CN105837270A - Method for preparing organic fertilizer from crop straws - Google Patents

Abstract

The invention provides a method for preparing organic fertilizer by using crop stalks. The invention also provides a fish scale protein enzymatic hydrolyzate and its preparation method and application. The organic fertilizer provided by the invention has comprehensive and balanced nutrients and excellent quality, and can greatly improve the yield and quality of agricultural products when applied alone, and the effect is stronger than that of chemical fertilizers and general straw organic fertilizers, and has achieved good technical effects and good application prospects.

Description

A method for preparing organic fertilizer from crop stalks

technical field

The invention belongs to the field of biological organic fertilizers, and relates to a straw organic fertilizer and a preparation method thereof.

Background technique

my country is a large agricultural country. The crop straw production exceeds 800 million tons per year, and the output in Sichuan Province is 50 million tons per year. A large amount of straw waste is burned in the wild, causing serious environmental pollution. In 2008, the General Office of the State Council issued the "Opinions on Strengthening and Promoting the Comprehensive Utilization of Crop Straws" (Guobanfa [2008] No. 105); The "five materialization" utilization methods of resource fertilizer, feed, raw material, base material and fuel are hoped to promote the technological development of straw utilization and realize the resource utilization of straw.

On the other hand, the use of a large amount of chemical fertilizers in domestic agriculture reduces the basic fertility of the soil and the content of soil organic matter, which directly affects the yield and quality of crops.

Turning crop straw into organic fertilizer can not only solve agricultural waste straw, but also improve soil and improve soil fertility, which is of great significance to national food security and sustainable agricultural development.

However, due to the unbalanced nutrients and low content of crop straw itself and not easy to decompose, in order to improve the quality of straw organic fertilizer, it is usually necessary to select specific fermentation strains and add some organic waste, such as livestock and poultry manure, sludge, etc., but the prepared organic The nutritional content of fat is not comprehensive enough, and the quality is not good.

Fish scale is a common aquaculture processing waste. According to the China Statistical Yearbook, in 2014, the national fish output was 39.728 million tons per year, and that of Sichuan Province was 1.307 million tons. The amount of fish scales produced therefrom is calculated based on 2-3% of fish production, about 800,000-1.2 million tons/year in the whole country, and about 26,000-39,000 tons/year in Sichuan Province. Only a small amount of fish scales are currently used to produce industrial products such as food such as fish scale jelly and isinglass, and most of the unused fish scales are discarded, resulting in a serious waste of fish scale resources.

At present, there are a few reports on using fish scales for organic fertilizers. For example, the patent application with publication number CN104557333A discloses a corn stalk and chicken manure organic fertilizer. 12% increase in production, the effect of fertilization is not ideal.

Contents of the invention

The object of the present invention is to provide a fish scale protein enzymatic hydrolyzate and the straw organic fertilizer prepared therefrom.

The invention provides a kind of preparation method of fish scale protein enzymatic hydrolyzate, it comprises the following steps:

a, take fish scales, deliming by acid method, obtain deliming fish scales;

b. Take the delimed fish scales in step a, add protease and water, adjust the pH to 2.5-10, and then keep at 45-60°C for 10-60 minutes to obtain fish scale protein enzymatic hydrolysis solution; wherein, the delimed fish scales are solid The concentration is 50-150g/l, and the added amount of protease is 5-10% of the solid weight of fish scales after deliming.

Deliming: Removing the ash contained in fish scales.

Fish scale proteolysis solution: refers to the amino acid solution (including polypeptide) obtained by enzymatic hydrolysis of fish scales.

Wherein, in step a, fish scales are cleaned before the acid deliming;

When the fish scales used as raw materials are dirty (there is a lot of dirt), use sodium alginate or emulsifier to clean them. Then wash with water. When the raw material is not dirty, there is no need to wash it.

And/or, in step a, the deliming method is: take fish scales, add hydrochloric acid solution with a final concentration of 0.5-2N and soak for 20-24 hours;

Preferably, the deliming method is as follows: take fish scales, add hydrochloric acid solution with a final concentration of 0.8N and soak for 24 hours.

N: Same as mol/L.

The soaking process may or may not be stirred.

