer.

[0054] Soil remediation: Return the prepared new soil matrix to the field and spread it on the gravelly sandy arable land to be remediated, with a paving thickness of more than 50 cm. After paving, the field roads and irrigation and drainage systems are arranged, and crops such as corn, peanuts, and sweet potatoes are planted. Conventional field management is carried out according to local management practices (see Figures 1 to 5 ).

[0055] After 12 months, the pH value, bulk density, organic matter and heavy metal content of the newly formed soil were found to be in compliance with the requirements of the Soil Environmental Quality Standard (GB15618-1995).

[0056] Example 3

[0057] In 2019, gravel sandy farmland to be restored in the north of Dawan Village, Xuanhua District, Zhangjiakou City, Hebei Province, with a restoration area of 100 acres.

[0058] A method for preparing a new soil matrix comprises the following steps:

[0059] Preliminary preparation: Separately, highly weathered rock and soil, de-graveled sandy soil, and loess raw materials were obtained. The highly weathered rock and soil were then softly rubbed, peeled, and sieved, the de-graveled sandy soil was sieved, and the loess was air-dried and sieved to obtain highly weathered rock and soil, de-graveled sandy soil, and loess with particle sizes less than 15 mm. The highly weathered rock and soil were obtained from the open-pit abandoned mine awaiting restoration in the project area, and the de-graveled sandy soil was obtained from the gravelly sandy farmland awaiting restoration north of Dawan Village, Xuanhua District, Zhangjiakou City, Hebei Province. Organic fertilizer was purchased from Hebei Fengnong Organic Fertilizer Manufacturing Co., Ltd. in the form of 40 kg of sheep manure organic fertilizer (Microbial Fertilizer (2017) Approval No. (2823)), with an index of 40% dry organic matter.

[0060] New soil matrix: composed of the following components in percentage by mass: 33% to 55% of strongly weathered rock soil, 20% to 30% of gravel-removed sandy soil, 15% to 30% of loess and 4% to 8% of organic fertilizer.

[0061] Soil Remediation: The prepared new soil matrix is returned to the gravelly sandy arable land to be remediated, spreading it to a thickness of at least 30 cm and arable land to form terraces based on the terrain being remediated. Following paving, two cash crops, apricot and crabapple, are planted, along with a single crop of peanuts. Conventional field management is then carried out according to local practices.

[0062] After 12 months, the pH value, bulk density, organic matter and heavy metal content of the newly formed soil were found to be in compliance with the requirements of the Soil Environmental Quality Standard (GB15618-1995).

[0063] Comparative Example 1

[0064] The difference from Example 2 is that samples were taken directly from gravelly sandy farmland without soil remediation.

[0065] Comparative Example 2

[0066] The difference from Example 3 is that samples were taken directly from gravelly sandy farmland without soil remediation.

[0067] Results and Analysis:

[0068] On May 11, 2020, after one cultivation cycle (12 months), soil samples were collected from the arable land with gravelly sandy soil to be restored in Comparative Example 1 and the newly formed soil arable land applied in Example 2. On May 12, 2020, after one cultivation cycle (12 months), soil samples were collected from the arable land with gravelly sandy soil to be restored in Comparative Example 2 and the newly formed soil arable land applied in Example 3. A sampling area of no less than 10 mu was randomly delineated for different land types in both regions. The 10 mu was divided into five equal parts of similar area. The center point of each area was used as a soil sampling point. Five samples were collected for each soil type, for a total of 20 soil samples.

[0069] 1) Determine the saturated water holding capacity of fresh soil. The experimental steps are as follows:

[0070] Unremediated soil collection: Determine 5 sampling points and use a combination of machinery and manual labor to excavate rectangular soil profile pits of about 1m×1.5m at the sampling points. The pit depth is about 0.35m. When the excavation reaches about 0.2m, take the loose soil from the bottom of the pit and put it into a sample bag marked with the sampling information for future use. After the excavation of the profile pit is completed, manually trim the four sides of the pit wall and cut out vertical surfaces. Select three surfaces with less debris and use a box ruler to mark the vertical center position sampling points. Use a leather hammer to drive a standard ring knife into the sampling point to take a sample, forming a covered ring knife soil sample. Mark the sampling point number, orientation, sampling date, sampler and other information. The soil samples in Comparative Example 1 are numbered A1 to A5, and the soil samples in Comparative Example 2 are numbered C1 to C5.

