Method for alleviating continuous cropping obstacles of momordica grosvenori by using biochar and application thereof

Abstract

The application discloses a method for relieving continuous cropping obstacles of momordica grosvenori by using biochar and application in the fields of momordica grosvenori planting technology and waste resource utilization, and comprises the following steps: S1, collecting momordica grosvenori waste by hand, and after enough momordica grosvenori waste is collected, removing the surface soil and impurities and then washing with water; S2, crushing and carbonizing the momordica grosvenori waste, in which the momordica grosvenori waste is crushed by a crushing device to form momordica grosvenori waste powder, and then high-temperature anaerobic carbonization is performed to form momordica grosvenori waste biochar; the momordica grosvenori waste biochar prepared by the application can be used as a soil conditioner for practical application, can effectively relieve the soil acidification of continuous cropping momordica grosvenori, improve the number of soil microorganisms and improve the soil fertility, reduce the risk of pollution of heavy metals such as cadmium, lead, arsenic and mercury in the soil, and inhibit the occurrence rate of diseases such as flower leaf disease, white thread disease and root knot nematode disease, and has a good removal effect on pesticides such as thiazolylphosphine, methylthiophanate, chlorothalonil and methamidophos.

Description

Technical Field

[0001] This invention relates to the fields of monk fruit cultivation technology and waste resource utilization technology, and in particular to a method and application of using biochar to alleviate the continuous cropping obstacles of monk fruit. Background Technology

[0002] Monk fruit, the fruit of a perennial vine belonging to the Cucurbitaceae family, is also known as lahan fruit, false bitter melon, smooth-fruited wood apple, gold-indispensable, and naked tortoise, and is hailed as the "fairy fruit." Its leaves are heart-shaped, and it is dioecious, flowering in summer and bearing fruit in autumn. It is rich in vitamin C, as well as glycosides, fructose, glucose, protein, and lipids, and has cough-relieving and phlegm-reducing effects. It is mainly cultivated in Guangxi and Hunan provinces. Monk fruit is an important medicinal and edible crop in my country. Its mogrosides are highly sweet and do not produce calories, making it a valuable raw material in the beverage and confectionery industries and one of the best substitutes for sucrose.

[0003] Continuous cropping obstacles refer to the phenomenon where, even under normal management conditions, continuous planting of the same crop or its closely related species on the same plot results in deteriorated growth, reduced yield and quality, and increased pests and diseases. The causes of continuous cropping obstacles generally include: changes in soil physicochemical properties, alterations in soil microbial community structure, crop pests and diseases, and autotoxicity and allelopathic effects. Monk fruit (Luo Han Guo) cultivation areas are mostly located on hilly slopes where land resources are scarce, leading to widespread large-scale continuous cropping. After 3-4 years of continuous planting of monk fruit on the same plot, most plots need to be replaced, with some delaying this up to 5 years. Long-term continuous cropping of monk fruit leads to soil acidification, decreased fertility, reduced microbial activity, and exacerbated pests and diseases, such as mosaic virus, white mold, and root-knot nematode disease, which are major pests and diseases affecting monk fruit. With the expansion of monk fruit cultivation areas, continuous cropping obstacles have become a major problem in monk fruit production, negatively impacting yield and quality and severely limiting the healthy development of the monk fruit industry.

[0004] Meanwhile, in the cultivation and management of monk fruit, to reduce diseases such as soil-knot nematodes, farmers often dig up the roots of the monk fruit at the end of the growing season and discard or burn them along with the plants as waste. Discarding them creates a potential source of disease transmission and exacerbates the problem of continuous cropping obstacles for monk fruit. Burning them has low added value, easily causes environmental pollution, affects the ecological environment, and wastes the resources of monk fruit roots and plants, which is also detrimental to the sustainable development of monk fruit. Therefore, exploring environmentally friendly and high-value-added resource utilization methods for monk fruit waste roots and plants is a problem that urgently needs to be solved by those skilled in the art.

[0005] Biochar is a carbon-rich solid substance produced by the pyrolysis of biomass materials under anaerobic conditions. It possesses strong adsorption properties and high thermal stability, and has a certain remediation effect on soil fertility, heavy metal pollution, and pesticide residues. The potential environmental benefits of biochar have attracted widespread attention. To date, research on biochar has largely focused on straw, manure, and sludge waste from herbaceous agricultural crops such as wheat, corn, and rice. However, the methods and properties for preparing biochar from waste materials from vine plants differ significantly. Preparing biochar from a mixture of roots and plants from the vine plant *Siraitia grosvenorii* (monk fruit) holds promise for alleviating the problems associated with continuous cropping of *Siraitia grosvenorii* while simultaneously solving the disposal challenges of these waste roots and plants, potentially creating greater economic value.

[0006] Currently, the common practice in production is to apply chemical fertilizers and pesticides to the soil to alleviate the continuous cropping obstacles of monk fruit. This technical approach has a certain effect on monk fruit orchards with a short planting history, but its efficiency will decrease as the number of consecutive cropping years increases. Moreover, long-term excessive use of chemical fertilizers and pesticides can also lead to problems such as soil acidification, heavy metal and pesticide pollution in monk fruit orchards. For example, high copper concentrations in the soil can cause serious imbalances in plant physiological and respiratory processes, thereby hindering plant growth, exacerbating soil environmental pollution, and posing certain risks to human health, which is not conducive to the sustainable and healthy development of the monk fruit industry.

[0007] Patent CN2016110831693 discloses a soil conditioner for continuous cropping of crops and its preparation method. It involves a biological conditioner, but the microorganisms have high requirements for activity, short shelf life, complicated preparation process, and high cost. In addition, the biological method is limited by field conditions, product price and other factors, which makes it difficult to apply. Furthermore, the biological conditioner does not contain alkaline substances and nutrients, so it cannot play a role in both alleviating soil acidification and improving soil fertility. Therefore, this method is not suitable for alleviating the obstacles of continuous cropping of monk fruit.

[0008] Patent CN117682919A provides an organic fertilizer and its preparation method that can improve soil and alleviate continuous cropping obstacles. It is a combination of 1.0-17.0 parts of black soldier fly sand, 1.0-17.0 parts of earthworm castings, 0.5-2.0 parts of straw and 0.5-2.0 parts of vermiculite. However, this invention patent is for alleviating the continuous cropping obstacles of traditional organic fertilizers, which is different from the research and development purpose and application objects described in this patent. This preparation method is not suitable for alleviating the continuous cropping obstacles of monk fruit.

[0009] Patent CN107586229B discloses a biochar-based soil conditioner for peanut continuous cropping, its preparation method, and its application. This method's soil conditioner includes the following raw materials: 18.0-36.0 parts straw or 3.3-6.6 parts peanut shells, 6.0-12.0 parts silicon fertilizer, 1.0-2.0 parts urea, 3.0-6.0 parts diammonium phosphate, and 4.0-8.0 parts potassium sulfate. The straw is present in the form of biochar. However, the preparation process is relatively complex, the added fertilizers can easily cause soil acidification, and there are no clearly defined important parameters such as the heating rate in biochar preparation, resulting in relatively high costs and unsuitability for large-scale application. In contrast, this patent uses the widely distributed roots and plants of *Siraitia grosvenorii* (monk fruit) as raw materials, employs a mobile carbonization furnace, utilizes locally sourced materials, and returns carbonized materials to the field. It is simple to operate, low in cost, suitable for large-scale production, and has greater practical significance in the resource utilization of agricultural waste.

