CN112552087A

CN112552087A - Application of back mixing material and strengthening bacteria in sheep manure composting

Info

Publication number: CN112552087A
Application number: CN201910854404.XA
Authority: CN
Inventors: 张昊; 王默涵; 杨红建; 罗海玲
Original assignee: China Agricultural University
Current assignee: China Agricultural University
Priority date: 2019-09-10
Filing date: 2019-09-10
Publication date: 2021-03-26

Abstract

The invention provides a method for obtaining sheep manure compost, which comprises the following steps: (1) mixing sheep manure, reinforcement bacteria and back-mixed materials; (2) and stacking the materials obtained by mixing so as to obtain the sheep manure compost. According to the invention, by adopting the reinforcement bacteria and the back mixing materials, the degradation of organic matters in the sheep manure can be effectively promoted, the composting efficiency is improved, meanwhile, the organic fertilizer has a positive effect on increasing the nutrient components in the compost, and can be applied as an organic fertilizer, so that the sheep manure is recycled.

Description

Application of back mixing material and strengthening bacteria in sheep manure composting

Technical Field

The invention relates to the technical field of livestock breeding, in particular to application of a back-mixed material and strengthening bacteria in sheep manure compost.

Background

Long-term application of chemical fertilizers is one of the characteristics of the current high-strength intensive agriculture, and can cause the deterioration of soil fertility and various ecological environment problems while meeting the yield increase requirement of crops. In contrast, recycling of organic materials such as livestock manure into compost is an efficient and win-win approach at the present stage. Researches show that the compost is applied, so that the fertilizer consumption can be reduced, the soil quality can be improved, the stability of an agricultural ecological system can be improved, and the sustainable management of the soil is facilitated.

At present, conventional compost is slow in fermentation speed and long in treatment time, and is not beneficial to resource utilization of organic wastes. Therefore, methods for obtaining compost of sheep manure still remain to be studied.

Disclosure of Invention

The present invention aims to solve at least to some extent at least one of the technical problems of the prior art.

The invention provides a method for obtaining sheep manure compost. According to an embodiment of the invention, the method comprises: mixing sheep manure, reinforcement bacteria and back-mixed materials; and stacking the mixed materials, turning and throwing the materials once a day, controlling the temperature below 50 ℃ after stacking for 10-15 days, turning the piles once every two days, and stacking for 38-45 days so as to obtain the sheep manure compost. By adopting the reinforcement bacteria and the back mixing materials, the degradation of organic matters in the sheep manure can be effectively promoted, the composting efficiency is improved, meanwhile, the organic fertilizer has a positive effect on increasing the nutrient components in the compost, and can be applied as an organic fertilizer, so that the sheep manure is recycled.

According to an embodiment of the invention, the method for obtaining sheep manure compost can also have the following additional technical features:

according to the embodiment of the invention, the addition amount of the reinforcement bacteria is 0.05-0.2% based on the total mass of the sheep manure. Therefore, the degradation of organic matters in the sheep manure can be further effectively promoted, the composting efficiency is improved, and meanwhile, the active effect of increasing the nutrient components in the compost is achieved.

According to the embodiment of the invention, the reinforcement bacteria are selected from aerobic fermentation reinforcement bacteria cultured by China institute of environmental science.

According to the embodiment of the invention, the addition amount of the back mixing material is 20-40% by mass based on the total mass of the sheep manure. Therefore, the degradation of organic matters in the sheep manure can be further effectively promoted, the composting efficiency is improved, and meanwhile, the active effect of increasing the nutrient components in the compost is achieved.

According to an embodiment of the present invention, the step (2) includes: and stacking the mixed materials, turning and throwing the materials once a day, controlling the temperature below 50 ℃ after stacking for 10-15 days, turning the piles once every two days, and stacking for 38-45 days so as to obtain the sheep manure compost. And the aerobic fermentation is carried out by ensuring enough oxygen introduction amount through multiple turning and stack turning treatments, and the activity of aerobic bacteria is ensured by controlling the temperature below 50 ℃.

