Special charcoal-based fertilizer for potatoes as well as preparation method and application of special charcoal-based fertilizer

Abstract

The invention discloses a special charcoal-based fertilizer for potatoes as well as a preparation method and application thereof, and belongs to the technical field of fertilizers. The special charcoal-based fertilizer for potatoes is prepared from the following raw materials in parts by mass: 15 to 20 parts of biomass charcoal, 18 to 30 parts of urea, 15 to 22 parts of diammonium phosphate, 8 to 15 parts of potassium sulfate, 5 to 10 parts of bentonite, 2 to 4 parts of borax, 3 to 6 parts of manganese sulfate and 0 to 5 parts of calcium sulfate. The special biochar base fertilizer for the potatoes is designed by researching the soil fertilizer supply characteristic of a main potato producing area and the potato fertilizer requirement rule, so that the compound fertilizer has a better nutrient slow release characteristic, the nutrient requirement of the potatoes in the whole growth period is met, nutrient loss is reduced, and the nutrient utilization efficiency is improved. While high yield of potatoes is ensured, the environment-friendly degree of the fertilizer to a main potato production site is also improved, the soil quality is improved, and the fertilizer has very good application and popularization values.

Description

Technical Field

[0001] The invention relates to the technical field of fertilizers, and in particular to a biochar-based fertilizer special for potatoes, and a preparation method and application thereof. Background Art

[0002] Potato (scientific name: Solanum tuberosumL), a perennial herbaceous plant belonging to the Solanaceae family, is the fourth most important food crop in the world, second only to wheat, rice and corn. At present, the potato industry has become the dominant industry in the main potato producing areas. With the continuous development of the potato industry, farmers have been planting potatoes year-round in pursuit of high yields and economic benefits, resulting in the continuous increase in the application of single-element fertilizers, especially nitrogen fertilizers, leading to excessive nitrogen fertilizer application, which not only causes an imbalance of nitrogen, phosphorus and potassium nutrients and soil acidification, but also causes waste of single nutrients and ecological environment pollution.

[0003] Biochar is the product of thermal cracking and carbonization of straw and biomass waste. It has the characteristics of high carbon content, high pH, ​​high porosity, large specific surface area, rich organic functional groups, high stability, etc., and its application in soil can reduce soil bulk density, increase soil porosity, balance acidic soil pH, increase soil CEC, enhance soil water and nutrient absorption capacity, and improve soil fertility. However, biochar itself has low mineral nutrient content, and the nutrients it directly supplies to crops are limited.

[0004] At present, the vast majority of research on special fertilizers is still focused on optimizing the ratio of nutrients, which has defects such as low fertilizer utilization rate, poor fertilizer efficiency, and inconvenient application. In order to improve fertilizer utilization rate and give full play to the economic and environmental benefits of fertilizers, designing a high-concentration, diversified, composite, slow-release and high-efficiency special fertilizer has become a hot spot and focus of current research on special fertilizers for crops. Summary of the invention

[0005] The present invention provides a biochar-based fertilizer for potatoes, a preparation method thereof, and an application thereof. The biochar-based fertilizer is prepared by studying the soil fertilizer supply characteristics and the fertilizer requirement law of potatoes in the main potato production areas, and can make the compound fertilizer have better nutrient slow-release characteristics to meet the nutrient requirements of potatoes throughout the entire growth period, reduce nutrient loss, and improve nutrient utilization efficiency. While ensuring a high yield of potatoes, the present invention also improves the environmental friendliness of the fertilizer to the main potato production areas, improves the soil quality, and has a good application and promotion value.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a biochar-based fertilizer for potatoes, wherein the raw materials, by weight, include: 15-20 parts of biochar, 18-30 parts of urea, 15-22 parts of diammonium phosphate, 8-15 parts of potassium sulfate, 0-10 parts of bentonite, 2-4 parts of borax, 3-6 parts of manganese sulfate and 0-5 parts of calcium sulfate;

[0008] Among them, bentonite and calcium sulfate are not 0 at the same time.

[0009] Preferably, the raw materials are calculated by mass as follows: 18 parts of biochar, 28 parts of urea, 22 parts of diammonium phosphate, 12 parts of potassium sulfate, 8 parts of bentonite, 4 parts of borax, 5 parts of manganese sulfate and 3 parts of calcium sulfate.