[0010] It is evident that, considering the specific characteristics of the mixture of monk fruit waste roots and plants, the above-mentioned methods are not applicable to alleviating the continuous cropping obstacle of monk fruit. Faced with the problem of continuous cropping obstacles in monk fruit cultivation, and the large amount of difficult-to-dispose monk fruit waste roots and plants, there is an urgent need to develop a soil regulation method for treating monk fruit continuous cropping obstacles based on biochar prepared from the mixture of monk fruit waste roots and plants. This method would not only reuse a large amount of monk fruit waste roots and plants as resources, but also ecologically restore the soil to address continuous cropping obstacles. This is of great significance for practicing the concept of green, ecological, and environmentally friendly crop cultivation.

[0011] However, in the existing technology, there are no reports on the research and development of biochar preparation using a mixture of waste roots and plants of monk fruit as raw materials and its application potential in alleviating the continuous cropping obstacles of monk fruit. Summary of the Invention

[0012] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of the invention, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0013] The purpose of this invention is to address the technical problems existing in the background art. This invention proposes a method and application for alleviating the continuous cropping obstacles of monk fruit using biochar. The biochar prepared from monk fruit waste by this invention can be used as a soil conditioner in practical applications. It can effectively alleviate soil acidification caused by continuous cropping of monk fruit, improve the number of soil microorganisms and enhance soil fertility, reduce the risk of soil pollution by heavy metals such as cadmium, lead, arsenic and mercury, inhibit the incidence of mosaic virus, white mold and root-knot nematode disease, and has a good removal effect on pesticides such as thiazophos, thiophanate-methyl, chlorothalonil and methamidophos. It can also improve the physiological and ecological functions of monk fruit leaves, the yield and quality of fruits, and effectively alleviate the continuous cropping obstacles of monk fruit. It can be applied in the fields of agriculture, forestry and environment, is suitable for large-scale production and promotion, and has good application prospects.

[0014] This invention proposes a method and application for alleviating continuous cropping obstacles of monk fruit using biochar, comprising the following steps: S1 is the step of collecting monk fruit waste. This step involves manually collecting monk fruit waste. After collecting enough monk fruit waste, the surface soil and impurities are removed and the fruit is washed with water. The S2 step involves crushing and carbonizing monk fruit waste. This step crushes the monk fruit waste using a crushing device to form monk fruit waste powder. After collecting the monk fruit waste powder, it is placed in a carbonization furnace for high-temperature anaerobic carbonization. The powder after high-temperature carbonization is then filtered to obtain monk fruit waste biochar. The S3 circular fertilization step involves digging a circular fertilization trench around the roots of the monk fruit and burying the aforementioned monk fruit waste biochar inside the trench.

[0015] By adopting the above technical solution, this solution can effectively avoid problems such as soil fertility decline during continuous planting by recycling and reusing monk fruit waste, thereby ensuring that the size of the monk fruit in each season meets the planting requirements.

[0016] Preferably, in the step of collecting monk fruit waste, after removing soil and impurities, the fruit is naturally dried for 8 hours, then baked at a temperature of 60℃~80℃ until the moisture content is 15%, and then crushed to 4~5cm.

[0017] By adopting the above technical solution, this solution can prevent the organic nutrients in the waste from decomposing due to high temperature by controlling the temperature between 60℃ and 80℃, thereby ensuring that the nutrients in the waste are not lost.

[0018] Preferably, in the step of crushing and carbonizing the monk fruit waste, the temperature is increased to 300℃~700℃ at a heating rate of 20℃ / min under a nitrogen or argon atmosphere, and carbonized at a constant temperature for 2h~4h. Then, it is cooled to room temperature, crushed, and passed through a 100-mesh sieve to obtain monk fruit waste biochar.

[0019] By adopting the above technical solution, this solution can avoid the oxidation of waste inside the carbonization furnace by carrying out high-temperature carbonization in a protective gas environment, and the high-temperature environment can kill bacteria and microorganisms in the waste.

[0020] Preferably, in the ring fertilization step, a ring fertilization trench is dug around the continuously cropped monk fruit plants, and then monk fruit waste biochar is applied to the 0-30cm soil of the continuously cropped monk fruit orchard at a ratio of 1% to 8% of the dry soil weight, and mixed evenly.

[0021] Preferably, the monk fruit waste consists of underground roots and above-ground plants, with a mass ratio of 1:2 between the roots and the plants.

[0022] By adopting the above technical solution, this solution ensures a more reasonable nutrient ratio in the monk fruit waste by using a root-to-plant mass ratio of 1:2, while a higher proportion of plants can supplement the trace elements needed for the growth of monk fruit plants.

[0023] Preferably, in the step of crushing and carbonizing the monk fruit waste, the carbonization equipment is a mobile carbonization furnace, the reaction pressure is maintained at 0.1 MPa, and the flow rate of nitrogen or argon is 200 mL / min.

[0024] By adopting the above technical solution, this solution can ensure that external oxygen and air cannot enter the carbonization furnace through the flow of protective gas.

[0025] Preferably, in the biochar step, the biochar yield is 40.09%~61.22%, and the specific surface area is 71.02~150.69 m². 2 / g, average pore size 4.59~7.56nm, cation exchange capacity 41.55~74.81cmol / kg, ash content 20.11%~46.19%, pH value 7.18~10.15, acidic functional groups 0.53~1.01mmol / g, basic functional groups 0.82~1.29mmol / g, total functional groups 1.83~2.13mmol / g, total carbon content 57.46%~68.08%, total nitrogen content 1.04%~1.4 3%, total phosphorus content 3.16~5.89g / kg, total potassium content 21.88~53.29g / kg, total sulfur content 0.34%~0.77%, available phosphorus content 70.98~168.02mg / kg, calcium content 10.01~23.22mg / g, magnesium content 10.12~17.68mg / g, iron content 6.22~15.42mg / g, manganese content 1.23~4.44mg / g, zinc content 1.31~4.10mg / g. The heavy metal content was 3.43~5.13 mg / kg for chromium, 1.97~2.54 mg / kg for lead, 1.43~1.96 mg / kg for arsenic, 0.044~0.098 mg / kg for cadmium, 2.02~2.56 mg / g for copper, and 14.52~24.96 mg / kg for nickel. Mercury was not detected.

[0026] By adopting the above technical solution, this solution avoids toxic reactions in plants by detecting heavy metals in biochar.

[0027] Preferably, the biochar from the monk fruit waste is used to return to the soil in the monk fruit orchard to improve the soil; the biochar from the monk fruit waste is used for ecological restoration of soil contaminated with heavy metals cadmium, lead, arsenic, or / and copper; and the biochar from the monk fruit waste is used to remove pesticides such as thiazophos, methyl thiophanate, chlorothalonil, or / and methamidophos from the soil.

