Soil conditioner for improving nitrogen and phosphorus utilization efficiency of soil and increasing yield of crops with selenium enrichment and application thereof

Abstract

The present application relates to a kind of soil conditioner for improving soil nitrogen and phosphorus utilization efficiency and crop selenium-enriched yield increase, it is characterized in that, the component of the soil conditioner includes by mass fraction: 50-70 parts fly ash, 20-40 parts straw fermented fertilizer, 5-15 parts livestock and poultry manure fermented fertilizer;Selenium content in the fly ash is not less than 4 mg / kg.The present application uses selenium-containing fly ash as main raw material, combines with straw fermented fertilizer and livestock and poultry manure fermented fertilizer raw material to form a kind of soil conditioner, and the soil conditioner can significantly improve the nitrogen and phosphorus utilization efficiency of soil, especially red soil, while it can significantly improve the selenium content and yield of planted crops.

Description

Technical Field

[0001] This invention belongs to the field of agricultural technology and relates to a soil conditioner that improves soil nitrogen and phosphorus use efficiency and synergistically enhances crop selenium enrichment and yield, as well as its application. Background Technology

[0002] Every year, coal-fired power plants produce a large amount of fly ash. The generation, storage, and transportation of fly ash inevitably occupy certain land resources and cause environmental pollution. Currently, due to its lightweight, loose, and porous physical properties, and the presence of elements needed by plants such as magnesium, boron, calcium, molybdenum, and manganese, fly ash can be widely used as a soil conditioner for soil improvement and agricultural production.

[0003] Nitrogen and phosphorus are essential soil nutrients, crucial for maintaining crop yields. The red soil regions of southern my country boast superior hydrothermal conditions and enormous agricultural potential. However, constrained by the relatively infertile nature of the red soil, nitrogen and phosphorus use efficiency in agricultural production is generally low. This significantly limits agricultural productivity and also leads to a waste of applied fertilizers. Improving the physicochemical properties of red soil and enhancing nitrogen and phosphorus use efficiency through techniques such as applying soil conditioners is an important way to increase agricultural productivity in these regions.

[0004] Selenium is an essential trace element for the human body, which helps boost immunity. Growing selenium-enriched crops requires selenium-enriched soil. National standards stipulate that soil with a selenium content of 0.4 mg / kg or higher can be classified as selenium-enriched soil. Currently, in the market, selenium-enriched agricultural products are 50-200% more expensive than non-selenium-enriched products of the same type, demonstrating their superior economic value.

[0005] Therefore, it would be very meaningful to develop a strategy that utilizes the large amount of fly ash produced by coal-fired power plants to improve the physical and chemical properties of red soil and increase crop yield by enriching it with selenium. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a soil conditioner that improves soil nitrogen and phosphorus use efficiency and synergistically increases crop selenium enrichment and yield, and its application.

[0007] To achieve this objective, the present invention employs the following technical solution:

[0008] In a first aspect, the present invention provides a soil conditioner for improving soil nitrogen and phosphorus use efficiency and synergistically increasing crop yield by enriching selenium. The soil conditioner comprises, by mass parts: 50-70 parts fly ash, 20-40 parts fermented straw fertilizer, and 5-15 parts fermented livestock and poultry manure fertilizer; wherein the fly ash contains a selenium content of not less than 4 mg / kg.

[0009] This invention uses selenium-containing fly ash as the main raw material, combined with fermented straw fertilizer and fermented livestock and poultry manure fertilizer, to form a soil conditioner. This soil conditioner can significantly improve the nitrogen and phosphorus utilization efficiency of soil, especially red soil, and at the same time, significantly increase the selenium content and yield of crops. This invention utilizes industrial and agricultural "waste" such as fly ash, crop straw, and livestock and poultry manure, which is green, environmentally friendly, and low-cost. Furthermore, increasing the selenium content of crops means increasing the commercial value of agricultural products.

