Nutrition slow-release type acid soil conditioner for facility agriculture and preparation method thereof

Abstract

The invention discloses a nutrient sustained-release acid soil conditioner for facility agriculture and a preparation method thereof. The preparation method comprises the following steps: drying fresh chicken manure, cow dung and sheep manure, crushing until the particle size is less than 1cm, and uniformly mixing the crushed chicken manure, cow dung, sheep manure and snakegourd seed shell powder according to a proper weight ratio; heating to 900 DEG C in an anaerobic environment for pyrolysis, and keeping for 2 hours; and cooling to room temperature, fully grinding, and screening with a 2mm screen to finally obtain the acid soil conditioner. The soil conditioner prepared through interaction of various raw materials not only can increase the pH value of soil and replace traditional lime, but also contains a large amount of organic matter (larger than or equal to 40%), nitrogen (4%) and phosphorus (8%) needed by plant growth, and is a high-quality organic nitrogen phosphate fertilizer. The product is wide in raw material source, rich and cheap in resource, simple in preparation process and suitable for popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of soil improvement, and in particular to a nutrient slow-release acidic soil conditioner for facility agriculture and a preparation method thereof. Background Art

[0002] Facility agriculture is a new agricultural development model that uses artificial technology to change natural light and temperature conditions, create environmental factors that optimize the growth of plants and animals, and enable them to grow around the clock. In order to increase agricultural product output and maximize economic benefits, facility agriculture has been cultivating for years and using excessive fertilizers, which has led to soil acidification and consumed organic matter, thus limiting the increase in crop yields and the sustainable development of facility agriculture production. With the rapid development of facility agriculture in my country, the scale of facility vegetable planting has continued to expand, and the years of facility cultivation have gradually increased, and the problem of soil acidification has become more and more serious. Traditional inorganic amendments such as lime are widely used in acid soil improvement due to their high alkalinity content, but lime-amended soil may have problems with soil salinization or rapid re-acidification, and the cost of facility agriculture construction is high. It is difficult for ordinary amendments on the market to meet its various needs. It is particularly important to find a high-quality acid soil amendment that can continuously maintain soil fertility.

[0003] At present, most common acidic soil conditioners have certain defects. The raw materials are expensive, the acid-base neutralization ability is limited, and the lack of environmental protection can easily lead to secondary soil pollution. In addition, their functions are single and not comprehensive enough, and their uses are limited. It is urgent to develop new acidic soil conditioners with rich resources, strong acid neutralization ability, and mitigation of soil fertility loss, and promote their use in facility agriculture. Summary of the invention

[0004] In order to overcome the single function and cost problems of traditional acidic soil improvement, the present invention provides a nutrient slow-release acidic soil conditioner for facility agriculture and a preparation method thereof. The raw material source is abundant and inexpensive, and it can not only enhance the structure of acidic soil and improve the soil pH value, but also increase the soil organic matter content and improve the soil moisture and nutrient retention capacity.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for preparing a nutrient slow-release acidic soil conditioner for facility agriculture, comprising the following steps:

[0007] Step 1, drying and crushing fresh chicken manure, cow manure, sheep manure and Trichosanthes fruit shell to a particle size of less than 1 cm, and then mixing the crushed chicken manure, cow manure, sheep manure and Trichosanthes fruit shell powder in a weight ratio of 1-2:1-2:1-2:0.2-1;

[0008] Step 2: In an anaerobic environment, heat to 900°C for pyrolysis and maintain for 2 hours;

[0009] Step 3: After cooling to room temperature, grind thoroughly and pass through a 2 mm sieve to finally obtain an acidic soil conditioner.

[0010] Preferably, in step 1, the crushed chicken manure, cow manure, sheep manure and Trichosanthes fruit shell powder are mixed in a weight ratio of 1:1:1:0.2.

[0011] Preferably, in step 1, the drying temperature is 50-60° C. and the drying time is 10-12 hours.

[0012] Preferably, in step 2, the heating rate of the pyrolysis is 5-10°C / min.

[0013] In a second aspect, the present invention provides a nutrient slow-release acidic soil conditioner for facility agriculture prepared by the above preparation method.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The raw materials of the soil conditioner provided by the present invention are animal feces waste and Trichosanthes fruit shell, which is a Cucurbitaceae plant with abundant yield, high potassium content of its seed shell, high cellulose, and water retention function; excrement comes from natural sources, is abundant in resources and cheap, and can provide a rich mixture of nutrients, containing alkaline substances and rich organic matter, but direct use is easy to reduce nutrients due to soil erosion, which is unsustainable. By optimizing the process, the improver of the present invention has the advantages of long-term (more than 120 days) improvement of soil structure and fertility improvement.

