A pretreatment method for vine vegetable straw fertilizer utilization

Abstract

The present invention belongs to the field of agricultural resource utilization, and specifically relates to a pretreatment method for the fertilizer utilization of vine vegetable straw. It comprises the following steps: S1: cutting the vine vegetable straw into segments; S2: mixing the vine vegetable straw obtained after the segmentation in S1 with slaked lime and ammonium sulfate, and adjusting the moisture content of the straw to 55%-65% with water, and sealing and placing it at room temperature for 1 day; S3: wet heat high temperature treatment; S4: sealing and placing: sealing and placing the high temperature treated straw at room temperature for 7 days. The present invention has the following advantages: (1) adding a certain amount of slaked lime and ammonium sulfate to the vine vegetable straw can realize the chemical pretreatment of the straw, enhance the softening effect, promote cellulose decomposition, and accelerate the composting process. (2) After chemical + high temperature pretreatment, not only the straw has a softening effect, but also the pathogens in the straw can be completely killed, providing safety protection for the fertilizer utilization of the straw.

Description

Technical Field

[0001] The invention belongs to the field of agricultural resource utilization, and particularly relates to the utilization of vine vegetable straws such as tomatoes and cucumbers in fertilizer, and more specifically to a pretreatment method for the utilization of vine vegetable straws in fertilizer. Background Art

[0002] With the rapid development of my country's social economy and the increasing level of agricultural modernization, my country has gradually become the world's largest vegetable producer and consumer. However, due to the high content of lignocellulose in vine vegetable straw and its tough texture, it is difficult to decompose in traditional compost, which limits its use as fertilizer.

[0003] The high degree of lignification of vine vegetable straws leads to slow composting temperature rise, which results in poor pathogen removal effect, and is an important factor limiting its fertilizer utilization. The key to improving the fertilizer utilization of vine vegetable straws is to soften the cellulose and lignin in the straws through straw pretreatment technology, accelerate the process of composting reaction, and help fundamentally solve the environmental pollution problems that vine vegetable straws may bring, and achieve sustainable development of agricultural resources and ecological environment. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a pretreatment method for utilizing vine vegetable straw as fertilizer.

[0005] The present invention is achieved in that:

[0006] A pretreatment method for utilizing vine vegetable straw as fertilizer comprises the following steps:

[0007] S1: Cut the vine vegetable stalks into small segments of 4-6 cm.

[0008] S2: The vine vegetable straw obtained after cutting in S1 is mixed with slaked lime (Ca(OH)2) and ammonium sulfate ((NH4)2SO4), and the moisture content of the straw is adjusted to 55%-65% with water. The mixture is sealed and placed at room temperature for 1 day. The main purpose is to fully soak the straw, which is beneficial to the removal of pathogens during the subsequent wet heat and high temperature treatment, and to prevent ammonia loss.

[0009] S3: Wet heat high temperature treatment: Put the vine vegetable straw obtained in S2 into a high temperature resistant sealed bag, and then heat it in a steam boiler at 90-100℃ for 1 hour, or in a high pressure steam boiler at 110-120℃ for 0.5 hour. Temperatures and durations below this will affect the sterilization effect.

[0010] S4: Sealed storage: The straw treated with high temperature is sealed and placed at room temperature for 7 days, after which it can be used as raw material for resource utilization such as traditional composting.

[0011] During sealed storage at room temperature, slaked lime and ammonium sulfate will react with the chemical equation Ca(OH)2+(NH4)2SO4→CaSO4+2NH3↑+2H2O. The generated calcium sulfate (CaSO4) can be used as fertilizer. Slaked lime and generated ammonia can destroy the lignocellulose structure of the straw and soften the straw. In addition, under sealed conditions, the straw is in an anaerobic environment, which can reduce the loss of dry matter during the reaction.

[0012] Furthermore, in step S2, the amount of slaked lime used is 0.2%-1% of the weight of the straw, and the amount of ammonium sulfate used is 0.4%-2% of the weight of the straw.

[0013] Preferably, in step S2, the amount of slaked lime used is 0.5%, and the amount of ammonium sulfate used is 0.9%.

[0014] The present invention has the following advantages:

[0015] (1) Adding a certain amount of slaked lime and ammonium sulfate to vine vegetable straw can achieve chemical pretreatment of the straw, enhance the softening effect, promote cellulose decomposition, and accelerate the composting process.

[0016] (2) Chemical + high temperature pretreatment not only softens the straw, but also completely kills the pathogens in the straw, providing a safe guarantee for the fertilizer use of the straw. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0018] Figure 1 Effects of different pretreatments on the contents of cellulose, hemicellulose and lignin in tomato straw.

[0019] Figure 2 The bacterial colony of straw treated with wet heat and high temperature and without wet heat and high temperature treatment. T-1 and T-2 refer to repeated tests treated with wet heat and high temperature.

[0020] Figure 3 The temperature changes during the composting fermentation process of Example 1 and Example 2. DETAILED DESCRIPTION

[0021] A pretreatment method for utilizing vine vegetable straw as fertilizer comprises the following steps:

[0022] S1: Cut the vine vegetable straw to be utilized as a resource into small segments of 4-6 cm.

[0023] S2: The vine vegetable straw obtained after cutting in S1 is mixed with a certain amount of slaked lime (Ca(OH)2) and ammonium sulfate ((NH4)2SO4), and the moisture content of the straw is adjusted to about 60% with water, and then sealed and placed at room temperature for 1 day. The amount of Ca(OH)2 is about 0.5% of the weight of the straw, and the amount of (NH4)2SO4 is about 0.9% of the weight of the straw.

[0024] S3: Wet heat high temperature treatment: The vine vegetable straw obtained in S2 is placed in a high temperature resistant sealed bag and heated in a steam boiler at 90-100°C for 1 hour, or in a high pressure steam boiler at 110-120°C for 0.5 hour.

