Application of a soil conditioner to improve planting millet in coastal plain saline soil

Abstract

The application discloses application of a soil improver in improving planting millet in coastal plain saline soil. The soil improver is prepared by the following method: ploughing land, mixing soil and excrement and straw, piling on the ploughed land to carry out fermentation, and obtaining the soil improver after the fermentation is finished; the improving method is ploughing the land again to uniformly mix the soil improver with the soil. The mass ratio of the soil and the excrement and the straw is 1:1; the straw is wheat straw. The total application amount of the excrement and the straw is 50-200 kg per mu. The excrement and the straw are fermented together, the fermentation product is used as the soil improver to improve the coastal plain saline soil and plant millet, the yield of the millet planted in the coastal plain saline soil can be improved, and the pH and the total salt content of the coastal plain saline soil can be reduced.

Description

Technical Field

[0001] This invention relates to the field of saline-alkali land improvement technology, specifically to the application of a soil conditioner in improving millet cultivation in saline soil of coastal plains. Background Technology

[0002] The formation of saline-alkali soil is essentially a redistribution of soluble salts in the soil, with salt accumulation in the topsoil exceeding normal levels. Slightly saline soil has a salt content of 0.1%–0.2%; moderately saline soil has a salt content of 0.2%–0.4%; and severely saline soil has a salt content of 0.4%–0.6%. Furthermore, based on their formation, saline-alkali land is further classified as follows: naturally formed saline-alkali land in coastal areas (primarily sodium chloride, mainly distributed along the coast); saline-alkali land formed by groundwater in inland areas (primarily sodium sulfate); soda saline-alkali land (primarily sodium carbonate and sodium bicarbonate); and anthropogenic saline-alkali land, including secondary salinization caused by excessive application of chemical fertilizers leading to soil compaction and decreased fertility.

[0003] Currently, the main methods for improving saline-alkali land include: 1. Irrigation and salt leaching: repeatedly flushing and removing salt from the soil to reduce its salinity; 2. Planting salt-tolerant crops; 3. Increasing organic matter application: organic fertilizer increases soil organic matter, promotes soil aeration and looseness, and regulates soil pH. Crushed or decomposed straw, combined with deep plowing, can improve soil aeration and looseness. Increasing organic matter application is primarily used to regulate soil pH and increase soil nutrients. However, for saline-alkali land, in addition to reducing pH, it is also necessary to reduce salt content to allow crops to grow. Increasing organic matter application is feasible for rice cultivation in saline-alkali land. Rice is more tolerant of saline-alkali soil than other grain crops, and through prolonged irrigation and frequent drainage, the salt in the soil will be continuously diluted and removed. While millet exhibits some salt tolerance, it can only grow in low salt concentrations. Growth is limited when salt concentrations reach 1-2%, and significantly restricted when concentrations exceed 2%. The study "The Influence of Different Fertilization Patterns on Soil Improvement and Millet Growth in Saline-Alkali Land" (Han Fei et al., Soil Bulletin, August 2020, Vol. 51, No. 4) noted that organic fertilizer substitution significantly increased millet yield, reduced total soil salt content, and decreased pH compared to conventional fertilization. However, its improvement effect on saline-alkali soil was limited, with total salt content decreasing by only 4.74% and pH by only 2.32% compared to the control (CK). Therefore, further improvement is needed for saline soils in coastal plains. Summary of the Invention

[0004] In view of the above-mentioned prior art, the purpose of this invention is to provide a soil conditioner for improving millet cultivation in saline soils of coastal plains. This invention utilizes the co-fermentation of earthworm manure and straw, and uses the fermentation products as a soil conditioner to improve saline soils in coastal plains for millet cultivation. This can increase millet yield in saline soils of coastal plains and reduce the pH and total salt content of the saline soils.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides an application of a soil conditioner in improving millet cultivation in saline soils of coastal plains, wherein the soil conditioner is prepared by the following method:

[0007] Till the land, mix the earthworm manure and straw, pile them on the tilled land for fermentation, and obtain a soil conditioner after fermentation;

[0008] The improvement involves tilling the land again to ensure the soil conditioner is evenly mixed with the soil.

[0009] Preferably, the depth of tilling is 0-20cm; the depth of the second tilling is 0-20cm.