[0028] By adopting the above technical solution, this method can achieve the effect of organic cultivation of monk fruit by removing pesticides from the soil.

[0029] Preferably, the biochar from the waste of monk fruit is used to improve the physiological and ecological functions of the leaves of continuously cropped monk fruit, as well as the yield and quality of the fruit, effectively alleviating the obstacles of continuous cropping of monk fruit.

[0030] Preferably, the biochar prepared at 500℃ has a better effect at an application rate of 6%. The biochar from the waste of monk fruit is used to reduce the absorption of heavy metals cadmium, lead, arsenic and / or mercury by intercropping monk fruit with leafy vegetables and root vegetables.

[0031] By adopting the above technical solution, the biochar prepared under 500℃ conditions can control the degree of carbonization of the biochar, thereby ensuring the stability of subsequent application effects.

[0032] In summary, the present invention has at least one of the following beneficial effects: 1. This invention is the first to use a mixture of the root system and plant of monk fruit waste as the raw material for biochar preparation. This material is abundant, inexpensive, and readily available. The preparation method is simple, reducing the cost of biochar preparation and turning waste into treasure. It effectively solves the problem of insufficient resource utilization of monk fruit waste in existing technologies, reduces the pollution to the environment caused by the incineration or disposal of monk fruit waste, and is beneficial to environmental protection. This invention can realize the on-site carbonization of monk fruit waste, avoiding the raw material storage and transportation problems that are difficult to alleviate in large-scale centralized treatment.

[0033] 2. The biochar prepared by this invention has a high yield, high pH value, large specific surface area, high cation exchange capacity, and the heavy metal elements chromium, lead, arsenic, cadmium, and nickel are all within the standard limits, and mercury is not detected. It has the advantages of being environmentally friendly and sustainable. It contains a variety of mineral elements in rich quantities. When returned to the field, it is an effective compensation measure for the loss of soil nutrients in Luo Han Guo orchards caused by the removal of Luo Han Guo root system and plant waste. It can be used as a soil conditioner to improve soil fertility in continuously cropped Luo Han Guo orchards and effectively alleviate soil acidification. It has good prospects for large-scale application and promotion.

[0034] 3. The biochar prepared by this invention has abundant surface functional groups and strong adsorption properties. It can be used as an environmental remediation material, reducing the pollution risk of heavy metals cadmium, lead, arsenic and copper in continuously cropped soil. It has a good removal effect on pesticides thiazophos, methyl thiophanate, chlorothalonil and / or methamidophos. It can improve the physiological and ecological functions of continuously cropped monk fruit leaves, as well as the yield and quality of fruits. It effectively alleviates the obstacles of continuous cropping of monk fruit and can reduce the absorption of heavy metals cadmium, lead, arsenic and / or mercury by intercropping leafy vegetables and root vegetables in monk fruit orchards. It has good ecological, environmental and economic effects. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart illustrating a method and application of using biochar to alleviate continuous cropping obstacles of monk fruit according to the present invention. Figure 2The changes in the physicochemical properties of the Luo Han Guo orchard soil one year after the preparation of Luo Han Guo waste biochar in Example 1; Figure 3 The changes in the physicochemical properties of the Luo Han Guo orchard soil one year after the application of Luo Han Guo waste biochar prepared in Example 2; Figure 4 The changes in the physicochemical properties of the Luo Han Guo orchard soil one year after the application of Luo Han Guo waste biochar prepared in Example 3; Figure 5 Comparison of changes in soil microbial counts in a monk fruit orchard one year after the application of monk fruit waste biochar. Figure 6 The changes (mg / kg) in available cadmium, available lead, available arsenic and available copper content in the soil one year after the application of monk fruit waste biochar. Figure 7 Changes in heavy metal content (mg / kg) in monk fruit fruit one year after application of monk fruit waste biochar. Figure 8 The effects of applying biochar from Luo Han Guo waste on the physiological ecology of Luo Han Guo leaves after continuous cropping; Figure 9 The effect of applying biochar from Luo Han Guo waste on the yield of Luo Han Guo fruit after continuous cropping; Figure 10 The effect of applying biochar from Luo Han Guo waste on the fruit quality of Luo Han Guo after continuous cropping; Figure 11 The effect of biochar from monk fruit waste on enzyme activity in monk fruit; Figure 12 The effects of biochar on mosaic and white mold diseases in continuously cropped monk fruit; Figure 13 The effects of biochar on soil root-knot nematodes in continuously cropped monk fruit; Figure 14 The effect of biochar on the absorption of heavy metals (mg / kg) in Chinese cabbage (leafy vegetables); Figure 15 The effect of biochar on the absorption of heavy metals in radish (root vegetable) (mg / kg); Detailed Implementation

[0037] The following is in conjunction with the appendix Figure 1-15 The present invention will be described in further detail below.

[0038] Example 1

[0039] like Figure 1-15As shown in this embodiment, in order to solve the existing problems, the present invention discloses a method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit. The method involves collecting the waste roots and plants of monk fruit, removing the surface soil and impurities, washing with water, air-drying naturally for 8 hours, then drying at a temperature of 60°C until the moisture content is 15%, and then crushing them into 4-5cm pieces. The crushed monk fruit waste was placed in a mobile carbonization device and heated to 300°C at a rate of 20°C / min under a nitrogen atmosphere with a gas flow rate of 200 mL / min. The carbonization was carried out at a constant temperature for 4 hours, then cooled to room temperature, crushed, and passed through a 100-mesh sieve to obtain monk fruit waste biochar.

[0040] Biochar quality index analysis: Accurately weigh the cooled biochar and calculate the biochar yield; use nitrogen as the adsorption medium and determine the specific surface area and pore volume using a specific surface area and porosity tester. Cation exchange capacity was determined using the ammonium acetate exchange method, and pH value was measured using a Sartorius PP-20 pH meter. The number of surface acid (alkaline) oxygen-containing functional groups was determined using the Boehm titration method. Ash content was determined using the charcoal test method (GB / T17664-1999). Carbon, nitrogen, and sulfur contents were determined using a German Elementar Vario ELIII elemental analyzer. Total phosphorus was determined by sulfuric acid-hydrogen peroxide decomposition and the vanadium-molybdenum yellow colorimetric method; available phosphorus was extracted with sodium bicarbonate and the molybdenum-antimony colorimetric method was used; total potassium was determined using a flame photometer. The contents of calcium, magnesium, iron, copper, manganese, and zinc were determined using inductively coupled plasma atomic emission spectrometry (ICP, PEoptima 5300DV, USA).

