Biochar fertilizer for sugarcane as well as preparation method and application of biochar fertilizer

Abstract

The invention relates to the technical field of agricultural planting, in particular to a biochar fertilizer for sugarcane as well as a preparation method and application of the biochar fertilizer. According to the technical scheme of the invention, a substrate material of sugarcane biochar is a mixture of sugarcane straw biochar and sugarcane leaf biochar; in the process of preparing the sugarcane straw biochar, the purpose of increasing the pores of the sugarcane straw biochar is achieved by adopting freezing and rapid sublimation modes; the water retention capacity of the sugarcane straw biochar is improved, a fresh leaf rapid carbonization method is adopted during preparation of the sugarcane leaf biochar, the content of organic matter in sugarcane leaves is guaranteed to the maximum extent, a sugaring stack retting mode is adopted during processing, and the diversity of microbial communities in the biochar is improved; in addition, corn straw biochar and rice straw biochar are added, the carbon-nitrogen ratio of the biochar is effectively improved, the biochar is more suitable for growth of ratoon sugarcanes, and the biochar prepared through the method has good water retention capacity and soil improvement capacity and can effectively prolong the growth period of the ratoon sugarcanes.

Description

[Technical field]

[0001] The present invention relates to the technical field of agricultural planting, and in particular to a biochar fertilizer for sugarcane, and a preparation method and application thereof. [Background technology]

[0002] Biochar is a new type of soil conditioner. It has been widely used in various planting fields in recent years because it can improve soil quality, regulate soil pH and nutrients, and change the structure of microbial communities. It is also an environmentally friendly soil conditioner. For example, the article "Effects of Cassava Straw Biochar on Root Growth of Sugarcane Seedlings" describes the study on the effects of cassava straw biochar on sugarcane seedlings. According to the article, adding biochar to the soil can promote the growth of sugarcane roots in the seedling stage and improve the absorption capacity of sugarcane roots in the seedling stage; perennial cane is another way of planting sugarcane. It has the advantages of saving seeds, saving labor, facilitating agricultural operations, and maturing early. It is an important part of sugarcane production. Generally, the yield of perennial cane decreases significantly after 2-3 years of growth. This may be related to the variety of perennial cane, and the greater reason is related to the method of field management. The applicant accidentally discovered in the study of the effect of biochar on sugarcane that the reasonable application of biochar can effectively increase the age of sugarcane perennial roots. For this reason, it is necessary to further study biochar and optimize a biochar fertilizer that can significantly increase the age of sugarcane perennial roots. [Summary of the invention]

[0003] In view of the above, it is necessary to conduct further research on biochar and optimize a biochar fertilizer that can significantly increase the perennial life of sugarcane roots.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] Biochar fertilizer for sugarcane, the biochar fertilizer comprises sugarcane biochar, and the sugarcane biochar is composed of sugarcane straw biochar and sugarcane leaf biochar in a mass ratio of 3-5:1.

[0006] Furthermore, the processing method of the sugarcane straw biochar is as follows: after drying the sugarcane straw, soak it in a mixture of ice water at 0°C until the straw completely absorbs water, and then freeze it in an ice storage at -20°C until the straw becomes hard; preheat the carbonization furnace to 100°C, and then directly put the frozen straw into the carbonization furnace and heat it for 10 minutes, then slowly increase the temperature at a rate of 3°C / min until the temperature reaches 400°C, stop heating, pyrolyze for 60 minutes, and then cool it with water.

[0007] Furthermore, the processing method of the sugarcane leaf biochar is: putting fresh leaves into a carbonization furnace and heating them at a speed of 10-12°C / s for rapid carbonization, stopping heating when the temperature rises to 300°C, pyrolyzing for 30 minutes, and cooling with water.

[0008] Furthermore, the biochar fertilizer also includes corn straw biochar and rice straw biochar; the added amount of corn straw biochar accounts for 10%-20% of the total weight of the fertilizer, and the added amount of rice straw biochar accounts for 5%-10% of the total weight of the fertilizer.

