A biochar-compost composition and its use in the control of potato scab

Abstract

The application discloses a biochar-mushroom residue composition and application thereof in prevention and treatment of potato scab, and relates to the technical field of agriculture. The biochar-mushroom residue composition is prepared by mixing wheat biochar and mushroom residue, and the biochar-mushroom residue composition is applied to the soil before potato seeding, so that the disease index of potato scab can be obviously reduced, the incidence of potato scab is reduced, and the potato scab has excellent prevention and treatment effect. The application provides an efficient and feasible technical scheme for green prevention and control of potato scab, can reduce the use of chemical fungicides, realizes recycling of agricultural wastes (wheat straw and mushroom residue), conforms to the concept of circular agriculture, has remarkable ecological and economic benefits, and is suitable for green popularization and application.

Description

Technical Field

[0001] This invention relates to the field of agricultural technology, and in particular to a biochar-microbial residue composition and its application in the prevention and control of potato scab. Background Technology

[0002] potato( Solanum tuberosum As a crucial food crop, potato production security is directly related to food security. China, a major potato producer, faces increasingly prominent potato disease problems due to expanded planting scale, extended continuous cropping years, agricultural restructuring, and improper management in some production stages. Among these, pathogenic Streptomyces (Streptomyces cerevisiae) pose a significant threat. Streptomyces spp.) cause potato scab ( potato common scab PCS (Polymorphic Sclerosis) is widespread and causes serious harm, and has become one of the key bottlenecks restricting the high-quality development of the industry, causing continuous economic losses to agricultural production.

[0003] Currently, potato scab control methods mainly include chemical control, breeding of disease-resistant varieties, agricultural interventions (such as crop rotation and soil pH adjustment), and biological control (such as the use of beneficial microorganisms). Among these, chemical control is the most widely used method, primarily involving seed potato treatment or pesticide application during the growing season to suppress the disease. While effective to some extent, it carries risks such as pesticide residues, environmental pollution, pathogen resistance, and damage to the soil microecology. Although breeding disease-resistant varieties is one of the preferred approaches for scab control, no potato variety currently possesses stable resistance to the disease. While agricultural interventions can mitigate the disease, their effectiveness in adjusting pH is limited by soil buffering capacity, and crop rotation is unsuitable for large-scale industrial development. Utilizing beneficial microorganisms for biological control is considered an eco-friendly alternative to chemical pesticides for scab control; however, the effectiveness of biocontrol agents is often constrained by complex field conditions, and their stability, persistence, and broad-spectrum efficacy need further improvement. Therefore, developing an efficient, environmentally friendly, and sustainable green control technology to combat potato scab has become an urgent need in current agricultural production and plant protection.

[0004] Agricultural waste is a key measure to promote the green transformation of agriculture and the development of ecological circular agriculture. It is characterized by its large quantity, wide distribution, and the fact that it is beneficial when used but harmful when discarded. It can be utilized as a resource, transformed into biomass energy, organic fertilizer, and soil conditioner to drive the development of ecological circular agriculture and the green transformation of agriculture. Biochar, as a novel environmental functional material, is formed by the high-temperature carbonization of biomass under anaerobic conditions. It possesses characteristics such as high specific surface area, strong adsorption capacity, and stable physicochemical properties. Mushroom residue (WMS), as a byproduct of agricultural waste composting, is rich in active organic matter, amino acids, and various beneficial microorganisms. Therefore, developing a highly efficient, stable, and environmentally friendly green control technology for potato scab by scientifically proportioning and synergistically applying these two wastes—biochar and mushroom residue—can not only reduce dependence on chemical pesticides but also greatly enhance the resource value of agricultural waste, possessing significant theoretical and practical value. Summary of the Invention

[0005] In view of the above-mentioned prior art, the purpose of this invention is to provide a biochar-microbial residue composition and its application in the prevention and control of potato scab.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a biochar-mushroom residue composition, which is prepared by mixing wheat biochar and mushroom residue in a mass ratio of (3-7):(3-7).