After deashing, use a filter to filter. After deliming, the fish scales are separated from the filtrate. The main component contained in the filtrate is hydroxyapatite Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ . In addition, since the inorganic matter in fish scales contains phosphorus and calcium required for organic fertilizers, it can be used not only for water regulation but also for phosphorus and calcium supply according to the composting process.

Wherein, in step b, the protease is alkaline protease, acid protease or neutral protease; stirring is carried out during the 45-60°C maintenance process.

Further, the protease source is Bacillus subtilis protease or Bacillus sp protease.

Wherein, in step b, the pH is adjusted to 7-8, and then kept at 50-60° C. for 30-60 minutes to obtain fish scale protein hydrolyzate; wherein, the solid concentration of fish scale after deliming is 50 g/l or 125 g/l, The amount of protease added is 5% of the scale solid weight after deliming;

Preferably, in step b, adjust the pH to 8, then keep at 60°C for 60 minutes, and stir during the hold at 60°C to obtain the enzymatic hydrolyzate of fish scale protein.

The invention also provides the enzymatic hydrolyzate of fish scale protein prepared by the method.

The invention also provides the use of the fish scale protein enzymatic hydrolyzate as an organic fertilizer additive.

Organic fertilizer additives: refer to microorganisms, organic or inorganic substances added to organic fertilizer materials in order to speed up the process of organic fertilizer or/and improve product quality.

Wherein, the organic fertilizer is straw organic fertilizer;

Preferably, the straw is at least one of corn straw, rice straw, wheat straw and rape straw.

The present invention also provides a kind of preparation method of stalk organic fertilizer, it comprises the steps:

Take 50 parts by weight of straw, 50 parts by weight of water, 10-50 parts by weight of the fish scale protein enzymatic hydrolyzate, and 10 parts by weight of mature compost, and accumulate and ferment for 7-21 days.

Wherein, the straw is pulverized so that the length is less than 50 mm; preferably, the length of the straw is less than 20 mm;

And/or, the enzymatic hydrolyzate of fish scales is 10-30 parts by weight, and it can be piled up and fermented for 12-21 days.

Wherein, the enzymatic hydrolyzate of fish scales is 25 parts by weight, stacked and fermented for 16 days, and stacked and fermented once every 4-5 days; and/or, aeration is performed during the stacked fermentation.

The invention also provides the straw organic fertilizer prepared by the method.

It is generally believed that the proportion of nutrients in organic fertilizers is unreasonable and cannot meet the needs of crops for nutrients, and the effect of single application is not good. It is better to combine organic fertilizers and chemical fertilizers to achieve better results [Zou Guoyuan, scientific application of organic fertilizers to ensure safe production of vegetables , Vegetables, 2003, 12:25].

The fish scale protein enzymatic hydrolyzate prepared by the method of the present invention is used as an organic fertilizer additive, and the straw organic fertilizer obtained has comprehensive and balanced nutrients and excellent quality, and can greatly improve the yield and quality of agricultural products when applied alone, and not only has the yield increasing effect stronger than that of chemical fertilizers and general straw organic fertilizers , and the taste of the obtained agricultural products is better, and better technical effects have been achieved.

In addition, corresponding nutrients can also be added to the organic fertilizer of the present invention according to actual needs. The organic fertilizer of the present invention can effectively increase the content of soil organic matter and improve the agricultural ecological environment. It is especially suitable for the development of green and pollution-free agriculture, and has a good application prospect.

Apparently, according to the above content of the present invention, according to common technical knowledge and conventional means in this field, without departing from the above basic technical idea of the present invention, other various forms of modification, replacement or change can also be made.

The content of the present invention will be further described below with examples, but the present invention is not limited to these examples. All technologies realized based on the above contents of the present invention belong to the scope of the present invention.

Description of drawings

Figure 1 is a schematic diagram of the production process of fish scale protein enzymatic hydrolyzate.

Figure 2 is a diagram of the growth of pakchoi in different fertilization areas, and the same letters in the figure indicate that the difference is not significant.

detailed description

The reagents used in the present invention are all commercially available.