[0010] The mass fractions of fly ash can be selected from 50, 52, 54, 56, 58, 60, 62, 65, 70, etc.; the mass fractions of fermented straw fertilizer can be selected from 20, 22, 24, 26, 28, 30, 32, 35, 40, etc.; the mass fractions of fermented livestock and poultry manure fertilizer can be selected from 5, 7, 8, 10, 12, 13, 14, 15, etc.; other unlisted values ​​within the above ranges can be selected, and will not be elaborated here.

[0011] Preferably, the fermented straw fertilizer is prepared by fermentation using any one or a combination of at least two of corn straw, rice straw, or wheat straw as raw materials.

[0012] Preferably, the fermented straw fertilizer is prepared by fermenting corn straw.

[0013] This invention reveals that, compared to other crop straws, fermented fertilizer made from corn straw has a superior effect on improving nitrogen and phosphorus utilization efficiency in soil, especially red soil, as well as increasing the selenium content and yield of planted crops.

[0014] Preferably, the fermentation process employs the following three-stage fermentation method:

[0015] Fermentation is carried out on days 1 to N1 at temperatures of 40-50℃ (e.g., 40℃, 42℃, 45℃, 48℃, 50℃, etc.) and humidity of 60-70% (e.g., 60%, 62%, 65%, 68%, 70%, etc.).

[0016] Fermentation is carried out on days N1+1 to N2 at temperatures of 55-65℃ (e.g., 55℃, 58℃, 60℃, 62℃, 65℃, etc.) and humidity of 60-70% (e.g., 60%, 62%, 65%, 68%, 70%, etc.).

[0017] Fermentation is carried out on days N2+1 to N3 under conditions of 35-45℃ (e.g., 35℃, 38℃, 40℃, 42℃, 45℃, etc.) and 60-70% humidity (e.g., 60%, 62%, 65%, 68%, 70%, etc.).

[0018] Where N1 is selected from any integer from 4 to 8 (4, 5, 6, 7, 8, etc.), N2 is selected from any integer from 18 to 22 (18, 19, 20, 21, 22, etc.), and N3 is selected from any integer from 25 to 30 (25, 26, 27, 28, 29, 30, etc.).

[0019] All other unlisted point values ​​within the above ranges can be selected, and will not be elaborated on here.

[0020] The straw fermented fertilizer used in this invention is more preferably produced by the fermentation method described above. Compared with other fermentation methods, the product produced by this fermentation method can improve the nitrogen and phosphorus utilization efficiency of the soil, especially red soil, and can also improve the selenium content and yield of the planted crops.

[0021] Preferably, during the fermentation process, the compost pile is turned over every 5-7 days.

[0022] Preferably, the fermented livestock and poultry manure fertilizer is prepared by fermentation treatment using any one or a combination of at least two of cow manure, sheep manure, or poultry manure as raw materials.

[0023] Preferably, the fermented livestock and poultry manure fertilizer is prepared by fermenting cow manure as raw material.

[0024] This invention has found that, compared to other livestock and poultry manure, fermented livestock and poultry manure fertilizer made from cow manure has a better effect on improving the nitrogen and phosphorus utilization efficiency of soil, especially red soil, as well as increasing the selenium content and yield of crops.

[0025] Preferably, the fermentation process employs the following three-stage fermentation method:

[0026] Fermentation is carried out on days 1 to N1 at temperatures of 40-50℃ (e.g., 40℃, 42℃, 45℃, 48℃, 50℃, etc.) and humidity of 60-70% (e.g., 60%, 62%, 65%, 68%, 70%, etc.).

[0027] Fermentation is carried out on days N1+1 to N2 at temperatures of 55-65℃ (e.g., 55℃, 58℃, 60℃, 62℃, 65℃, etc.) and humidity of 60-70% (e.g., 60%, 62%, 65%, 68%, 70%, etc.).

[0028] Fermentation is carried out on days N2+1 to N3 under conditions of 35-45℃ (e.g., 35℃, 38℃, 40℃, 42℃, 45℃, etc.) and 60-70% humidity (e.g., 60%, 62%, 65%, 68%, 70%, etc.).