[0007] Preferably, the wheat biochar has an organic carbon content of 70%-75%, a nitrogen content of 0.6%-1.4%, a available phosphorus content of 900-1600 mg / kg, a available potassium content of 14-40 mg / kg, a pH of 6-9, a pore volume of 45%-55%, and a pore size of 0.30-0.40 cm³. 3 / g, particle size is 150-250 mesh.

[0008] Preferably, the mushroom residue is obtained by naturally composting the waste mushroom logs after oyster mushroom cultivation.

[0009] Furthermore, the natural composting process takes 25-35 days.

[0010] In a second aspect, the present invention provides the application of the above-described biochar-microbial residue composition in the prevention and control of potato scab.

[0011] Preferably, the potato scab disease is caused by Streptomyces scabii (Streptomyces scabii). Streptomyces bottropensis This was caused by ( ).

[0012] A third aspect of the present invention provides a method for preventing and controlling potato scab, comprising the following steps: (1) After deep tillage of the soil, dig planting trenches, then spread the above biochar-microbial residue composition on the planting trenches and perform rotary tillage. (2) Sow potato seed potatoes in the planting furrow after rotary tillage, ridge the soil and carry out field management.

[0013] As a preferred option, in step (1), the deep tillage depth is 20-25cm and the planting ditch depth is 15-20cm.

[0014] Preferably, in step (1), the amount of biochar-sludge composition applied is 44-76 g / potato.

[0015] As a preferred option, in step (2), the spacing between potato seed tubers is 20-30 cm and the planting depth is 8-10 cm.

[0016] Preferably, in step (2), the height of the planting ridge is 20-30cm.

[0017] As a preferred option, in step (2), the soil moisture content is 60%-70% during field management.

[0018] The beneficial effects of this invention are: This invention utilizes a mixture of wheat biochar and mushroom residue to prepare a biochar-mushroom residue composition. Applying this composition to the soil before potato planting significantly reduces the disease index and incidence of potato scab, demonstrating excellent control over the disease. This invention provides an efficient and feasible technical solution for the green control of potato scab, reducing the use of chemical fungicides and achieving the recycling and reuse of agricultural waste (wheat straw and mushroom residue), aligning with the concept of circular agriculture. It offers significant ecological and economic benefits and is suitable for green promotion and application. Attached Figure Description

[0019] Figure 1 : Average disease index of different treatment groups; Figure 2 : Average incidence rate in different treatment groups. Detailed Implementation

[0020] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0021] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0022] The experimental materials used in the embodiments of this invention are all conventional experimental materials in the art and can be purchased through commercial channels.

[0023] In this invention, the wheat straw biochar was purchased from Henan Lanri Environmental Protection Co., Ltd., and it has an organic carbon content of 72%, a nitrogen content of 0.6-1.4%, a available phosphorus content of 900-1600 mg / kg, a available potassium content of 14-40 mg / kg, a pH of 6-9, a pore volume of 50%, and a pore size of 0.35 cm³. 3 / g, with a particle size of 200 mesh. This biochar was prepared under the process conditions of carbonization temperature of 500℃ and heating rate of 7.8℃ / min.

[0024] The mushroom residue was purchased from a Taobao store selling peanut shell wholesale. It is made from waste mushroom logs after oyster mushroom cultivation. After being manually dismantled and impurities removed, it was naturally composted for 30 days.

[0025] The seed potatoes were provided by the Zaozhuang Academy of Agricultural Sciences, with a size of approximately 50-60 g per piece, free from disease spots and damage.

[0026] Streptomyces scabiei ( Streptomyces bottropensis The strain numbered AMCC 400023 is preserved in the AMCC laboratory of Shandong Agricultural University.