[0010] Biochar is a slightly alkaline, porous, loose carbonaceous mixture rich in various organic components. By utilizing its rich and stable organic matter components and its nutrient absorption and soil structure improvement properties, and by adding a certain amount of clay and inorganic nutrients, as well as compounding, mixing, granulation and other operations, the organic-inorganic compound fertilizer produced can have better fertilizer efficiency, thereby improving soil retention rate and crop absorption rate, maintaining the biological turnover of nutrients such as nitrogen, improving soil structure, increasing soil moisture and promoting crop root growth.

[0011] Preferably, the bentonite is calcium-based bentonite.

[0012] The present invention has found through research that although calcium-based bentonite is not as effective as lime and sodium-based bentonite in improving the pH value of acidic soil in the early stage, with the extension of time, especially after 1 year, the effect of calcium-based bentonite on increasing pH gradually becomes stronger than the two. This may be because lime makes the pH value of soil more difficult to control, accelerates soil acidification, and makes soil compaction more serious; the base saturation (BS%) of soil treated with calcium-based bentonite is lower than that of sodium-based bentonite, and the soil after treatment is less sensitive to acid, and calcium-based bentonite can transform deeper soil.

[0013] Preferably, the biochar preparation method is: crushing corn stalks to pass through a 25-80 mesh sieve, drying to a moisture content of ≤10wt%, and then carbonizing at 300-500°C for 0.5-1h to obtain the biochar.

[0014] The second technical solution of the present invention is to provide a method for preparing the above-mentioned biochar-based fertilizer for potatoes, comprising the following steps:

[0015] The raw materials are added in proportion, mixed evenly, granulated, dried and sieved to obtain the biochar-based fertilizer for potatoes.

[0016] Preferably, the reaction medium of the granulation is high-temperature steam, the steam temperature of the high-temperature steam is 100-140° C., and the steam volume is 25-30% of the total mass of the raw materials.

[0017] Preferably, the drying is carried out at 300-400° C. to a water content of ≤5wt%; and the particle size of the particles after screening is 1-4.75 mm.

[0018] The third technical solution of the present invention is to provide an application of the above-mentioned potato-specific biochar-based fertilizer in potato planting.

[0019] The beneficial technical effects of the present invention are as follows:

[0020] The biomass charcoal-based fertilizer for potatoes provided by the present invention has better nutrient ratio and sustained release properties than traditional compound fertilizers and charcoal-based fertilizers. The granulation process of the present invention combines physical and chemical reactions, and the selected specific binder provides a better bonding effect for the granulation process. Under high-temperature steam conditions, the amide bond of urea in the fertilizer and the nitrogen-phosphorus bond of diammonium phosphate combine with the groups on the biomass charcoal to cause chemical shift, and the nutrients and the charcoal frame are interconnected, and the raw materials are more closely combined; the nutrient release rate under the control of multiple conditions of the present invention can be better combined with the entire growth period of potatoes, so that the prepared fertilizer can play the maximum effect and improve the fertilizer efficiency.

[0021] The biomass charcoal-based fertilizer for potatoes provided by the invention has comprehensive nutrition and long fertilizer effect, is particularly suitable for potato cultivation areas with irrigation conditions, and the harvested potato tubers are uniform, which can increase the rate of large and medium potatoes by 12.7-19.0% and increase the yield by 5.4-13.7%.

[0022] The present invention studies the soil fertilizer supply characteristics and potato fertilizer requirement rules in the main potato producing areas, designs a biochar-based fertilizer specifically for potatoes, and enables the compound fertilizer to have better nutrient slow-release characteristics to meet the nutrient requirements of potatoes throughout the entire growth period, reduce nutrient loss, and improve nutrient utilization efficiency. While ensuring a high yield of potatoes, the present invention also improves the environmental friendliness of fertilizers to the main potato producing areas, improves soil quality, and has great application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1This is a test diagram of nitrogen slow-release performance of potato-specific base fertilizers prepared in Examples 1-3 and Comparative Examples 1-4 of the present invention. DETAILED DESCRIPTION

[0025] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0026] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0027] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0028] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0029] The preparation method of the biomass charcoal used in the following examples and comparative examples of the present invention is as follows: the corn stalks are crushed to pass through a 40-mesh sieve, dried to a moisture content of 10 wt%, and then placed in a muffle furnace and carbonized at 350° C. for 40 min to obtain the biomass charcoal.