[0009] The present invention also includes a method for preparing the biochar fertilizer for sugarcane, which comprises: weighing sugarcane straw biochar, sugarcane leaf biochar, corn straw biochar and rice straw biochar according to the weight percentage or weight ratio; crushing the corn straw biochar and rice straw biochar, adding water until the surface is moistened, and composting them in a closed manner at room temperature. After composting for 2 days, adding sucrose water with a sucrose mass concentration of 3%-6% at a ratio of 100-150 ml / kg, and then adding the crushed sugarcane straw biochar, stirring evenly, and continuing to compost in a closed manner at room temperature for 3 days. After the composting is completed, the crushed sugarcane straw biochar is added, and the particle diameter of the sugarcane straw biochar is between 5 mm and 10 mm.

[0010] The present invention also includes the effect of the biochar fertilizer for sugarcane in extending the life of sugarcane ratoons.

[0011] The present invention also includes a method for fertilizing sugarcane using the biochar fertilizer for sugarcane, wherein the fertilization method comprises mixing the sugarcane biochar and compound fertilizer in a mass ratio of 1:2 for conventional fertilization.

[0012] Furthermore, the mass ratio of N, P and K in the compound fertilizer is 8:11:10.

[0013] The present invention has the following beneficial effects:

[0014] 1. The biochar of the present invention is a mixture of sugarcane straw biochar and sugarcane leaf biochar. The hardness of sugarcane straw is higher than that of other crop straws. When burned into biochar, its structure can basically remain the same, and it has good water retention. When processing the sugarcane straw biochar, the applicant adopts a method of first soaking in ice water, freeze-drying and freezing, and then rapid sublimation. This method can form denser holes inside the biochar under the influence of ice particles during the early freeze-drying. After rapid sublimation, there are more holes. The holes per unit area of ​​the burned biochar are more than those burned by conventional methods, which increases the water absorption performance of the biochar and can achieve a good water retention effect.

[0015] 2. When processing sugarcane leaf biochar, fresh leaves are used for direct processing. At this time, many effective ingredients in the sugarcane are not taken away by water as they are dried. Moreover, most importantly, the biochar directly processed from fresh leaves is easier to shape and process into carbon, and is not easy to be burned into wood ash due to improper operation, which can ensure that there is more abundant organic matter in it. Afterwards, the sugarcane leaf biochar is piled and fermented, and a certain concentration of sugar water is added to increase the carbon source, which can effectively stimulate the growth of microorganisms and make the microbial community richer. These microorganisms can effectively improve the growth environment of perennial sugarcane. At the same time, it is also possible to breed endophytic fungi that can parasitize in perennial sugarcane and promote the growth of perennial sugarcane or have a disease prevention effect, effectively extending the service life of perennial sugarcane.

[0016] 3. After years of research, the present application has found that in sugarcane biochar, the ratio of sugarcane straw biochar to sugarcane leaf biochar of 3-5:1 is the most effective for the growth of perennial sugarcane. Within this range, the biochar has good water retention, moisture retention, and soil improvement effects. If the ratio of sugarcane straw biochar is too low, the water retention performance of the biochar is poor, the air permeability is poor, and the perennial root growth is not good; if the ratio of sugarcane straw biochar is too high, the soil improvement ability in the biochar is poor, the fertility is insufficient, and the growth of perennial sugarcane is also affected. After years of research by the applicant, it has also been found that adding corn straw biochar and rice straw biochar to sugarcane biochar can further improve the (C, N, P, K) ratio in the biochar, making the biochar more suitable for the growth of perennial sugarcane. Similarly, the microbial community is more diverse, which can further play a role in optimizing the soil environment for the growth of perennial sugarcane. Therefore, the use of the biochar of the present application has a good water retention effect, can effectively improve the soil environment of perennial sugarcane, and make the perennial sugarcane service life longer. [Specific implementation method]

[0017] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation of the present invention is described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific implementation disclosed below.

[0018] Embodiment 1:

[0019] The preparation method of the biochar fertilizer in this embodiment is:

[0020] (1) Preparation of sugarcane straw biochar: Referring to the oxygen-limited pyrolysis method, the sugarcane straw was dried and then soaked in a mixture of ice and water at 0°C until the straw completely absorbed the water, and then placed in a -20°C ice storage to freeze until the straw became hard; the carbonization furnace was preheated to 100°C, and then the frozen straw was directly placed in the carbonization furnace and heated for 10 minutes, and then the temperature was slowly increased at a rate of 3°C / min until the temperature reached 400°C and the heating was stopped. After pyrolysis for 60 minutes, water was sprayed to cool.

[0021] (2) Preparation of sugarcane leaf biochar: fresh leaves were placed in a carbonization furnace and heated at a rate of 10-12°C / s for rapid carbonization until the temperature reached 300°C. The heating was stopped, pyrolyzed for 30 minutes, and then cooled by pouring water.