[0041] In Example 1, the biochar prepared from monk fruit waste had a yield of 61.22% and a specific surface area of ​​71.02 m². 2 / g, average pore size 4.59nm, cation exchange capacity 41.55cmol / kg, ash content 20.11%, pH value 7.18, acidic functional groups 1.01mmol / g, basic functional groups 0.82mmol / g, total functional groups 1.83mmol / g, total carbon content 57.46%, total nitrogen content 1.04%, total phosphorus content 3.16g / kg, total potassium content 21.88g / kg, total sulfur content 0.34%, available phosphorus content 70.98mg / kg, calcium content 10.01mg / g, magnesium content 10.12mg / g, iron content 6.22mg / g, manganese content 1.23mg / g, zinc content 1.31mg / g. The levels of heavy metals present were: chromium 3.43 mg / kg, lead 1.97 mg / kg, arsenic 1.43 mg / kg, cadmium 0.044 mg / kg, copper 2.02 mg / g, nickel 14.52 mg / kg, and mercury was not detected. This invention also provides a method and application for alleviating the continuous cropping obstacles of monk fruit by preparing monk fruit waste biochar using the above method. The monk fruit waste biochar is used for ecological remediation of soil contaminated with heavy metals cadmium, lead, arsenic and / or copper in continuously cropped monk fruit orchards.

[0042] The present invention also provides a method and application for alleviating the continuous cropping obstacles of monk fruit by preparing the above-mentioned method using monk fruit waste biochar. The monk fruit waste biochar is used to improve the physiological and ecological functions of the leaves of continuously cropped monk fruit, as well as the yield and quality of the fruit.

[0043] This invention also provides a method and application for alleviating the continuous cropping obstacles of monk fruit by preparing the above-mentioned monk fruit waste biochar. The monk fruit waste biochar is used to remove pesticides such as thiazophos, methyl thiophanate, chlorothalonil / methamidophos from the soil of monk fruit orchards.

[0044] The present invention also provides the application of the monk fruit waste biochar prepared by the above method, characterized in that the monk fruit waste biochar is used to reduce the absorption of heavy metals cadmium, lead, arsenic and / or mercury by intercropping leafy vegetables and root vegetables in monk fruit orchards.

[0045] Example 2

[0046] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: (1) Collect the waste roots and plants of monk fruit, remove the surface soil and impurities, wash with water, air dry for 8 hours, then dry at 70℃ until the moisture content is 15%, and then crush to 4~5cm. (2) Place the crushed monk fruit waste in a mobile carbonization device, heat it to 500°C at a heating rate of 20°C / min under an argon atmosphere with a gas flow rate of 200 mL / min, carbonize it at a constant temperature for 3 hours, then cool it to room temperature, crush it, and pass it through a 100-mesh sieve to obtain monk fruit waste biochar.

[0047] In Example 2, the biochar prepared from monk fruit waste had a yield of 55.83% and a specific surface area of ​​150.69 m². 2 / g, average pore size 6.44nm, cation exchange capacity 73.12cmol / kg, ash content 44.28%, pH value 9.66, acidic functional groups 0.84mmol / g, basic functional groups 1.29mmol / g, total functional groups 2.13mmol / g, total carbon content 62.11%, total nitrogen content 1.43%, total phosphorus content 5.89g / kg, total potassium content 53.29g / kg, total sulfur content 0.77%, available phosphorus content 168.02mg / kg, calcium content 23.22mg / g, magnesium content 17.68mg / g, iron content 15.42mg / g, manganese content 4.44mg / g, zinc content 4.10mg / g. The heavy metal content was 4.48 mg / kg for chromium, 2.22 mg / kg for lead, 1.78 mg / kg for arsenic, 0.069 mg / kg for cadmium, 2.31 mg / g for copper, and 20.30 mg / kg for nickel. Mercury was not detected.

[0048] Example 3

[0049] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: (1) Collect the waste roots and plants of monk fruit, remove the surface soil and impurities, wash with water, air dry for 8 hours, then dry at 80℃ until the moisture content is 15%, and then crush to 4~5cm. (2) Place the crushed monk fruit waste in a mobile carbonization device, heat it to 700°C at a rate of 20°C / min under a nitrogen atmosphere with a gas flow rate of 200 mL / min, carbonize it at a constant temperature for 2 hours, then cool it to room temperature, crush it, and pass it through a 100-mesh sieve to obtain monk fruit waste biochar.

[0050] In Example 3, the biochar prepared from monk fruit waste had a yield of 40.09% and a specific surface area of ​​100.14 m². 2 / g, average pore size 7.56nm, cation exchange capacity 74.81cmol / kg, ash content 46.19%, pH value 10.15, acidic functional groups 0.53mmol / g, basic functional groups 1.13mmol / g, total functional groups 1.66mmol / g, total carbon content 68.08%, total nitrogen content 1.22%, total phosphorus content 4.63g / kg, total potassium content 49.85g / kg, total sulfur content 0.52%, available phosphorus content 112.29mg / kg, calcium content 17.66mg / g, magnesium content 10.12mg / g, iron content 9.85mg / g, manganese content 4.12mg / g, zinc content 3.75mg / g. The heavy metal content was 5.13 mg / kg for chromium, 2.54 mg / kg for lead, 1.96 mg / kg for arsenic, 0.098 mg / kg for cadmium, 2.56 mg / g for copper, and 24.96 mg / kg for nickel. Mercury was not detected.

[0051] The biochar prepared from Luo Han Guo waste in Examples 1-3 of this invention all exhibited alkaline pH values. The biochar contained a wide variety and high content of mineral elements such as carbon, nitrogen, phosphorus, and potassium, serving as an external source of soil nutrients. Referring to the standards of "Biochar-based Organic Fertilizers" (NY / T3618-2020) and GB4284-2018 Class A limits, the content of heavy metals chromium, lead, arsenic, cadmium, and nickel in the biochar did not exceed the standards and was also lower than the limits in "Ecological Indicators for Arsenic, Cadmium, Lead, Chromium, and Mercury in Fertilizers" (GB / T23349-2009). Mercury was not detected, indicating environmental friendliness and no secondary pollution. The biochar had a large specific surface area and cation exchange capacity, and abundant surface functional groups, providing more adsorption sites for the removal of heavy metals and pesticide residues from contaminated soil. In particular, the biochar obtained in Example 2 at 500℃ showed superior overall quality in terms of physical properties, surface composition, and mineral element content.

[0052] Example 4

[0053] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The soil improvement effect of continuous cropping of Luo Han Guo orchard 1.