[0071] Fresh soil sample collection: Determine 5 sampling points and manually excavate rectangular soil profile pits of about 1×1.5m at the sampling points. Based on different soil sampling characteristics, the pit depth for fresh soil sample collection is about 0.6m. When the excavation reaches about 0.2m, take the loose soil from the bottom of the pit and put it into a sample bag with the sampling information marked for standby use; after the profile pit is excavated, select the long side with less debris and cut a vertical surface on the pit wall. Use a box ruler to determine the sampling points of 10cm, 20cm, and 40cm from the ground. Use a leather hammer to drive a standard ring knife into the sampling point to take a sample, forming a covered ring knife soil sample. Mark the sampling point number, orientation, sampling date, sampler and other information. The soil samples in Example 2 are numbered B1 to B5, and the soil samples in Example 3 are numbered D1 to D5.

[0072] Drying of bulk soil samples: Pour the bulk soil samples collected in the field into a porcelain plate, spread them out, place them in an oven, set the temperature to 105°C, dry them for 8 hours, grind them, sieve them, and put them into a ring knife for use;

[0073] Weighing and numbering of aluminum boxes: Number and weigh the aluminum boxes used in the experiment and record them.

[0074] Soaking of original soil samples collected by ring cutters in the field: Place the original soil samples collected by ring cutters in the field into a flat-bottomed container with the hole cover side facing down and the non-hole cover side facing up. Slowly add tap water, keeping the water level 1-2 mm lower than the upper edge of the ring cutter, and soak for 24 hours.

[0075] Water infiltration: Take out the soaked original soil sample with the ring knife, remove the bottom hole cover, stick the filter paper on it, and place the filter paper face down on the ring knife containing the loose soil sample. After alignment, compact it with a heavy object to make it in close contact and allow water to infiltrate for 8 hours.

[0076] Weighing wet soil samples: After filtering out the water, take out the soil sample, take 20-30g of soil sample from the upper and lower ring cutters, put them into an aluminum box and weigh the total weight of the aluminum box;

[0077] Constant temperature drying: Place the weighed soil sample with the aluminum box in a constant temperature oven, set the temperature to 105℃, and dry it for 12 hours.

[0078] Drying and cooling: Take out the dried soil sample and immediately place it in a desiccator to cool to room temperature.

[0079] Weigh dry soil samples: Open the dryer, weigh each soil sample one by one, and keep records.

[0080] Soil field water holding capacity determination and calculation: The soil saturated water holding capacity calculation formula is as follows:

[0081] X = (m1-m2) / (m2-m0) × 100 (X: soil saturated water holding capacity; m0: weight of the empty aluminum box after drying; m1: weight of the aluminum box and wet soil sample before drying; m2: weight of the aluminum box and wet soil sample after drying)

[0082] The results are shown in Tables 1 to 4. The results of parallel determinations are expressed as arithmetic mean values.

[0083] Table 1 Saturated water holding capacity of gravel sand in comparative example 1 (unit: %)

[0084]

[0085] Table 2 Saturated water holding capacity of newly formed soil in reclaimed farmland in Example 2 (unit: %)

[0086]

[0087]

[0088] Table 3 Saturated water holding capacity of gravel sand in comparative example 2 (unit: %)

[0089]

[0090] Table 4 Saturated water holding capacity of newly formed soil in reclaimed farmland in Example 3 (unit: %)

[0091]

[0092] The water holding capacities in Tables 1 through 4 are summarized and compared, with N1 through N5 representing the water holding capacities of the five sampling points in each treatment. Table 5 compares the saturated water holding capacities of gravelly sand and newly formed soils in the different improvement areas.

[0093] Table 5 Comparison of saturated water holding capacity of gravelly sand and newly formed soil in different improvement areas (unit: %)

[0094]

[0095] Table 5 shows that, compared to unremediated gravelly sand, the saturated water holding capacity of the newly formed soil matrix provided by this application increased by 87.4% to 101.2% when used to restore farmland. This indicates that after 12 months of natural aging and cultivation, the saturated water holding capacity of the newly formed soil provided by this invention is significantly increased, significantly strengthening its water-holding capacity.

[0096] 2) Determination of total NPK in fresh soil. The experimental steps are as follows:

[0097] Unremediated soil collection: Randomly determine 3 sampling points among the 5 saturated water holding capacity soil sampling points, number the samples and mark the sampling point locations. When the saturated water holding capacity sampling points are manually excavated to about 0.2m, take the loose soil from the bottom of the pit and put it into sample bags marked with sampling information for later use.

[0098] Collection of new soil samples: Randomly determine 3 sampling points among the 5 saturated water holding capacity soil sampling points, number the samples and mark the sampling point locations. When the saturated water holding capacity sampling points are manually excavated to a depth of about 0.2m, take the loose soil from the bottom of the pit and put it into a sample bag marked with the sampling information for later use.

