A method for applying biogas slurry coated straw compressed pellets to dry farming agriculture in black soil region

Abstract

The application discloses a kind of black soil region dry farming agricultural biogas slurry encapsulated straw compressed granule's fertilization method, carbon content 42.69% of straw compressed granule is mixed with nitrogen content 1.036g / L of biogas slurry, and it is mixed after half an hour of standing and fully coupled fermentation, and biogas slurry dosage is 6.67L / m 2 , straw granule dosage is 2.2kg / m 2 . Soil is ploughed when adding above-mentioned biogas slurry encapsulated straw compressed granule, while appropriate liquid supplement in crop growth period.The application reasonably utilizes straw compressed granule and biogas slurry, not only solve the problem that traditional straw is returned to field and causes soil run-off, ploughing is difficult, straw is slow to rot, and is prone to disease and pest problems, but also can improve biogas slurry nutrient use efficiency.In addition, the application avoids the problem of air pollution caused by straw burning, and improves soil moisture condition, prevents soil desertification and soil hardening, promotes the synergistic promotion of soil productivity and ecological benefit in black soil region.

Description

Technical Field

[0001] This invention belongs to the field of black soil protection technology, and specifically relates to a fertilization method for encapsulating straw compressed granules with biogas slurry in dryland agriculture in black soil areas. Background Technology

[0002] Soil fertility is the foundation and crucial guarantee for bumper grain yields, and fertilizers are often referred to as the "food of grains." Fertilization not only increases crop yields but is also a vital way to improve soil fertility. Statistics show that 40% of my country's grain output comes from increased production through chemical fertilizers, with nitrogen fertilizer being the most produced and consumed type. Behind the continuous increase in grain production lies the ever-increasing consumption of chemical fertilizers. Long-term application of chemical fertilizers causes a series of damages to the soil, such as soil structure destruction, compaction, acidification, nutrient imbalance, and heavy metal contamination. Improving fertilizer utilization efficiency is an urgent problem to be solved.

[0003] As a major agricultural country, my country produces a large amount of straw every year. Returning straw to the field is an important utilization method and a crucial measure for sustainable agricultural development. Straw is mainly composed of lignin, cellulose, and hemicellulose, with high carbon and nitrogen content and low moisture content. This results in slow straw decomposition, affecting the sowing and growth of the next season's crops, becoming a technical bottleneck restricting the widespread application of straw return. While improved straw pellets can be prepared for straw return, the effect of returning straw pellets alone is limited. Even after returning straw pellets, some straw still decomposes incompletely, leading to difficulties in crop germination and growth, thus affecting crop yield. Furthermore, due to years of cultivation, soil fertility in large areas of black soil regions has significantly declined. Although directly returning crop straw to the field is an effective way to accelerate the fertilization of infertile soils, the extremely loose density of crop straw, far lower than that of soil, makes it difficult to achieve effective straw return in the field. Crushing crop straw and covering it with topsoil has limited effect on soil fertilization and affects tillage and crop root development.

[0004] my country has increasingly focused on the role of biogas slurry in sustainable agricultural development and has established a systematic system for producing high-quality biogas slurry. However, the effectiveness of returning biogas slurry to the field has not been ideal. On the one hand, nutrients in biogas slurry are easily volatile and difficult for plants to absorb and utilize, resulting in low nutrient utilization rates. On the other hand, if the components in biogas slurry are not fully fermented, they can alter the soil's organic structure and affect crop respiration, leading to reduced yields. Currently, there is a lack of systematic research, both domestically and internationally, on the application methods, appropriate dosages, and concentrations of biogas slurry and straw in the synergistic return of biogas slurry to the field, and its impact on soil environmental quality and crop yield remains unclear.