[0022] (3) The sugarcane leaf biochar was crushed into a size of about 20 meshes; the sugarcane straw biochar was crushed into particles with a diameter of 5 mm to 10 mm; the sugarcane leaf biochar was fermented at room temperature for 2 days, and then a sucrose solution with a sucrose mass concentration of 5% was added to ferment at room temperature for 3 days, and then the crushed sugarcane straw biochar was added and stirred.

[0023] Sugarcane biochar fertilizer was prepared by mixing sugarcane straw biochar with sugarcane leaf biochar in a gradient ratio of 1:1, 2:1, 3:1, 4:1, 5:1 and 6:1;

[0024] Control group: The method for preparing biochar in the control group was different from that in Example 1 in only one respect, that is, no sucrose solution was added, and the crushed sugarcane leaf biochar was directly composted in a closed pile at room temperature for 5 days.

[0025] The first-year ratoon sugarcane of the same sugarcane variety in the ratoon sugarcane planting area was divided into 13 plots (50 ratoons in each plot), of which 6 plots were fertilized with the biochar prepared by the method of Example 1, and the other 6 plots were fertilized with the biochar prepared by the control group. The remaining 1 plot was the control group, which did not use biochar but used conventional compound fertilizer (NPK: 8-11-10) for fertilization. The fertilization method of Example 1 and the control group was: the sugarcane biochar fertilizer and the compound fertilizer were mixed at a mass ratio of 1:2, and conventional fertilization was performed as the control group, wherein the biochar was mixed according to different mass ratios of straw and leaves. The specific results are shown in Table 1:

[0026] Table 1 Example 1 Effect of different biochar fertilization on sugarcane ratoon germination rate

[0027]

[0028] As can be seen from Table 1, the mortality rate of ratoon cane in the first year was not much different among the embodiment, control group and control group. In the second year, the ratoon mortality rate of the embodiment was lower than that of the control group and the control group; but at this time, the ratoon cane of the embodiment, control group and control group could maintain a good survival rate, indicating that the ratoon cane still had a strong survival ability; and in the third year, the ratoon cane mortality rate of the embodiment and control group was much lower than that of the control group, and the ratoon cane mortality rate of 3:1, 4:1 and 5:1 in the embodiment was significantly lower than that of 1:1 and 6:1 in the embodiment and control group; after research, this may be caused by the following reasons: the sugarcane biochar of the present application is composed of sugarcane straw biochar with larger particles and higher density, and ice water immersion and rapid heating and sublimation are used during processing, so that the pores of the fired biochar are larger and more uniform than those of general biochar, and have stronger Water retention and water storage capacity, and the microbial community in the fermented sugarcane leaf biochar is richer and has a stronger soil improvement ability; if the proportion of sugarcane straw biochar is too low, it is very likely that the pores of the biochar will be blocked by the crushed sugarcane leaf biochar, resulting in insufficient water retention capacity and unsuitable for sugarcane perennial root growth; if the proportion of sugarcane straw biochar is too high, it will cause too few microbial communities and fail to improve the soil; and when the sugarcane leaf biochar is fermented, adding sucrose solution can effectively increase the carbon source, stimulate the reproduction of microorganisms of different populations, and effectively affect the microbial community structure in the biochar. These microorganisms are adsorbed in the biochar and applied to the soil to effectively improve the microbial structure in the soil. Some of these microorganisms may promote sugarcane growth or have endophytic fungi with disease inhibition ability, which can extend the service life of perennial root sugarcane. Based on this judgment, the best configuration ratio for perennial root sugarcane when applying the sugarcane biochar of this application is 3:1-5:1.

[0029] Water retention test:

[0030] Under the same water and fertilizer conditions (watering and fertilizing on the same day), the soil moisture content tested after watering was recorded as the moisture content on the 0th day, and then the soil moisture content was tested on the 5th, 10th, and 20th days respectively and the water retention rate was calculated. The results are shown in Table 2:

[0031] The calculation method of water retention rate is as follows:

[0032]

[0033] Table 2 Effect of different biochar fertilization on water retention rate of sugarcane planting land

[0034]

[0035] It can be seen from Table 2 that the water retention rates of the embodiment and the control group on the 5th, 10th and 20th days are greater than those of the control group, and the water retention rate can be as high as about 40%. The difference in water retention rate between the embodiment and the control group is not large. From the perspective of the biochar ratio, the higher the proportion of sugarcane straw biochar, the higher the water retention rate, indicating that the higher the content of sugarcane straw biochar, the higher its water retention rate, indicating that the freezing and sublimation process used in this application can effectively increase the pores of sugarcane straw biochar, and the increase in these pores can effectively improve the water retention rate of sugarcane straw biochar.

