A soil conditioner, its preparation method and use
By using straw, anhydrous calcium chloride, and proanthocyanidins, a biological denitrification inhibitor, a granular soil conditioner was made, which solved the problems of acidification and nutrient loss in low- and medium-yield fields, achieving an environmentally friendly and efficient soil improvement effect and simplifying the preparation process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG ACADEMY OF AGRICULTURE SCIENCES
- Filing Date
- 2023-12-12
- Publication Date
- 2026-07-14
AI Technical Summary
Existing soil conditioners cannot effectively improve acidification, physical structure and nutrient loss in low- and medium-yield fields, and they also pose environmental pollution and complex preparation issues. Most existing products are high molecular polymers or contain urease inhibitors and nitrification inhibitors, which pose ecological risks and dust problems.
Using straw, anhydrous calcium chloride, and proanthocyanidins as the main components, the soil conditioner is made into granular soil conditioner by stirring and rolling. The addition of biological denitrification inhibitors inhibits the denitrification process, improves soil structure, and reduces nutrient loss.
It effectively alleviates soil acidification, increases organic matter content, promotes soil aggregate formation, reduces nitrate nitrogen loss, avoids dust, and achieves environmentally friendly and efficient soil improvement. Moreover, it is simple to prepare and low in cost.
Smart Images
Figure CN117682925B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of agricultural soil improvement technology, and in particular to a soil conditioner, its preparation method, and its application. Background Technology
[0002] Low- and medium-yield farmland commonly suffers from soil acidification, heavy clay soil, compaction, and low fertility. Developing soil improvement products can effectively improve soil properties in these fields, promoting increased crop yield and quality. Straw is a nutrient-rich, renewable organic resource, containing abundant cellulose, hemicellulose, lignin, protein, and other organic matter, as well as various trace elements such as nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, and silicon. Currently, the main method of straw resource utilization is straw return to the field as fertilizer, accounting for about 70%. When straw is returned to the field, it can be decomposed into humus by soil microorganisms, increasing soil organic carbon content, improving soil quality, and enhancing soil fertility. This is a simple, cost-effective, and efficient measure to return nutrients to the soil. However, returned straw can provide usable carbon sources for heterotrophic microorganisms such as those involved in denitrification and nitrate dissimilatory reduction to ammonium (DNRA), promoting their growth and metabolism, which in turn leads to a decrease in the content of available nitrogen components in the soil. It is evident that adopting a single method of returning straw to the field, such as straw crushing, burying in ditches, or returning straw pellets, will inevitably lead to the loss of available nitrogen nutrients in the soil. Therefore, it is necessary to make better use of straw resources to develop soil-reducing fertilizer products.
[0003] Currently, there are few soil conditioners on the market that can simultaneously improve acidification, physical structure, and reduce nutrient loss in low- and medium-yield fields. Among soil nutrient reduction products, most are nitrification inhibitors. For example, patent application CN110078557A discloses a fertilizer enhancer and its preparation method and application. It inhibits fertilizer nitrification by adding nitrification inhibitors. However, under straw return conditions, denitrification is enhanced, and the nitrate nitrogen content decreases significantly. Nitrification inhibitors further reduce the nitrate nitrogen content in the soil, which is not conducive to nutrient absorption by nitrate-loving dryland crops. Most existing soil conditioners are high-molecular-weight polymers, resulting in high production costs and complex manufacturing processes. They are also not easily biodegradable, posing potential ecological risks to the environment. To make soil conditioners more environmentally friendly, patent application CN112374950A discloses a nitrogen fertilizer synergist containing plant-derived denitrification inhibitors, its preparation method, and its application. The synergistic effect of adding urease inhibitors, nitrification inhibitors, and denitrification inhibitors comprehensively regulates soil nitrogen transformation. However, this solution includes urease and nitrification inhibitors, requiring complex processes to ensure its stability. Furthermore, existing soil conditioners are usually in powder form, which can easily generate dust and other environmental pollution problems during application. Summary of the Invention
[0004] To address the aforementioned technical problems, one objective of this invention is to provide a multifunctional soil conditioner capable of simultaneously improving acidification, physical structure, and nutrient loss in low- and medium-yield fields. Another objective is to provide a method for preparing the aforementioned soil conditioner. A third objective is to provide an application of the aforementioned soil conditioner.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] A soil conditioner, comprising the following raw material components in parts by weight:
[0007] 65-70 parts straw, 25-30 parts silica, 2.5-4.9 parts anhydrous calcium chloride, and 0.1-0.5 parts biological denitrification inhibitor.