[0029] Where N1 is selected from any integer from 4 to 8 (4, 5, 6, 7, 8, etc.), N2 is selected from any integer from 18 to 22 (18, 19, 20, 21, 22, etc.), and N3 is selected from any integer from 25 to 30 (25, 26, 27, 28, 29, 30, etc.).

[0030] All other unlisted point values ​​within the above ranges can be selected, and will not be elaborated on here.

[0031] The fermented livestock and poultry manure fertilizer used in this invention is more preferably produced by the fermentation method described above. Compared with other fermentation methods, the product produced by this fermentation method can improve the nitrogen and phosphorus utilization efficiency of the soil, especially red soil, and can also improve the selenium content and yield of the planted crops.

[0032] Preferably, during the fermentation process, the compost pile is turned over every 5-7 days.

[0033] Preferably, the fly ash contains lead ≤120 mg / kg, cadmium ≤0.3 mg / kg, mercury ≤2.4 mg / kg, arsenic ≤30 mg / kg, and chromium ≤200 mg / kg.

[0034] Preferably, the soil conditioner contains the following components: selenium content ≥ 0.4 mg / kg, lead content ≤ 120 mg / kg, cadmium content ≤ 0.3 mg / kg, mercury content ≤ 2.4 mg / kg, arsenic content ≤ 30 mg / kg, chromium content ≤ 200 mg / kg, organic matter content ≥ 1.4%, total nitrogen content ≥ 0.074%, available phosphorus content ≥ 3 mg / kg, available potassium content ≥ 33 mg / kg, pH value 5.5-8.5, moisture content ≤ 30%, and particle size ≤ 5 mm.

[0035] Secondly, the present invention provides a method for improving soil nitrogen and phosphorus use efficiency and synergistically increasing crop yield through selenium enrichment. The method includes: applying the soil conditioner described in the first aspect to the growth hole of the crop seedling using a hole application method, and thoroughly mixing it with the base soil in the growth hole.

[0036] Preferably, the application rate of the soil conditioner is 1.5-3.5 tons / mu, such as 1.5 tons / mu, 2 tons / mu, 2.5 tons / mu, 3 tons / mu, 3.5 tons / mu, etc. Other unlisted values ​​within the above ranges are also acceptable and will not be elaborated here. More preferably, it is 2.0-3.5 tons / mu.

[0037] Preferably, the crop includes corn or potato.

[0038] Preferably, the soil is red soil.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] This invention uses selenium-containing fly ash as the main raw material, combined with fermented straw fertilizer and fermented livestock and poultry manure fertilizer, to form a soil conditioner. This soil conditioner can significantly improve the nitrogen and phosphorus utilization efficiency of soil, especially red soil, and at the same time, significantly increase the selenium content and yield of crops. This invention utilizes industrial and agricultural "waste" such as fly ash, crop straw, and livestock and poultry manure, which is green, environmentally friendly, and low-cost. Furthermore, increasing the selenium content of crops means increasing the commercial value of agricultural products. Detailed Implementation

[0041] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.

[0042] The fly ash used in the following examples or comparative examples is fly ash from Pannan Power Plant in Guizhou Province, with selenium content ≥4 mg / kg, lead content ≤120 mg / kg, cadmium content ≤0.3 mg / kg, mercury content ≤2.4 mg / kg, arsenic content ≤30 mg / kg, and chromium content ≤200 mg / kg.

[0043] Example 1

[0044] This embodiment provides a soil conditioner with the following formula: 60% fly ash, 30% fermented straw fertilizer, and 10% fermented livestock and poultry manure fertilizer.

[0045] The preparation methods for straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer are as follows:

[0046] Corn stalks and cow dung are used as raw materials for natural fermentation, which is carried out in a three-stage fermentation process:

[0047] Fermentation was carried out on days 1 to 5 at a temperature of 45°C and a humidity of 65%.

[0048] Fermentation was carried out from day 6 to day 20 at a temperature of 60°C and a humidity of 65%.

[0049] Fermentation was carried out from day 21 to day 30 at a temperature of 40°C and a humidity of 65%.

[0050] During the fermentation process, the pile is turned over every 6 days to ensure oxygen supply and uniform fermentation.

[0051] After fermentation, both types of fermented fertilizer turned dark brown.

[0052] The soil conditioner tested showed that it contained the following components: selenium ≥ 0.4 mg / kg, lead ≤ 120 mg / kg, cadmium ≤ 0.3 mg / kg, mercury ≤ 2.4 mg / kg, arsenic ≤ 30 mg / kg, chromium ≤ 200 mg / kg, organic matter ≥ 1.4%, total nitrogen ≥ 0.074%, available phosphorus ≥ 3 mg / kg, available potassium ≥ 33 mg / kg, pH 5.5-8.5, moisture content ≤ 30%, and particle size ≤ 5 mm.

[0053] Example 2

[0054] This embodiment provides a soil conditioner with the following formula: 65% fly ash, 20% fermented straw fertilizer, and 15% fermented livestock and poultry manure fertilizer.

[0055] The preparation methods for straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer are as follows:

[0056] Corn stalks and cow dung are used as raw materials for natural fermentation, which is carried out in a three-stage fermentation process:

[0057] Fermentation was carried out on days 1 to 4 at a temperature of 50°C and a humidity of 70%.

[0058] Fermentation was carried out from day 5 to day 18 at a temperature of 65°C and a humidity of 70%.

[0059] Fermentation was carried out from day 19 to day 25 at a temperature of 45°C and a humidity of 70%.

[0060] During the fermentation process, the pile is turned over every 5 days to ensure oxygen supply and uniform fermentation.

[0061] After fermentation, both types of fermented fertilizer turned dark brown.

[0062] The soil conditioner tested showed that it contained the following components: selenium ≥ 0.4 mg / kg, lead ≤ 120 mg / kg, cadmium ≤ 0.3 mg / kg, mercury ≤ 2.4 mg / kg, arsenic ≤ 30 mg / kg, chromium ≤ 200 mg / kg, organic matter ≥ 1.4%, total nitrogen ≥ 0.074%, available phosphorus ≥ 3 mg / kg, available potassium ≥ 33 mg / kg, pH 5.5-8.5, moisture content ≤ 30%, and particle size ≤ 5 mm.

[0063] Example 3

[0064] This embodiment provides a soil conditioner with the following formula: 55% fly ash, 40% fermented straw fertilizer, and 5% fermented livestock and poultry manure fertilizer.

[0065] The preparation methods for straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer are as follows:

[0066] Corn stalks and cow dung are used as raw materials for natural fermentation, which is carried out in a three-stage fermentation process:

[0067] Fermentation was carried out from day 1 to day 7 at a temperature of 40°C and a humidity of 60%.

[0068] Fermentation was carried out from day 8 to day 22 at a temperature of 55°C and a humidity of 60%.

[0069] Fermentation was carried out from day 23 to day 30 at a temperature of 35°C and a humidity of 60%.

[0070] During the fermentation process, the pile is turned over every 6 days to ensure oxygen supply and uniform fermentation.

[0071] After fermentation, both types of fermented fertilizer turned dark brown.

[0072] The soil conditioner tested showed that it contained the following components: selenium ≥ 0.4 mg / kg, lead ≤ 120 mg / kg, cadmium ≤ 0.3 mg / kg, mercury ≤ 2.4 mg / kg, arsenic ≤ 30 mg / kg, chromium ≤ 200 mg / kg, organic matter ≥ 1.4%, total nitrogen ≥ 0.074%, available phosphorus ≥ 3 mg / kg, available potassium ≥ 33 mg / kg, pH 5.5-8.5, moisture content ≤ 30%, and particle size ≤ 5 mm.

[0073] Example 4

[0074] This embodiment provides a soil conditioner whose formula differs from that of Example 1 only in the preparation method of the straw fermentation fertilizer: rice straw is used as raw material for natural fermentation, and the fermentation method is the same as that of Example 1.