In another aspect of the invention, the invention provides another method for obtaining the sheep manure compost. According to an embodiment of the invention, the method comprises: stacking the mixture containing the sheep manure, the reinforcement bacteria and the return mixing material into a triangular pile with the length of 300cm, the width of 140cm and the height of 100cm, and turning over once every day in the first 11 days; and after 11 days, reducing the temperature of the materials to be below 50 ℃, entering an aging stage, turning and throwing the materials once every two days to continuously reduce the water content, and continuously stacking the materials for 18 days so as to obtain the sheep manure compost. Therefore, the method for obtaining the sheep manure compost, provided by the embodiment of the invention, can effectively promote the degradation of organic matters in the sheep manure, improve the composting efficiency, has a positive effect on increasing the nutrient components in the compost, and can be applied as an organic fertilizer, so that the sheep manure is recycled.

In another aspect of the invention, the invention provides a method for improving the contents of calcium, nitrogen, phosphorus and potassium in sheep manure compost and promoting organic matter degradation. According to an embodiment of the invention, the method comprises: stacking the mixture containing the sheep manure, the reinforcement bacteria and the return mixing material into a triangular pile with the length of 300cm, the width of 140cm and the height of 100cm, and turning over once every day in the first 11 days; after 11 days, the temperature of the materials is reduced to below 50 ℃, the materials are turned and thrown once every two days, and the materials are continuously stacked for 18 days, so that the sheep manure compost is obtained. Therefore, the method provided by the embodiment of the invention can effectively promote the degradation of organic matters in the sheep manure, improve the composting efficiency, has a positive effect on increasing the nutrient components in the compost, and can be applied as an organic fertilizer to recycle the sheep manure.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 shows a schematic representation of the change in temperature of a heap during composting in accordance with an embodiment of the invention;

FIG. 2 shows a schematic representation of the change in moisture content of a compost heap in accordance with one embodiment of the present invention;

FIG. 3 shows a schematic representation of the change in pH of the heap during composting in accordance with an embodiment of the invention;

figure 4 shows a schematic representation of the variation of plant nutrients during composting according to one embodiment of the invention.

Detailed Description

The scheme of the invention will be explained with reference to the examples. It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1

1. Design of compost experiment

In the experiment, sheep manure is selected as a compost raw material, and fresh sheep manure is taken from a pasture of Heishihou stockbreeding technology Limited. And (3) turning and throwing the material pile into a triangular pile with the length of 300cm, the width of 140cm and the height of 100cm once a day for the first 11 days, cooling the material to below 50 ℃ after 11 days, entering an aging stage, and turning and throwing the material once every two days to continuously reduce the water content. The composting experiment was designed into 4 groups, each of which was: the test method comprises the steps of adding only sheep manure (a control group), adding 30% of decomposed return materials (a back-mixing group), adding fermentation enhancing bacteria (an enhancing group), simultaneously adding 30% of decomposed return materials and fermentation enhancing bacteria (a back-mixing enhancing group) and an unadditized blank control group. The fermentation enhancing bacteria added in the composting process come from China institute of environmental science, and the adding proportion is 0.1 percent, namely 1L of liquid zymocyte is added into 1 ton of fermented material (sheep manure). The back mixing material is obtained by adopting the compost experiment on the strengthening bacteria and the sheep manure, so that the microorganisms are fermented in advance, the activity of the microorganisms is improved, and the mature fermented sheep manure is also provided. During sampling, samples were collected from the bottom, middle and top of the stack and mixed well, each in triplicate.

2. Physical and chemical performance monitoring

The temperature and the water content of the compost are monitored within 30 days by a WST-WSS-411500 mm thermometer and a DSH-50A-1 halogen moisture rapid tester, the pH value is measured by a MP512-01 type laboratory pH meter on the 0 th day, the 7 th day, the 14 th day, the 21 th day and the 29 th day of the compost, and the change of the physical and chemical properties of different materials is recorded.

(1) Detection of essential nutrient components of plants

Measuring the organic matter (NY/T525-2012) and the contents of nitrogen, phosphorus and potassium (NY/T525-2012) on days 0, 7, 14, 21 and 29 of the compost according to a national standard method, and calculating the loss rate of the organic matter and the change of the contents of available nitrogen, phosphorus and potassium of each group in the composting process.