[0008] Preferably, the straw is rice, corn, or wheat straw, and the moisture content of the straw is 30% to 35%.
[0009] Preferably, the biological denitrification inhibitor is proanthocyanidin.
[0010] Proanthocyanidins are a class of polyphenolic compounds, including catechins, epicatechins, and dimers, trimers, tetramers to decamers formed by catechins and epicatechins. As a type of polyphenolic compound, they can significantly inhibit the metabolic activity of denitrifying bacteria, effectively suppress the soil denitrification process, and reduce the loss of nitrate nitrogen in the soil. They are a safe, green, and efficient denitrification inhibitor derived from plants.
[0011] A method for preparing a soil conditioner as described above includes the following steps:
[0012] (1) Add 65 to 70 parts of straw to the automatic blender and blend for 30 to 45 minutes. After the temperature of the straw pile rises to 60°C, continue blending for 10 to 15 minutes.
[0013] (2) Add 25-30 parts of silicon dioxide and continue stirring for 20-30 minutes until completely mixed;
[0014] (3) Add 0.1 to 0.5 parts of biological denitrification inhibitor and stir for 10 to 20 minutes until completely mixed;
[0015] (4) Add 2.5 to 4.9 parts of anhydrous calcium chloride and stir until completely mixed to obtain a mixture;
[0016] (5) The mixture obtained in (4) is conveyed to a roller press by a conveyor belt for granulation to obtain the soil conditioner.
[0017] This preparation method enables the raw materials of the soil conditioner to be fully mixed and cross-linked, and effectively kills pathogenic microorganisms in straw, maximizing the synergistic effect.
[0018] Preferably, the mixing speed of the mixer is 200-400 rpm during the process of shredding straw and mixing raw materials for soil conditioner.
[0019] Preferably, in step (5), the roller press has a roller pressing efficiency of 60-150 kg / hour, and the roller pressing granulation yields particles with a diameter of 1-5 mm and a length of 2-3 cm, which are the soil conditioner.
[0020] Application of a soil conditioner as described above in soil improvement.
[0021] Preferably, the soil is arable land soil with a pH below 5.0 and an organic matter content below 3%. Applying the aforementioned soil conditioner based on straw and biological denitrification inhibitors to improve low- and medium-yield farmland soils allows the improved soil to better resist external damage and dispersion, effectively alleviating problems such as acidification and soil nutrient loss.
[0022] Preferably, the soil conditioner is applied evenly to a depth of 10-30 cm below the soil surface to complete the soil improvement.
[0023] Preferably, the application rate of the soil conditioner is 1500-2000 kg / mu.
[0024] The present invention, by adopting the above technical solution, has the following beneficial effects:
[0025] 1. The soil conditioner provided by this invention is a multifunctional soil conditioner based on straw and biological denitrification inhibitors. First, it can alleviate soil acidification and increase soil organic matter; second, it can promote the formation of soil aggregates and improve the structural stability of soil; third, it can reduce the loss of available nitrogen components in the soil, especially the loss of nitrate nitrogen, which is beneficial to the growth of dryland crops.
[0026] 2. The soil conditioner provided by this invention uses straw as the main raw material. After stirring and rolling, it is made into granules. Compared with most powdered soil conditioners, it avoids environmental pollution problems such as dust when applied. It is easier to directly improve the obstacles in the topsoil layer or even deeper soil layers through deep application. It is more conducive to the formation of soil aggregates and effectively improves the soil pore structure.
[0027] 3. The soil conditioner provided by this invention uses crop straw as raw material. After stirring and rolling, it is made into granules, which greatly compresses the straw volume, increases the straw density, and increases the soil's absorbability. Especially for newly reclaimed land or barren land, applying the soil conditioner once can improve the land and realize the resource reuse of crop straw. Moreover, the soil conditioner is easily biodegradable, meeting the requirements of green environmental protection.