[0010] Preferably, the mass ratio of the earthworm excrement to the straw is 1:1; the straw is wheat straw.

[0011] Preferably, the straw is crushed to a length of no more than 1 cm.

[0012] Preferably, the fermentation involves mixing earthworms with straw, adjusting the moisture content to 50-70 wt%, and then evenly spreading the mixture onto the tilled land for natural fermentation.

[0013] Preferably, the fermentation time is 7-15 days, and the pile is turned over every two days.

[0014] Preferably, the total salt content of the coastal plain saline soil is 0.1-0.3%.

[0015] Preferably, the total amount of earthworm manure and straw applied is 50~200 kg / mu.

[0016] Preferably, the improvement increases millet yield and reduces the pH and total salt content of saline soils in coastal plains.

[0017] Preferably, the row spacing of the millet is 40cm; the millet sowing rate is 1.0 kg / mu.

[0018] The beneficial effects of this invention are:

[0019] (1) This invention prepares a soil conditioner by mixing and fermenting earthworm manure with straw on cultivated land. The soil conditioner is then plowed into the soil, which not only reduces the pH and total salt content of the saline soil in the coastal plain, but also increases the yield of millet, which is 22% higher than that of millet grown in the saline soil of the coastal plain.

[0020] (2) The preparation of the improver of the present invention is simple. It only requires spreading earthworm manure and straw on the saline soil of the coastal plain for natural fermentation. The improvement of pH and total salt content of the saline soil of the coastal plain is significantly higher than that of using finished organic fertilizer. Attached Figure Description

[0021] Figure 1 Photos of the ears of grain, stems, and roots of each treatment group. Detailed Implementation

[0022] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0023] As described in the background section, although millet has a certain degree of salt and alkali tolerance, it can only grow in low salt concentrations. When the salt concentration reaches 1-2%, the growth of millet will be limited, and when the salt concentration is above 2%, the growth of millet will be significantly restricted.

[0024] Based on this, the purpose of this invention is to provide a soil conditioner for improving the cultivation of millet in saline soils of coastal plains. In researching millet-soybean intercropping (see patent application CN2024114887809, "A Method for Strip Intercropping of Millet and Soybean"), this invention uses fermented earthworm manure and soybean straw to increase intercropping yield, reduce weed growth, and mitigate crop pests and diseases. During this research, it was unexpectedly discovered that fermenting earthworm manure and soybean straw can act as a conditioner, improving the pH and total salt content of saline soils in coastal plains. Therefore, further research revealed that mixing earthworm manure and wheat straw in a 1:1 mass ratio yields even better results. The microorganisms produced by the fermentation of earthworm manure and wheat straw, once introduced into the soil, can improve soil structure, increase organic matter, and promote salt degradation. Wheat straw also has the effect of improving saline-alkali soils; therefore, this invention improves saline soils in coastal plains through multiple mechanisms.

[0025] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be described in detail below with reference to specific embodiments.

[0026] The test materials used in the embodiments of this invention are all conventional test materials in the art and can be purchased through commercial channels.

[0027] Example

[0028] Mix 100 kg of earthworm manure and 100 kg of wheat straw (<1 cm thick) evenly, then spray with water to achieve a moisture content of 70%. Spread the total mass of earthworm manure and wheat straw at 200 kg / mu evenly on the land to be cultivated, cover with plastic film and ferment for 10 days, turning over every two days to obtain a soil conditioner. Spread evenly on the land to be cultivated and till to a depth of 20 cm.

[0029] Comparative Example 1

[0030] The difference from the previous example is that no wheat straw was added, resulting in a soil conditioner. The land was then tilled again to ensure the soil conditioner was evenly mixed with the soil, at a depth of 20cm.

[0031] Comparative Example 2

[0032] The difference from the previous example is that no soil insect manure was added, resulting in a soil conditioner. The land was then tilled again to ensure the soil conditioner was evenly mixed with the soil, with a tilling depth of 20cm.

[0033] Comparative Example 3

[0034] Commercially available sheep manure organic fertilizer (purchased from Shijiazhuang Wofuwo Fertilizer Co., Ltd.) was used as a soil conditioner, spread evenly at a rate of 200 kg / mu on the land to be cultivated, and then tilled to a depth of 20 cm. Commercially available sheep manure organic fertilizer is already fermented and can be used directly as a soil conditioner.