[0036] Embodiment 2:

[0037] The preparation method of biochar in this embodiment is:

[0038] The preparation methods of sugarcane straw biochar and sugarcane leaf biochar are the same as those in Example 1;

[0039] The biochar of this embodiment also includes corn straw biochar and rice straw biochar;

[0040] The preparation method of corn straw biochar is as follows: fresh corn straw is placed in a carbonization furnace and heated at a rate of 5°C / s for rapid carbonization until the temperature reaches 400°C, heating is stopped, pyrolysis is performed for 60 minutes, and then cooling is performed by spraying water;

[0041] The preparation method of rice straw biochar is as follows: fresh rice straw is placed in a carbonization furnace, heated at a rate of 10°C / s until the temperature reaches 300°C, the heating is stopped, pyrolyzed for 60 minutes, and then cooled by water;

[0042] The amount of corn straw biochar added is 10%-20% of the total weight of the fertilizer, and the amount of rice straw biochar added is 5%-10% of the total weight of the fertilizer.

[0043] Biochar mixing: After crushing corn straw biochar and rice straw biochar, add water to moisten the surface, and compost them in a closed manner at room temperature. After composting for 2 days, add sucrose water with a sucrose mass concentration of 5% at a ratio of 150 ml / kg, and then add the crushed sugarcane straw biochar. After stirring evenly, continue to compost in a closed manner at room temperature for 3 days. After the end, add the crushed sugarcane straw biochar. The particle diameter of the sugarcane straw biochar in this embodiment is between 5 mm and 10 mm.

[0044] Control group: The method for preparing biochar in the control group was different from that in Example 1 in that no sucrose solution was added, and the crushed sugarcane leaf biochar, corn straw biochar and rice straw biochar were crushed and mixed separately and then directly composted in a closed manner at room temperature for 5 days.

[0045] The biochar ratio selection of Example 2 and the control group, the optimal group of Example 1, that is, the mass ratio of sugarcane straw biochar to sugarcane leaf biochar was selected as 4:1 as the base fertilizer, and then the corn straw biochar and rice straw biochar were calculated and weighed according to the amount gradient of 0%-20% of the fertilizer, and then the biochar was prepared according to the above method. The corresponding ratios are shown in Table 3:

[0046] Table 3 Biochar ratio table

[0047]

[0048]

[0049] Biochar was prepared according to the ratio of the above groups 1 to 5, and the biochar was applied to the study of perennial sugarcane. The same sugarcane variety was selected, and the first-year perennial sugarcane in the perennial sugarcane planting area of ​​the same sugarcane variety was divided into 13 plots (50 perennials in each plot), of which 6 plots were fertilized with the biochar prepared by the method of Example 1, and the other 6 plots were fertilized with the biochar prepared by the control group. The remaining 1 plot was a control group that did not use biochar but used conventional compound fertilizer for fertilization (NPK: 8-11-10). The fertilization method of Example 1 and the control group was: sugarcane biochar and compound fertilizer were mixed in a mass ratio of 1:2, and conventional fertilization was performed, wherein the biochar was mixed according to Table 3. The specific results obtained are shown in Table 4:

[0050] Table 4 Effect of different biochar fertilization on sugarcane ratoon germination rate in Example 2

[0051]

[0052] As can be seen from the above table, the mortality rate of ratoon cane in the first year was not much different between the embodiments of groups 1-6, the control group and the control group. In the second year, the ratoon mortality rate of the embodiments of groups 1-5 was lower than that of the embodiments of group 6, the control group and the control group. However, at this time, the ratoon cane of the embodiments, the control group and the control group could maintain a good survival rate, indicating that the ratoon cane still had a strong survival ability. In the third year, the ratoon cane mortality rate of the embodiments of groups 1-5 and the control group was much lower than that of the control group and the embodiment of group 6. In the biochar of the present application, the main component that can extend the life of sugarcane ratoon is the basal fertilizer (i.e., the sugarcane straw biochar and the sugarcane leaf biochar). The main ingredients of the biochar are corn straw biochar and rice straw biochar, while corn straw biochar and rice straw biochar play an additional regulatory role. If corn straw biochar and rice straw biochar are used as the main ingredients, the growth of sugarcane perennial roots will be affected and the perennial root period will not be extended. This is because: the chemical composition content of biochar burned from different crops is different, which results in different contents of (C, N, P, K) elements in biochar and different pH values ​​of biochar, which have different effects on the growth of perennial sugarcane. Among various biochars, the reasonable ratio of sugarcane straw biochar and sugarcane leaf biochar can best affect the growth of perennial sugarcane.