[0028] 4. The soil conditioner provided by this invention, by adding proanthocyanidins, a biological denitrification inhibitor, can effectively solve the problem of nutrient loss caused by the decrease in nitrate nitrogen content due to the increase in soil organic matter and the promotion of soil denitrification process. In the process of soil improvement, it can maintain the content of soil organic carbon and available nitrogen components very well.
[0029] 5. The preparation method of the soil conditioner provided by the present invention has a simple production process, is easy to operate, and has a low preparation cost. Attached Figure Description
[0030] Figure 1 The graph shows the effect of the soil conditioner prepared in Examples 1-9 on soil pH after application.
[0031] Figure 2 The graph shows the effect of the soil conditioners prepared in Examples 1-9 on the soil organic carbon content after application.
[0032] Figure 3 The graph shows the effect of the soil conditioners prepared in Examples 1-9 on the content of available nitrogen in the soil after application.
[0033] Figure 4 The graph shows the effect of the soil conditioner prepared in Examples 1-9 on the average weight diameter of soil aggregates after application. Detailed Implementation
[0034] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions or as recommended by the manufacturer.
[0035] Example 1: A soil conditioner, comprising the following raw material components by weight:
[0036] 69.8 parts straw, 27.5 parts silicon dioxide, 2.5 parts anhydrous calcium chloride, and 0.2 parts proanthocyanidins.
[0037] Example 2: A soil conditioner, comprising the following raw material components by weight:
[0038] 67.8 parts straw, 29.5 parts silicon dioxide, 2.5 parts anhydrous calcium chloride, and 0.2 parts proanthocyanidins.
[0039] Example 3: A soil conditioner, comprising the following raw material components by weight:
[0040] 65.8 parts straw, 31.5 parts silicon dioxide, 2.5 parts anhydrous calcium chloride, and 0.2 parts proanthocyanidins.
[0041] Example 4: A soil conditioner, comprising the following raw material components by weight:
[0042] 69.9 parts straw, 26.5 parts silicon dioxide, 3.5 parts anhydrous calcium chloride, and 0.1 parts proanthocyanidins.
[0043] Example 5: A soil conditioner, comprising the following raw material components by weight:
[0044] 67.9 parts straw, 28.5 parts silicon dioxide, 3.5 parts anhydrous calcium chloride, and 0.1 parts proanthocyanidins.
[0045] Example 6: A soil conditioner, comprising the following raw material components by weight:
[0046] 65.9 parts straw, 30.5 parts silicon dioxide, 3.5 parts anhydrous calcium chloride, and 0.1 parts proanthocyanidins.
[0047] Example 7: A soil conditioner, comprising the following raw material components by weight:
[0048] 69.7 parts straw, 25.5 parts silicon dioxide, 4.5 parts anhydrous calcium chloride, and 0.3 parts proanthocyanidins.
[0049] Example 8: A soil conditioner, comprising the following raw material components by weight:
[0050] 67.7 parts straw, 27.5 parts silicon dioxide, 4.5 parts anhydrous calcium chloride, and 0.3 parts proanthocyanidins.
[0051] Example 9: A soil conditioner, comprising the following raw material components by weight:
[0052] 65.7 parts straw, 29.5 parts silicon dioxide, 4.5 parts anhydrous calcium chloride, and 0.3 parts proanthocyanidins.
[0053] In Examples 1-9, the straw is rice straw with a moisture content of 35%, and the proanthocyanidins, silica, and anhydrous calcium chloride are commercially available proanthocyanidins, silica, and anhydrous calcium chloride. The commercial proanthocyanidins have a mesh size of 120-80 mesh and a purity of over 90%, while the commercial silica and anhydrous calcium chloride both have a purity of over 85%.
[0054] Soil conditioners were prepared according to the raw material components of Examples 1-9 above. The preparation process for the above nine examples is the same, and the preparation process includes the following steps:
[0055] (1) Add the corresponding amount of straw to the automatic mixer and mix for 30 to 45 minutes. After the temperature of the straw pile rises to 60°C, continue mixing for 10 to 15 minutes.
[0056] (2) Add the corresponding amount of silicon dioxide and continue stirring for 20 to 30 minutes until completely mixed;
[0057] (3) Add the corresponding amount of biological denitrification inhibitor and stir for 10-20 minutes until completely mixed;
[0058] (4) Add the corresponding amount of initiator anhydrous calcium chloride, stir until completely mixed, and obtain a mixture;
[0059] (5) The mixture obtained in (4) is conveyed to a roller press by a conveyor belt for granulation to obtain the corresponding soil conditioner.