[0025] S4: The straw treated with high temperature is placed at room temperature for another 7 days, after which it can be used as raw material for resource utilization such as traditional composting.

[0026] 1. Effects of different pretreatments on cellulose, hemicellulose and lignin contents in tomato straw

[0027] Tomato straw was pretreated, and the specific techniques of each treatment are shown in the following table (Table 1).

[0028] After pretreatment, the contents of cellulose, hemicellulose and lignin in tomato straw were Figure 1 It can be seen that the cellulose content was significantly reduced under the T7 treatment (i.e., Ca(OH)2 accounted for 0.5% of the straw weight, 0.9% (NH4)2SO4 was added at the same time, and the wet heat and high pressure was placed for 0.5h and then left for 7d), the lignin content was the lowest but not significant, and the hemicellulose content was the highest. The T7 treatment was better than the other treatments ( Figure 1 ).

[0029] Table 1 Pretreatment technology

[0030]

[0031]

[0032] 2. Effects of wet heat and high temperature treatment on pathogenic microorganisms

[0033] Cut the tomato straw that has been treated with high temperature and humidity (T7 treatment in Table 1) and the untreated tomato straw into pieces, weigh 3g of each, put them into 50ml sterile water and shake them thoroughly to make a stock solution, and pipette 5ml of the stock solution into 45ml sterile water to make a dilution. Pipette 100μl of the stock solution and the dilution onto the pre-prepared LB plate, spread them evenly, and culture them at 30℃ for 2 days, and observe the number of colonies ( Figure 2 ).

[0034] T-1 and T-2 are the colony conditions of straw after wet, hot and high temperature treatment. It can be seen that the straw will not carry pathogenic microorganisms after wet, hot and high temperature treatment.

[0035] CK-1-1 and CK-2-1 are the colony conditions of straw that have not been treated with high temperature and humidity. It can be seen that the untreated straw carries a large number of microorganisms, including a large number of pathogens.

[0036] Example 1

[0037] (1) Cut the tomato stalks into small segments of 4-6 cm.

[0038] (2) Mix the cut tomato straw and corn straw in a weight ratio of 7:3 to prepare a mixed material, adjust the C / N ratio to 25:1 with urea, add 4% magnesium phosphate and 0.1% glucose according to the weight of the mixed material, and then adjust the moisture content to 55%-65%. Magnesium phosphate is a nitrogen retainer that reduces nitrogen loss during composting. Glucose is an initiator that can achieve rapid temperature rise. It is generally not added in traditional composting, but it is added considering that vine straw has a high degree of lignification and is not easy to decompose.

[0039] (3) Make the pile in strips and cover it with film. Turn the pile once every 10 days, for a total of 2 times.

[0040] Example 2

[0041] (1) Cut the tomato stalks into small segments of 4-6 cm.

[0042] (2) The cut tomato straw is pretreated by first mixing it with 0.5% slaked lime and 0.9% ammonium sulfate, adjusting the moisture content to 55%-65%, and then sealing and storing it at room temperature for 1 day. Then, it is subjected to a wet heat high temperature treatment (120°C, 0.5h), and the high temperature treated straw is sealed and placed at room temperature for 7 days.

[0043] (3) The pretreated tomato straw and corn straw were mixed in a weight ratio of 7:3 to prepare a mixed material, the C / N ratio was adjusted to 25:1 with urea, 4% magnesium phosphate and 0.1% glucose were added according to the weight of the mixed material, and then the moisture content was adjusted to 55%-65%.

[0044] (4) Make the pile in strips and cover it with film. Turn the pile once every 10 days, for a total of 2 times.

[0045] According to my country's high temperature fermentation hygiene standard (GB7959-87), the maximum fermentation temperature is required to reach 50-55°C or above and last for 5-7 days. The temperature of the traditional compost (Example 1) only rose to 54.5°C on the 4th and 5th days of composting, and then began to drop below 50°C. After turning the compost on the 10th and 20th days, the temperature did not reach 50°C again ( Figure 3 ), mold and other pathogens grew on the fermentation material during the fermentation process, and the requirements for harmless treatment were not met.

[0046] The temperature of the pretreated tomato straw compost (Example 2) reached 57.1°C on the first day of composting, and the high temperature above 50°C was maintained until the sixth day. After the fermentation was completed, the fermented material was brown in color and the germination index was 88%, indicating that the pretreatment was beneficial to the fermentation and decomposition of the straw. Example 2 basically met the requirements for harmless treatment. The organic fertilizer made from the treated straw was returned to the field, which can play a good role in supplementing soil nutrients.

[0047] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A pretreatment method for vine vegetable straw fertilizer utilization, characterized in that: The steps include: S1: Cut the vine vegetable stalks into small segments of 4-6 cm; S2: Mix the vine vegetable straw obtained after cutting in S1 with slaked lime and ammonium sulfate, adjust the moisture content of the straw to 55%-65% with water, and seal and place at room temperature for 1 day; in step S2, the amount of slaked lime is 0.2%-1% of the weight of the straw, and the amount of ammonium sulfate is 0.4%-2% of the weight of the straw; S3: Wet heat high temperature treatment: put the vine vegetable straw obtained in S2 into a high temperature resistant sealed bag, and then heat it in a steam boiler at 90-100°C for 1 hour, or in a high pressure steam boiler at 110-120°C for 0.5 hour; S4: Seal and place: Seal and place the high temperature treated straw at room temperature for 7 days.

2. The pretreatment method for utilizing vine vegetable straw as fertilizer according to claim 1, characterized in that: In step S2, the amount of slaked lime is 0.5%, and the amount of ammonium sulfate is 0.9%.

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