[0030] The bentonite used in the following examples and comparative examples of the present invention is calcium-based bentonite.

[0031] All raw materials used in the following examples and comparative examples of the present invention are commercially available products.

[0032] The purity requirements of each raw material in the present invention are shown in the following table:

[0033] Table 1 Raw material purity requirements

[0034]

[0035]

[0036] Example 1

[0037] Calculated by mass, the content of each component of biomass charcoal-based fertilizer for potatoes is:

[0038] 15 parts of biochar, 23 parts of urea, 22 parts of diammonium phosphate, 15 parts of potassium sulfate, 10 parts of bentonite, 4 parts of borax, 6 parts of manganese sulfate, and 5 parts of calcium sulfate.

[0039] The specific preparation steps are as follows:

[0040] (1) Add the raw materials according to the proportion and mix them evenly;

[0041] (2) the mixed raw materials are passed into a granulator using 100° C. high-temperature steam as a reaction medium for granulation;

[0042] (3) Dry the particles obtained in step (2) at 400° C. to a moisture content of 5 wt %, and then pass through a 20-mesh sieve to obtain a biochar-based fertilizer for potatoes.

[0043] Example 2

[0044] Calculated by mass, the content of each component of biomass charcoal-based fertilizer for potatoes is:

[0045] 20 parts of biochar, 20 parts of urea, 15 parts of diammonium phosphate, 15 parts of potassium sulfate, 5 parts of bentonite, 4 parts of borax, 6 parts of manganese sulfate, and 5 parts of calcium sulfate.

[0046] The specific preparation steps are as follows:

[0047] (1) Add the raw materials according to the proportion and mix them evenly;

[0048] (2) the mixed raw materials are passed into a granulator using 120° C. high-temperature steam as a reaction medium for granulation;

[0049] (3) Dry the particles obtained in step (2) at 300° C. to a moisture content of 5 wt %, and then pass through a 20-mesh sieve to obtain a biochar-based fertilizer for potatoes.

[0050] Example 3

[0051] Calculated by mass, the content of each component of biomass charcoal-based fertilizer for potatoes is:

[0052] 18 parts of biochar, 28 parts of urea, 22 parts of diammonium phosphate, 12 parts of potassium sulfate, 8 parts of bentonite, 4 parts of borax, 5 parts of manganese sulfate, and 3 parts of calcium sulfate.

[0053] The specific preparation steps are as follows:

[0054] (1) Add the raw materials according to the proportion and mix them evenly;

[0055] (2) the mixed raw materials are passed into a granulator using 120° C. high-temperature steam as a reaction medium for granulation;

[0056] (3) Dry the particles obtained in step (2) at 350° C. to a moisture content of 5 wt %, and then pass through a 20-mesh sieve to obtain a biochar-based fertilizer for potatoes.

[0057] Comparative Example 1

[0058] A potato-specific fertilizer without added biochar (NPK nutrient content 15-5-4, purchased from Gansu Sudi Fertilizer Co., Ltd.) was selected as Comparative Example 1.

[0059] Comparative Example 2

[0060] Calculated by mass, the content of each component of biomass charcoal-based fertilizer for potatoes is:

[0061] 18 parts of biochar, 25 parts of urea, 22 parts of diammonium phosphate, 15 parts of potassium sulfate, 10 parts of bentonite, 4 parts of borax, and 6 parts of manganese sulfate.

[0062] The specific preparation steps are as follows:

[0063] (1) Add the raw materials according to the proportion and mix them evenly;

[0064] (2) the mixed raw materials are passed into a granulator using 120° C. high-temperature steam as a reaction medium for granulation;

[0065] (3) Dry the particles obtained in step (2) at 350° C. to a moisture content of 5 wt %, and then pass through a 20-mesh sieve to obtain a biochar-based fertilizer for potatoes.

[0066] Comparative Example 3

[0067] Calculated by mass, the content of each component of biomass charcoal-based fertilizer for potatoes is:

[0068] 18 parts of biochar, 30 parts of urea, 22 parts of diammonium phosphate, 15 parts of potassium sulfate, 4 parts of borax, 6 parts of manganese sulfate, and 5 parts of calcium sulfate.