[0060] Performance tests of the soil conditioners described in Examples 1 to 9:
[0061] I. Experiments on the effects of the soil conditioners prepared in Examples 1-9 on alleviating acidified soil and reducing fertilization loss in pot simulation experiments.
[0062] Experimental method: Nine plastic pots with a height of 42.0 cm, an outer diameter of 28.0 cm, an inner diameter of 25.7 cm, and a bottom diameter of 20.0 cm were selected. Each pot was filled with 12.73 kg of soil from the 0-20 cm layer, 6.84 kg of soil from the 20-40 cm layer, and 1.53 kg of soil from the 40-60 cm layer. Here, the 0-20 cm soil refers to the soil taken from the 0-20 cm soil layer of the land to be improved, the 20-40 cm soil refers to the soil taken from the 20-40 cm soil layer of the land to be improved, and the 40-60 cm soil refers to the soil taken from the 40-60 cm soil layer of the land to be improved. After adjusting the soil moisture content to 20%, 160g of each of the soil conditioner sample particles prepared in Examples 1 to 9 were taken and evenly applied to a depth of 15-20cm below the topsoil for cultivation. Soil samples from 0-20cm were taken after 120 days, and the soil pH, organic carbon content and available nitrogen content of the soil samples after applying the soil conditioners in Examples 1 to 9 were measured.
[0063] II. Experiment on the structural improvement effect of the soil conditioners prepared in Examples 1-9 on acidified soil in a pot simulation experiment.
[0064] The experimental method was as follows: Nine plastic pots with a height of 42.0 cm, an outer diameter of 28.0 cm, an inner diameter of 25.7 cm, and a bottom diameter of 20.0 cm were selected. Each pot was filled with 12.73 kg of soil from the 0-20 cm layer, 6.84 kg of soil from the 20-40 cm layer, and 1.53 kg of soil from the 40-60 cm layer. Here, the 0-20 cm soil refers to the soil taken from the 0-20 cm soil layer of the land to be improved, the 20-40 cm soil refers to the soil taken from the 20-40 cm soil layer of the land to be improved, and the 40-60 cm soil refers to the soil taken from the 40-60 cm soil layer of the land to be improved. After adjusting the soil moisture content to 20%, 160g of each of the soil conditioner sample particles prepared in Examples 1 to 9 were taken and evenly applied to a depth of 15-20cm below the surface soil for cultivation. At 120 days, a sample of the bulk density of the surface soil was taken using a ring cutter. The soil sample in the ring cutter was then sieved into grades with a certain particle size. The soil aggregates in each grade were weighed, and the average weight diameter of the soil aggregates was calculated.
[0065] The experimental results of the above experiment are shown in Table 1 below:
[0066] Table 1. Improvement of acidified soil by different soil conditioners
[0067]
[0068] According to Table 1 and Figures 1 to 4It can be seen that the soil conditioners obtained in Examples 1-9 can increase the soil pH by 2 units from 4.9 to 6.9-7.1, and at the same time increase the soil organic matter content from 9.2 g / kg to 12.9-13.7 g / kg, with Examples 7, 8, and 9 showing the highest values. Except for Examples 4, 5, and 6, the other examples can significantly increase the content of available nitrogen in the soil, with an increase of 44%-67%, which is mainly related to the ratio of proanthocyanidins, the biological denitrification inhibitors in the formula. When the proanthocyanidin content is less than 0.2 parts, the effect on soil nutrient reduction is generally weak, and the effect on increasing soil organic matter content is also weakened.
[0069] Examples 1-9 can all effectively increase the average weight diameter of soil aggregates by 16.6% to 22.6%, with Examples 7, 8, and 9 showing the largest increases. This is related to the high proportion of proanthocyanidins in the formulation. Since proanthocyanidins can effectively inhibit soil denitrification, they can reduce the decomposition of organic carbon caused by the denitrification process. Therefore, they can effectively increase the average weight diameter of soil aggregates, which is beneficial to the improvement of soil physical properties.
[0070] III. The soil conditioner obtained in Example 7 was applied in the field to determine its effects on soil pH, nutrients, average weight diameter of aggregates, and crop yield.