[0016] 2. The soil conditioner provided by the present invention has wide applicability and can significantly reduce the acidity of different types of acidic soils in facility agriculture in different regions of southern my country. In addition, the conditioner contains a large amount of organic matter (>40%), nitrogen (>4%), and phosphorus (>8%) required for plant growth, and is also a high-quality organic nitrogen and phosphorus fertilizer.

[0017] 3. The soil conditioner provided by the present invention will not cause secondary pollution, is green and environmentally friendly, and is a high-quality acidic soil conditioner that can replace traditional lime. In addition, the raw materials of this product have a wide range of sources and a simple preparation process. Through the interaction between various raw materials, the prepared finished product can improve acidic soil, eliminate obstacles to continuous cropping in facility agriculture, ensure the healthy growth of plants, and overcome the problems of soil acidification and fertility loss in facility agriculture, and is suitable for promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram showing the improvement effect of the nutrient slow-release acidic soil conditioner provided in an embodiment of the present invention on the acidity of different types of acidic soils in facility agriculture.

[0019] Figure 2 A diagram showing the improvement effect of the nutrient slow-release acidic soil conditioner provided in an embodiment of the present invention on the moisture content of acidic soil in facility agriculture.

[0020] Figure 3 A diagram showing the improvement effect of the nutrient slow-release acidic soil conditioner provided in an embodiment of the present invention on organic matter in acidic soil of facility agriculture.

[0021] Figure 4 A diagram showing the improvement effect of the nutrient slow-release acidic soil conditioner provided in an embodiment of the present invention on total nitrogen in acidic soil of facility agriculture.

[0022] Figure 5 A diagram showing the improvement effect of the nutrient slow-release acidic soil conditioner provided by an embodiment of the present invention on the available phosphorus in acidic soil of facility agriculture. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Example 1

[0025] (I) The preparation method is as follows:

[0026] 1) drying fresh chicken manure, cow manure, sheep manure and Trichosanthes fruit shell at 50-60° C. and crushing them to a particle size of less than 1 cm, and then mixing the crushed chicken manure, cow manure, sheep manure and Trichosanthes fruit shell powder in a weight ratio of 1:1:1:0.2;

[0027] 2) In an anaerobic environment, the pyrolysis rate was increased to 900°C at 5-10°C / min and maintained for 2 hours;

[0028] 3) After cooling to room temperature, grind thoroughly and pass through a 2 mm sieve to finally obtain an acidic soil conditioner.

[0029] Among them, chicken manure can be used as organic fertilizer, but it needs to be processed and cannot be directly applied to the soil.

[0030] The organic matter in cow dung is difficult to decompose and needs to be processed before being mixed with soil. It has a fine texture and is a slow-release fertilizer. Its own loose nature can improve soil structure and increase soil aeration and water retention.

[0031] Sheep manure contains a large number of pathogenic microorganisms and cannot be applied directly to the soil. It is rich in phosphorus, potassium and trace elements, which can improve soil quality and prevent soil compaction.

[0032] Trichosanthes kirilowii is a plant of the Cucurbitaceae family with abundant yield. Its seed shell is high in potassium and cellulose and has water-retaining properties.

[0033] Verification of the acid neutralization ability of the improver: The improver of the present invention and lime were added to an acidic solution (pH=3) respectively, with a volume ratio of the improver to the acidic solution of 1:5, and the pH value of the solution was measured after equilibrium and stability for 24-48 hours, using an acidometer method, and the results are shown in Table 1. This shows that the acid neutralization ability of the improver of the present invention is highly close to the level of quicklime.

[0034] Table 1 pH value of solution after the modifier of the present invention and lime are added to the acidic solution

[0035] Improver quicklime Improver of the present invention Solution pH 12.9 12.5

[0036] Test of the ingredients of the improver: The inorganic components of the improver were analyzed using an element analyzer, and the results are shown in Table 2. It can be seen that the improver of the present invention contains a large amount of organic matter, with a content of up to 44.5%. In addition, the content of N, P, and K elements is rich, indicating that it not only has acid neutralization ability, but also is a high-quality fertilizer. In addition, the improver of the present invention contains almost no toxic and harmful elements (below the detection limit level), and there is no risk of secondary soil pollution.