[0005] This invention discloses a fertilization method for dryland agriculture in black soil regions, which involves encapsulating straw compressed pellets with biogas slurry. The method uses straw compressed pellets with good return-to-field effects, soaks them in biogas slurry, and applies the solution to the farmland before planting crops. This fertilization method significantly increases crop yields, not only solving the problem of crop straw utilization but also improving soil physicochemical properties, enhancing soil fertility, and increasing crop output. Summary of the Invention

[0006] Straw contains a large amount of nutrients needed for crop growth. Currently, the most common way to utilize straw is by returning it to the field to increase soil organic matter and nutrient content. However, in practice, untreated straw decomposes slowly, hindering crop germination and growth. At the same time, straw alone has a high carbon-nitrogen ratio or carbon-phosphorus ratio, which may lead to competition for nutrients between crops and microorganisms, resulting in a nitrogen-phosphorus imbalance. Therefore, applying biogas slurry after soaking straw can effectively solve the above-mentioned carbon-nitrogen-phosphorus imbalance problem, and can also address the issues of large volume, low density, low soil absorbability, inconvenient application, and low nutrient release rate associated with conventional straw return to the field. Furthermore, when straw particles and biogas slurry are fully fermented, the biogas slurry contains various microorganisms and abundant nitrogenous substances. This allows for synergistic treatment of the biogas slurry and straw. The microorganisms in the biogas slurry promote straw degradation, shortening the decomposition time of straw particles, and the nitrogenous substances in the biogas slurry can also serve as a nitrogen source to regulate the carbon-nitrogen ratio of straw, alleviating the need for additional nitrogen fertilizer when returning straw particles to the field.

[0007] Based on the above analysis, the present invention provides a fertilization method that involves compressing crop straw into pellets, soaking it in biogas slurry, and then returning it to the field, thus solving the problems of difficult straw treatment and low nutrient utilization efficiency of straw and biogas slurry.

[0008] This invention is achieved through the following means:

[0009] A method for applying compressed straw pellets encapsulated with biogas slurry in dryland agriculture in black soil regions includes:

[0010] (1) Preparation of straw pellets: Using crop straw left over from the previous year's farmland, the straw was cleaned of impurities and soil. The straw after removing impurities was dried at a constant temperature of 80°C for 2 hours. After drying, it was left to stand for 0.5 hours. The fully dried straw was then placed in a pulverizer to be pulverized to obtain straw powder. The straw powder was then thoroughly mixed with water and adsorbent to obtain a powder mixture. The powder mixture was then pyrolyzed at a constant temperature of 700°C for 1 hour. The pyrolyte was then pressed to obtain straw pellets for later use.

[0011] (2) Preparation of biogas slurry-encapsulated straw compressed pellets: Before farming, straw pellets are mixed with biogas slurry, stirred thoroughly and allowed to stand for fermentation, and then the mixture is compressed into biogas slurry-straw compressed pellets for later use.

[0012] (3) Returning to the field: The biogas slurry straw compressed pellets obtained by mixing and pressing are evenly spread in the field at a content of 30t / ha, and then the land is turned over. The biogas slurry straw pellets should be mixed and used as soon as possible. If they are stored for too long, nutrients will be lost.

[0013] (4) Liquid replenishment during the growth period: According to the growth period of the crops, the biogas slurry with a nitrogen content of 1.036 g / L is evenly sprayed in the field.

[0014] Furthermore, the amount of water used in step (1) is 1.5 times the mass of the straw powder.

[0015] Further, the amount of adsorbent used in step (1) is 0.25 times the mass of the straw powder.

[0016] Furthermore, the adsorbent is biochar.

[0017] Furthermore, the carbon content of the straw pellets in step (1) is 42.69%.

[0018] Furthermore, the mass-to-volume ratio of straw pellets to biogas slurry in step (2) is 2.2 kg: 6.67 L.

[0019] Furthermore, the sufficient stirring time in step (2) is 2 hours, and the settling time is 0.5 hours.

[0020] Further, the biogas slurry described in step (2) is prepared by the following method:

[0021] The mixture of pig manure, pig urine, and straw pellets in a mass ratio of 5:4:1 is fermented at 50℃ for 21 days to obtain the final product.

[0022] Furthermore, the nitrogen content of the biogas slurry is 1.036 g / L.

[0023] Further, the tilling operation in step (3) includes:

[0024] The plowing of biogas slurry and straw pellets begins before agricultural operations, but plowing is required after the autumn harvest of the previous year. No straw pellets or biogas slurry are applied during the plowing operation after the autumn harvest.