[0054] A circular fertilization trench was dug around the monk fruit plants. The monk fruit waste biochar prepared in Example 1 was applied in situ to the 0-30cm soil layer of a monk fruit orchard that had been continuously cropped for four years. The biochar content was 0% (control, no biochar applied), 1%, 2%, 4%, 6%, and 8% of the soil dry weight, for a total of six treatments, with four replicates for each treatment. The biochar was thoroughly mixed. The soil was acidic. Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used can be purchased commercially unless otherwise specified. Figure 2 It can be seen that one year after application, compared with the control, based on the average value of the 0~30cm soil layer, the soil bulk density (BD, g / cm³) was significantly higher. 3 The soil pH value decreased by 2.56%–21.79%, the natural water content (SWC, %) increased by 0.22–1.13, the soil organic carbon (SOC, g / kg) increased by 5.25%–30.53%, the soil organic carbon (SOC, g / kg) increased by 5.39%–34.48%, the total nitrogen (TN, g / kg) increased by 5.48%–69.86%, the total phosphorus (TP, g / kg) increased by 12.50%–62.50%, the total potassium (TK, g / kg) increased by 12.52%–63.21%, the available nitrogen (AN, mg / kg) increased by 3.92%–59.05%, the available phosphorus (AP, mg / kg) increased by 1.39%–39.58%, and the available potassium (AK, mg / kg) increased by 6.25%–33.27%. Total calcium (TCa, mg / kg) increased by 3.99%–45.72%, total magnesium (TMg, mg / kg) increased by 3.03%–6.70%, total sodium (TNa, mg / kg) decreased by 4.23%–23.29%, total aluminum (TAI, mg / kg) decreased by 0.53%–21.14%, exchangeable calcium (EXCa, mg / kg) increased by 2.60%–42.61%, exchangeable magnesium (EXMg, mg / kg) increased by 11.22%–55.90%, exchangeable sodium (EXNa, mg / kg) decreased by 12.01%–24.67%, exchangeable aluminum (EXAI, cmol / kg) decreased by 5.61%–51.95%, exchangeable acid (EXAc, cmol / kg) decreased by 9.52%–48.41%, and exchangeable hydrogen (EXHy, cmol / kg) decreased by 17.99%–40.74%.

[0055] Example 5

[0056] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The soil improvement effect of continuous cropping of Luo Han Guo orchard 2.

[0057] A circular fertilization trench was dug around the monk fruit plants. The monk fruit waste biochar prepared in Example 2 was applied in situ to the 0-30cm soil layer of a monk fruit orchard that had been continuously cropped for four years. The biochar content was 0% (control, no biochar applied), 1%, 2%, 4%, 6%, and 8% of the soil dry weight, for a total of six treatments, with four replicates for each treatment. The biochar was thoroughly mixed. The soil was acidic. Figure 3 It can be seen that one year after application, compared with the control, based on the average value of the 0~30cm soil layer, the soil bulk density (BD, g / cm³) was significantly higher. 3 The soil pH value decreased by 4.49% to 27.56%, the soil pH value increased by 0.46 to 1.50, the natural water content (SWC, %) increased by 10.59% to 38.23%, the soil organic carbon (SOC, g / kg) increased by 18.30% to 82.19%, the total nitrogen (TN, g / kg) increased by 27.40% to 113.70%, the total phosphorus (TP, g / kg) increased by 37.50% to 140.63%, the total potassium (TK, g / kg) increased by 21.92% to 87.08%, the available nitrogen (AN, mg / kg) increased by 10.73% to 94.95%, the available phosphorus (AP, mg / kg) increased by 7.64% to 76.39%, and the available potassium (AK, mg / kg) increased by 18.03% to 56.01%. Total calcium (TCa, mg / kg) increased by 35.98%–71.31%, total magnesium (TMg, mg / kg) increased by 8.13%–29.26%, total sodium (TNa, mg / kg) decreased by 10.12%–24.75%, total aluminum (TAI, mg / kg) decreased by 12.74%–31.27%, exchangeable calcium (EXCa, mg / kg) increased by 14.11%–61.06%, and exchangeable magnesium (EXMg) increased by 14.11%–61.06%. The exchangeable sodium (EXNa, mg / kg) increased by 32.12%~98.42%, the exchangeable aluminum (EXAI, cmol / kg) decreased by 19.90%~37.81%, the exchangeable aluminum (EXAI, cmol / kg) decreased by 14.63%~68.29%, the exchangeable acid (EXAc, cmol / kg) decreased by 17.70%~61.44%, and the exchangeable hydrogen (EXHy, cmol / kg) decreased by 24.34%~46.56%.

[0058] Example 6

[0059] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The soil improvement effect of continuous cropping of Luo Han Guo orchard 3.

[0060] A circular fertilization trench was dug around the monk fruit plants. The monk fruit waste biochar prepared in Example 3 was applied in situ to the 0-30cm soil layer of a monk fruit orchard that had been continuously cropped for four years. The biochar content was 0% (control, no biochar applied), 1%, 2%, 4%, 6%, and 8% of the soil dry weight, for a total of six treatments, with four replicates for each treatment. The biochar was thoroughly mixed. The soil was acidic. Figure 4 It can be seen that one year after application, compared with the control, based on the average value of the 0~30cm soil layer, the soil bulk density (BD, g / cm³) was significantly higher. 3 The soil pH value decreased by 9.62%–35.26%, the soil pH value increased by 0.80–1.63, the natural water content (SWC, %) increased by 12.74%–45.18%, the soil organic carbon (SOC, g / kg) increased by 14.54%–61.11%, the total nitrogen (TN, g / kg) increased by 10.96%–90.41%, the total phosphorus (TP, g / kg) increased by 31.25%–90.63%, the total potassium (TK, g / kg) increased by 19.57%–80.82%, the available nitrogen (AN, mg / kg) increased by 6.83%–83.81%, the available phosphorus (AP, mg / kg) increased by 4.86%–56.94%, and the available potassium (AK, mg / kg) increased by 11.06%–49.86%. Total calcium (TCa, mg / kg) increased by 13.01%–52.48%, total magnesium (TMg, mg / kg) increased by 4.10%–22.13%, total sodium (TNa, mg / kg) decreased by 6.86%–23.17%, total aluminum (TAI, mg / kg) decreased by 5.08%–27.62%, exchangeable calcium (EXCa, mg / kg) increased by 5.86%–55.53%, exchangeable magnesium (EXMg, mg / kg) increased by 20.97%–77.72%, exchangeable sodium (EXNa, mg / kg) decreased by 17.79%–33.75%, exchangeable aluminum (EXAI, cmol / kg) decreased by 9.51%–54.88%, exchangeable acid (EXAc, cmol / kg) decreased by 12.85%–51.92%, and exchangeable hydrogen (EXHy, cmol / kg) decreased by 20.11%–45.50%.

[0061] As can be seen from Examples 4-6 above, the biochar made from Luo Han Guo waste prepared in Examples 1-3 can increase the content of organic carbon, total nitrogen, and total phosphorus in the soil of Luo Han Guo orchards that have been continuously cropped for 4 years after one year of application, and increase the content of mineral elements such as calcium and magnesium. At the same time, it can increase the soil pH value and reduce the content of sodium, aluminum, exchangeable acid and exchangeable hydrogen, which can characterize soil acidity and alkalinity, effectively alleviating soil acidification in Luo Han Guo orchards and showing a significant soil improvement effect. Among them, the biochar made from Luo Han Guo waste prepared in Example 2 has the best comprehensive performance, and 6% is the optimal application rate.

[0062] Example 7

[0063] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The effect of continuous cropping of monk fruit on improving the number of soil microorganisms.

[0064] A circular fertilization trench was dug around the monk fruit plants. The monk fruit waste biochar 1 (Example 1), biochar 2 (Example 2), and biochar 3 (Example 3) prepared in Examples 1-3 were applied in situ to the 0-30cm soil layer of a monk fruit orchard that had been continuously cropped for 4 years. The mass ratio of biochar to soil dry weight was 0% (control, no biochar applied) and 6%, with two treatments and four replicates per treatment. The biochar was thoroughly mixed. One year after biochar application, the average value of the 0-30cm soil layer was used to... Figure 5 Compared with the control, the number of bacteria and actinomycetes increased to varying degrees among the three major soil microorganisms, with increases of 72.52%–111.45% and 28.86%–75.76%, respectively, while the number of fungi decreased by 33.33%–67.99% (P<0.05). Biochar significantly improved the number of soil microorganisms in the Luo Han Guo orchard. The number of bacteria and actinomycetes was significantly higher than that of the control, while the number of fungi that easily cause plant diseases tended to decrease. This is beneficial to slow down the occurrence of soil-borne root diseases and plays a role in improving the soil in Luo Han Guo continuous cropping fields.

[0065] Example 8

[0066] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The remediation effect on soils lightly contaminated with heavy metals cadmium, lead, arsenic and copper.

[0067] Using a ring-ditch application method, the *Siraitia grosvenorii* waste biochar 1 (Example 1), biochar 2 (Example 2), and biochar 3 (Example 3) prepared in Examples 1-3 were applied once to the 0-30 cm soil layer of a *Siraitia grosvenorii* orchard that had been continuously cropped for 4 years and was slightly contaminated with heavy metals cadmium, lead, arsenic, and copper. The mass ratio of *Siraitia grosvenorii* waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were four treatments, with four replicates for each treatment. Figure 6The results showed that, compared with the control, the contents of available cadmium, lead, arsenic, and copper in the soil decreased to varying degrees after one year of biochar application, with reductions of 25.81%–64.52%, 23.59%–72.04%, 31.63%–60.20%, and 32.48%–64.79% respectively (P < 0.05). This indicates that biochar from monk fruit waste can significantly reduce the absorbability of available heavy metals cadmium, lead, arsenic, and copper in lightly polluted soil from monk fruit orchards that have been continuously cropped for four years, thereby reducing the toxicity of heavy metals to monk fruit.

[0068] Example 9

[0069] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The effect of restoring the heavy metal content in monk fruit.

[0070] Using a ring trench application method, the Luo Han Guo waste biochar 1 (Example 1), biochar 2 (Example 2), and biochar 3 (Example 3) prepared in Examples 1-3 were applied once to the 0-30 cm soil of a Luo Han Guo orchard that had been continuously cropped for 4 years and was slightly contaminated with heavy metals cadmium, lead, arsenic, and copper. The mass ratio of Luo Han Guo waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were 4 treatments, with 4 replicates for each treatment. Figure 7 The study investigated the changes in cadmium, lead, arsenic, and copper content in monk fruit fruits after continuous cropping in soils with mild cadmium, lead, arsenic, and copper contamination. Compared with the control, the application of monk fruit waste biochar 1, biochar 2, and biochar 3 significantly reduced the content of heavy metals cadmium, lead, arsenic, and copper in monk fruit fruits one year later, with reductions of 31.82%~59.09%, 32.49%~64.98%, 42.69%~71.35%, and 46.21%~72.50%, respectively. This reduced the accumulation of heavy metals in monk fruit fruits, and all levels met the national food contaminant limits (GB2762-2017, GB15199-94).

[0071] As can be seen from Examples 8 and 9 above, the biochar made from Luo Han Guo waste prepared in Examples 1 to 3 can significantly reduce the available content of heavy metals cadmium, lead, arsenic and copper in lightly polluted soil in Luo Han Guo orchards that have been continuously cropped for 4 years after one year of application, reduce the accumulation of heavy metals in Luo Han Guo fruits, and have good soil heavy metal pollution remediation function, and are suitable for ecological remediation of soils polluted by cadmium, lead, arsenic and copper.

[0072] Example 10

[0073] like Figure 1-15As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: Effects on the physiological and ecological properties of monk fruit leaves.

[0074] Using a ring trench application method, the Luo Han Guo waste biochar 1 (Example 1), biochar 2 (Example 2) and biochar 3 (Example 3) prepared in Examples 1-3 were applied once to a Luo Han Guo orchard that had been continuously cropped for 4 years. The mass ratio of Luo Han Guo waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were 4 treatments, and each treatment was replicated 4 times. Figure 8 To investigate the changes in physiological and ecological indicators of *Siraitia grosvenorii* leaves after one year of continuous cropping for four years following the application of *Siraitia grosvenorii* waste biochar, compared with the control, the application of *Siraitia grosvenorii* waste biochar 1, biochar 2, and biochar 3 significantly increased the content of chlorophyll a, chlorophyll b, carotene c, relative chlorophyll, free proline, soluble sugar, and soluble protein in *Siraitia grosvenorii* leaves. It also increased leaf area, net photosynthetic rate, intercellular carbon dioxide concentration, and stomatal conductance. The increases in each indicator were as follows: The percentages of biochar were 6.34%–18.31%, 19.35%–54.84%, 10.71%–32.14%, 5.52%–22.02%, 14.11%–46.24%, 29.13%–70.08%, and 29.21%–75.28%; and 8.87%–107.95%, 8.59%–27.34%, 25.25%–68.05%, and 58.23%–392.41%, respectively. This indicates that biochar application is beneficial to the synthesis and accumulation of chlorophyll and carbonaceous compounds in the leaves of *Siraitia grosvenorii* plants, promotes the synthesis of osmotic substances such as free proline, soluble sugars, and soluble proteins, improves the osmotic balance capacity of *Siraitia grosvenorii* under continuous cropping, enhances the photosynthetic efficiency and growth development of leaves, and effectively alleviates the adverse effects of continuous cropping of *Siraitia grosvenorii*.

[0075] Example 11

[0076] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The effect on promoting the yield of monk fruit.

[0077] Using a ring trench application method, the Luo Han Guo waste biochar 1 (Example 1), biochar 2 (Example 2) and biochar 3 (Example 3) prepared in Examples 1 to 3 were applied once to Luo Han Guo orchards that had been continuously cropped for 2 to 5 years. The mass ratio of Luo Han Guo waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were 4 treatments, and each treatment was replicated 4 times. Figure 9 The study investigated the changes in the yield of continuously cropped monk fruit one year after the application of monk fruit waste biochar. Compared with the control, the application of monk fruit waste biochar 1, biochar 2, and biochar 3 significantly increased the yield of monk fruit, with average yield increases per plant of 20.75%–53.35%, 18.62%–41.31%, 46.28%–65.69%, 153.30%–225.94%, and 211.64%–354.11%, respectively.

[0078] Example 12

[0079] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The effect on improving the quality of monk fruit.

[0080] Using a ring trench application method, the Luo Han Guo waste biochar 1 (Example 1), biochar 2 (Example 2) and biochar 3 (Example 3) prepared in Examples 1-3 were applied once to a Luo Han Guo orchard that had been continuously cropped for 4 years. The mass ratio of Luo Han Guo waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were 4 treatments, and each treatment was replicated 4 times. Figure 10 The study investigated the changes in the quality of continuously cropped monk fruit one year after the application of monk fruit waste biochar. Compared with the control, the application of monk fruit waste biochar 1, biochar 2, and biochar 3 significantly increased the content of soluble solids, vitamins, total sugars, glycosides, protein, starch, and amino acids in the monk fruit. The increases for each index were 9.14%–25.53%, 11.89%–18.63%, 8.58%–19.15%, 15.98%–42.27%, 6.73%–13.41%, 17.99%–27.25%, and 8.46%–21.14%, respectively. This indicates that the application of monk fruit waste biochar improved the quality of continuously cropped monk fruit.