[0099] Screening of bulk soil samples: The bulk soil samples collected in the field were crushed with a laboratory crusher and passed through a 2 mm sieve for later use.

[0100] The total NPK of gravel sand and newly formed soil is measured using the TPY-6A Top Soil Nutrient Analyzer rapid measurement method. The specific steps are as follows:

[0101] Prepare the test solution and standard solution:

[0102] Take 4g of air-dried soil from the test soil sample and put it into the sample bottle, add 20mL, and then add 1g of the No. 1 powder reagent provided with the TPY-6A soil nutrient rapid tester, cover the bottle cap, and shake for 10 minutes to prepare the nitrogen and potassium test solution;

[0103] (2) Fill a glass cuvette to 2 / 3 of its capacity with distilled water as a blank solution.

[0104] (3) Use a pipette to add 900 μL of water to another glass cuvette, then add 100 μL of nitrogen standard solution and shake well to prepare the standard solution. The concentration of the standard solution is now 20 mg / kg.

[0105] (4) Use a plastic pipette to draw 1000 μL of the nitrogen and potassium test solution into a glass cuvette. Add 100 μL of nitrogen reagent No. 1 to the glass cuvettes containing the standard solution and the test solution, shake well, then add 100 μL of nitrogen reagent No. 2 and shake well. Let it stand for 10 minutes, then add 800 μL of water to each and shake well, then immediately operate on the machine.

[0106] On-machine testing:

[0107] (1) Start the system and log in to the nitrogen content test interface. Select the standard solution concentration. This experiment uses 20 mg / kg.

[0108] (2) Click Blank Test and put the blank liquid into the test channel corresponding to the red light and press OK;

[0109] (3) Click Standard Test to place the stabilized standard solution into the ninth channel and press OK. The absorbance will display the corresponding value. After the standard test is completed, click Sample Test to place one or more stabilized test solutions and press OK.

[0110] Results: The results of the comparison of total NPK content of gravelly sand and newly formed soil in different improvement areas are shown in Table 6.

[0111] Table 6 Comparison of total NPK content of gravelly sand and newly formed soil in different improvement areas (unit: g / kg)

[0112]

[0113] It can be concluded from Table 6 that, compared with the gravelly sandy soil without soil restoration, after the farmland was restored using the newly formed soil matrix provided by this application, the increases in N, P and K elements in the newly formed soil reached 138%, 120.5% and 38.65% respectively.

[0114] In summary, even after 12 months of soil restoration using the newly formed soil matrix provided in this application, the soil's saturated water holding capacity and total NPK content remained at high levels. Therefore, the newly formed soil provided by the present invention can eliminate multiple soil barrier factors and / or improve soil moisture retention.

[0115] Although the above embodiment provides a detailed description of the present invention, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the scope of protection of the present invention.

Claims

1. A newly formed soil matrix, characterized in that: The composition comprises the following components in percentage by mass: 33% to 55% of strongly weathered rock soil, 20% to 30% of gravel-removed sandy soil, 15% to 30% of loess and 4% to 8% of organic fertilizer; The particle sizes of the strongly weathered rock soil, gravel-removed sandy soil and loess are respectively less than 15 mm.

2. The newly formed soil matrix according to claim 1, characterized in that The highly weathered rock and soil includes processed highly weathered rock and soil; The processing method comprises: performing soft rubbing and peeling and screening on the strongly weathered rock and soil.

3. The newly formed soil matrix according to claim 1, characterized in that The loess includes processed loess; the processing method includes: drying and sieving the loess in sequence.

4. The newly formed soil matrix according to claim 3, characterized in that After the drying, the moisture content of the loess is ≤8%.

5. The method for preparing the newly formed soil matrix according to any one of claims 1 to 4, characterized in that: The steps include: The newly formed soil matrix is obtained by mixing strongly weathered rock soil, gravel-removed sandy soil and loess, and then adding organic fertilizer and stirring.

6. The preparation method according to claim 5, characterized in that The preparation method further comprises adding water during the mixing process.

7. The preparation method according to claim 6, characterized in that The added amount of the water is 10% to 12% of the total mass of the strongly weathered rock soil, gravel-removed sandy soil, loess and organic fertilizer.

8. Use of the newly formed soil matrix according to any one of claims 1 to 4 or the newly formed soil matrix prepared according to any one of claims 5 to 7 in eliminating multiple soil barrier factors and / or improving soil moisture retention.

9. The use according to claim 8, characterized in that The soil includes yellow soil type barren arable land.

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