(2) Detection of content of metal element

The 14 elements of Na, Mg, Ca, Fe, Mn, Cu, Zn, Cr, Ni, Cd, Sn, Pb, Sb, Co in the digestate were analyzed for elements by inductively coupled plasma mass spectrometry (ICP-MS, spectral Analytical Instruments, Kleve, Germany) on days 0, 7, 14, 21 and 29 of composting. All glassware and plastic containers used in the experiments were soaked overnight in pure nitric acid (Merck, usa) and rinsed clean with deionized water. The continuous extraction (SEE) method used in the experiment is developed by Tessier et al and widely applied to various compost researches (Tessier et al 1979), blank experiments and sample measurement are carried out simultaneously, and the obtained blank concentration is lower than the detection limit, which indicates that the experiment is not disturbed by the system. In order to test the accuracy of the result, the recovery rate of the standard sample with known concentration is measured, and the recovery rate is between 95 and 105 percent. Each sample was assayed in at least triplicate and repeated until the relative standard deviation was less than 5%. All the above test results were measured on a dry matter basis.

3. Results

(1) Change of compost physical and chemical properties in composting process

As shown in figure 1, the temperature change trend of the compost of 4 compost groups is the same, and the normal temperature change of the composting process is met, namely the compost is subjected to three typical stages of intermediate temperature, moderate temperature and cooling. In 0-5 days after the compost is started, the temperature of the compost is rapidly increased due to the activity of microorganisms, the temperature of the compost of each compost group is increased to more than 60 ℃ in the 4 th day, and the compost enters a thermophilic stage. According to the requirements for sanitation of soil innocent treatment (GB7959-2012), the temperature of the compost is kept above 50-55 ℃ for 5-7 d or above 55 ℃ for 3 days so as to reach the sterilization standard. The results show that all experimental temperatures were maintained above 55 ℃ for 3 days, and after the thermophilic phase, the temperature dropped rapidly to room temperature due to heat loss. After 25 days the temperature of the stack began to remain constant, approaching ambient temperature.

The moisture was lost as steam due to heat generation during composting and in all composting groups the moisture content dropped from around 60% to around 45% (figure 3), and no formation of percolate was observed during composting. Another important parameter influencing the composting process is the pH value, and the optimal fermentation pH values suitable for bacteria and fungi in the compost are respectively in the range of 6.0-7.5 and 5.5-8.0. The addition of the regrind and the strengthening bacteria increases the initial pH of the compost to 8.0 or above, and the pH value of the 4 groups of composts is rapidly reduced by about 0.5 unit (figure 2) in the early period of the experiment due to the fact that the fungus violently moves to generate low molecular weight fatty acid and carbon dioxide, and then the pH value is gradually gentle and finally is stabilized between 7.5 and 8.0.

(2) Variation of essential nutrient components of plants in composting process

FIG. 4 shows the organic matter, available nitrogen, available phosphorus and available potassium contents of each experimental group as a function of composting time within 30 days of composting. The organic matters are main carbon sources and energy sources of microorganisms, and in the composting process, the microorganisms decompose and convert the organic matters into stable humus compounds to become potential nutrient sources of plants. The organic matter content of the compost reflects the maturity and the quality of the compost, the loss rates of the organic matters of the control group and the back-mixing group without adding the strengthening bacteria are respectively 29.7 percent and 27.9 percent, and the loss rates of the organic matters of the strengthening group and the back-mixing group without adding the strengthening bacteria are respectively 32.9 percent and 43.5 percent, which are obviously higher than those of the control group and the back-mixing group. Nitrogen, phosphorus and potassium are essential nutrients for plant growth and development, and are helpful for plant growth and developmentThe plant growth and environment regulation ability play an important role in plant growth and metabolism. The available nitrogen content in all compost groups decreased 7 days before the composting process, probably due to strong NH₃And (5) discharging. After 7 days, the available nitrogen content in each compost group began to increase. After 30 days, the effective nitrogen increase of the strengthening group and the back mixing strengthening group is up to 38.1 to 40.9 percent, while the effective nitrogen increase of the contrast group and the back mixing group is only 1.6 to 5.5 percent. The increase of the available nitrogen content mainly comes from the decomposition and release of organic matters, the activity of nitrogen-fixing bacteria and the loss of dry organic carbon into CO₂. The effective phosphorus content of each compost group shows different trends, the effective phosphorus content of 3 treatment groups continuously increases in the composting process, the effective phosphorus content of a control group decreases in the initial composting period, and the phosphorus element is presumed to be caused by the fact that the water content of fresh sheep manure is high and the phosphorus element decreases along with the seepage effect of water. The available potassium content continues to increase during composting, mainly due to the release of organic matter breakdown and the concentration effect of water evaporation. As shown in fig. 4, the increase amount of the plant essential nutrients in the treatment group added with the enhancing bacteria is significantly higher than that of the control group and the back-mixed group without the enhancing bacteria, and the experimental result further illustrates that the enhancing bacteria has the effect of significantly promoting the decomposition of organic matters, thereby having a positive effect of increasing the nutrients in the compost. While the change of the nutrient substances of the back mixing group is about the same as that of the control group, and the influence of the independent addition of the back mixing material on the nutrient substances of the compost is not obvious.