[0037] Table 2 Composition and structure test of the improver of the present invention

[0038]

[0039] Example 2

[0040] The steps for preparing the improver in this embodiment are substantially the same as those in Embodiment 1, except that the raw material ratio of the improver is that in this embodiment, chicken manure, cow manure, sheep manure, and Trichosanthes fruit shell powder are mixed in a weight ratio of 1:1:1:1.

[0041] The results showed that the higher the proportion of Trichosanthes kirilowii shell, the lower the nutrient nitrogen (<3%) and phosphorus (<5%) content of the product.

[0042] Example 3

[0043] The steps for preparing the improver in this embodiment are substantially the same as those in Embodiment 1, except that the raw material ratio of the improver is that chicken manure, cow manure, sheep manure, and Trichosanthes fruit shell powder are mixed in a weight ratio of 2:1:1:0.2 in this embodiment.

[0044] The results showed that the pH value of the improver obtained in this example decreased, and the pH value of the solution was 11.9 after being added to the acidic solution (the volume ratio of the improver to the acidic solution was 1:5).

[0045] Example 4

[0046] The steps for preparing the improver in this embodiment are substantially the same as those in Embodiment 1, except that the raw material ratio of the improver is that chicken manure, cow manure, sheep manure, and Trichosanthes fruit shell powder are mixed in a weight ratio of 1:2:1:0.2 in this embodiment.

[0047] The results showed that the pH value of the improver obtained in this example decreased, and the pH value of the solution was 11.3 after being added to the acidic solution (the volume ratio of the improver to the acidic solution was 1:5).

[0048] Example 5

[0049] The steps for preparing the improver in this embodiment are substantially the same as those in Embodiment 1, except that the raw material ratio of the improver is that chicken manure, cow manure, sheep manure, and Trichosanthes fruit shell powder are mixed in a weight ratio of 1:1:2:0.2 in this embodiment.

[0050] The results showed that the pH value of the improver obtained in this example decreased, and the pH value of the solution was 10.2 after being added to the acidic solution (the volume ratio of the improver to the acidic solution was 1:5).

[0051] Example 6

[0052] A small-scale experiment was conducted in a greenhouse of facility agriculture. 0.2% of the composite modifier of the present invention and the product made of a single raw material were fully mixed with Hunan brown red soil (pH value of about 3.5), and soil samples were taken after 120 days for soil nutrient determination.

[0053] Table 3 Effect of compounding of improver of the present invention

[0054]

[0055] It can be seen from Table 3 that the compounding effect of the improver of the present invention is that the sustained-release effect of the product made of animal feces or Trichosanthes fruit shell alone is significantly worse than that of the composite product, and various indicators of soil nutrient are lower than those of the composite improver at the same time.

[0056] Example 7: Effects of improving the acidity of different types of acidic soils in facility agriculture in different regions of the south

[0057] Three typical acidic soils of southern facility agriculture were selected: Guangxi red soil, Zhejiang yellow soil, and Hunan brown red soil. In a large number of literatures and practical applications, the empirical dosage range of the modifier is 0.1-5%. In this example, 0.2% of the modifier of the present invention and quicklime (control group) were fully mixed with the soil to keep the soil moisture content constant. After 120 days, the soil samples were air-dried and sieved, and the soil pH value was measured. The results are as follows: Figure 1 shown.

[0058] Depend on Figure 1It can be seen that the improver of the present invention has a wide range of applicability. For different regions and different similar acidic soils in southern facility agriculture, the improver at a lower dose shows excellent acid neutralization ability, and after long-term cultivation, there is no problem of soil re-acidification. The improver of the present invention is also universal for pH value. The lower the initial soil pH value, the less it affects the improvement effect.

[0059] Example 8: Improvement effect on moisture content of acidic soil in facility agriculture

[0060] A small pot experiment was conducted in a greenhouse of facility agriculture. 0.2% of the improver of the present invention and quicklime (control group) were fully mixed with Guangxi red soil (pH value of about 4) in advance, and then turnip seeds of uniform shape and size were selected and sown in the soil. Water was irrigated, and soil samples were taken at 30 / 60 / 90 / 120 days to measure the soil moisture content. The results are as follows: Figure 2 shown.

[0061] Depend on Figure 2 It can be seen that the improver of the present invention increases soil water retention, improves soil structure, and significantly increases soil water content. This effect becomes more and more obvious as time goes by.