[0035] Comparative Example 4

[0036] The difference from the previous example is that commercially available sheep manure organic fertilizer (purchased from Shijiazhuang Wofuwo Fertilizer Co., Ltd.) was used in equal amounts to replace the earthworm manure, resulting in a soil conditioner. The land was then tilled again to ensure the soil conditioner was evenly mixed with the soil, with a tilling depth of 20cm.

[0037] Experimental example: Pot experiment

[0038] A pot experiment was conducted in November 2023. The millet variety used was Jigu 42. The potting soil was prepared by adding NaCl and NaCO3 to simulate saline soil, achieving a total salt content of 0.3%, a pH of 7.70, and an organic matter content of 6.0 g / kg. Soil density was measured using the ring sampler method, and the amount of soil conditioner added was calculated. The experiment was divided into six groups: a control group (CK) without soil conditioner; the example group (0.4 g / kg of the prepared conditioner from the example was added to the potting soil); Comparative Example 1 (0.2 g / kg of the prepared conditioner from Comparative Example 1 was added to the potting soil); Comparative Example 2 (0.2 g / kg of the prepared conditioner from Comparative Example 2 was added to the potting soil); Comparative Example 3 (0.4 g / kg of the prepared conditioner from Comparative Example 3 was added to the potting soil); and Comparative Example 4 (0.4 g / kg of the prepared conditioner from Comparative Example 4 was added to the potting soil). Each group consisted of 20 pots, with one plant per pot. All groups underwent the same routine management, without the use of additional pesticides or fertilizers. During the millet's maturity period, five pots of uniformly growing millet were randomly selected from each group, and their plant height, stem diameter, and leaf area were measured using a steel ruler, with the average values ​​calculated. After maturity, the millet was harvested and threshed, weighed, and the average grain weight per plant was calculated. The results are shown in Table 1. Photos of the millet ears, stems, and roots were taken. Figure 1 After the millet was harvested, the pH, total salt content, and organic matter content of the soil in each pot were measured; and the change rates of soil pH, total salt content, and organic matter before the addition of the soil conditioner and after the millet harvest were calculated. The average values ​​of the results are shown in Table 2.

[0039] Soil samples were collected from potted plants, air-dried, and sieved. The soil pH was determined using a 2.5:1 water-to-soil ratio and a CO2-free water extraction-pH meter method. The soil organic matter content was determined using the potassium dichromate volumetric method with external heating. The soil soluble salt content was determined using a 5:1 water-to-soil ratio and a CO2-free water extraction-drying residue gravimetric method.

[0040] Table 1

[0041]

[0042] According to Table 1 and Figure 1 It can be seen that the plant height, stem diameter, and leaf area of ​​the Example Group were significantly greater than those of the CK Group and Comparative Examples 1-3, and the grain weight per plant was also significantly higher than that of the CK Group. Since millet does not tiller under saline-alkali conditions, each plant produces only one ear of grain, and the grain weight per plant equals the total grain weight per ear. It can be seen that the millet in the Example Group has a well-developed root system, with longer roots than the CK and Comparative Examples 1-4, the thickest stems, and fuller ears of grain. The plant height, stem diameter, leaf area, and yield of the Example Group were also higher than those of Comparative Example 4, indicating that the soil improvement effect of this invention using earthworm manure and wheat straw fermentation is better than that of finished organic fertilizer + straw.

[0043] Table 2

[0044]

[0045] As shown in Table 2, the pH and total salt content of the Example Group were significantly lower than those of the CK Group, while the organic matter content was significantly higher. It can be seen that the organic matter content decreased in the CK Group before and after the addition of the soil conditioner, while it increased in the Example Group. Although the decrease in organic matter is related to the planting of millet, some of the soil conditioners in the Example Group and Comparative Examples 1, 3, and 4 contained fermented organic fertilizer. The microorganisms produced during fermentation can improve soil structure, increase organic matter, and promote salt degradation; however, due to the limitations of pot cultivation, the increase in soil organic matter content was limited. Compared with Comparative Examples 1-4, the Example Group showed a greater decrease in pH and total salt content, and a greater increase in organic matter content.