Embodiment 1 Preparation of straw organic fertilizer of the present invention

1. Preparation of enzymatic hydrolyzate of fish scale protein

The preparation flow chart is shown in Figure 1.

Pigskin, fish bones, and fish scales were selected for component analysis, and the analysis values were based on dry weight. The results are shown in Table 1.

Table 1 Composition of raw materials for protein enzymatic hydrolyzate

protein Lipid other organic matter Inorganic matter (ash content) pigskin 44.4 38.1 16.7 0.8 fish bone 35.7 42.9 7.1 14.3 fish scales* 51.2 0.1 1.4 47.3

＊The protein content in fish scales is about 50-80% (depending on the fish species).

Other organic matter: the value obtained by subtracting protein and lipid from the total amount of organic matter.

It can be seen from Table 1 that the fish scale itself basically does not contain lipids (less than 1%), and there is no need for degreasing pretreatment, and the method of preparing proteolytic solution is relatively simple; while pig skin and fish bones contain relatively high lipids, it is necessary to use hexane, etc. Organic solvents are used for complex degreasing pretreatment. In addition, because the protein content in fish scales is high, exceeding 50%, the effect of proteolysis is better, so fish scales are selected as raw materials for preparing proteolysis solution.

details as follows:

1) Take fish scales and clean them with sodium alginate or emulsifier. Then wash with water.

2) Deliming with hydrochloric acid solution: immerse fish scales in 0.8N hydrochloric acid solution, stir during immersion, and place at room temperature for 24 hours.

3) Filtration: use a filter to separate the delimed fish scales from the filtrate. The main component contained in the filtrate is hydroxyapatite Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ . In addition, because the inorganic substances in fish scales contain phosphorus and calcium required by organic fertilizers, the filtrate can be used not only for water regulation but also for supply of phosphorus and calcium during the composting process.

4) Hydrolyze fish scales after deliming: take the dry matter concentration of fish scales after deliming at 5%, add 5% protease from Bacillus sp., hydrolyze for 60 minutes under the conditions of 60°C and pH 8, and obtain fish scale proteolysis Liquid, namely amino acid solution (containing polypeptide).

2. Straw treatment

Take crop stalks (moisture content: 50%) and crush them so that the length of the stalks is 20mm.

3, prepare straw organic fertilizer of the present invention

Take the enzymatic hydrolyzate of fish scale protein and mature compost, add it to the crushed straw, the corresponding weight ratio is 25% when the amount of enzymatic hydrolyzate of fish scale protein is 100% of raw material straw, and the corresponding weight ratio is 10% when the amount of mature compost is 100% of raw material straw, By stacking. Once every 4 days, the stack was turned by hand, and the total stacking days were 16 days to obtain the straw organic fertilizer of the present invention.

Among the present invention, used mature compost is in order to provide the microorganism that composting process needs, can obtain by buying commercially available product, also can adopt existing method to prepare, the present invention adopts following method to prepare:

The raw material of milk cow manure is squeezed, and the moisture content of the solid residue is about 70%. Put the solid residue into the composting room, raise the temperature to 60°C, then keep the temperature at 60°C for 3 days, then cool down naturally to 35°C, and then keep the temperature at 35°C to The composting is over; the whole composting process lasts for 60 days, during this period, the air is continuously injected at 0.2L/min/kg-dry weight to obtain mature compost.

Embodiment 2 Preparation of straw organic fertilizer of the present invention

1. Preparation of enzymatic hydrolyzate of fish scale protein

The preparation flow chart is shown in Figure 1.

details as follows:

1) Fish scales are taken, and deliming is carried out directly with hydrochloric acid solution because the raw material is not much dirty: the fish scales are impregnated with a hydrochloric acid solution with a concentration of 1N, and left for 24 hours.

3) Filtration: use a filter to separate the delimed fish scales from the filtrate. The main component contained in the filtrate is hydroxyapatite Ca ₁₀ (PO ₄ ) ₆ (OH) ₂ . In addition, because the inorganic substances in fish scales contain phosphorus and calcium required by organic fertilizers, the filtrate can be used not only for water regulation but also for supply of phosphorus and calcium during the composting process.