[0053] In the above ratios, it was found that the growth years of ratoon sugarcane in groups 3-5 were slightly better than those in other ratios, indicating that the optimal ratio for the application of these four types of biochars is 10%-20% of the total weight of corn straw biochar and 5%-10% of the total weight of rice straw biochar.

[0054] Water retention rate impact experiment:

[0055] Under the same water and fertilizer conditions (watering and fertilizing on the same day), the soil moisture content tested after watering was recorded as the moisture content on the 0th day, and then the soil moisture content was tested on the 5th, 10th, and 20th days respectively and the water retention rate was calculated. The results are shown in Table 5:

[0056] The calculation method of water retention rate is as follows:

[0057]

[0058] Table 5 Effect of different biochar fertilization on water retention rate of sugarcane planting land

[0059]

[0060] As can be seen from the above table, there is little difference in the water retention rate on the 5th day, the 10th day and the 20th day between the embodiment and the control groups 1-5, and there is little difference within groups 1-5, indicating that the rice straw biochar and corn straw biochar in the biochar have little effect on the water retention effect of the biochar; and whether sugar is added during the fermentation process has little effect on the water retention rate, while the water retention rate of group 6 is much lower than that of groups 1-5 and slightly higher than that of the control group, indicating that the rice straw biochar and corn straw biochar have a certain water retention capacity, but the effect is not as strong as the water retention capacity of sugarcane straw biochar.

[0061] In summary, the biochar of the present application can effectively improve the water retention capacity, improve the soil microbial community structure for the growth of ratoon sugarcane, thereby improving the soil environment of the ratoon sugarcane and the ratio of each element in the fertilizer, is suitable for the growth of ratoon sugarcane, and can effectively extend the service life of the ratoon sugarcane. Compared with other fertilizers, biochar is more economical, simpler to process, and environmentally friendly.

[0062] The above examples only express several embodiments of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. Biochar fertilizer for sugarcane, characterized in that The biochar fertilizer includes sugarcane biochar, and the sugarcane biochar is composed of sugarcane straw biochar and sugarcane leaf biochar in a mass ratio of 3-5:

1.

2. The biochar fertilizer for sugarcane according to claim 1, characterized in that: The biochar fertilizer also includes corn straw biochar and rice straw biochar; the added amount of corn straw biochar accounts for 10%-20% of the total weight of the fertilizer, and the added amount of rice straw biochar accounts for 5%-10% of the total weight of the fertilizer.

3. A method for preparing the biochar fertilizer for sugarcane as claimed in claim 4, characterized in that: The method comprises: weighing sugarcane straw biochar, sugarcane leaf biochar, corn straw biochar and rice straw biochar according to the weight percentage or weight ratio; crushing the corn straw biochar and rice straw biochar, adding water until the surface is moistened, and performing closed composting at room temperature; after composting for 2 days, adding sucrose water with a sucrose mass concentration of 3%-6% at a ratio of 100-150 ml / kg, and then adding the crushed sugarcane straw biochar, stirring evenly, and continuing to perform closed composting at room temperature for 3 days, and adding crushed sugarcane straw biochar after the completion, wherein the particle diameter of the sugarcane straw biochar is between 5 mm and 10 mm.

4. The biochar fertilizer for sugarcane according to any one of claims 1 or 2 has an effect on extending the life of sugarcane ratoons.

5. A method for fertilizing sugarcane using the biochar fertilizer for sugarcane according to any one of claims 1 or 2, characterized in that: The fertilization method is to mix the sugarcane biochar and the compound fertilizer in a mass ratio of 1:2 for conventional fertilization.

6. The method according to claim 5, characterized in that The mass ratio of N, P and K in the compound fertilizer is 8:11:10.

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