[0046] Experimental Example 2: Field Experiment

[0047] On June 18, 2024, millet was planted in Beishangzhuang Village, Nandagang Industrial Park, Huanghua City, using the Jigu 42 variety. The soil characteristics in this area were as follows: 0-20cm soil had a total salt content of 0.285%, pH of 7.74, and organic matter content of 5.61 g / kg; 20-40cm soil had a total salt content of 0.288%, pH of 7.81, and organic matter content of 5.51 g / kg. The row spacing for millet was 40cm, and the sowing rate was 1.0 kg / mu. The experiment was divided into 6 groups: a control group (CK) without soil amendment, an example group, and comparative groups 1-4, with each group having an experimental area of ​​10m × 10m. All groups underwent the same routine management, without the use of additional pesticides or fertilizers. Before adding the soil amendment, soil samples were taken from 10 points in each group to test the soil pH, total salt content, and organic matter content. After the millet was harvested, soil samples were taken from the same location to test the soil pH, total salt content, and organic matter content. The dry weight of the millet produced in each group was weighed and the yield was calculated. The results are shown in Table 3.

[0048] pH change rate = (soil pH before amendment addition - soil pH after millet harvest) / soil pH before amendment addition × 100%;

[0049] Total salt change rate = (Total salt content of soil before amendment addition - Total salt content of soil after millet harvest) / Total salt content of soil before amendment addition × 100%;

[0050] Organic matter change rate = (soil organic matter content after millet harvest - soil organic matter content before amendment addition) / soil organic matter content before amendment addition × 100%.

[0051] Soil samples were collected from 0–20 cm and 20–40 cm depths, air-dried, and sieved. The soil pH was determined using a 2.5:1 water-to-soil ratio and a CO2-free water extraction-pH meter method. The soil organic matter content was determined using the potassium dichromate volumetric method with external heating. The soil soluble salt content was determined using a 5:1 water-to-soil ratio and a CO2-free water extraction-drying residue gravimetric method.

[0052] Table 3

[0053]

[0054] Table 4

[0055]

[0056] As shown in Tables 3 and 4, the yield of the Example Group was approximately 22% higher than that of the CK Group. The pH and total salt content of the Example Group were significantly lower than those of the CK Group, while the organic matter content was significantly higher.

[0057] In the pot experiment of Example 1, the rate of change in total salt content and organic matter content in each group was not as high as that in the field experiment of Example 2, but the rate of pH decrease was significantly higher than that in Example 2. However, overall, it can be seen that the present invention, by fermenting earthworm manure and straw, can significantly increase the yield of millet planted in saline-alkali land, reduce H and total salt content, and increase organic matter content.

[0058] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. The application of a soil conditioner in improving millet cultivation in saline soil of coastal plains, characterized in that, The soil conditioner is prepared by the following method: Till the land, mix the earthworm manure and straw, pile them on the tilled land for fermentation, and obtain a soil conditioner after fermentation; The improvement method is to till the land again to mix the soil conditioner evenly with the soil. The mass ratio of the earthworm excrement to the straw is 1:1; the straw is wheat straw. The fermentation process involves mixing earthworm manure with straw, adjusting the moisture content to 50-70 wt%, and then evenly spreading the mixture onto the tilled land for natural fermentation.

2. The application according to claim 1, characterized in that, The depth of tilling is 0-20cm; the depth of the second tilling is 0-20cm.

3. The application according to claim 1, characterized in that, The straw is shredded to a length of no more than 1 cm.

4. The application according to claim 1, characterized in that, The fermentation time is 7-15 days, and the pile is turned over every two days.

5. The application according to claim 1, characterized in that, The total salt content of the saline soil in the coastal plain is 0.1-0.3%.

6. The application according to claim 1, characterized in that, The total amount of earthworm manure and straw applied is 50~200 kg / mu.

7. The application according to claim 1, characterized in that, The improvements increased millet yield and reduced the pH and total salt content of saline soils in coastal plains.

8. The application according to claim 1, characterized in that, The row spacing of the millet is 40cm; the millet sowing rate is 1.0 kg / mu.

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