[0069] The specific preparation steps are as follows:

[0070] (1) Add the raw materials according to the proportion and mix them evenly;

[0071] (2) the mixed raw materials are passed into a granulator using 120° C. high-temperature steam as a reaction medium for granulation;

[0072] (3) Dry the particles obtained in step (2) at 350° C. to a moisture content of 5 wt %, and then pass through a 20-mesh sieve to obtain a biochar-based fertilizer for potatoes.

[0073] Comparative Example 4 (conventional granulation)

[0074] Calculated by mass, the content of each component of biomass charcoal-based fertilizer for potatoes is:

[0075] 18 parts of biochar, 28 parts of urea, 22 parts of diammonium phosphate, 12 parts of potassium sulfate, 8 parts of bentonite, 4 parts of borax, 5 parts of manganese sulfate, and 3 parts of calcium sulfate.

[0076] The specific preparation steps are as follows:

[0077] (1) Add the raw materials according to the proportion and mix them evenly;

[0078] (2) passing the mixed raw materials into a rotary drum granulator at room temperature for granulation;

[0079] (3) Dry the particles obtained in step (2) at 350° C. to a moisture content of 5 wt %, and then pass through a 20-mesh sieve to obtain a biochar-based fertilizer for potatoes.

[0080] Effect verification

[0081] (1) In order to verify the slow-release performance of the prepared compound fertilizer, the present invention carried out a dissolution rate test, and the process steps are as follows:

[0082] 10 compound fertilizer granules prepared in Examples 1-3 and Comparative Examples 2-4 were selected and placed in the same culture dish, and water was added to just cover the fertilizer granules. The mixture was allowed to stand, and the time for all the fertilizer granules to disperse was recorded. The average water-dissolving time of different types of fertilizers was calculated. The test results are shown in Table 2.

[0083] Table 2 Water dissolution time of different types of fertilizers

[0084] Fertilizer Type Binder type Water dissolution time / min Example 1 Bentonite + calcium sulfate 57 Example 2 Bentonite + calcium sulfate 60 Example 3 Bentonite + calcium sulfate 62 Comparative Example 2 Calcium sulfate 11 Comparative Example 3 Bentonite 30 Comparative Example 4 Bentonite + calcium sulfate 43

[0085] As can be seen from Table 2, different binders have a great influence on the water dissolution time of fertilizers. Among them, the biomass carbon-based fertilizer with bentonite and calcium sulfate as binders maintains its form in water for a much longer time than the fertilizer using bentonite and calcium sulfate alone, which can greatly prolong the time for fertilizer particles to disperse. From the comparison between Example 3 and Comparative Example 4 in Table 2, it can be seen that the unique granulation process of the present invention also has a significant effect on improving the water dissolution time, which may be because the high temperature improves the degree of cross-linking between the raw materials.

[0086] (2) In order to verify the slow-release performance of the prepared compound fertilizer, the present invention conducted a nitrogen slow-release performance test on the fertilizers prepared in Examples 1-3 and Comparative Examples 1-4, and the process steps are as follows:

[0087] Except that the culture temperature was 25°C and the sampling time was 10min, 20min, 30min, 40min, 50min, and 60min, the rest of the operations were carried out in accordance with the national standard "GB / T 23348-2009 Slow-release Fertilizer". Figure 1 shown.

[0088] Figure 1 This is a test chart of nitrogen slow-release performance of biomass carbon-based fertilizers for potatoes prepared in Examples 1-3 and Comparative Examples 1-4 of the present invention. Figure 1 It can be seen that before 15 minutes, there is no obvious difference in the nitrogen release rate between the embodiment and the comparative example, and the nitrogen dissolution rate basically reaches 20%-35%. At 60 minutes, the nitrogen release rate of the comparative example basically reaches about 80%, while the nitrogen release rate of the embodiment only reaches about 70%, which is significantly lower than the nitrogen release rate of the comparative example. It can be seen that the fertilizer scheme designed by the present invention can greatly slow down the nutrient release rate and extend the effective action time of the fertilizer.

[0089] (3) In order to verify the fertilizer effect of the prepared compound fertilizer, the present invention conducted a fertilization test on the fertilizers prepared in Examples 1-3 and Comparative Examples 1-4, and the process steps are as follows:

[0090] 1) Test location: This test is located in Xiangquan Town, Anding District, Dingxi City. Overview: The area is 1993m above sea level, 104°36'44" longitude, 35°29'14" latitude, with an average annual temperature of 5.27℃, 162d frost-free period, 3016℃ effective accumulated temperature ≥10℃, large temperature difference between day and night, 2323mm evaporation, and a temperate continental arid climate. The soil is black loam soil with a deep soil layer. The nutrient status of the 0-20cm tillage layer is: organic matter 8.2mg / kg, total nitrogen 0.66g / kg, total phosphorus 0.82g / kg, total potassium 20.1g / kg, available nitrogen 102.3mg / kg, available phosphorus 17.9mg / kg, available potassium 213mg / kg, pH 8.24, uniform soil fertility, and the previous crop is potato.