4) After deliming, fish scales are hydrolyzed: the dry matter concentration of delimed fish scales is 5%, the amount of protease added from Bacillus subtilis is 5%, and hydrolysis is carried out for 30 minutes at 50° C. and pH 7 to obtain fish scale protein enzymatic hydrolyzate, That is, amino acid solution (containing polypeptide).

2. Straw treatment

Take crop stalks and crush them so that the length of the stalks is 50mm.

3, prepare straw organic fertilizer of the present invention

Take the enzymatic hydrolyzate of fish scale protein and mature compost, add it to the crushed straw, the amount of addition is 100% of raw material straw (moisture 50%), the corresponding weight ratio is 10%, and the amount of mature compost is corresponding to 100% of raw material straw (moisture 50%) The weight ratio is 10%, and the method of stacking is adopted. Use a loader or forklift to turn the pile every 4 to 5 days. During the composting process, the bottom of the pile is continuously ventilated. The total accumulation days are 7 days, and the straw organic fertilizer of the present invention is obtained.

Example 3 Preparation of straw organic fertilizer of the present invention

Except that the accumulation days is 21 days, other are all identical with the method of embodiment 1.

The beneficial effects of the present invention are illustrated below with specific test data.

The effect comparison of different organic fertilizer additives of test example 1

1. Test method

1) Preparation of different organic fertilizer additives

Fish scale acid hydrolyzate: obtained by extracting the delimed fish scales in Example 1 with hydrochloric acid solution. The operation is as follows: put the fish scales after deliming into a 10L rotary evaporator (Rotary VacuumEvaporator N-11, EYELA, Tokyo) to a total solid concentration of 125g/L. Add an acidic solution (pH3, by adding 1 /15M acetate buffer to pH 3), extract and react at 60°C for 1h.

Alkaline hydrolyzate of fish scale: obtained by extracting the delimed fish scale in Example 1 with sodium hydroxide solution. The operation is as follows: put the fish scales after deliming into a 10L rotary evaporator (Rotary VacuumEvaporator N-11, EYELA, Tokyo) to a total solid concentration of 125g/L. Add water to dilute to pH 12), extract and react at 60°C for 1h.

Enzymatic hydrolyzate of fish scale protein: the enzymatic hydrolyzate of fish scale protein prepared in Example 3 of the present invention.

Control: ultrapure water.

The acid hydrolyzate of fish scale, the alkali hydrolyzate of fish scale and the enzymatic hydrolyzate of fish scale protein were added to the straw respectively, and the straw was piled up for 21 days to prepare straw organic fertilizer.

2) Different organic fertilizer samples were used in the germination experiment of cress seeds (Lepidium sativum L.)

Put a piece of filter paper (Whatman#2) with a diameter of about 9cm into a sterilized 9cm petri dish, put 10 cress seeds evenly, and use a pipette to absorb 8.0ml compost sample water extract or ultrapure water (Control) In a petri dish, each sample was repeated three times, and incubated in a 20°C incubator in the dark for 48 hours. By counting the number of germinated seeds and measuring the root length, the seed germination index was calculated according to the following formula.

2. Test results

See Table 2.

Table 2 Seed germination test

It is generally believed that more than 80% of the seed germination rate indicates that the organic fertilizer is mature (document: Tiquia SM, Tam NFY. Elimination of phytotoxicity during co-composting of spentpig-manure sawdust litter and pig sludge [J]. Bioresour Technol, 1998, 65: 43 –49).

It can be seen from Table 2 that the seed germination index of the straw organic fertilizer obtained by using the additive prepared by acid or alkali hydrolysis is very low, less than 50%; while the straw organic fertilizer added with fish scale protein enzymatic hydrolysis solution has a germination index greater than 100% after 21 days.

Therefore, the straw organic fertilizer added with ichthyosine acid hydrolyzate and ichthysine alkali hydrolyzate has a poor degree of decomposition and cannot produce mature organic fertilizer. However, the straw organic fertilizer added with the enzymatic hydrolyzate of fish scale protein of the present invention has a high decomposing degree, and a mature organic fertilizer is obtained.

Test example 2 the protease screening test of fish scale proteolysis solution of the present invention

16 kinds of enzyme preparations sold in the market were selected, and the decomposition ability of each enzyme preparation was evaluated with delimed fish scale as the substrate.

The reaction time is 1 h, and the reaction pH, temperature and protein decomposition efficiency of each enzyme preparation are shown in Table 3.

Table 3 Decomposition effect of delimed fish scales and evaluation of market enzyme preparations

It can be seen from Table 3 that all 16 kinds of enzyme preparations have a certain proteolytic ability, and the decomposition rate is 36.5% to 85.8%. Among them, 6 enzyme preparations achieved a decomposition rate of more than 60%, especially the enzymes derived from Bacillus subtilis (enzyme preparation K) and Bacillus sp (enzyme preparation L) had the best effect, reaching 69.2% and 85.8% respectively.

We adjusted the source of Bacillus sp. (enzyme preparation L) to pH 8 (the weight ratio of the relative substrate concentration added was 5%) and evaluated the effect of the enzyme preparation again, and found that the proteolytic efficiency of the enzyme preparation of Bacillus sp. source also reached 83% (see number Q).

The specific steps of using Bacillus sp. source enzyme preparation (enzyme preparation L) to prepare fish scale protein enzymatic hydrolyzate are as follows: Utilize a fermenter with stirring with a working volume of 1 L, the reaction pH is 8, the temperature is 60 ° C, and the substrate concentration is 125 g/ L, enzyme concentration 6.25g/L, reaction time is 1 hour.

The higher the enzymatic hydrolysis efficiency of fish scales, the higher the degree of amino acid conversion, the richer the nutrients in the organic fertilizer added to the straw, and the higher the quality of the organic fertilizer.

Considering that too high pH is not conducive to the next step of straw organic fertilizer maturation, the enzymatic hydrolyzate of fish scale protein prepared from Bacillus sp. source enzyme preparation (enzyme preparation L) at a pH of 8 was added to the straw to prepare organic fertilizer in the experiment and production.

Test Example 3 Straw organic fertilizer of the present invention is used for seed germination test

1. Sample preparation

1) Preparation of straw organic fertilizer: except for the number of days of accumulation, other methods are the same as in Example 1. Stacked for 4 days, 8 days, 12 days and 16 days respectively to obtain different straw organic fertilizers.

2) Raw material straw: only straw is used, no accumulation of fermentation.

3) Control: ultrapure water.

2. For the germination test of cress seeds (Lepidium sativum L.)

The results are shown in Table 4.

Table 4 Seed germination test

Use different composts raw material straw 4 days 8 days Stacked for 12 days Stacked for 16 days germination index 8% 40% 82% 97% 125%

It can be seen from Table 4 that the straw organic fertilizer prepared by stacking for 8-16 days using the method of the present invention has a seed germination rate of more than 80%, indicating that the organic fertilizer has good maturity and stable product quality, and can be used as fertilizer preferably.

Experimental example 4 Straw organic fertilizer of the present invention is used in fertilization test of Chinese cabbage

1. Test method

The experiment began in early May, and the control experiment in 4 districts was carried out, and the Chinese cabbage was harvested one month later.

Area A Soil only (no fertilizer added) Area B Apply chemical fertilizers Area C apply compost District D Compost and chemical fertilizer mix (80:20)

Note: Chemical fertilizers: Nitrogen, phosphorus, and potassium fertilizers purchased from the market, mixed after N, P ₂ O ₅ and K ₂ O composition determination, so that the ratio of N:P ₂ O ₅ :K ₂ O in chemical fertilizers is 1:1: 1;

Compost: refers to straw organic fertilizer prepared according to the method of Example 1 of the present invention.

Fertilization area in areas B, C, and D: based ^on the amount of nitrogen, add 25kg/1000m2 of nitrogen. Composting first calculates the nitrogen content, and determines the amount of fertilizer based on the nitrogen content in the compost.

2. Test results

1) The influence of fertilization on the growth of pakchoi is shown in Figure 2.

It can be seen from Figure 2 that the aboveground weight, root weight, leaf number, and leaf length of pakchoi in areas A and B are all the same, and the effect of increasing the yield of pakchoi by using only chemical fertilizers is not obvious; compared with areas A and B, C The above-ground weight and root weight of pakchoi in district and D district increased significantly; the number of pakchoi leaves was the best in district C, and the length of leaves in each district was the same.

It can be seen that the straw organic fertilizer of the present invention can significantly increase the weight and root weight of the aboveground part of Chinese cabbage, which is equivalent to the effect of mixed application of organic fertilizers and chemical fertilizers; compared with only chemical fertilizers, the weight gain effect can be increased by more than 2 times, thereby greatly improving crop yield. Yield.

2) The effect of fertilization on pakchoi taste

10 researchers tested pakchoi cultivated in areas B and C. They didn't know what kind of fertilizer was used before the test, but all 10 people thought that the pakchoi with straw organic fertilizer tasted better and tasted sweeter.

Therefore, the fish scale protein enzymatic hydrolyzate prepared by the method of the present invention is used as an organic fertilizer additive, and the obtained straw organic fertilizer has comprehensive and balanced nutrients, excellent quality, and stable quality. It can greatly improve the output and quality of agricultural products when applied alone, and the application effect is stronger than that of ordinary straw. Organic fertilizers and chemical fertilizers have good application prospects.

Claims (12)

1. a preparation method of fish scale protein enzymatic hydrolyzate, is characterized in that, it comprises the steps: a, take fish scales, deliming by acid method, obtain deliming fish scales; b. Take the delimed fish scales in step a, add protease and water, adjust the pH to 2.5-10, and then keep at 45-60°C for 10-60 minutes to obtain fish scale protein enzymatic hydrolysis solution; wherein, the delimed fish scales are solid The concentration is 50-150g/l, and the added amount of protease is 5-10% of the solid weight of fish scales after deliming. 2. The method according to claim 1, characterized in that, in step a, fish scales are cleaned before the acid deliming; And/or, in step a, the deliming method is: take fish scales, add hydrochloric acid solution with a final concentration of 0.5-2N and soak for 20-24 hours; Preferably, the deliming method is as follows: take fish scales, add hydrochloric acid solution with a final concentration of 0.8N and soak for 24 hours. 3. The method according to claim 1, characterized in that, in step b, the protease is alkaline protease, acid protease or neutral protease; stirring is carried out during the maintenance at 45-60°C. 4. The method according to claim 3, wherein the protease source is Bacillus subtilis protease or Bacillus sp protease. 5. The method according to claim 1, characterized in that, in step b, the pH is adjusted to 7-8, and then kept at 50-60° C. for 30-60 minutes to obtain the enzymatic hydrolyzate of fish scale protein; wherein, after deliming The solid concentration of fish scales is 50g/l or 125g/l, and the amount of protease added is 5% of the solid weight of fish scales after deliming; Preferably, in step b, adjust the pH to 8, then keep at 60°C for 60 minutes, and stir during the hold at 60°C to obtain the enzymatic hydrolyzate of fish scale protein. 6. the enzymatic hydrolyzate of fish scale protein prepared by any one method of claim 1-5. 7. the purposes of claim 6 described fish scale protein enzymatic hydrolyzate as organic fertilizer additive. 8. The use according to claim 7, wherein the organic fertilizer is straw organic fertilizer; Preferably, the straw is at least one of corn straw, rice straw, wheat straw and rape straw. 9. A preparation method of stalk organic fertilizer, characterized in that it comprises the steps of: Take 50 parts by weight of straw, 50 parts by weight of water, 10-50 parts by weight of the enzymatic hydrolyzate of fish scale protein according to claim 6, and 10 parts by weight of mature compost, and pile up and ferment for 7-21 days. 10. The preparation method according to claim 9, characterized in that, the straw is pulverized so that the length is less than 50 mm; preferably, the length of the straw is less than 20 mm; And/or, the enzymatic hydrolyzate of fish scales is 10-30 parts by weight, and it can be piled up and fermented for 12-21 days. 11. The preparation method according to claim 10, characterized in that, the enzymatic hydrolyzate of fish scales is 25 parts by weight, stacked and fermented for 16 days, and piled up and fermented once every 4-5 days; and/or, stacked and fermented ventilate in. 12. The straw organic fertilizer prepared by the method according to any one of claims 9-11.