(3) Content of metal elements and change thereof in composting process

The metal elements in the compost mainly contain three major types of nutrient elements, trace elements and harmful heavy metal elements, and the content and the change of each metal element in the organic waste sheep manure composting process are shown in table 1. Na, Mg, Ca and Fe are all nutrient elements necessary for plant growth, and Table 1 shows that the Ca content in the sheep manure is 19406-20474 Mg/kg, which is obviously higher than other nutrient elements, and is increased by 9.0-26.0% after composting. Since Ca is one of the most important nutrients required by organisms and is harmless to human health, the increase of Ca content after composting has a positive effect on maintaining plant cell structure and soil conditions.

Besides the nutrient elements, the compost also contains some trace elements required for plant growth. As shown in Table 1, compared with other elements, the content of Zn, Cu and Mn in sheep manure is not changed greatly after composting, and the concentration is kept relatively stable. It has been shown that Zn and Mn exist in sheep manure mainly in the form of Mn-Zn-Fe oxide (more than 70% of the total content) and carbonate (more than 20% of the total content), and Cu is very likely to precipitate or co-precipitate due to its high affinity with carbonate, and these compounds and precipitate forms are possible reasons for the stability of the concentration during composting.

When the compost is used for agricultural production, heavy metals are easy to accumulate and transform in soil and water environments and can be accumulated to a high level in plants, so that the heavy metal content in the compost product is particularly concerned and is an important standard for evaluating the compost product. The contents and changes of heavy metal elements in the sheep manure and the compost products determined by the experiment are shown in table 1, and Co element is not detected in the sheep manure and the compost products, so that the contents and changes of the heavy metal elements are not listed in table 1. In the composting process, the content of 6 heavy metal elements is obviously increased, and particularly, the content of partial heavy metal elements can be increased by more than 100 percent by adding a treatment group of strengthening bacteria. Therefore, the strengthening bacteria increase the heavy metal content of the compost while increasing the nutrient elements in the compost, thereby increasing the pollution risk of applying the compost to farmlands. In order to evaluate the influence of the composting process on the environmental risk evaluation of the organic waste land utilization, according to the regulation in the content and requirement of fertilizer identification GB 18382-2001, the content of heavy metals in the compost is lower than the standard limit value, wherein the standard limit values of Cd, Cr, Co, Sb and Pb are respectively 10mg/kg, 500mg/kg, 100mg/kg, 25mg/kg and 200mg/kg, and the concentration limit values of Sn and Ni are not regulated in the standard. The experimental determination proves that the 7 heavy metal elements in the sheep manure and the compost product do not exceed the critical limit value of the GB 18382-2001 agricultural compost, the pollution risk to the environment is low, and the method can be used for farmland application.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A method for obtaining sheep manure compost, which is characterized by comprising the following steps:

(1) mixing sheep manure, reinforcement bacteria and back-mixed materials;

(2) and stacking the materials obtained by mixing so as to obtain the sheep manure compost.

2. The method according to claim 1, wherein the amount of the enhancing bacteria is 0.5 to 1.5 liters based on 1 ton of the sheep manure.

3. The method according to claim 1, characterized in that the amount of the back-mix is 20-40 mass% based on the total mass of the sheep manure.

4. The method of claim 1, wherein step (2) comprises:

and stacking the mixed materials, turning and throwing the materials once a day, controlling the temperature below 50 ℃ after stacking for 10-15 days, turning the piles once every two days, and stacking for 38-45 days so as to obtain the sheep manure compost.

5. A method for obtaining sheep manure compost, which is characterized by comprising the following steps:

stacking the mixture containing the sheep manure, the reinforcement bacteria and the return mixing material into a triangular pile with the length of 300cm, the width of 140cm and the height of 100cm, and turning over once every day in the first 11 days; after 11 days, the temperature of the materials is reduced to below 50 ℃, the materials are turned and thrown once every two days, and the materials are continuously stacked for 18 days, so that the sheep manure compost is obtained.

6. A method for improving the contents of calcium, nitrogen, phosphorus and potassium in sheep manure compost and promoting organic matter degradation is characterized by comprising the following steps: