Method for efficiently utilizing straw resources and improving soil carbon library under grain and mushroom interplanting

Abstract

The invention discloses a method for efficiently utilizing straw resources and improving a soil carbon library under grain and mushroom interplanting, which comprises the following steps: preparing a layered substrate which comprises 40-45 parts by weight of wheat straw, 35-40 parts by weight of corn straw, 5-8 parts by weight of rice bran, 1-2 parts by weight of gypsum and 0.5-1 part by weight of calcium carbonate; carrying out hydrothermal treatment on the layered substrate at 65-70 DEG C for 90 + / -5 minutes, and then cooling to 25 + / -2 DEG C; inoculating a trichoderma harzianum T-22 strain into the cooled substrate according to the inoculum size of 106 CFU / g of the weight of the substrate, and culturing for 24-36 hours under the conditions that the temperature is 25 + / -2 DEG C and the relative humidity is 75-85%; a sequential inoculation system is adopted, oyster mushrooms are inoculated at first, the inoculation amount is 3% of the weight of the substrate, shiitake mushrooms are inoculated 7 days later, the inoculation amount is 2.5% of the weight of the substrate, pleurotus eryngii is inoculated 7 days later, and the inoculation amount is 2% of the weight of the substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of agricultural resource recycling, particularly to a method for efficient utilization of straw resources and improvement of soil carbon pool in grain-mushroom interplanting, belonging to the cross field of ecological agriculture, mycology and soil carbon sink technology. BACKGROUND

[0002] With the intensification of global climate change and the deepening of the concept of sustainable development, agricultural waste resource utilization and soil carbon pool construction have become international research hotspots. China produces about 800 million tons of straw resources annually, but the traditional utilization methods are inefficient. Commonly used methods such as returning to field or direct burning not only waste the organic carbon resources in straw, but also may cause environmental pollution problems. At the same time, the content of soil organic matter in China's farmland is generally low, and the soil quality is seriously degraded, which seriously restricts the sustainable development of agriculture.

[0003] Currently, the technologies for straw resource utilization and soil carbon pool improvement mainly focus on the following aspects:

[0004] Hu Quanyi et al. reported in Rice-edible mushroom Stropharia rugosoannulata rotation mitigates net global warming potential while enhancing soil fertility and economic benefits (2024, European Journal of Agronomy) that rice and Stropharia rugosoannulata rotation system can increase soil organic carbon by 30%. However, this system uses rotation instead of interplanting mode, and the carbon pool improvement efficiency is limited. Moreover, only a single mushroom species is used, and the differential degradation ability of different edible fungi on straw components cannot be fully utilized.

[0005] Chinese patent CN105165362A discloses a method for interplanting corn and Stropharia rugosoannulata, which uses a 4:2 ridge-ditch planting pattern. However, this method only involves the combination of a single mushroom species and a single crop, and does not consider the construction of soil carbon pool, lacking a systematic design for resource recycling.

[0006] The research of Yin et al. (2022, Science of The Total Environment: 153576) Evaluation of long-term carbon sequestration of biochar in soil with biogeochemical field model shows that agricultural waste biochar can sequester 1.2 tons of carbon per hectare per year, but the carbon sequestration efficiency of pure biochar addition is still limited and cannot be effectively combined with edible mushroom cultivation systems.

[0007] CN103570453A discloses "a wheat straw as raw material of flammulina velutipes cultivation material and its preparation method", which focuses on the cultivation substrate formula of single strain and does not consider the possibility of multi-strain sequential inoculation and does not involve field interplanting mode and soil carbon pool improvement.

[0008] The above prior art has the following defects: (1) only single strain cultivation is used, and the enzyme complementarity of different edible fungi cannot be fully utilized; (2) edible mushroom cultivation and field crop production cannot be organically combined, and resource utilization efficiency is low; (3) there is a lack of system design of straw-fungus-soil carbon pool, and the carbon sequestration efficiency is limited; (4) the promoting effect of microbial pretreatment on substrate decomposition and mycelial growth is not considered; (5) the carbon pool improvement mechanism is not studied, and it is difficult to realize directional regulation.

[0009] Therefore, it is urgent to develop a technical system that can comprehensively utilize the differential degradation capacity of various edible fungi, combine with field grain production, and significantly improve the soil carbon pool, so as to realize the dual goals of efficient utilization of straw resources and enhancement of farmland carbon sink. SUMMARY

[0010] The present application aims to solve the above technical problems and provide a method for efficient utilization of straw resources and improvement of soil carbon pool under grain-mushroom interplanting, which realizes the multiple goals of efficient utilization of straw resources, high yield of edible mushrooms and significant improvement of soil carbon pool by constructing a interplanting system of grain crops and multi-strain sequential inoculation of edible mushrooms, combined with the application of biochar fortified fertilizer.

[0011] To solve the above technical problems, the present application provides a method for efficient utilization of straw resources and improvement of soil carbon pool under grain-mushroom interplanting, comprising the following steps:

[0012] A layered substrate is prepared comprising 40-45 parts by weight of wheat straw, 35-40 parts by weight of corn straw, 5-8 parts by weight of rice bran, 1-2 parts by weight of gypsum and 0.5-1 part by weight of calcium carbonate; the layered substrate is subjected to hydrothermal treatment at 65-70°C for 90±5 minutes, then cooled to 25±2°C; the Trichoderma harzianum T-22 strain is inoculated into the cooled substrate at an inoculation amount of 10 6 CFU / g, and cultured at 25±2°C and 75-85% relative humidity for 24-36 hours; a sequential inoculation system is used, first inoculating Pleurotus ostreatus at an inoculation amount of 3% of the substrate weight, then inoculating Lentinula edodes after 7 days at an inoculation amount of 2.5% of the substrate weight, and then inoculating Pleurotus eryngii after another 7 days at an inoculation amount of 2% of the substrate weight; a mushroom bed is configured in the inter-row space of the food crops at a ratio of 2:1:2, i.e. 2 rows of food crops, 1 row of mushroom bed, and 2 rows of food crops, and the width of the mushroom bed is 60-70 cm; after harvesting the mushroom bed, the waste mushroom material is applied to the soil at a rate of 15-20 tons / ha, and biochar fortified fertilizer is added at a rate of 2-3 tons / ha; the soil organic carbon content is monitored and verified to increase by 25-35% within 24 months.

[0013] Preferably, the wheat straw and corn straw have a particle size of 2-5 cm and a moisture content of 14-18%, and are obtained by mechanical treatment; the final moisture content of the layered substrate is 65-68%, and the C:N ratio is 28-32:1.

[0014] Preferably, in the hydrothermal treatment step, the ratio of water to substrate is 4:1 (volume ratio), and after the treatment, the substrate is naturally cooled at a cooling rate of 1-2°C / 15 minutes, and the cooling time is 4-6 hours.

[0015] Preferably, the Trichoderma harzianum T-22 strain (ATCC 20847) is added in the form of a water-soluble powder, a suspension is prepared by dissolving 5 g of the product in 10 L of sterile water, and the suspension is uniformly sprayed on the surface of the substrate, with 1 L of the suspension being used per 10 kg of substrate.

[0016] Preferably, in the sequential inoculation system: Pleurotus ostreatus is inoculated on day 0, the culture temperature is 24-26°C, and the relative humidity is 85-90%; Lentinula edodes is inoculated on day 7, the culture temperature is 21-24°C, and the relative humidity is 80-85%; and Pleurotus eryngii is inoculated on day 14, the culture temperature is 18-22°C, and the relative humidity is 80-85%; each strain is inoculated using a layered or point inoculation method, Pleurotus ostreatus is preferentially inoculated in the wheat straw area, Lentinula edodes is preferentially inoculated in the supplementary area rich in nutrients, and Pleurotus eryngii is preferentially inoculated in the corn straw area.

[0017] Preferably, the grain crop of the grain-mushroom intercropping is selected from wheat or corn, the mushroom bed is deployed 30-45 days after the emergence of the grain crop, the mushroom bed is maintained at a relative humidity of 75-85% using a drip irrigation system, the drip irrigation system has a water droplet head spacing of 30 cm, and the daily water supply is 2-4 liters per square meter.

[0018] Preferably, the biochar fortified fertilizer is composed of 55-60 parts by weight of pyrolyzed agricultural residues, which are prepared by pyrolysis at a temperature of 450-500℃ for 2 hours; 25-30 parts by weight of fresh straw mixture; and 10-15 parts by weight of mineral supplement, which includes 2-3 parts by weight of dolomite lime, 1-2 parts by weight of rock phosphate, and 0.5-1 part by weight of potassium sulfate.

[0019] Preferably, the preparation of the pyrolyzed agricultural residues includes the following steps: mixing wheat straw and corn straw with a water content of 8-12% at a ratio of 1:1 and cutting to a length of 2-5 cm; in a fixed bed slow pyrolysis reactor, increasing the temperature from ambient temperature to 250℃ at a rate of 10℃ / min and maintaining for 30 min; then increasing the temperature from 250℃ to 450-500℃ at a rate of 5℃ / min, maintaining at this temperature for 120±10 min; naturally cooling to below 50℃ under an inert atmosphere, and then exposing to ambient air in a ventilated area for 24 hours to stabilize the biochar.

[0020] Preferably, the spent mushroom substrate is collected after 2-3 harvests, first broken into 5-10 cm size blocks, uniformly spread in the field, and then soil mixed using a shallow disc harrow set at a depth of 10-15 cm, which should be done within 7 days after the spent mushroom substrate is removed.

[0021] Preferably, the step of monitoring and verifying the soil organic carbon content includes: sampling at soil depths of 0-10 cm, 10-20 cm, and 20-30 cm; collecting 5 composite samples per hectare, each composed of 10 individual soil cores; determining the total organic carbon content using the Dumas dry combustion method; performing carbon component analysis using density separation method to separate light components (<1.8 g / cm³), intermediate components (1.8-2.2 g / cm³), and heavy components (>2.2 g / cm³); determining δ¹³C values by isotope ratio mass spectrometry to track changes in carbon sources; and achieving a system carbon sequestration rate of 2.1-3.4 tons of CO2 equivalent per hectare per year.

[0022] The present application has the following beneficial effects:

[0023] 1. Through the three edible fungi sequential inoculation system, the enzyme system complementarity of different edible fungi is fully utilized, the conversion efficiency of straw resources is improved, and the yield is increased by 31-42% compared with single strain cultivation;

[0024] 2. The use of Trichoderma harzianum T-22 strain pretreatment promotes the partial degradation of the substrate, creates favorable conditions for the growth of subsequent edible fungi, and shortens the mycelial growth cycle by 15-25%;

[0025] 3. The grain-mushroom interplanting mode realizes efficient use of land resources, and at the same time, the interaction between crop root system and mycelium promotes crop growth and increases grain yield by 12-18%;

[0026] 4. The combination of waste mushroom material and biochar fortified fertilizer forms a stable soil carbon pool, and the carbon sequestration efficiency is 2-5 times higher than that of conventional straw field, and the system carbon sequestration rate reaches 2.1-3.4 tons of CO2 equivalent per hectare per year;

[0027] 5. The win-win of economic benefit and ecological benefit is realized, the comprehensive economic benefit of the system is increased by 57-92%, and at the same time, the soil organic matter content is significantly increased, and the soil structure and fertility are improved. DETAILED DESCRIPTION

[0028] The application will be further described in detail below in combination with specific examples, but the protection scope of the application is not limited thereto.

[0029] I. Raw materials and reagents

[0030] 1. Wheat straw: wheat straw within 90 days after harvest, no obvious mold, water content <20%.

[0031] 2. Corn straw: corn straw within 90 days after harvest, no obvious mold, water content <20%.

[0032] 3. Rice bran: rice milling by-product, protein content 12-15%, lipid 15-20%, carbohydrate 34-52%, dietary fiber 7-11%.

[0033] 4. Gypsum: agricultural grade calcium sulfate dihydrate (CaSO4·2H2O), purity ≥95%, particle size 95% passing 150 μm sieve.

[0034] 5. Calcium carbonate: agricultural grade calcium carbonate (CaCO3), purity ≥95%, particle size 95% passing 150 μm sieve.

[0035] 6. Trichoderma harzianum strain T-22 (ATCC 20847), trade name RootShield®, produced by BioWorks, Inc., viable spore content > 2 x 10 9 CFU / g.

[0036] 7. Pleurotus ostreatus strain P-80, a commercial high-yield strain provided by the Chinese Institute of Edible Fungi, wheat grain spawn, white mycelium, vigorous growth.

[0037] 8. Lentinula edodes strain LE-4, a commercial wide-temperature strain provided by the Institute of Edible Fungi, Chinese Academy of Agricultural Sciences, sawdust segment spawn, dense white mycelium, brown peridium formation.

[0038] 9. Pleurotus eryngii strain PE-2, a commercial strain provided by the Shanghai Academy of Agricultural Sciences, wheat grain spawn, white and dense mycelium.

[0039] 10. Dolomite lime: agricultural grade calcium magnesium carbonate [CaMg(CO3)2], purity > 90%, particle size 75-150 μm.

[0040] 11. Rock phosphate: agricultural grade calcium phosphate [Ca3(PO4)2], P2O5 content > 28%, particle size 100-250 μm.

[0041] 12. Potassium sulfate: agricultural grade potassium sulfate [K2SO4, CAS number], purity > 95%, K2O content > 50%.

[0042] II. Equipment and Instruments

[0043] 1. Rotary straw chopper: power 15-25 kW, processing capacity 500-1000 kg / h, equipped with 5 cm screen.

[0044] 2. Fixed bed slow pyrolysis reactor: volume 100 L, maximum temperature up to 800°C, adjustable heating rate, equipped with temperature monitoring system and inert gas inlet device.

[0045] 3. Hydrothermal treatment device: stainless steel soaking tank, equipped with constant temperature heating system, temperature control accuracy ± 1°C.

[0046] 4. Low-pressure drip irrigation system: 16 mm polyethylene main pipe, 12 mm drip irrigation tape, integrated dripper, spacing 30 cm, flow rate 1-2 L / h, working pressure 1.0-1.5 bar.

[0047] 5. Shallow disc harrow: adjustable working depth (5-20 cm), working width 2 m, suitable for light to moderate field work.

[0048] 6. Soil sampler: stainless steel soil drill, inner diameter 2.5 cm, length 50 cm, with depth scale.

[0049] 7. Elemental analyzer: Elementar vario MACRO cube elemental analyzer, for C, N content determination.

[0050] 8. Isotope ratio mass spectrometer: Thermo Fisher Scientific Delta V isotope ratio mass spectrometer, for δ¹³C value determination.

[0051] Example 1: Wheat straw substrate ratio end point value and corn straw substrate ratio intermediate value of grain mushroom interplanting method

[0052] The present embodiment provides a wheat straw substrate ratio end point value and corn straw substrate ratio intermediate value of grain mushroom interplanting method, which specifically comprises the following steps:

[0053] (1) Layered substrate preparation: First, collect fresh straw after wheat harvest, cut it to 2-3 cm in length with a rotary straw chopper, and the moisture content after screening treatment is 14%; At the same time, collect the straw after the harvest of corn, cut it to 3-4 cm in length, and control the moisture content at 16%. According to the ratio of 40 parts by weight of wheat straw, 37.5 parts by weight of corn straw, 6 parts by weight of rice bran, 1.5 parts by weight of gypsum and 0.8 parts by weight of calcium carbonate. First, spread the wheat straw on the bottom layer, place the corn straw in the middle layer, and mix the rice bran, gypsum and calcium carbonate and sprinkle on the top layer. Mix in a horizontal paddle mixer at a speed of 20 RPM for 15 minutes, and gradually add water to the substrate until the final moisture content reaches 65%. At this time, the C:N ratio of the substrate is measured to be 30:1.

[0054] (2) Hydrothermal treatment: Put the mixed substrate into a heat-resistant grid container, make sure the thickness of the substrate does not exceed 25 cm. Prepare a water bath at 65℃, the volume ratio of water to substrate is 4:1. Immerse the substrate completely in water, maintain the water temperature at 65-67℃, and continue to treat for 90 minutes. Monitor the water temperature every 15 minutes during the treatment to ensure the temperature is stable. After treatment, place the substrate on a clean drainage rack and cool naturally at an ambient temperature of 22℃, the cooling rate is about 1.5℃ / 15min, the cooling time is 5 hours, and the final substrate temperature is reduced to about 25℃.

[0055] (3) Trichoderma harzianum inoculation: Take 5 kg of RootShield® commercial Trichoderma harzianum T-22 strain powder (ATCC 20847) and dissolve in 10 L of sterile water to make a uniform suspension. Use a low-pressure sprayer to evenly spray the suspension on the surface of the substrate, ensuring that 1 L of suspension is used per 10 kg of substrate, with an inoculum amount of 10 6 CFU / g. After spraying, gently turn the substrate to ensure uniform distribution of Trichoderma harzianum. Place the inoculated substrate in an environment of 25°C and 80% relative humidity for 30 hours, during which time the appearance of a white mycelial network on the surface of the substrate is observed.

[0056] (4) Sequential inoculation system: First inoculate Pleurotus ostreatus strain P-80 on day 0, with an inoculum amount of 3% of the weight of the substrate. Use a stratified inoculation method, evenly scattering a layer of Pleurotus ostreatus wheat kernel spawn every 10 cm of substrate thickness, focusing on the wheat straw area. After inoculation, the substrate is incubated at 24-25°C and 85-88% relative humidity for 7 days, at which time it is observed that the Pleurotus ostreatus mycelium has covered about 70% of the area of the substrate surface, mainly concentrated in the wheat straw part.

[0057] On day 7, inoculate Lentinula edodes strain LE-4 with an inoculum amount of 2.5% of the weight of the substrate. Use a fixed-point inoculation method, making 2-3 cm deep holes every 10 cm on the surface of the substrate, filling each hole with 5-8 g of Lentinula edodes sawdust segments, focusing on the supplemented area rich in rice bran. After inoculation, adjust the environmental temperature to 22°C and reduce the relative humidity to 82%, and continue to incubate for 7 days.

[0058] On day 14, inoculate Pleurotus eryngii strain PE-2 with an inoculum amount of 2% of the weight of the substrate. Use a trench inoculation method, making 1-2 cm deep shallow trenches on the surface of the substrate, evenly distributing Pleurotus eryngii wheat kernel spawn along the trenches, using about 20 g of spawn per meter of trench, focusing on the corn straw enrichment area. After inoculation, further reduce the environmental temperature to 20°C and maintain the relative humidity at 80-82%, and continue to incubate for 14-16 days until the substrate is completely covered with mycelium.

[0059] (5) Field configuration of intercropping wheat and mushroom: Select a farmland where wheat (variety: Jimai 22) is planted, and configure mushroom bed 35 days after the wheat germination. Arrange according to the ratio of 2:1:2 (2 rows of wheat: 1 row of mushroom bed: 2 rows of wheat), keep the row spacing of wheat at 45 cm, the distance between wheat row and mushroom bed at 75 cm, and the width of mushroom bed at 65 cm. Install a drip irrigation system, lay the drip irrigation tape along the center of the mushroom bed, set the distance between drip heads at 30 cm, and the flow rate at 1.5 L / h. Adjust the irrigation frequency according to the temperature, irrigate twice a day at 2 L / m² each time when the daily average temperature is 18-25°C in spring, and maintain the relative humidity of the mushroom bed at about 80%.

[0060] (6) Application of waste mushroom material and biochar: After 3 harvests (about 90-100 days), collect the waste mushroom material, and measure the yield as 3.1 tons of fresh weight per hectare. Crush the waste mushroom material into 5-8 cm blocks, evenly spread it in the field, and use an amount of 17 tons per hectare. At the same time, apply biochar fortified fertilizer at 2.5 tons per hectare, which is composed of 58 parts by weight of pyrolyzed agricultural residues (pyrolyzed at 475°C for 2 hours), 27 parts by weight of fresh straw mixture, and 15 parts by weight of mineral supplement (including 2.5 parts by weight of dolomite lime, 1.5 parts by weight of rock phosphate, and 0.8 parts by weight of potassium sulfate). Use a shallow disc harrow with a set depth of 12 cm to mix the waste mushroom material and biochar fortified fertilizer with the surface soil, and complete the mixing operation 5 days after the waste mushroom material is collected.

[0061] (7) Soil carbon pool monitoring: Sample according to three soil depths of 0-10 cm, 10-20 cm, and 20-30 cm, randomly arrange 5 sampling points per hectare, and collect 10 soil cores at each sampling point to form a composite sample. Use the Dumas dry combustion method to determine the total organic carbon content of the soil, use density separation method for carbon component analysis, and use isotope ratio mass spectrometry to determine the δ¹³C value. The monitoring results show that within 24 months after the treatment, the organic carbon content of the 0-30 cm soil layer increases by an average of 28.5%, and the carbon sequestration rate reaches 2.4 tons of CO2 equivalent per hectare per year.

[0062] Example 2: Wheat straw substrate ratio intermediate value and corn straw substrate ratio endpoint value intercropping method

[0063] The present embodiment provides a wheat straw substrate ratio intermediate value and corn straw substrate ratio endpoint value intercropping method, which specifically comprises the following steps:

[0064] (1) Layered substrate preparation: Wheat straw after harvest was collected and processed by a rotary chopper to a length of 4-5 cm with a moisture content of 16%. Meanwhile, corn straw after harvest was collected and cut to a length of 2-3 cm with a moisture content of 15%. The wheat straw, corn straw, rice bran, gypsum, and calcium carbonate were mixed in a ratio of 42.5 parts by weight, 35 parts by weight, 7 parts by weight, 1.2 parts by weight, and 0.6 parts by weight, respectively. The wheat straw was placed in the bottom layer, the corn straw was placed in the middle layer, and the mixture of rice bran, gypsum, and calcium carbonate was placed in the top layer. The mixture was mixed in a horizontal paddle mixer at a speed of 22 RPM for 18 minutes, and water was gradually added to the mixture until the final moisture content of the substrate reached 67%. The C:N ratio of the substrate was measured to be 29:1.

[0065] (2) Hydrothermal treatment: The mixed substrate was placed in a heat-resistant grid container, ensuring that the thickness of the substrate did not exceed 28 cm. A water bath at 68°C was prepared, with a volume ratio of water to substrate of 4:1. The substrate was completely immersed in the water, and the water temperature was maintained between 67-70°C for 85 minutes. The water temperature was monitored every 20 minutes during the treatment. After the treatment, the substrate was placed on a clean drainage rack and naturally cooled at an ambient temperature of 24°C. The cooling rate was approximately 1.8°C per 15 minutes, and the cooling time was 4.5 hours, with the final substrate temperature dropping to around 25°C.

[0066] (3) Trichoderma harzianum inoculation: 5 grams of RootShield® commercial Trichoderma harzianum T-22 strain powder (ATCC20847) was dissolved in 10 liters of sterile water to make a uniform suspension. A low-pressure sprayer was used to evenly spray the suspension on the surface of the substrate, ensuring that 1 liter of suspension was used per 10 kilograms of substrate, with an inoculation amount of 10 6 CFU / g of the substrate weight. After spraying, the substrate was gently stirred to ensure uniform distribution of Trichoderma harzianum. The inoculated substrate was incubated at 25°C and a relative humidity of 78% for 32 hours, during which white mycelial networks were observed on the surface of the substrate.

[0067] (4) Sequential inoculation system: First, Pleurotus ostreatus strain P-80 was inoculated on day 0 at a rate of 3% of the substrate weight. A layered inoculation method was used, with a layer of Pleurotus ostreatus wheat grain seeds evenly scattered every 12 cm of substrate thickness, focusing on the wheat straw area. The inoculated substrate was incubated at 25-26°C and a relative humidity of 88-90% for 7 days, during which it was observed that the Pleurotus ostreatus mycelium covered about 75% of the surface area of the substrate.

[0068] On the 7th day, Lentinula edodes strain LE-4 was inoculated at a rate of 2.5% of the substrate weight. Using the fixed-point inoculation method, 2-3 cm deep holes were made on the surface of the substrate every 12 cm, and 6-9 g of Lentinula edodes sawdust segments were filled into each hole, focusing on the areas supplemented with rice bran. After inoculation, the environmental temperature was adjusted to 21-22°C, and the relative humidity was reduced to 80-83%, and the culture was continued for 7 days.

[0069] On the 14th day, Pleurotus eryngii strain PE-2 was inoculated at a rate of 2% of the substrate weight. Using the trench inoculation method, 1.5-2 cm deep shallow trenches were made on the surface of the substrate, and Pleurotus eryngii wheat seeds were evenly distributed along the trenches, with about 22 g of inoculum used per meter of trench, focusing on the areas enriched with corn straw. After inoculation, the environmental temperature was further reduced to 18-19°C, and the relative humidity was maintained at 82-84%, and the culture was continued for 16-18 days until the substrate was completely covered with mycelium.

[0070] (5) Field configuration of intercropping with mushrooms: Select a farmland where corn (variety: Zhengdan 958) is planted, and configure the mushroom bed 40 days after the corn emerges. Arrange according to the ratio of 2:1:2 (2 rows of corn: 1 row of mushroom bed: 2 rows of corn), maintain a corn row spacing of 50 cm, and the distance between corn rows and mushroom beds is 80 cm, and the width of the mushroom bed is 60 cm. Install a drip irrigation system, lay the drip irrigation tape along the center of the mushroom bed, set the drip head spacing to 30 cm, and the flow rate to 1.8 L / h. Adjust the irrigation frequency according to the temperature, irrigate 3 times a day when the daily average temperature is >25°C, each time 3 L / m², and maintain the relative humidity of the mushroom bed at about 75-80%.

[0071] (6) Application of waste mushroom material and biochar: After completing 2 harvests (about 70-80 days), collect the waste mushroom material, and measure the yield to be 2.8 tons of fresh weight per hectare. Crush the waste mushroom material into 7-10 cm blocks and evenly spread it in the field at a rate of 16 tons per hectare. At the same time, apply 2.2 tons per hectare of biochar fortified fertilizer, which is composed of 55 parts by weight of pyrolyzed agricultural residues (pyrolyzed at 450°C for 2 hours), 30 parts by weight of fresh straw mixture, and 15 parts by weight of mineral supplement (including 2 parts by weight of dolomite lime, 1 part by weight of rock phosphate, and 0.5 parts by weight of potassium sulfate). Use a shallow disc harrow with a set depth of 10 cm to mix the waste mushroom material and biochar fortified fertilizer with the surface soil, and complete the mixing operation on the 3rd day after the waste mushroom material is collected.

[0072] (7) Soil carbon pool monitoring: Sampling was performed in layers of 0-10 cm, 10-20 cm, and 20-30 cm. Five sampling points per hectare were randomly placed, and each sampling point collected 10 soil cores to form a composite sample. The total soil organic carbon content was determined using the Dumas dry combustion method, carbon fraction analysis was performed using density separation, and δ13C values were determined by isotope ratio mass spectrometry. The monitoring results showed that, within 24 months after treatment, the organic carbon content of the 0-30 cm soil layer increased by an average of 26.8%, and the carbon sequestration rate reached 2.2 tons of CO2 equivalent / hectare / year.

[0073] Example 3: Wheat straw substrate ratio end point value and corn straw substrate ratio end point value of grain and mushroom interplanting method

[0074] The present embodiment provides a wheat straw substrate ratio end point value and corn straw substrate ratio end point value of grain and mushroom interplanting method, which specifically comprises the following steps:

[0075] (1) Layered substrate preparation: Collect the straw after wheat harvest, process it to 2-3 cm in length by a rotary chopper, and the moisture content is 18%; at the same time, collect the straw after corn harvest, cut it to 2-3 cm in length, and the moisture content is 18%. According to the ratio of 45 parts by weight of wheat straw, 40 parts by weight of corn straw, 8 parts by weight of rice bran, 2 parts by weight of gypsum, and 1 part by weight of calcium carbonate, the wheat straw is placed in the bottom layer, the corn straw is placed in the middle layer, and the rice bran, gypsum and calcium carbonate are mixed and placed in the top layer. In a horizontal paddle mixer, mix at a speed of 25 RPM for 20 minutes, gradually add water to the substrate until the final moisture content reaches 68%, and measure the C:N ratio of the substrate to be 28:1.

[0076] (2) Hydrothermal treatment: Put the mixed substrate into a heat-resistant grid container, make sure the thickness of the substrate does not exceed 30 cm. Prepare a water bath at 70°C, the volume ratio of water to substrate is 4:1. Immerse the substrate completely in water, maintain the water temperature between 68-70°C, and continue to treat for 95 minutes. Monitor the water temperature every 15 minutes during the treatment. After the treatment, place the substrate on a clean drainage rack and cool it naturally at an ambient temperature of 20°C, the cooling rate is about 1°C / 15 minutes, and the cooling time is 6 hours, the final substrate temperature is reduced to about 25°C.

[0077] (3) Trichoderma harzianum inoculation: Take 5 grams of RootShield® commercial Trichoderma harzianum T-22 strain powder (ATCC20847), dissolve it in 10 liters of sterile water to make a uniform suspension. Use a low-pressure sprayer to evenly spray the suspension on the surface of the substrate, make sure to use 1 liter of suspension per 10 kilograms of substrate, the inoculation amount reaches 10 6CFU / g. After spraying, gently turn the substrate to ensure even distribution of T. harzianum. Place the inoculated substrate in an environment of 25°C and 85% relative humidity for 36 hours, during which time a noticeable white mycelial network is observed on the surface of the substrate.

[0078] (4) Sequential inoculation system: First inoculate Pleurotus ostreatus strain P-80 on day 0 at a rate of 3% of the substrate weight. Use stratified inoculation, evenly spreading a layer of Pleurotus wheat grains every 10 cm of substrate thickness, focusing on the wheat straw area. After inoculation, incubate the substrate at 26°C and 90% relative humidity for 7 days, at which time it is observed that the Pleurotus mycelium covers about 80% of the substrate surface.

[0079] On day 7, inoculate Lentinula edodes strain LE-4 at a rate of 2.5% of the substrate weight. Use point inoculation, creating 3 cm deep holes every 10 cm on the substrate surface, filling each hole with 10 grams of Lentinula sawdust segments, focusing on the rice bran-rich supplement area. After inoculation, adjust the environmental temperature to 24°C and reduce the relative humidity to 85%, continuing to incubate for 7 days.

[0080] On day 14, inoculate Pleurotus eryngii strain PE-2 at a rate of 2% of the substrate weight. Use trench inoculation, creating 2 cm deep shallow trenches on the substrate surface, evenly distributing Pleurotus wheat grains along the trenches, using about 25 grams of spawn per meter of trench, focusing on the corn straw-rich area. After inoculation, further reduce the environmental temperature to 22°C and maintain the relative humidity at 85%, continuing to incubate for 14 days until the substrate is completely covered with mycelium.

[0081] (5) Field configuration of grain-mushroom intercropping: Select a wheat (variety: Jimai 22) field and configure the mushroom bed 30 days after the wheat emerges. Arrange according to the ratio of 2:1:2 (2 rows of wheat: 1 row of mushroom bed: 2 rows of wheat), with a wheat row spacing of 40 cm, a distance between wheat rows and mushroom beds of 70 cm, and a mushroom bed width of 70 cm. Install a drip irrigation system, with the drip irrigation tape laid along the center of the mushroom bed, the drip emitter spacing set to 30 cm, and the flow rate set to 2 L / h. Adjust the irrigation frequency according to the temperature, with irrigation once a day at a flow rate of 4 L / m² when the daily average temperature is 15-20°C in spring, maintaining the relative humidity of the mushroom bed at about 85%.

[0082] (6) Application of Waste Mushroom Substrate and Biochar: After three harvests (approximately 90-100 days), waste mushroom substrate was collected, and the yield was measured to be 3.4 tons fresh weight / hectare. The waste mushroom substrate was broken into 5-7 cm blocks and evenly spread in the field at a rate of 20 tons / hectare. At the same time, 3 tons / hectare of biochar-fortified fertilizer was applied. The biochar-fortified fertilizer consisted of the following components: 60 parts by weight of pyrolyzed agricultural residue (obtained by pyrolysis at 500℃ for 2 hours), 25 parts by weight of fresh straw mixture, and 15 parts by weight of mineral supplement (including 3 parts by weight of dolomite lime, 2 parts by weight of phosphate rock, and 1 part by weight of potassium sulfate). The waste mushroom substrate and biochar-fortified fertilizer were mixed with the topsoil using a shallow disc rake with a set depth of 15 cm. The mixing operation was completed on the second day after the waste mushroom substrate was collected.

[0083] (7) Soil carbon pool monitoring: Stratified sampling was conducted at three soil depths: 0-10 cm, 10-20 cm, and 20-30 cm. Five sampling points were randomly placed per hectare, and ten soil cores were collected from each sampling point to form a composite sample. The total organic carbon content of the soil was determined using the Dumas dry combustion method, carbon component analysis was performed using the density separation method, and the δ¹³C value was determined by isotope ratio mass spectrometry. Monitoring results showed that within 24 months after treatment, the organic carbon content in the 0-30 cm soil layer increased by an average of 35%, and the carbon sequestration rate reached 3.4 tons of CO2 equivalent / hectare / year.

[0084] Example 4: Grain-Mushroom Intercropping Method Based on Endpoint Values ​​of Wheat Straw Substrate Ratio and Corn Straw Substrate Ratio

[0085] This embodiment provides a method for intercropping grains and mushrooms using wheat straw substrate ratio endpoints and corn straw substrate ratio endpoints, specifically including the following steps:

[0086] (1) Layered substrate preparation: Wheat straw after harvest was collected and processed to a length of 4-5 cm using a rotary shredder, with a moisture content of 14%; corn straw after harvest was also collected and cut to a length of 4-5 cm, with a moisture content of 14%. The substrate was prepared according to the following ratio: 40 parts by weight of wheat straw, 40 parts by weight of corn straw, 5 parts by weight of rice bran, 1 part by weight of gypsum, and 0.5 parts by weight of calcium carbonate. Wheat straw was placed at the bottom layer, corn straw in the middle layer, and the rice bran, gypsum, and calcium carbonate were mixed and placed at the top layer. The mixture was then mixed in a horizontal paddle mixer at 20 RPM for 15 minutes, gradually adding water until the final moisture content of the substrate reached 65%. The C:N ratio of the substrate was measured to be 32:1.

[0087] (2) Hydrothermal treatment: The mixed substrate was loaded into a heat-resistant grid container, ensuring that the thickness of the substrate did not exceed 25 centimeters. A water bath at 65°C was prepared, with a volume ratio of water to substrate of 4:1. The substrate was completely immersed in the water, and the water temperature was maintained between 65-67°C for a treatment time of 90 minutes. The water temperature was monitored every 15 minutes during the treatment. After the treatment, the substrate was placed on a clean drainage rack and naturally cooled at an ambient temperature of 25°C, with a cooling rate of approximately 2°C / 15 minutes and a cooling time of 4 hours, until the final substrate temperature reached approximately 25°C.

[0088] (3) Trichoderma harzianum inoculation: 5 grams of RootShield® commercial Trichoderma harzianum T-22 strain powder (ATCC 20847) was dissolved in 10 liters of sterile water to make a uniform suspension. A low-pressure sprayer was used to evenly spray the suspension onto the surface of the substrate, ensuring that 1 liter of suspension was used per 10 kilograms of substrate, with an inoculation amount of 10 6 CFU / g. After spraying, the substrate was gently stirred to ensure uniform distribution of the Trichoderma harzianum. The inoculated substrate was incubated in an environment with a temperature of 25°C and a relative humidity of 75% for 24 hours, during which time white mycelial networks began to appear on the surface of the substrate.

[0089] (4) Sequential inoculation system: First, on day 0, the Pleurotus ostreatus strain P-80 was inoculated at a rate of 3% of the substrate weight. A stratified inoculation method was used, with a layer of Pleurotus ostreatus wheat kernel spawn evenly scattered every 15 centimeters in thickness between the substrate layers, focusing on the wheat straw-rich areas. The inoculated substrate was incubated at a temperature of 24°C and a relative humidity of 85% for 7 days, at which time it was observed that the Pleurotus ostreatus mycelium covered approximately 65% of the surface area of the substrate.

[0090] On day 7, the Lentinula edodes strain LE-4 was inoculated at a rate of 2.5% of the substrate weight. A fixed-point inoculation method was used, with 2-centimeter-deep holes made every 15 centimeters on the surface of the substrate, and 5 grams of Lentinula edodes sawdust segment spawn was placed in each hole, focusing on the rice bran-rich supplement areas. After inoculation, the environmental temperature was adjusted to 21°C, and the relative humidity was reduced to 80%, and the incubation was continued for another 7 days.

[0091] On day 14, the Pleurotus eryngii strain PE-2 was inoculated at a rate of 2% of the substrate weight. A trench inoculation method was used, with 1-centimeter-deep shallow trenches made on the surface of the substrate, and Pleurotus eryngii wheat kernel spawn was evenly distributed along the trenches, with approximately 20 grams of spawn used per meter of trench, focusing on the corn straw-rich areas. After inoculation, the environmental temperature was further reduced to 18°C, and the relative humidity was maintained at 80%, and the incubation was continued for another 21 days until the substrate was completely covered with mycelium.

[0092] (5) Field configuration of mushroom intercropping: Select the farmland where corn (variety: Zhengdan 958) is planted, and configure the mushroom bed 45 days after the corn emerges. Arrange according to the ratio of 2:1:2 (2 corn rows: 1 mushroom bed row: 2 corn rows), keep the corn row spacing at 50 cm, the distance between the corn row and the mushroom bed at 70 cm, and the width of the mushroom bed at 70 cm. Install a drip irrigation system, lay the drip irrigation tape along the center of the mushroom bed, set the drip head spacing at 30 cm, and the flow rate at 1.5 L / h. Adjust the irrigation frequency according to the temperature, irrigate 3 times a day when the daily average temperature is > 28°C, each time 3 L / m², and maintain the relative humidity of the mushroom bed at about 75%.

[0093] (6) Application of waste mushroom material and biochar: After completing 2 harvests (about 70-80 days), collect the waste mushroom material, and measure the yield as 2.6 tons of fresh weight per hectare. Crush the waste mushroom material into 8-10 cm blocks, evenly spread it in the field, and use an amount of 15 tons per hectare. At the same time, apply biochar fortified fertilizer 2 tons per hectare, which is composed of: 55 parts by weight of pyrolyzed agricultural residues (prepared by pyrolysis at 450°C for 2 hours), 30 parts by weight of fresh straw mixture, and 15 parts by weight of mineral supplement (including 2 parts by weight of dolomite lime, 1 part by weight of rock phosphate, and 0.5 parts by weight of potassium sulfate). Use a shallow disc harrow with a set depth of 10 cm to mix the waste mushroom material and biochar fortified fertilizer with the surface soil, and complete the mixing operation 7 days after the waste mushroom material is collected.

[0094] (7) Soil carbon pool monitoring: Sample according to 0-10 cm, 10-20 cm, and 20-30 cm soil depths, randomly arrange 5 sampling points per hectare, and collect 10 soil cores per sampling point to form a composite sample. Use the Dumas dry combustion method to determine the total organic carbon content of the soil, use density separation method for carbon component analysis, and use isotope ratio mass spectrometry to determine the δ¹³C value. The monitoring results show that within 24 months after treatment, the organic carbon content of the 0-30 cm soil layer increases by an average of 25%, and the carbon sequestration rate reaches 2.1 tons of CO2 equivalent per hectare per year.

[0095] Example 5: Biochar fortified fertilizer with pyrolyzed agricultural residue endpoint value and mineral supplement endpoint value

[0096] This example provides a biochar fortified fertilizer with pyrolyzed agricultural residue endpoint value and mineral supplement endpoint value, specifically including the following steps:

[0097] (1) Preparation of pyrolyzed agricultural residues: Wheat straw and corn stover with 8% moisture content were collected and mixed in a 1:1 ratio, and treated by mechanical cutting to a length of 2 centimeters. The treated mixture was loaded into a fixed-bed slow pyrolysis reactor, and raised from ambient temperature 25°C to 250°C at a heating rate of 10°C / min, and held for 30 minutes to fully release moisture; then raised from 250°C to 500°C at a heating rate of 5°C / min, and held at this temperature for 130 minutes. Subsequently, it was naturally cooled to 45°C under nitrogen protection, and after removal, exposed to ambient air in a well-ventilated area for 24 hours to stabilize the biochar. The prepared biochar had a pH value of 9.5, a specific surface area of 230 m² / g, and a fixed carbon content of 75%.

[0098] (2) Preparation of biochar-enhanced fertilizer: A mixture of 60 parts by weight of the above-mentioned pyrolyzed agricultural residues, 25 parts by weight of fresh straw mixture (wheat straw and corn stover mixed in a 1:1 ratio, cut to a length of 1 centimeter), and 15 parts by weight of mineral supplement, which includes 3 parts by weight of dolomite lime, 2 parts by weight of rock phosphate, and 1 part by weight of potassium sulfate, was prepared. First, the mineral supplement components were mixed uniformly, then fully mixed with the biochar, and then water was added to 30% moisture content, and finally the fresh straw mixture was added, and mixed in a rotary mixer at a speed of 15 RPM for 20 minutes. After mixing was completed, the material was stacked in aerobic conditions for a curing period of 72 hours, with the curing temperature maintained at 30°C, and the pile was turned over every 24 hours to ensure uniform conditions.

[0099] (3) Application of biochar-enhanced fertilizer: The prepared biochar-enhanced fertilizer was uniformly applied to the field at a rate of 3 tons per hectare, and then soil mixing was performed using a shallow disc harrow with a depth of 15 centimeters to ensure that the biochar-enhanced fertilizer was fully mixed with the surface soil. The application time was during the soil preparation period after crop harvest or simultaneously with the application of mushroom waste.

[0100] (4) Effect evaluation: The impact of biochar-enhanced fertilizer on the soil carbon pool was evaluated through soil sampling and analysis. The density separation method and thermogravimetric analysis method were used to evaluate the changes in carbon components, and the results showed that the proportion of stable carbon components (half-life > 100 years) in the total organic carbon in the treated area increased from 35% in the control area to 65%, indicating that the biochar-enhanced fertilizer significantly improved the stability and persistence of soil carbon.

[0101] Example 6: Biochar-enhanced fertilizer with pyrolyzed agricultural residues endpoint values and mineral supplement endpoint values

[0102] This example provides a biochar-enhanced fertilizer with pyrolyzed agricultural residues endpoint values and mineral supplement endpoint values, specifically including the following steps:

[0103] (1) Preparation of pyrolyzed agricultural residues: Wheat straw and corn straw with 12% moisture content were collected and mixed in a 1:1 ratio, and treated by mechanical cutting to a length of 5 centimeters. The treated mixture was loaded into a fixed-bed slow pyrolysis reactor, and raised from ambient temperature 22°C to 250°C at a heating rate of 10°C / min, and maintained at 250°C for 30 minutes; then raised from 250°C to 450°C at a heating rate of 5°C / min, and maintained at 450°C for 110 minutes. Subsequently, it was naturally cooled to 50°C under nitrogen protection, and after being taken out, exposed to ambient air in a ventilated area for 24 hours to stabilize the biochar. The prepared biochar had a pH value of 8.8, a specific surface area of 200 m² / g, and a fixed carbon content of 70%.

[0104] (2) Preparation of biochar fortified fertilizer: The above pyrolyzed agricultural residues were mixed in a ratio of 55 parts by weight, 30 parts by weight of fresh straw mixture (wheat straw and corn straw mixed in a 1:1 ratio, cut to a length of 2 centimeters), and 15 parts by weight of mineral supplement, which included 2 parts by weight of dolomite lime, 1 part by weight of rock phosphate, and 0.5 parts by weight of potassium sulfate. First, the mineral supplement components were mixed uniformly, then mixed thoroughly with the biochar, and then added water to 35% moisture content, and finally added the fresh straw mixture, and mixed in a rotary mixer at a speed of 18 RPM for 15 minutes. After mixing was completed, the material was stacked in aerobic conditions for a 48-hour curing period, with the curing temperature maintained at 25°C, and the pile turned over every 24 hours to ensure uniform conditions.

[0105] (3) Application of biochar fortified fertilizer: The prepared biochar fortified fertilizer was uniformly applied to the field at a rate of 2 tons / ha, and then soil mixing was performed using a shallow disc harrow with a depth of 10 cm to ensure that the biochar fortified fertilizer was thoroughly mixed with the surface soil. The application time was during the soil preparation period after crop harvest or simultaneously with the mushroom waste.

[0106] (4) Effect evaluation: The impact of biochar fortified fertilizer on the soil carbon pool was evaluated through soil sampling and analysis. The density separation method and thermogravimetric analysis method were used to evaluate the changes in carbon components, and the results showed that the proportion of stable carbon components (half-life > 100 years) in the total organic carbon in the treated area increased from 32% in the control area to 58%, indicating that the biochar fortified fertilizer significantly improved the stability and persistence of soil carbon.

[0107] Example 7: Grain-mushroom interplanting method with optimized combination of intermediate value parameters

[0108] The present embodiment provides a grain-mushroom interplanting method with optimized combination of intermediate value parameters, which specifically comprises the following steps:

[0109] (1) Layered substrate preparation: Wheat straw after harvest was collected and processed by a rotary chopper to 3-4 cm in length with 16% moisture content. Meanwhile, corn straw after harvest was collected and cut to 3-4 cm in length with 16% moisture content. The wheat straw, corn straw, rice bran, gypsum and calcium carbonate were mixed in the ratio of 42.5 parts by weight, 37.5 parts by weight, 6.5 parts by weight, 1.5 parts by weight and 0.75 parts by weight, respectively. The wheat straw was placed in the bottom layer, the corn straw was placed in the middle layer, and the mixture of rice bran, gypsum and calcium carbonate was placed in the top layer. The mixture was mixed in a horizontal paddle mixer at a speed of 22 RPM for 18 minutes, and water was gradually added to the mixture until the final moisture content of the substrate reached 66.5%. The C:N ratio of the substrate was measured to be 30:1.

[0110] (2) Hydrothermal treatment: The mixed substrate was placed in a heat-resistant grid container, ensuring that the thickness of the substrate did not exceed 27 cm. A water bath at 67°C was prepared, with a volume ratio of water to substrate of 4:1. The substrate was completely immersed in the water, and the water temperature was maintained between 67-68°C for 90 minutes. The water temperature was monitored every 15 minutes during the treatment. After the treatment, the substrate was placed on a clean drainage rack and naturally cooled at an ambient temperature of 23°C. The cooling rate was about 1.5°C / 15 minutes, and the cooling time was 5 hours. The final substrate temperature was reduced to about 25°C.

[0111] (3) Trichoderma harzianum inoculation: 5 grams of RootShield® commercial Trichoderma harzianum T-22 strain powder (ATCC20847) was dissolved in 10 liters of sterile water to make a uniform suspension. A low-pressure sprayer was used to evenly spray the suspension on the surface of the substrate, ensuring that 1 liter of suspension was used per 10 kilograms of substrate, with an inoculation amount of 10 6 CFU / g of the substrate weight. After spraying, the substrate was gently stirred to ensure uniform distribution of Trichoderma harzianum. The inoculated substrate was incubated at 25°C and 80% relative humidity for 30 hours, during which time a clear white mycelial network was observed on the surface of the substrate.

[0112] (4) Sequential inoculation system: First, Pleurotus ostreatus strain P-80 was inoculated on day 0 at a rate of 3% of the substrate weight. A layered inoculation method was used, with one layer of Pleurotus ostreatus wheat grain seeds evenly scattered between every 12 cm thick layer of substrate, focusing on the wheat straw area. The inoculated substrate was incubated at 25°C and 87% relative humidity for 7 days, during which time it was observed that the Pleurotus ostreatus mycelium covered about 75% of the surface area of the substrate.

[0113] On day 7, Lentinula edodes strain LE-4 was inoculated at 2.5% of the substrate weight. Using the point inoculation method, 2.5 cm deep holes were made every 12 cm on the surface of the substrate, and 7 g of Lentinula edodes sawdust pieces were placed in each hole, focusing on the rice bran-rich supplement area. After inoculation, the environmental temperature was adjusted to 22°C, and the relative humidity was reduced to 82%, and the cultivation was continued for 7 days.

[0114] On day 14, Pleurotus eryngii strain PE-2 was inoculated at 2% of the substrate weight. Using the trench inoculation method, 1.5 cm deep shallow trenches were made on the surface of the substrate, and Pleurotus eryngii wheat seed was evenly distributed along the trench, with about 22 g of seed per meter of trench, focusing on the corn straw-rich area. After inoculation, the environmental temperature was further reduced to 20°C, and the relative humidity was maintained at 82%, and the cultivation was continued for 17 days until the substrate was completely covered with mycelium.

[0115] (5) Field configuration of wheat-mushroom intercropping: Select a farmland where wheat (variety: Jimei 22) is planted, and configure the mushroom bed 38 days after the wheat emerges. Arrange according to the ratio of 2:1:2 (2 rows of wheat: 1 row of mushroom bed: 2 rows of wheat), with a wheat row spacing of 45 cm, a distance between wheat rows and mushroom beds of 75 cm, and a mushroom bed width of 65 cm. Install a drip irrigation system, lay the drip irrigation tape along the center of the mushroom bed, set the drip head spacing to 30 cm, and the flow rate to 1.7 L / h. Adjust the irrigation frequency according to the temperature, and when the daily average temperature is 18-22°C in spring, irrigate twice a day, each time 2.5 L / m², to maintain the relative humidity of the mushroom bed at about 80%.

[0116] (6) Application of waste mushroom material and biochar: After completing 3 harvests (about 85-95 days), collect the waste mushroom material, and measure the yield to be 3.2 tons of fresh weight per hectare. Crush the waste mushroom material into 6-8 cm blocks and evenly spread it in the field at a rate of 17.5 tons per hectare. At the same time, apply biochar fortified fertilizer at a rate of 2.5 tons per hectare, which is composed of 57.5 parts by weight of pyrolyzed agricultural residues (pyrolyzed at 475°C for 2 hours), 27.5 parts by weight of fresh straw mixture, and 15 parts by weight of mineral supplement (including 2.5 parts by weight of dolomite lime, 1.5 parts by weight of rock phosphate, and 0.75 parts by weight of potassium sulfate). Use a shallow disc harrow with a set depth of 12 cm to mix the waste mushroom material and biochar fortified fertilizer with the surface soil, and complete the mixing operation on the 4th day after the waste mushroom material is collected.

[0117] (7) Soil carbon pool monitoring: Sampling was performed in layers of 0-10 cm, 10-20 cm, and 20-30 cm. Five sampling points per hectare were randomly placed, and 10 soil cores were collected at each sampling point to form a composite sample. The total soil organic carbon content was determined using the Dumas dry combustion method, carbon fraction analysis was performed using density separation, and δ13C values were determined by isotope ratio mass spectrometry. The monitoring results showed that, within 24 months after treatment, the organic carbon content in the 0-30 cm soil layer increased by an average of 30%, and the carbon sequestration rate reached 2.8 tons of CO2 equivalent / hectare / year.

[0118] Example 8: Biochar-enhanced fertilizer with pyrolysis temperature endpoint value

[0119] This example provides a biochar-enhanced fertilizer with a pyrolysis temperature endpoint value, specifically comprising the following steps:

[0120] (1) Preparation of pyrolyzed agricultural residues: Collect wheat straw and corn straw with a moisture content of 10%, mix them in a 1:1 ratio, and mechanically cut them to a length of 3.5 cm. Load the treated mixture into a fixed-bed slow pyrolysis reactor, and raise the temperature from ambient temperature 23°C to 250°C at a rate of 10°C / min, maintain for 30 min; then raise the temperature from 250°C to 475°C at a rate of 5°C / min, maintain at this temperature for 120 min. Subsequently, cool naturally to 48°C under nitrogen protection, and expose to ambient air in a well-ventilated area for 24 hours to stabilize the biochar. The prepared biochar has a pH value of 9.2, a specific surface area of 215 m² / g, and a fixed carbon content of 73%.

[0121] (2) Preparation of biochar-enhanced fertilizer: Mix 57.5 parts by weight of the above-mentioned pyrolyzed agricultural residues, 27.5 parts by weight of fresh straw mixture (wheat straw and corn straw mixed in a 1:1 ratio, cut to a length of 1.5 cm), and 15 parts by weight of mineral supplement, which includes 2.5 parts by weight of dolomite lime, 1.5 parts by weight of rock phosphate, and 0.75 parts by weight of potassium sulfate. First, mix the mineral supplement components uniformly, then mix them thoroughly with the biochar, add water to 32.5% moisture content, and finally add the fresh straw mixture. Mix in a rotary mixer at a speed of 17 RPM for 17 minutes. After mixing is complete, stack the material in aerobic conditions for a 60-hour curing period, maintaining the curing temperature at 28°C, and turn the pile every 24 hours to ensure uniform conditions.

[0122] (3) Application of biochar-enhanced fertilizer: The prepared biochar-enhanced fertilizer was uniformly applied to the field at a rate of 2.5 tons per hectare, followed by soil mixing using a shallow disc harrow with a depth of 12.5 centimeters to ensure thorough mixing of the biochar-enhanced fertilizer with the surface soil. The application time was during the soil preparation period after crop harvest or simultaneous with the application of waste mushroom material.

[0123] (4) Effect evaluation: The impact of biochar-enhanced fertilizer on the soil carbon pool was assessed through soil sampling and analysis. The density separation method and thermogravimetric analysis were used to evaluate the changes in carbon components, and the results showed that the proportion of stable carbon components (half-life > 100 years) in the total organic carbon in the treated area increased from 34% in the control area to 62%, indicating that the biochar-enhanced fertilizer significantly improved the stability and persistence of soil carbon.

[0124] Comparative Example 1: Single-strain cultivation without sequential inoculation system

[0125] This comparative example used the same substrate formulation as Example 1 (40 parts by weight of wheat straw, 37.5 parts by weight of corn straw, 6 parts by weight of rice bran, 1.5 parts by weight of gypsum, and 0.8 parts by weight of calcium carbonate), but only inoculated with a single strain of Pleurotus ostreatus strain P-80 at an inoculation amount of 3% of the substrate weight. Other conditions were the same as in Example 1, including substrate preparation, hydrothermal treatment, Trichoderma harzianum pretreatment, field configuration, and waste mushroom material treatment.

[0126] The results showed that the yield of Pleurotus ostreatus cultivated with a single strain was 2.2 tons of fresh weight per hectare, which was 29.0% lower than the 3.1 tons of fresh weight per hectare in Example 1. At the same time, the soil organic carbon content only increased by 15.3% in 24 months, with a carbon sequestration rate of 1.3 tons of CO2 equivalent per hectare per year, which was significantly lower than the 2.4 tons of CO2 equivalent per hectare per year in Example 1. This indicates that the sequential inoculation system can significantly improve the utilization efficiency of straw resources and the soil carbon sequestration capacity, which is mainly due to the complementarity of different edible fungus enzyme systems and the phased degradation of the substrate.

[0127] Comparative Example 2: Grain-mushroom intercropping method without Trichoderma harzianum pretreatment

[0128] This comparative example used the same substrate formulation and sequential inoculation system as Example 3, but omitted the Trichoderma harzianum T-22 strain pretreatment step. Other conditions were the same as in Example 3.

[0129] The results show that without Trichoderma harzianum pretreatment, the total yield of the three edible fungi is 2.8 tons of fresh weight per hectare, which is 17.6% lower than 3.4 tons of fresh weight per hectare in Example 3. At the same time, the mycelial growth rate is significantly slowed down, and the coverage rate of Pleurotus ostreatus mycelium is only 65% on the 7th day (80% in Example 3), and the overall cultivation period is extended by about 15%. The soil organic carbon content increases by 28.4% within 24 months, and the carbon sequestration rate is 2.7 tons of CO2 equivalent per hectare per year, which is lower than 3.4 tons of CO2 equivalent per hectare per year in Example 3. This indicates that Trichoderma harzianum pretreatment creates favorable conditions for subsequent edible fungi growth by degrading part of the complex substrate in advance, and can accelerate the transformation and stabilization of carbon elements in the soil.

[0130] Comparative Example 3: Grain and mushroom interplanting method without biochar fortified fertilizer

[0131] This comparative example uses the same substrate formula, Trichoderma harzianum pretreatment and sequential inoculation system as Example 7, but does not add biochar fortified fertilizer when applying waste mushroom material, only applies waste mushroom material to the soil at a dosage of 17.5 tons per hectare. Other conditions are the same as Example 7.

[0132] The results show that without biochar fortified fertilizer, the edible fungi yield is similar to Example 7, which is 3.1 tons of fresh weight per hectare. However, the soil organic carbon content only increases by 18.2% within 24 months, which is significantly lower than 30% in Example 7. The carbon sequestration rate is 1.5 tons of CO2 equivalent per hectare per year, which is much lower than 2.8 tons of CO2 equivalent per hectare per year in Example 7. At the same time, density separation method analysis shows that the proportion of light components (<1.8 grams per cubic centimeter) in total organic carbon is 45%, which is higher than 28% in Example 7, indicating that without biochar fortified fertilizer, the newly added organic carbon is mainly in the form of easy-to-decompose, which has poor stability. This indicates that biochar fortified fertilizer plays an irreplaceable role in improving the stability and durability of the soil carbon pool.

[0133] Comparative Example 4: Traditional straw return to field method

[0134] This comparative example uses the traditional method of directly returning straw to the field, mixes wheat and corn straw in a 1:1 ratio, cuts them to 5-10 centimeters, and directly applies them to the soil surface at a dosage of 40 tons per hectare, then uses a shallow disc harrow to till and mix.

[0135] The results show that the traditional straw returning method increased the soil organic carbon content by 10.5% within 24 months, with a carbon sequestration rate of only 0.7 tons of CO2 equivalent per hectare per year, which is much lower than the levels of Examples 1-8. At the same time, the emission of methane and nitrous oxide during the decomposition of straw is relatively high, which partially offsets the carbon sequestration benefits. In addition, the slow decomposition of untreated straw affects the growth of the following crop, resulting in a slight decrease (about 3%) in grain yield. This shows that the combination of the grain-mushroom interplanting method of the present application with the biochar-enhanced fertilizer has significant advantages in straw resource utilization efficiency and soil carbon pool improvement.

[0136] Comparative Example 5: Separate mushroom bed cultivation without grain-mushroom interplanting

[0137] This comparative example uses the same substrate formulation, Trichoderma harzianum pretreatment, and sequential inoculation system as Example 2, but does not use the field grain-mushroom interplanting mode, but carries out edible fungus cultivation in a separate mushroom house. Other conditions are the same as Example 2.

[0138] The results show that the total yield of edible fungi in separate mushroom bed cultivation is 3.5 tons of fresh weight per hectare of mushroom bed, slightly higher than 2.8 tons of fresh weight per hectare in Example 2, but considering that the grain crop is also planted in Example 2, the overall land use efficiency is significantly lower. After the spent mushroom substrate is applied to the soil, the soil organic carbon content increases by 21.3% within 24 months, with a carbon sequestration rate of 1.8 tons of CO2 equivalent per hectare per year, which is lower than the 2.2 tons of CO2 equivalent per hectare per year in Example 2. This shows that the grain-mushroom interplanting mode promotes the conversion of organic matter to stable soil carbon through the interaction of crop roots and mycelium, while improving land use efficiency.

[0139] To evaluate the effect of the grain-mushroom interplanting method of the present application, each example and comparative example was systematically tested, including edible fungus yield, grain crop yield change, soil organic carbon content change, carbon component distribution, and greenhouse gas emission. The test results are shown in Tables 1-3.

[0140] Table 1. Edible fungus yield and grain crop yield increase effect

[0141] Sample No. Pleurotus ostreatus yield (tons fresh weight / ha) Lentinula edodes yield (tons fresh weight / ha) Pleurotus eryngii yield (tons fresh weight / ha) Total yield (tons fresh weight / ha) Grain crop yield increase rate (%) Example 1 1.4 0.9 0.8 3.1 14.2 Example 2 1.2 0.8 0.8 2.8 12.5 Example 3 1.5 1 0.9 3.4 17.8 Example 4 1.1 0.7 0.8 2.6 12.1 Example 7 1.4 0.9 0.9 3.2 15.3 Comparative Example 1 2.2 0 0 2.2 8.5 Comparative Example 2 1.2 0.8 0.8 2.8 14.1 Comparative Example 3 1.4 0.8 0.9 3.1 15 Comparative Example 4 0 0 0 0 -3.2 Comparative Example 5 1.6 1 0.9 3.5 0

[0142] Table 2. Soil organic carbon content change and carbon sequestration effect

[0143] Sample No. Initial SOC content (g / kg) SOC content after 24 months (g / kg) SOC increase rate (%) Carbon sequestration rate (tonnes CO2e / ha / year) Example 1 12.8 16.4 28.5 2.4 Example 2 13.2 16.7 26.8 2.2 Example 3 11.5 15.5 35 3.4 Example 4 12 15 25 2.1 Example 7 12.5 16.3 30 2.8 Comparative Example 1 12.8 14.7 15.3 1.3 Comparative Example 2 11.5 14.8 28.4 2.7 Comparative Example 3 12.5 14.8 18.2 1.5 Comparative Example 4 12.3 13.6 10.5 0.7 Comparative Example 5 13 15.8 21.3 1.8

[0144] Table 3. Soil carbon component distribution and greenhouse gas emission

[0145] Sample No. Light component carbon (%) Intermediate component carbon (%) Heavy component carbon (%) Stable carbon ratio (%) Methane emissions (kg CH4 / ha / yr) Nitrous oxide emissions (kg N2O / ha / year) Example 1 30 22 48 58 -1.2 0.8 Example 2 32 21 47 56 -1 0.7 Example 3 25 25 50 65 -1.5 0.6 Example 4 35 20 45 55 -0.8 0.9 Example 7 28 23 49 62 -1.3 0.7 Comparative Example 1 40 20 40 45 -0.5 1.2 Comparative Example 2 32 23 45 52 -0.9 0.8 Comparative Example 3 45 20 35 42 -0.7 1 Comparative Example 4 55 25 20 30 2.5 1.8 Comparative Example 5 38 22 40 48 -0.6 1.1

[0146] Note: Light fraction carbon (<1.8 g / cm3), intermediate fraction carbon (1.8-2.2 g / cm3), and heavy fraction carbon (>2.2 g / cm3) represent different stability of soil organic carbon fractions, respectively; Stable carbon ratio refers to the percentage of carbon fraction with half-life >50 years in total organic carbon; Methane emission is negative value indicating net absorption.

[0147] From the test results of Tables 1-3, the grain-mushroom interplanting method of the present application has the following remarkable effects:

[0148] 1. Edible fungus yield: The sequential inoculation system (Examples 1-8) increased the total yield by 18-55% compared to single species cultivation (Comparative Example 1), demonstrating the advantages of multiple species complementary utilization of straw resources. Trichoderma harzianum pretreatment (Example 3 vs. Comparative Example 2) increased the total yield of edible fungi by 17.6%, verifying the growth-promoting effect of microbial pretreatment.

[0149] 2. Grain crop yield increase: The grain-mushroom interplanting system increased the grain crop yield by 12-18% on average, significantly better than traditional straw return (-3.2%) and mushroom bed cultivation alone (0%), indicating the promoting effect of mycorrhizal interaction on crop growth.

[0150] 3. Soil carbon pool improvement: The soil organic carbon increase rate of the method of the present application is 25-35%, and the carbon sequestration rate is 2.1-3.4 tons CO2 equivalent / ha / year, which is much higher than the 10.5% and 0.7 tons CO2 equivalent / ha / year of traditional straw return. In particular, the examples with added biochar fortified fertilizer significantly improved the carbon sequestration efficiency (30% vs. 18.2%) compared to Comparative Example 3 without added biochar fortified fertilizer.

[0151] 4. Carbon fraction stability: The method of the present application increased the proportion of stable carbon (half-life >50 years) to 55-65%, while traditional straw return was only 30%, indicating that the present application significantly improved the stability and persistence of soil carbon through microbial transformation and biochar fortification.

[0152] 5. Greenhouse gas emission reduction: The method of the present application not only increased the soil carbon pool, but also showed net methane absorption (-0.8 to -1.5 kg CH4 / ha / year) and lower nitrous oxide emission (0.6-0.9 kg N2O / ha / year), which was significantly better than traditional straw return (2.5 and 1.8 kg / ha / year), further improving the climate change mitigation benefits.

[0153] Based on the test results of all the examples, Example 3 showed the best performance, which adopted a substrate formula of 45 parts by weight of wheat straw and 40 parts by weight of corn straw, and cooperated with 3 tons / ha of biochar fortified fertilizer (containing 60 parts by weight of pyrolysis of agricultural residues), and the carbon sequestration rate reached 3.4 tons of CO2 equivalent / ha / year, and the stable carbon proportion reached 65%. This shows that a high proportion of wheat and corn straw formula, combined with a high dose of biochar fortified fertilizer, can maximize the effect of soil carbon pool improvement.

[0154] The straw resource efficient utilization and soil carbon pool improvement method of the grain-mushroom interplanting of the present application involves a variety of complex biological and chemical processes. According to the experimental results, the mechanism of action can be analyzed from the following aspects:

[0155] 1. Multi-species enzyme complementation mechanism: The present application adopts a sequential inoculation system of Pleurotus ostreatus, Lentinula edodes and Pleurotus eryngii, which fully utilizes the enzyme complementation of different edible fungi. Pleurotus ostreatus produces high-activity laccase (150-300 U / g substrate) and manganese peroxidase (50-100 U / g substrate), which preferentially degrades lignin components; Lentinula edodes produces high-activity manganese peroxidase (120-250 U / g substrate) and medium-activity laccase (80-150 U / g substrate), which can balance the degradation of each component; Pleurotus eryngii produces high-activity multifunctional peroxidase (100-200 U / g substrate), which can degrade more stubborn substrates.

[0156] This enzyme complementation makes the lignin, cellulose and hemicellulose in the straw fully degraded, improving the resource utilization efficiency. Experiments have shown that the total yield of the sequential inoculation system is increased by 18-55% compared with single strain cultivation (Comparative Example 1), which confirms this mechanism.

[0157] 2. Trichoderma harzianum pretreatment growth promotion mechanism: Trichoderma harzianum T-22 strain pretreatment promotes the growth of edible fungi in the following ways: on the one hand, it produces cellulase (β-1,4-endoglucanase, cellulose hydrolysis enzyme) and hemicellulase (endo-1,4-β-xylanase, β-xylosidase) to partially degrade the complex substrate, providing more easily accessible nutrients for subsequent edible fungi; on the other hand, it produces volatile organic compounds (such as 6-pentyl-α-pyrone) and bioactive substances to stimulate the growth and branching of edible fungus mycelium.

[0158] Experiments showed that Trichoderma harzianum pretreatment (Example 3 vs. Comparative Example 2) increased the mycelium coverage rate by about 23% (80% coverage in 7 days vs. 65%) and the total yield by 17.6%, verifying this growth-promoting mechanism.

[0159] 3. Growth-promoting mechanism of the interaction between crops and mushrooms: In the crop-mushroom interplanting system, a symbiotic relationship similar to mycorrhiza is formed between the crop roots and the mycelium. The mushroom mycelium can help the crop roots obtain insoluble nutrients such as phosphorus and potassium in the soil, and at the same time, it can secrete plant hormone substances (such as auxin and gibberellin) to promote root development; the crop provides the mycelium with easily available carbon sources through root exudates.

[0160] In addition, the development of the mycelial network also improves soil structure and enhances soil drought resistance and water retention capacity. This symbiotic relationship results in an average increase of 12-18% in crop yield in the crop-mushroom interplanting system, while traditional straw return leads to a 3.2% decrease in yield due to temporary nutrient fixation.

[0161] 4. Carbon stabilization mechanism: The carbon stabilization of the present application is mainly achieved through the following ways:

[0162] (1) Fungal transformation pathway: The edible fungus converts the carbonaceous substances in the straw into more stable fungal chitin and melanin. Chitin (β-(1→4)-N-acetylglucosamine polymer) has a half-life of 5-15 years in soil, and melanin (a complex heterocyclic aromatic polymer) has a half-life of more than 10-50 years.

[0163] (2) Physical protection of biochar: Biochar has a highly developed microporous structure (0.1-10 μm), which can physically wrap organic carbon molecules, preventing them from being attacked by microbial enzymes. At the same time, the aromatic structure on the surface of biochar can form π-π interaction with organic matter, further enhancing the protection effect.

[0164] (3) Mineral-organic matter complex: The mineral supplements (dolomite lime, phosphate rock) in the biochar fortified fertilizer provide Ca²⁺, Mg²⁺ and other multivalent cations, which can bridge the negatively charged organic matter and the mineral surface to form stable mineral-organic matter complexes.

[0165] (4) Carbonate precipitation: The fungal-mediated calcium carbonate precipitation process fixes CO2 as stable carbonate minerals (CaCO3), and these mineral carbon can be preserved in the soil for hundreds of years.

[0166] These pathways work together to make the proportion of stable carbon (half-life > 50 years) formed by the method of the present application reach 55-65%, which is much higher than the 30% of traditional straw return, explaining the excellent carbon sequestration effect.

[0167] 5. Greenhouse gas emission reduction mechanism: The method of the present application exhibits net methane uptake and lower nitrous oxide emission, the mechanism of which lies in:

[0168] (1) Methane oxidation: The porous structure of biochar provides an ideal habitat for methanotrophs, and the trace elements contained in biochar, such as copper, can act as cofactors for methane monooxygenase, promoting methane oxidation.

[0169] (2) Nitrogen transformation regulation: Biochar slows down the rate of nitrogen transformation by adsorbing NH4⁺ and NO3⁻, and its alkaline property inhibits the key enzyme of nitrification, thereby reducing N2O production.

[0170] (3) Electron donor-acceptor balance: The stable organic carbon in the waste mushroom material serves as an electron donor, forming a good balance with the electron acceptors (such as NO3⁻, Fe³⁺) in the soil, reducing the production of methane and nitrous oxide under anaerobic conditions.

[0171] These mechanisms work together to not only increase the soil carbon pool but also achieve net reduction of greenhouse gases, further improving the benefits of climate change mitigation.

[0172] The present application provides a method for efficient utilization of straw resources and improvement of soil carbon pool in interplanting of grain and mushroom, which realizes efficient utilization of straw resources and significant improvement of soil carbon pool through technical measures such as construction of multi-strain sequential inoculation system, Trichoderma harzianum pretreatment, interplanting mode of grain and mushroom, and application of biochar fortified fertilizer.

[0173] The experimental results show that the method of the present application has the following advantages over traditional straw field: (1) the yield of edible fungi reaches 2.6-3.4 tons fresh weight per hectare; (2) the yield of grain crops increases by 12-18%; (3) the increase rate of soil organic carbon reaches 25-35%; (4) the carbon sequestration rate reaches 2.1-3.4 tons CO2 equivalent per hectare per year; (5) the proportion of stable carbon reaches 55-65%; (6) net methane uptake and nitrous oxide emission reduction are achieved.

[0174] These effects benefit from the synergistic effect of mechanisms such as multi-strain enzyme complementation, Trichoderma harzianum pretreatment for growth promotion, grain-mushroom interaction for growth promotion, multi-pathway carbon stabilization, and greenhouse gas emission reduction. Among them, the formula and process parameters used in Example 3 (45 parts by weight of wheat straw, 40 parts by weight of corn straw, and high-dose biochar fortified fertilizer) show the best performance, with a carbon sequestration rate of 3.4 tons CO2 equivalent per hectare per year and a stable carbon proportion of 65%.

[0175] The method of the present application not only solves the problem of resource utilization of agricultural waste, but also achieves the dual environmental benefits of soil quality improvement and climate change mitigation, while bringing significant economic benefits through the increase of edible fungi and grain production, providing a new idea and new technology for sustainable agricultural development.

[0176] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for efficient utilization of straw resources and enhancement of soil carbon pool in grain-mushroom intercropping, characterized in that, Includes the following steps: A layered matrix is ​​prepared, comprising 40-45 parts by weight of wheat straw, 35-40 parts by weight of corn straw, 5-8 parts by weight of rice bran, 1-2 parts by weight of gypsum and 0.5-1 parts by weight of calcium carbonate; The layered matrix was subjected to hydrothermal treatment at 65-70°C for 90±5 minutes, and then cooled to 25±2°C. Trichoderma harzianum strain T-22 was inoculated into the cooled substrate at an inoculum size of 10% of the substrate weight. 6 CFU / g, and incubated at 25±2℃ and 75-85% relative humidity for 24-36 hours; A sequential inoculation system was used. First, oyster mushrooms were inoculated at a rate of 3% of the substrate weight. Seven days later, shiitake mushrooms were inoculated at a rate of 2.5% of the substrate weight. Seven days after that, king oyster mushrooms were inoculated at a rate of 2% of the substrate weight. Mushroom beds are arranged between rows of grain crops in a ratio of 2:1:2, where the ratio refers to 2 rows of grain crops, 1 row of mushroom bed, and 2 rows of grain crops, and the width of the mushroom bed is 60-70 cm. After harvesting the mushroom beds, apply 15-20 tons / hectare of waste mushroom substrate to the soil and add 2-3 tons / hectare of biochar-enhanced fertilizer. Monitoring and verification showed that soil organic carbon content increased by 25-35% within 24 months.

2. The method according to claim 1, characterized in that, The wheat straw and corn straw have a particle size of 2-5 cm and a moisture content of 14-18%, obtained through mechanical processing; the final moisture content of the layered matrix is ​​65-68%, and the C:N ratio is 28-32:

1.

3. The method according to claim 1, characterized in that, In the hydrothermal treatment step, the ratio of water to substrate is 4:1 (volume ratio). After treatment, the substrate is naturally cooled at a cooling rate of 1-2℃ / 15 minutes for 4-6 hours.

4. The method according to claim 1, characterized in that, The Trichoderma harzianum strain T-22 (ATCC 20847) was added in the form of a water-soluble powder. A suspension was prepared by dissolving 5 grams of the product in 10 liters of sterile water and spraying it evenly on the surface of the substrate. 1 liter of suspension was used for every 10 kilograms of substrate.

5. The method according to claim 1, characterized in that, The sequential inoculation system: Oyster mushroom (Pleurotus ostreatus) was inoculated on day 0, and the culture temperature was 24-26℃, with a relative humidity of 85-90%. Shiitake mushrooms (Lentinula edodes) were inoculated on day 7, and cultured at a temperature of 21-24℃ and a relative humidity of 80-85%. King oyster mushroom (Pleurotus eryngii) was inoculated on day 14, and cultured at a temperature of 18-22℃ and a relative humidity of 80-85%. Each strain was inoculated using either a stratified or fixed-point inoculation method. Oyster mushrooms were preferentially inoculated in wheat straw areas, shiitake mushrooms in nutrient-rich supplementary areas, and king oyster mushrooms in corn straw areas.

6. The method according to claim 1, characterized in that, The grain crop used in the grain-mushroom intercropping is selected from wheat or corn. The mushroom bed is deployed 30-45 days after the grain crop emerges. The mushroom bed uses a drip irrigation system to maintain a relative humidity of 75-85%. The drip irrigation system has a drip head spacing of 30 cm and a daily water supply of 2-4 liters / square meter.

7. The method according to claim 1, characterized in that, The biochar-fortified fertilizer is composed of the following components: 55-60 parts by weight of pyrolytic agricultural residues, wherein the pyrolytic agricultural residues are obtained by pyrolysis at 450-500°C for 2 hours; 25-30 parts by weight of fresh straw mixture; 10-15 parts by weight of a mineral supplement, said mineral supplement comprising 2-3 parts by weight of dolomite lime, 1-2 parts by weight of phosphate rock and 0.5-1 parts by weight of potassium sulfate.

8. The method according to claim 7, characterized in that, The preparation of the pyrolytic agricultural residue includes the following steps: Mix wheat straw and corn straw with a moisture content of 8-12% in a 1:1 ratio and cut them into lengths of 2-5 cm. In a fixed-bed slow pyrolysis reactor, the temperature was increased from ambient temperature to 250°C at a rate of 10°C / min and held for 30 minutes. Then, increase the temperature from 250℃ to 450-500℃ at a rate of 5℃ / min, and maintain this temperature for 120±10 minutes. The biochar was naturally cooled to below 50°C in an inert atmosphere and then exposed to ambient air in a ventilated area for 24 hours to stabilize it.

9. The method according to claim 1, characterized in that, The waste mushroom substrate is collected after 2-3 harvests. First, the waste mushroom substrate is broken into 5-10 cm pieces and spread evenly in the field. Then, a shallow disc rake with a depth of 10-15 cm is used to mix the soil. Mixing should be carried out within 7 days after the waste mushroom substrate is removed.

10. The method according to claim 1, characterized in that, The steps for monitoring and verifying soil organic carbon content include: Soil samples were taken at depths of 0-10 cm, 10-20 cm, and 20-30 cm. Five composite samples were collected per hectare, and each composite sample consisted of 10 individual soil cores; Total organic carbon content was determined using the Dumas dry combustion method; Carbon composition analysis was performed using density separation method, separating light components (<1.8 g / cm³), intermediate components (1.8–2.2 g / cm³), and heavy components (>2.2 g / cm³). δ was determined by isotope ratio mass spectrometry. 13 C value, used to track changes in carbon sources; The system's carbon sequestration rate reaches 2.1-3.4 tons of CO2 equivalent per hectare per year.