[0027] Example 1: Field Trial The experiment was conducted at the Zaozhuang Academy of Agricultural Sciences experimental base in Shandong Province. The soil type was brown soil with a sandy texture, which is the main soil type in the major potato-producing area of ​​Zaozhuang City. Soil samples were collected from the 0-20cm soil layer of the experimental field. The basic physicochemical properties of the soil were as follows: pH 8.12, organic matter 1.37%, total nitrogen 1240 mg / kg, available phosphorus 47.08 mg / kg, and available potassium 236.1 mg / kg. The previous crop in the experimental field was potatoes. The soil was prepared by plowing, sun-drying, and leveling. The soil moisture content was suitable for potato growth and met the environmental conditions for the occurrence of scab disease.

[0028] The experiment will take place from August 2025 to December 2025; the crop variety is "Dutch Fifteen", also known as Favorita.

[0029] This experiment set up 7 treatment groups, as shown in Table 1.

[0030] Table 1 Design dosage for each treatment group A fully randomized block design was used, with one parallel plot for each treatment. The plot size was 4.9 m × 3 m, with 4 rows of 25 plants per row, a plant spacing of 25 cm, a row spacing of 60 cm, and 100 plants per plot. A guard row was set up around the perimeter, and a 0.8 m walkway was left between blocks.

[0031] 1. The experimental procedure is as follows: (1) Land preparation and material application: Three days before sowing, the experimental field was thoroughly plowed to a depth of 20-25cm to remove weeds, crop residues, stones and other impurities. After leveling the land, planting ditches were dug according to the design specifications of the plot, with a depth of 15-20cm.

[0032] (2) Applying materials: According to the treatment design dosage in Table 1, the wheat biochar / mushroom residue / biochar-residue composition was spread in the planting furrow. A small rotary tiller was used to thoroughly mix the spread material with the 0-20 cm soil layer, and the mixing depth was consistent with the planting furrow depth.

[0033] (3) Potato planting: The method of manual planting is adopted. Potato seed tubers are directly planted in the planting furrows where the materials have been spread. One seed tuber is placed in each hole, with a spacing of 25 cm. The planting depth is controlled at 8-10 cm to ensure that the seed tuber has a small amount of contact with the materials.

[0034] (4) Ridging and mixing: After planting, immediately create raised beds manually, turning the soil from both sides of the planting furrow into the furrow to thoroughly mix the seed potatoes, materials, and the 0-20 cm soil layer, forming planting beds about 25 cm high. Then water thoroughly once to maintain a high soil moisture content, which will promote subsequent sprouting and growth of the potatoes.

[0035] (5) Inoculation with pathogens: The pathogen—Streptomyces scabies ( Streptomyces bottropensis Inoculate the bacteria onto Gao's No. 1 solid medium. Invert the inoculated culture dish in a 28°C incubator and incubate for 7 days to activate the pathogen. Pick a typical single colony of the activated pathogen and inoculate it onto SNB liquid medium. Incubate at 28°C with a shaker at 180 rpm for 3 days. After incubation, perform aseptic operations in a laminar flow hood, inoculate 100 μL onto Gao's No. 1 solid medium and spread it. Incubate at 28°C until gray spores appear. Gently scrape off the spores with a sterile scalpel, rinse with 100 μL of sterile water and transfer to a 1.5 mL centrifuge tube. Filter the suspension using sterile gauze and store at 4°C for later use.

[0036] The prepared spore suspension was used for root irrigation during the potato tuber formation and tuber enlargement stages, with 200 mL applied to each seedling each time.

[0037] (6) Field management: Throughout the entire growth period, field management is uniformly carried out by the Zaozhuang Academy of Agricultural Sciences. After emergence, watering is carried out in a timely manner according to soil moisture to maintain soil moisture content at 60%-70%. During this period, weeds are removed manually.

[0038] 2. Experimental statistics and analysis of experimental results: To ensure the scientific validity and reliability of the experimental data, all data were systematically processed using SPSS 25.0 statistical analysis software. One-way ANOVA was used to analyze data differences to determine the significance of differences between treatment groups with different biochar ratios. Subsequently, Duncan's multiple comparison method was used for pairwise comparisons between groups, with the significance level set at P < 0.05, meaning that a P value less than 0.05 was considered statistically significant.