[0025] Furthermore, the amount of fluid replenishment in step (4) is gradually reduced.

[0026] Furthermore, the gradient reduction includes: supplementing with 50L of biogas slurry during the first reproductive period, and then gradually reducing by 10L for each subsequent reproductive period.

[0027] The beneficial effects of this invention are as follows:

[0028] This invention provides a fertilization method for dryland agriculture in black soil regions, using biogas slurry to encapsulate compressed straw pellets. This method rationally utilizes straw and biogas slurry, solving problems such as straw accumulation, slow straw decomposition upon returning to the field, air pollution from straw burning, and susceptibility to pests and diseases. Simultaneously, it improves soil moisture, mitigates desertification and compaction, and achieves water retention and moisture conservation, increasing soil nutrients. The combined reaction of straw pellets and biogas slurry can absorb and reduce the content of heavy metals in the soil, protecting the environment. The straw pellets expand when wet and shrink when dry, continuously loosening the soil and improving its structure. Farmland fertilized in this way experiences significantly increased soil nutrients, promoting crop growth and achieving increased yields. Detailed Implementation

[0029] This patent will systematically illustrate the technical problems encountered in practical applications through specific examples. The description herein represents only one practical application, not all applications. Any instances achieved using this method without innovative labor are within the scope of protection of this patent.

[0030] Example 1

[0031] A method for applying compressed straw pellets encapsulated with biogas slurry in dryland agriculture in black soil regions includes:

[0032] (1) Preparation of straw pellets: Using crop straw left over from the previous year's farmland, the straw was cleaned of impurities and soil. The straw after removing impurities was dried at a constant temperature of 80℃ for 2 hours. After drying, it was left to stand for 0.5 hours. The fully dried straw was then placed in a pulverizer for crushing to obtain straw powder. 1.5 times the amount of water and 0.25 times the amount of biochar were added to the straw powder and stirred thoroughly to obtain a powder mixture. The powder mixture was then pyrolyzed at a constant temperature of 700℃ for 1 hour. The pyrolyte was pressed to obtain straw pellets with a carbon content of 42.69% for later use.

[0033] (2) Preparation of biogas slurry: Pig manure, pig urine and straw particles are mixed in a mass ratio of 5:4:1 and fermented at 50℃ for 21 days to obtain biogas slurry with a nitrogen content of 1.036 g / L for later use.

[0034] (3) Preparation of biogas slurry-encapsulated straw compressed pellets: Before farming, take 2.2 kg of straw pellets and mix with 6.67 L of biogas slurry. Stir thoroughly for 2 hours and let stand for 0.5 hours to ferment. Then compress the mixture into biogas slurry-straw compressed pellets for later use.

[0035] (4) Returning to the field: The biogas slurry and straw compressed pellets obtained by mixing and pressing are evenly spread in the field at a content of 30t / ha, and then the land is turned over. The turning over includes: the turning over of biogas slurry and straw pellets should begin before the cropping, but the turning over should be carried out after the autumn harvest of the previous year. No straw pellets or biogas slurry should be added during the turning over after the autumn harvest. The biogas slurry and straw pellets should be mixed and used as soon as possible. If they are stored for too long, nutrients will be lost.

[0036] (5) Liquid replenishment during the growth period: Based on the growth period of the crop, the biogas slurry with a nitrogen content of 1.036 g / L is evenly sprayed in the field. The amount of liquid replenishment is gradually reduced. 50 L of biogas slurry is replenished in the first growth period, and then 10 L is gradually reduced in each subsequent growth period.

[0037] Comparative Example 1

[0038] A method for applying biogas slurry to straw in dryland agriculture in black soil areas includes:

[0039] The preparation and returning methods are the same as in Example 1, except that the preparation of straw pellets in step (1) is omitted. The straw used does not need to be compressed; it is directly crushed from the crop straw left over from the previous year's farmland.

[0040] Comparative Example 2

[0041] A method for applying biogas slurry-encapsulated compressed straw granules as fertilizer in dryland agriculture in black soil regions includes:

[0042] The preparation method and the method of returning straw to the field are the same as in Example 1, except that the straw pellets used in step (2) are replaced with 50% straw pellets and 50% straw residue.