[0062] Example 9: Improvement effect on organic matter in acidic soil of facility agriculture

[0063] A small-scale pot experiment was conducted in a greenhouse of facility agriculture. 0.2% of the improver of the present invention and quicklime (control group) were fully mixed with red soil (pH value of about 4) in Guangxi in advance, and then turnip seeds of the same shape and size were selected and sown in the soil. After watering, soil samples were taken at 30 / 60 / 90 / 120 days to determine the soil organic matter. The organic matter was determined by potassium dichromate bulk density method (GB9834-1988). The results are as follows: Figure 3 shown.

[0064] Depend on Figure 3 It can be seen that the improver of the present invention has a good nutrient slow-release effect, continuously inputs nutrients into the soil, and maintains soil fertility. The effect is most obvious around 120 days, and soil organic matter is not only not consumed and reduced, but increased by about 25% compared with the original.

[0065] Example 10: Improvement effect on total nitrogen in acidic soil of facility agriculture

[0066] A small-scale pot experiment was conducted in a greenhouse of facility agriculture. 0.2% of the improver of the present invention and quicklime (control group) were fully mixed with Guangxi red soil (pH value of about 4) in advance, and then turnip seeds of the same shape and size were selected and sown in the soil. After watering, soil samples were taken at 30 / 60 / 90 / 120 days to determine the total nitrogen in the soil. The organic matter was determined by the Kjeldahl method (HJ 717-2014). The results are as follows: Figure 4 shown.

[0067] Total nitrogen is one of the important indicators to measure soil nutrient status. Figure 4 It is explained that the improver of the present invention slowly releases total nitrogen to the acidic soil of facility agriculture, so that the total nitrogen nutrient content of the soil is maintained at a high level after 30 days and is increased by more than 15% compared with the initial total nitrogen content.

[0068] Example 11: Improvement effect of available phosphorus in acidic soil of facility agriculture

[0069] A small-scale pot experiment was conducted in a greenhouse of facility agriculture. 0.2% of the improver of the present invention and quicklime (control group) were fully mixed with Guangxi red soil (pH value of about 4) in advance, and then turnip seeds of the same shape and size were selected and sown in the soil. Water was applied, and soil samples were taken at 30 / 60 / 90 / 120 days to determine the available phosphorus in the soil. The available phosphorus was determined according to the sodium bicarbonate extraction-molybdenum antimony spectrophotometry method (HJ 704-2014). The results are as follows: Figure 5 shown.

[0070] Available phosphorus refers to phosphorus in the soil that is easily absorbed and utilized by plants, reflecting the important role of soil nutrients in plant growth. Figure 5 It can be seen that the available phosphorus content in the soil of the traditional lime-added group continued to decrease, and the nutrient slow-release effect of the improver of the present invention can maintain the available phosphorus content at more than 20% of the initial value for a long time. After improvement, the acidity of the facility agricultural soil is neutralized, and the soil nutrients are continuously at a high level, which is conducive to plant growth and can promote the economic benefits of facility agriculture.

[0071] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a nutrient slow-release acidic soil conditioner for facility agriculture, characterized in that: The following steps are involved: Step 1, drying and crushing fresh chicken manure, cow manure, sheep manure and Trichosanthes fruit shell to a particle size of less than 1 cm, and then mixing the crushed chicken manure, cow manure, sheep manure and Trichosanthes fruit shell powder in a weight ratio of 1-2:1-2:1-2:0.2-1; Step 2: In an anaerobic environment, heat to 900°C for pyrolysis and maintain for 2 hours; Step 3: After cooling to room temperature, grind thoroughly and pass through a 2 mm sieve to finally obtain an acidic soil conditioner.

2. The method for preparing a nutrient slow-release acidic soil conditioner for facility agriculture according to claim 1, characterized in that: In step 1, the crushed chicken manure, cow manure, sheep manure and Trichosanthes kirilowii shell powder are mixed in a weight ratio of 1:1:1:0.

2.

3. The method for preparing a nutrient slow-release acidic soil conditioner for facility agriculture according to claim 1, characterized in that: In step 1, the drying temperature is 50-60° C. and the drying time is 10-12 hours.

4. The method for preparing a nutrient slow-release acidic soil conditioner for facility agriculture according to claim 1, characterized in that: In step 2, the heating rate of the pyrolysis is 5-10°C / min.

5. A nutrient slow-release acidic soil conditioner for facility agriculture prepared by the preparation method according to any one of claims 1 to 4.

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