[0081] Example 13

[0082] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: Effects of the enzymes protecting the fruit of Luo Han Guo.

[0083] Using a ring trench application method, the Luo Han Guo waste biochar 1 (Example 1), biochar 2 (Example 2) and biochar 3 (Example 3) prepared in Examples 1-3 were applied once to a Luo Han Guo orchard that had been continuously cropped for 4 years. The mass ratio of Luo Han Guo waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were 4 treatments, and each treatment was replicated 4 times. Figure 11 This study investigated the changes in enzyme activity in *Siraitia grosvenorii* fruit one year after application of *Siraitia grosvenorii* waste biochar. Compared to the control, the application of *Siraitia grosvenorii* waste biochar 1, biochar 2, and biochar 3 significantly increased the content of protective enzymes (nitrate reductase, peroxidase, catalase, and superoxide dismutase) in *Siraitia grosvenorii* fruit, with increases of 10.11%–58.69%, 5.13%–32.10%, 29.66%–109.08%, and 61.54%–126.92%, respectively, while malondialdehyde (MDA) decreased by 48.28%–71.03%. MDA is a product of cell membrane lipid peroxidation and can indicate the degree of membrane damage; higher MDA content indicates a greater degree of oxidation in plant cells. These findings suggest that *Siraitia grosvenorii* waste biochar improved the activity of protective enzymes in *Siraitia grosvenorii* fruit, maintained cell membrane integrity, and helped enhance the stress resistance of *Siraitia grosvenorii* under continuous cropping.

[0084] As can be seen from Examples 10-13 above, the application of biochar from Luo Han Guo waste can significantly improve the physiological and ecological functions of Luo Han Guo leaves after continuous cropping, increase fruit yield, promote the accumulation of soluble solids, vitamin C, total sugar, reducing sugar and glycosides in Luo Han Guo, improve the resistance of Luo Han Guo to continuous cropping stress, and improve the quality of Luo Han Guo fruit. In comparison, the effect of preparing Luo Han Guo waste biochar at 500℃ in Example 2 is better.

[0085] Example 14

[0086] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The inhibitory effect on diseases and pests of monk fruit.

[0087] Using a ring trench application method, the Luo Han Guo waste biochar 1 (Example 1), biochar 2 (Example 2) and biochar 3 (Example 3) prepared in Examples 1-3 were applied once to a Luo Han Guo orchard that had been continuously cropped for 4 years. The mass ratio of Luo Han Guo waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were 4 treatments, and each treatment was replicated 4 times. Figure 12To investigate the effects of applying biochar from monk fruit waste on mosaic virus and white mold disease in continuously cropped monk fruit, compared with the control, one year after the application of monk fruit waste biochar, the incidence rates of mosaic virus and white mold disease decreased by 44.22%~77.26% and 48.16%~83.45%, respectively; the disease index gradually decreased, and the control effect was 40.96%~76.39% and 42.64%~80.21%, respectively. In comparison, the effects of Examples 2 and 3 were better.

[0088] The control effect on root-knot nematodes in monk fruit.

[0089] Using a ring-ditch application method, the *Siraitia grosvenorii* waste biochar 1 (Example 1), biochar 2 (Example 2), and biochar 3 (Example 3) prepared in Examples 1-3 were applied once to a *Siraitia grosvenorii* orchard that had been continuously cropped for 4 years. The mass ratio of *Siraitia grosvenorii* waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were 4 treatments, with 4 replicates for each treatment. Figure 13 It can be seen that, compared with the control, one year after applying Luo Han Guo waste biochar 1, biochar 2 and biochar 3, the number of root-knot nematodes J2 in Luo Han Guo soil, the number of root egg masses, the number of egg masses per gram of root, the number of eggs per single egg mass and the incidence of root-knot nematodes were significantly reduced, with reductions of 16.11%~46.33%, 20.00%~55.00%, 17.36%~38.61%, 4.50%~21.38%, and 63.28%~83.20%, respectively. In comparison, the effects of Examples 2 and 3 were better.

[0090] Example 15

[0091] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The effect of pesticides commonly used in monk fruit orchards on removal.

[0092] Biochar 1 (Example 1), Biochar 2 (Example 1), and Biochar 3 (Example 3) prepared from Luo Han Guo waste in Examples 1-3 were thoroughly mixed with aqueous solutions of thiazophos, thiophanate-methyl, chlorothalonil, and methamidophos at a certain concentration in a solid-liquid ratio of 6%. No biochar was applied as a control (CK). There were four treatments, with five replicates per treatment, for a total of 80 experimental tubes. Adsorption experiments were conducted under light-protected conditions at 30°C with constant shaking for 24 hours at a shaker speed of 150 rpm. The results showed that the removal rates of thiazophos were 88.11%, 92.19%, and 90.33%, respectively; the removal rates of thiophanate-methyl were 91.28%, 94.48%, and 96.13%, respectively; the removal rates of chlorothalonil were 87.59%, 91.78%, and 89.02%, respectively; and the removal rates of methamidophos were 92.12%, 96.58%, and 93.86%, respectively. The results show that the biochar from Luo Han Guo waste has a significant removal effect on commonly used pesticides such as thiazophos, thiophanate-methyl, chlorothalonil and methamidophos in Luo Han Guo orchards. In comparison, the biochar from Luo Han Guo waste prepared in Example 2 has a better removal effect.

[0093] Example 16

[0094] like Figure 1-15 As shown, in this embodiment, in order to solve the existing problems, based on the same concept as in Embodiment 1 above, the method and application of using biochar to alleviate the continuous cropping obstacle of monk fruit further includes: The effect of intercropping monk fruit with leafy green vegetables such as bok choy and root vegetables such as radish on inhibiting the absorption of heavy metals.

[0095] Using a ring trench application method, the monk fruit waste biochar 1 (Example 1), biochar 2 (Example 2), and biochar 3 (Example 3) prepared in Examples 1-3 were applied once to the soil of leafy vegetables, bok choy, which were lightly contaminated with cadmium, lead, arsenic, and mercury. The mass ratio of monk fruit waste biochar to soil dry weight was 6%. No biochar was applied as a control (CK). There were 4 treatments, with 4 replicates for each treatment. Figure 14 The study investigated the changes in cadmium, lead, arsenic, and mercury content in leafy green vegetables (Bok choy) in soils with mild cadmium, lead, arsenic, and mercury contamination. Compared with the control, the application of Luo Han Guo waste biochar 1, biochar 2, and biochar 3 significantly reduced the absorption of cadmium, lead, arsenic, and mercury by Bok choy after one growing season (P < 0.05), with reductions of 69.56%–78.65%, 33.33%–70.96%, 56.71%–82.20%, and 12.50%–43.75%, respectively. These reductions met the national standards for cadmium, lead, arsenic, and mercury in GB2752, BG4810, GB14961, and BG15201.