[0071] Experimental groups: CK was the soil sample without soil conditioner, serving as the control group; M1 was the soil sample with 1000 kg / mu of soil conditioner; M2 was the soil sample with 2000 kg / mu of soil conditioner; M3 was the soil sample with 5000 kg / mu of soil conditioner; M4 was commercially available soil conditioner 1, whose main components were oyster shells and anhydrous calcium chloride; M5 was commercially available soil conditioner 2, whose main components were oyster shells, calcium silicate minerals, and humic acid-containing organic fertilizer. For soil conditioners M1-M3, the soil conditioners were evenly applied to a soil depth of 15-20 cm, followed by routine field corn fertilization, sowing, and pest and disease control management. For soil conditioners M4 and M5, the soil conditioners were applied by spreading on the soil surface and then tilling to a depth of 15-20 cm. According to the product instructions, the application rate for soil conditioners in M4 and M5 was 350 kg / mu, and other management practices were the same as for M1, M2, and M3.
[0072] Experimental methods: After the corn harvest, soil samples were collected from the 0-20cm soil layer using a soil auger, and the contents of soil pH, exchangeable acid, organic carbon, and available nitrogen were measured. The bulk density of the topsoil was collected using a ring cutter, and the average weight and diameter of soil aggregates were measured. The fresh weight of corn within a certain area was weighed.
[0073] The experimental results of the above experiment are shown in Table 2 below.
[0074] Table 2. Statistical results of soil properties and maize yield after field application of soil samples with different treatments.
[0075]
[0076] Table 2 shows that soil pH, nutrient content, average weight diameter of soil aggregates, and maize yield were significantly improved and increased with the addition of this multifunctional soil conditioner. Furthermore, the soil improvement effect increased with the application rate of the soil conditioner. Among the treatments, M2 showed the highest maize yield, increasing by 74% compared to the control (CK) treatment, 57% compared to M4, and 42% compared to M5. There were no significant differences in soil properties between the M2 and M3 treatments. Considering practical application costs, a soil conditioner application rate of 2000 kg / mu (approximately 1333 kg / acre) is recommended for optimal results in the field.
[0077] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.
Claims
1. A soil conditioner, characterized in that: The raw material components are included in parts by weight as follows: The mixture contains 65-70 parts straw, 25-30 parts silica, 2.5-4.9 parts anhydrous calcium chloride, and 0.1-0.5 parts biological denitrification inhibitor; wherein the straw is rice, corn, or wheat straw, and the moisture content of the straw is 30%-35%; the biological denitrification inhibitor is proanthocyanidins. The preparation method includes the following steps: (1) Add 65-70 parts of straw to the automatic blender and blend for 30-45 minutes. After the temperature of the straw pile rises to 60℃, continue blending for 10-15 minutes. (2) Add 25-30 parts of silica and continue stirring for 20-30 minutes until completely mixed; (3) Add 0.1~0.5 parts of biological denitrification inhibitor and stir for 10~20 minutes until completely mixed; (4) Add 2.5 to 4.9 parts of anhydrous calcium chloride and stir until completely mixed to obtain a mixture; (5) The mixture obtained in (4) is conveyed to a roller press for granulation via a conveyor belt to obtain the soil conditioner.
2. The soil conditioner according to claim 1, characterized in that, During the process of using a mixer to shred straw and mix raw materials for soil conditioner, the mixing speed of the mixer is 200-400 rpm.
3. The soil conditioner according to claim 1, characterized in that, In step (5), the roller press has a roller pressing efficiency of 60-150 kg / hour, and the roller pressing granulation yields particles with a diameter of 1-5 mm and a length of 2-3 cm, which are the soil conditioner.
4. The application of a soil conditioner as described in any one of claims 1-3 in soil improvement.
5. The application of the soil conditioner according to claim 4 in soil improvement, characterized in that, The soil in question is arable land soil with a pH below 5.0 and an organic matter content below 3%.
6. The application of the soil conditioner according to claim 5 in soil improvement, characterized in that, The soil conditioner is evenly applied to a depth of 10-30 cm below the soil surface to complete the soil improvement.
7. The application of the soil conditioner according to claim 6 in soil improvement, characterized in that, The application rate of the soil conditioner is 1000–5000 kg / mu.