[0091] 2) Experimental raw materials: The potato variety used for the test was the original variety Longshu No. 6.

[0092] 3) Experimental treatment: This experiment has 8 treatments, treatment 1: no fertilizer, treatment 2: comparative example 1, treatment 3: example 1, treatment 4: example 2, treatment 5: example 3, treatment 6: comparative example 2, treatment 7: comparative example 3, treatment 8: comparative example 4. 3 repetitions, a total of 24 plots, plot area 40m 2 (5×8m), and the plot distribution adopted random block design. The sowing date was April 18, 2018, and the sowing method was ridge cultivation, with a ridge width of 50cm and a ridge furrow of 40cm. Double rows were planted on the ridges, and the row spacing of potatoes on the ridges was 20cm, the plant spacing was 10cm, and the sowing depth was 15cm. The planting density was 5000 plants / mu. Topdressing was applied in holes during the clustering period, and drip irrigation was used. Irrigation was carried out 6 times during the entire growth period, and the harvest was carried out on October 5, 2018. Other field management measures were carried out according to the high-yield cultivation management measures of local fields.

[0093] 4) Fertilizer application amount and method: The application amount of treatment 2 to treatment 8 is 100 kg / mu, which is applied as a one-time basal application at the time of sowing, and then broadcast and deep plowed.

[0094] The test results are shown in Table 3.

[0095] Table 3 Growth characteristics and yield of potato

[0096]

[0097] It can be seen from the data in Table 3 that the potato-specific biochar-based fertilizer provided by the present invention can significantly increase potato yield. In terms of potato growth traits, the data of single plant height, tuber number, tuber weight, number of large and medium potatoes, and large and medium potato rate are also significantly higher than those of the treatment group without fertilization.

[0098] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A biochar-based fertilizer for potatoes, characterized in that: The raw materials include, by weight: 15-20 parts of biochar, 18-30 parts of urea, 15-22 parts of diammonium phosphate, 8-15 parts of potassium sulfate, 0-10 parts of bentonite, 2-4 parts of borax, 3-6 parts of manganese sulfate and 0-5 parts of calcium sulfate; Among them, bentonite and calcium sulfate are not 0 at the same time.

2. The biochar-based fertilizer for potatoes according to claim 1, characterized in that: The raw materials are calculated by weight and are: 18 parts of biochar, 28 parts of urea, 22 parts of diammonium phosphate, 12 parts of potassium sulfate, 8 parts of bentonite, 4 parts of borax, 5 parts of manganese sulfate and 3 parts of calcium sulfate.

3. The biochar-based fertilizer for potatoes according to claim 1 or 2, characterized in that: The bentonite is calcium-based bentonite.

4. The biochar-based fertilizer for potatoes according to claim 1, characterized in that: The preparation method of the biomass charcoal comprises: crushing corn stalks to pass through a 25-80 mesh sieve, drying to a moisture content of ≤10wt%, and then carbonizing at 300-500°C for 0.5-1h to obtain the biomass charcoal.

5. A method for preparing the biochar-based fertilizer for potatoes according to any one of claims 1 to 4, characterized in that: The following steps are involved: The raw materials are added in proportion, mixed evenly, granulated, dried and sieved to obtain the biochar-based fertilizer for potatoes.

6. The method for preparing biochar-based fertilizer for potatoes according to claim 5, characterized in that: The reaction medium of the granulation is high-temperature steam, the steam temperature of the high-temperature steam is 100-140° C., and the steam volume is 25-30% of the total mass of the raw materials.

7. The method for preparing biochar-based fertilizer for potatoes according to claim 5, characterized in that: The drying is carried out at 300-400° C. until the water content is less than or equal to 5wt%; and the particle size of the particles after screening is 1-4.75mm.

8. Use of the biochar-based fertilizer for potatoes according to any one of claims 1 to 4 in potato planting.

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