[0039] (1) Average disease index and baseline corrected disease index: After the potatoes matured, 24 plants were randomly selected from each plot using a five-point sampling method. Field harvesting and sampling were completed in Zaozhuang on December 11th. From December 12th to December 27th, potatoes were cleaned, photographed, and their scab disease severity was assessed in the laboratory. The average disease index and the baseline corrected disease index were calculated. The results are shown in Table 3. Figure 1 As shown in Table 2, the grading criteria for potato scab are as follows.

[0040] Table 2 Grading Criteria for Potato Scab Disease index = ∑(Disease level × Number of potatoes at that level) / (Highest disease level × Total number of potatoes) × 100%; The average disease index is the average of the disease index of 24 plants. Baseline corrected disease index = treatment disease index − negative control disease index.

[0041] Table 3 Mean disease index and baseline corrected disease index for different treatment groups From Table 3 and Figure 1It can be seen that the negative control (ZCK), without any substrate or pathogen inoculation, had an average disease index of 17.27% for potato scab, representing the baseline level of natural disease occurrence in the field. The positive control (ZPCS), without substrate but inoculated with the pathogen, had the highest average disease index, reaching 44.28%, with a baseline-corrected disease index of 27.01%, indicating that successful artificial inoculation of the pathogen exerted stable disease pressure. The disease indices of 100% wheat biochar (Z100XC) and 100% mushroom substrate (Z0XC) were significantly lower than those of the positive control group, indicating that both single substrates had a certain inhibitory effect on potato scab. However, the control effect of both single substrates was limited, and the disease index was still significantly higher than that of the negative control group.

[0042] The disease index of the biochar-mushroom residue combination was significantly lower than that of the single-material treatment groups (Z100XC and Z0XC), indicating a significant synergistic effect between biochar and mushroom residue. As the proportion of mushroom residue increased, the disease index of the mixed material treatment groups continued to decrease, indicating that mushroom residue played a dominant role in the synergistic effect. Among them, the biochar-mushroom residue combination (Z30XC), prepared by mixing wheat biochar and mushroom residue at a mass ratio of 3:7, had an average disease index of only 17.81% and a baseline corrected disease index of only 0.54%, showing no significant difference from the negative control group. It almost completely inhibited the pathogenicity of artificially inoculated pathogens and was the optimal ratio in this experiment.

[0043] (2) Incidence rate: The incidence of potato scab in each treatment group was statistically analyzed, and the results are shown in Table 4 and 5. Figure 2 As shown.

[0044] The incidence rate is the ratio of the number of diseased potato tubers to the total number of potato tubers in each potato plant. The average incidence rate is the average incidence rate of 24 plants.

[0045] Table 4. Incidence of potato scab in different treatment groups From Table 4 and Figure 2 It can be seen that when only a single material (wheat biochar / mushroom residue) was applied, the incidence rate exceeded 85%, with no significant difference compared to the positive control group, indicating that the single material had a very weak inhibitory effect on the incidence of scab. Therefore, it is evident that wheat biochar or mushroom residue, when applied alone, is insufficient to form an effective control barrier and cannot significantly reduce the incidence rate.

[0046] The incidence of disease was significantly lower in the single-material treatment group when the biochar-mushroom residue combination was applied (Z70XC, Z50XC and Z30XC), and the incidence continued to decrease with the increase of the proportion of mushroom residue, indicating that the combined application of biochar and mushroom residue has a significant synergistic effect.

[0047] (3) Prevention and control effects and baseline correction prevention and control effects The control effects of each treatment group on potato scab and the baseline correction control effects were statistically analyzed, and the results are shown in Table 4.

[0048] Prevention and control effect = (Control disease index - Treatment disease index) / Control disease index × 100%; The average control effect is the average control effect of 24 plants; Baseline correction prevention effect = (Positive control baseline correction disease index - Treatment baseline correction disease index) / Positive control baseline correction disease index × 100%.

[0049] Table 5. Control effects of different treatment groups on potatoes Table 5 shows that the control efficacy of single-material (wheat biochar / mushroom residue) application treatments (Z100XC, Z0XC) against potato scab was only 29.83%-31.41%, and the baseline-corrected control efficacy was only 48.91%-51.50%, indicating that the inhibitory effect of single materials on scab is weak. The control efficacy of biochar-mushroom residue combinations (Z70XC, Z50XC, and Z30XC) was significantly higher than that of the single-material treatment groups, and continued to increase with the increase of the proportion of mushroom residue. Among them, the biochar-mushroom residue combination prepared by mixing wheat biochar and mushroom residue at a mass ratio of 3:7 showed the best control efficacy.

[0050] The Q-value was calculated using the Jin Zhengjun method to evaluate the interaction effect between wheat biochar and mushroom residue.

[0051] The formula for calculating Q is: Q = (Ea + b) / (Ea + Eb - Ea × Eb); where Ea + b is the control effect of group Z30XC / baseline-corrected control effect; Ea and Eb are the control effects of wheat biochar and mushroom residue applied separately / baseline-corrected control effects, respectively.

[0052] In the formula, the numerator represents the "measured combined effect," the denominator is the "expected combined effect," and Q is the ratio of the two. Q < 0.85 indicates antagonism, 0.85 ≤ Q < 1.15 indicates addition, and Q ≥ 1.15 indicates synergy. Specifically, the control effect of the Z30XC treatment group reached 57.98%, with a Q value of 1.1525; the baseline-corrected control effect was as high as 98.00%, with a Q value of 1.3028. This shows that there is a combined synergistic effect between wheat biochar and mushroom residue. Furthermore, when wheat biochar and mushroom residue are mixed at a mass ratio of 3:7 to prepare a biochar-residue composition, the pathogenicity of artificially inoculated pathogens can be almost completely inhibited, which is the optimal ratio in this experiment.

[0053] In conclusion, the biochar-mushroom residue composition, consisting of wheat biochar and mushroom residue, has a significant inhibitory effect on potato scab, effectively reducing the disease index and improving the control effect. Compared with single material treatment, the synergistic effect of the two is significant.

[0054] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A biochar-microbial residue composition, characterized in that, The biochar-mushroom residue composition is prepared by mixing wheat biochar and mushroom residue in a mass ratio of (3-7):(3-7).

2. The biochar-microbial residue composition as described in claim 1, characterized in that, The wheat biochar has an organic carbon content of 70%-75%, a nitrogen content of 0.6%-1.4%, a available phosphorus content of 900-1600 mg / kg, a available potassium content of 14-40 mg / kg, a pH of 6-9, a pore volume of 45%-55%, and a pore size of 0.30-0.40 cm³. 3 / g, particle size is 150-250 mesh.

3. The biochar-microbial residue composition as described in claim 1, characterized in that, The mushroom residue is obtained by naturally composting the waste mushroom logs after oyster mushroom cultivation for 25-35 days.

4. The use of the biochar-inoculum composition according to any one of claims 1-3 in the prevention and control of potato scab.

5. The application as described in claim 4, wherein the potato scab is caused by Streptomyces scabii (… Streptomyces bottropensis Caused by ).

6. A method for preventing and controlling potato scab, characterized in that, Includes the following steps: (1) After deep tillage of the soil, a planting trench is dug, and the biochar-microbial residue composition according to any one of claims 1-3 is spread on the planting trench and rotary tillage is performed; (2) Sow potato seed potatoes in the planting furrow after rotary tillage, ridge the soil and carry out field management.

7. The method for controlling potato scab as described in claim 6, characterized in that, In step (1), the deep tillage depth is 20-25cm and the planting ditch depth is 15-20cm.

8. The method for controlling potato scab disease as described in claim 6, characterized in that, In step (1), the amount of biochar-sludge composition applied is 44-76g / potato.

9. The method for controlling potato scab as described in claim 6, characterized in that, In step (2), the spacing between potato seed tubers is 20-30cm and the planting depth is 8-10cm.

10. The method for controlling potato scab as described in claim 6, characterized in that, In step (2), the height of the planting ridges is 20-30cm; during field management, the soil moisture content is 60%-70%.

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