[0043] Test case

[0044] The selected site is the Modern Agricultural High-tech Demonstration Park of Heilongjiang Agricultural Engineering Vocational College, Xinglong Village, Wanggang Town, Nangang District, Harbin, Heilongjiang Province (126°54′E, 45°61′N). It has a cold-temperate monsoon continental climate, characterized by cold, dry winters, windy and dry springs, and warm, humid summers. Meteorological factors such as sunshine, temperature, and rainfall vary significantly with the seasons. The average annual temperature is 3.5℃, the frost-free period is 135 days, the average annual sunshine duration is 2636 hours, the average annual water surface evaporation is 796.3 mm, and the average annual precipitation is 545.7 mm. Agricultural water supply is primarily from natural precipitation. The soil in this case study is typical black soil, and the crop planted is summer maize, grown once a year in four growth stages.

[0045] 1. Grouping:

[0046] In this example, four groups of 3m×3m experimental fields were divided, and the fields were randomly selected from the farm.

[0047] Group CK was cultivated based on farmers' experience, and the fertilizer used was a compound fertilizer (Type II) containing glutathione plant synergist and fertilizer efficiency maintainer from Heilongjiang Wofeng Fertilizer Co., Ltd. Both fertilizers were produced in January 2022.

[0048] The SB group used the product prepared in Comparative Example 1 for returning to the field. The amount of biogas slurry used was converted to ensure that the nitrogen content was the same as that in the fertilizer of the CK group, thus ensuring the principle of equal nitrogen content.

[0049] The SSPB group used the product obtained from Comparative Example 2 for returning to the field, and the amount of biogas slurry used was the same as that of the SB group.

[0050] The SPB group used the product prepared in Example 1 for returning to the field, and the amount of biogas slurry used was the same as that of the SB and SSPB groups. This experiment ensured that the amount of straw was the same, as well as the nitrogen content was the same.

[0051] Based on a calculated biogas slurry usage of 60L, the calculated replenishment amounts are 50L, 40L, 30L, and 20L.

[0052] 2. Handling method:

[0053] (1) When turning over the land in early spring, mix the straw, straw particles and biogas slurry in SB, SSPB and SPB, and slowly mix them with a slow mixer for 2 hours. After the mixing is completed, let it stand for 0.5 hours to allow it to fully ferment and obtain mixed fertilizer.

[0054] (2) Apply the mixed fertilizer evenly to each 3m×3m farmland, use a tiller to till the topsoil to a depth of 28cm, and then plant corn on the land.

[0055] (3) During the four growth stages of corn, the biogas slurry of 1.036 g / L was evenly sprayed in the farmland at a gradient of 50 L, 45 L, 40 L, and 35 L.

[0056] 3. Results:

[0057] The pH value of the biogas slurry was measured using a calomel electrode pH meter (HJ1147-2020); the organic matter content in the biogas slurry was measured using a Shimadzu TOC-VCPH analyzer (NY / T1976-2010); the total nitrogen content was measured using the potassium persulfate oxidation-ultraviolet spectrophotometer method (DB23 / T3310-2022); the total phosphorus content was measured using the molybdenum antimony-ultraviolet spectrophotometer method (HJ670-2013); the total potassium content was measured using the flame photometry method (NY / T1977-2010); soil samples obtained before the implementation of the patent were used for soil property determination before cultivation, and soil samples obtained after the autumn harvest were used for comparative determination; plant yield samples were measured at maturity.

[0058] Table 1. Basic physicochemical properties of biogas slurry and topsoil before tillage.

[0059] sample pH value Organic matter (g / kg) Total nitrogen (g / kg) Ammonia nitrogen (g / kg) Total phosphorus (g / kg) Topsoil 7.02 8.09 1.52 1.31 1.57 biogas slurry 8.13 37.62 0.96 0.68 1.46

[0060] Table 2 Production Data

[0061] Group Number of rows of grains number of grains per ear <![CDATA[Yield / (kg·hm -2 )]]> <![CDATA[Dry matter mass / (kg·hm -2 )]]> CK 16.9 885 11018.5 24902.2 SB 17.1 901 11215.3 25085.3 SSPB 18.5 955 13557.2 25935.4 SPB 18.9 984 14214.4 26514.2

[0062] Table 2 details the maize yield, number of grains per ear, and yield results obtained using the biogas slurry-encapsulated straw compression pellet return technology. Compared with the CK group, the maize yields of the SB, SSPB, and SPB groups increased by 1.7%, 23.1%, and 29.0%, respectively; similarly, the number of grains per ear increased by 1.9%, 7.96%, and 11.2%, respectively. Under biogas slurry encapsulation, the straw pellet return effect is superior to that of straw alone. The results indicate that the biogas slurry-encapsulated straw compression pellet return method of this invention can significantly improve maize yield.

[0063] Table 3 Comparison of physicochemical properties of topsoil under different treatments after autumn harvest.

[0064]

[0065] The soil physicochemical properties of each treatment using biogas slurry-encapsulated straw compressed pellets are detailed in Table 3. Compared with the control group (CK), the soil physicochemical properties of groups SB, SSPB, and SPB were all superior, with SPB showing the most significant improvement. The results indicate that the SPB group's biogas slurry-encapsulated straw compressed pellets effectively increased organic matter content, improved soil fertility, and achieved yield increase and soil enrichment.

[0066] It should be noted that this example is merely one specific embodiment of the present invention and does not represent all specific embodiments of the present invention. Any substitutions, modifications, or alterations made by those skilled in the art to the steps, materials, or equipment in this example without departing from the spirit and principles of the present invention are within the scope of the appended claims.

Claims

1. A method for applying compressed straw pellets encapsulated with biogas slurry in dryland agriculture in black soil regions, comprising: (1) Preparation of straw pellets: After the straw is crushed, water and adsorbent are added and mixed evenly. Then, it is pyrolyzed at a constant temperature. Finally, the pyrolyte is pressed to obtain straw pellets for use. (2) Preparation of biogas slurry-encapsulated straw compressed pellets: Before farming, straw pellets are mixed with biogas slurry, stirred thoroughly and allowed to stand for fermentation, and then the mixture is compressed into biogas slurry-encapsulated straw compressed pellets for later use. (3) Returning to the field: The mixed and compressed biogas slurry straw particles are evenly spread in the field at a rate of 30t / ha, and then the land is turned over. (4) Liquid replenishment during the growth period: According to the growth period of the crops, the biogas slurry with a nitrogen content of 1.036 g / L is evenly sprayed in the field.

2. The fertilization method according to claim 1, wherein: The isothermal pyrolysis in step (1) is performed at a temperature of 700°C for 1 hour.

3. The fertilization method according to claim 1, wherein: The adsorbent in step (1) is biochar; The carbon content of the straw pellets is 42.69%.

4. The fertilization method according to claim 1, wherein: The mass-to-volume ratio of straw pellets to biogas slurry in step (2) is 2.2 kg: 6.67 L.

5. The fertilization method according to claim 1, wherein: The stirring time in step (2) is 2 hours, and the settling time is 0.5 hours.

6. The fertilization method according to claim 1, wherein: The biogas slurry mentioned in step (2) is prepared by the following method: Pig manure, pig urine, and straw pellets are mixed in a mass ratio of 5:4:1 and fermented at 50℃ for 21 days to obtain biogas slurry.

7. The fertilization method according to claim 6, wherein: The nitrogen content of the biogas slurry is 1.036 g / L.

8. The fertilization method according to claim 1, wherein: The tilling operation described in step (3) includes: The plowing of biogas slurry and straw pellets begins before agricultural operations, but plowing is required after the autumn harvest of the previous year. No straw pellets or biogas slurry are applied during the plowing operation after the autumn harvest.

9. The fertilization method according to claim 1, wherein: The amount of fluid replenishment in step (4) is gradually reduced.

10. The fertilization method according to claim 9, wherein: The gradient reduction includes: During the first reproductive period, supplement with 50L of biogas slurry, and then gradually reduce by 10L for each subsequent reproductive period.

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