[0096] Figure 15To investigate the changes in cadmium, lead, arsenic, and mercury content in root vegetable radishes in moderately contaminated soil (cadmium, lead, arsenic, and mercury), four treatments were used, with four replicates for each treatment, without biochar application as the control (CK). Compared with the control, the application of Luo Han Guo waste biochar 1 (Example 1), biochar 2 (Example 2), and biochar 3 (Example 3) significantly reduced the absorption of heavy metals cadmium, lead, arsenic, and mercury in radishes after one growing season (P < 0.05), with reductions of 74.55%–82.44%, 51.42%–77.43%, 57.90%–82.80%, and 69.23%–79.49%, respectively, and met the national standards for heavy metals cadmium, lead, arsenic, and mercury GB2752, BG4810, GB14961, and BG15201.

[0097] above Figure 14 and Figure 15 This indicates that the application of biochar from monk fruit waste can effectively reduce the absorption of heavy metals cadmium, lead, arsenic, and mercury by intercropping monk fruit with leafy and root vegetables, and all levels do not exceed national limits.

[0098] In summary, the biochar prepared from monk fruit waste in this invention has a high content of mineral nutrients, a large specific surface area and cation exchange capacity, and abundant surface functional groups. This improves soil nutrient content, increases soil microbial abundance, and significantly alleviates soil acidification. The biochar also exhibits significant remediation capabilities for soils contaminated with heavy metals such as cadmium, lead, arsenic, and copper. Furthermore, it promotes photosynthetic efficiency and growth of monk fruit leaves under continuous cropping conditions, significantly increases the content of osmotic substances within the leaves, enhances the protective enzyme activity of the monk fruit fruit, and strengthens its resistance and adaptability. This positively impacts the yield and quality of monk fruit under continuous cropping conditions, effectively alleviating the obstacles posed by continuous cropping. Simultaneously, it solves the current problem of difficult disposal of monk fruit waste roots and plants, avoids potential environmental pollution, and significantly reduces the absorption of heavy metals by intercropped leafy vegetables such as bok choy and root vegetables such as radish. Comparatively, the monk fruit waste biochar obtained at 500℃ in Example 2 shows better application results at a 6% application rate. This invention is simple to operate, has low input costs, is environmentally friendly, and has good effects. It has good promotion and application value under field conditions where continuous cropping obstacles exist for monk fruit and other crops.

[0099] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for alleviating continuous cropping obstacles of monk fruit using biochar, characterized in that, Includes the following steps: S1 is the step of collecting monk fruit waste. This step involves manually collecting monk fruit waste. After collecting enough monk fruit waste, it is washed with water to remove the surface dirt and impurities. S2 Crushing and Carbonizing Monk Fruit Waste Step: In this step, the monk fruit waste is crushed by a crushing device to form monk fruit waste powder. After collecting the monk fruit waste powder, it is placed in a carbonization furnace and carbonized at high temperature. After high-temperature carbonization, the monk fruit waste carbonized powder is filtered to obtain monk fruit waste biochar. S3 Circular fertilization step involves digging a circular fertilization trench around the roots of the monk fruit tree and burying the aforementioned monk fruit waste biochar inside the circular fertilization trench. In the step of collecting monk fruit waste, after removing soil and impurities, the fruit is naturally air-dried for 8 hours, and then dried at a temperature of 60℃~80℃ until the moisture content is 15%. In the step of crushing and carbonizing monk fruit waste, the monk fruit waste is first crushed to 4-5 cm, and then in the high-temperature carbonization process, under the atmosphere of nitrogen or argon, the temperature is raised to 300-700℃ at a heating rate of 20℃ / min, and carbonized at a constant temperature for 2-4 hours. Then it is cooled to room temperature, pulverized, and passed through a 100-mesh sieve to obtain monk fruit waste biochar. In the ring fertilization step, a ring fertilization trench is dug around the roots of the continuously cropped monk fruit trees. Then, monk fruit waste biochar is applied to the 0-30cm soil in the continuously cropped monk fruit orchard at a ratio of 1% to 8% of the dry soil weight and mixed evenly. The Luo Han Guo waste consists of underground roots and above-ground plants, with a mass ratio of underground roots to above-ground plants of 1:

2. The prepared biochar from monk fruit waste had a yield of 40.09%–61.22%, a specific surface area of ​​71.02–150.69 m² / g, an average pore size of 4.59–7.56 nm, a cation exchange capacity of 41.55–74.81 cmol / kg, an ash content of 20.11%–46.19%, a pH of 7.18–10.15, an acidic functional group content of 0.53–1.01 mmol / g, a basic functional group content of 0.82–1.29 mmol / g, a total functional group content of 1.83–2.13 mmol / g, a total carbon content of 57.46%–68.08%, a total nitrogen content of 1.04%–1.43%, a total phosphorus content of 3.16–5.89 g / kg, and a total potassium content of 21.88–53.29 g / kg. The total sulfur content is 0.34%~0.77%, available phosphorus content is 70.98~168.02 mg / kg, calcium content is 10.01~23.22 mg / g, magnesium content is 10.12~17.68 mg / g, iron content is 6.22~15.42 mg / g, manganese content is 1.23~4.44 mg / g, zinc content is 1.31~4.10 mg / g, heavy metal elements chromium content is 3.43~5.13 mg / kg, lead content is 1.97~2.54 mg / kg, arsenic content is 1.43~1.96 mg / kg, cadmium content is 0.044~0.098 mg / kg, copper content is 2.02~2.56 mg / g, nickel content is 14.52~24.96 mg / kg, and mercury was not detected.

2. The method for alleviating continuous cropping obstacles of monk fruit using biochar according to claim 1, characterized in that, In the step of crushing and carbonizing the monk fruit waste, the carbonization equipment is a mobile carbonization furnace, the reaction pressure is maintained at 0.1 MPa, and the flow rate of nitrogen or argon is 200 mL / min.

3. A method for alleviating continuous cropping obstacles of monk fruit using biochar according to claim 2, characterized in that, The biochar from the waste of monk fruit is used to return to the field in monk fruit orchards to improve the soil. The biochar from the waste of monk fruit is used for ecological restoration of soil contaminated with heavy metals such as cadmium, lead, arsenic, and / or copper. The biochar from the waste of monk fruit is used to remove pesticides such as thiazophos, methyl thiophanate, chlorothalonil, and / or methamidophos from the soil.

4. A method for alleviating continuous cropping obstacles of monk fruit using biochar according to claim 3, characterized in that, The biochar from the waste of monk fruit is used to improve the physiological and ecological functions of the leaves of continuously cropped monk fruit, as well as the yield and quality of the fruit, effectively alleviating the obstacles of continuous cropping of monk fruit.

5. A method for alleviating continuous cropping obstacles of monk fruit using biochar according to claim 4, characterized in that, The biochar made from monk fruit waste prepared at 500℃ showed better effects at an application rate of 6%. The biochar was used to reduce the absorption of heavy metals cadmium, lead, arsenic and / or mercury by intercropping monk fruit with leafy vegetables and root vegetables.

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