[0075] Example 5

[0076] This embodiment provides a soil conditioner whose formula differs from that of Example 1 only in the preparation method of the fermented livestock and poultry manure fertilizer: sheep manure is used as raw material for natural fermentation, and the fermentation method is the same as that of Example 1.

[0077] Example 6

[0078] This embodiment provides a soil conditioner, the only difference between its formula and that of Example 1 being the preparation methods of straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer:

[0079] Corn stalks and cow dung were used as raw materials for natural fermentation, which was carried out in a single-stage fermentation process.

[0080] Fermentation was carried out from day 1 to day 30 at a temperature of 45°C and a humidity of 65%.

[0081] During the fermentation process, the pile is turned over every 6 days to ensure oxygen supply and uniform fermentation.

[0082] Example 7

[0083] This embodiment provides a soil conditioner, the only difference between its formula and that of Example 1 being the preparation methods of straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer:

[0084] Corn stalks and cow dung were used as raw materials for natural fermentation, which was carried out in a single-stage fermentation process.

[0085] Fermentation was carried out from day 1 to day 30 at a temperature of 60°C and a humidity of 65%.

[0086] During the fermentation process, the pile is turned over every 6 days to ensure oxygen supply and uniform fermentation.

[0087] Example 8

[0088] This embodiment provides a soil conditioner, the only difference between its formula and that of Example 1 being the preparation methods of straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer:

[0089] Corn stalks and cow dung are used as raw materials for natural fermentation, which is carried out in a two-stage fermentation process.

[0090] Fermentation was carried out on days 1 to 5 at a temperature of 45°C and a humidity of 65%.

[0091] Fermentation was carried out from day 6 to day 30 at a temperature of 60°C and a humidity of 65%.

[0092] During the fermentation process, the pile is turned over every 6 days to ensure oxygen supply and uniform fermentation.

[0093] Example 9

[0094] This embodiment provides a soil conditioner, the only difference between its formula and that of Example 1 being the preparation methods of straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer:

[0095] Corn stalks and cow dung are used as raw materials for natural fermentation, which is carried out in a three-stage fermentation process:

[0096] Fermentation was carried out from day 1 to day 10 at a temperature of 45°C and a humidity of 65%.

[0097] Fermentation was carried out from day 11 to day 24 at a temperature of 60°C and a humidity of 65%.

[0098] Fermentation was carried out from day 25 to day 30 at a temperature of 40°C and a humidity of 65%.

[0099] During the fermentation process, the pile is turned over every 6 days to ensure oxygen supply and uniform fermentation.

[0100] Example 10

[0101] This embodiment provides a soil conditioner, the only difference between its formula and that of Example 1 being the preparation methods of straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer:

[0102] Corn stalks and cow dung are used as raw materials for natural fermentation, which is carried out in a three-stage fermentation process:

[0103] Fermentation was carried out on days 1 to 5 at a temperature of 35°C and a humidity of 75%.

[0104] Fermentation was carried out from day 6 to day 20 at a temperature of 70°C and a humidity of 75%.

[0105] Fermentation was carried out from day 21 to day 30 at a temperature of 50°C and a humidity of 75%.

[0106] During the fermentation process, the pile is turned over every 6 days to ensure oxygen supply and uniform fermentation.

[0107] Comparative Example 1

[0108] This comparative example provides a soil conditioner whose formula differs from that of Example 1 only in that it lacks straw fermented fertilizer, and the reduced mass of straw is allocated to the mass of livestock and poultry manure fermented fertilizer, while other conditions remain unchanged.

[0109] Comparative Example 2

[0110] This comparative example provides a soil conditioner whose formula differs from that of Example 1 only in that it lacks livestock and poultry manure fermented fertilizer, and the reduced mass of the manure is allocated to the mass of straw fermented fertilizer, while other conditions remain unchanged.

[0111] Test Example 1

[0112] Corn planting experiment:

[0113] (1) Soil sampling: 0-15 cm soil samples were collected from the Zengcheng experimental base of the Institute of Ecology, Environment and Soil, Guangdong Academy of Sciences. After removing stones and plant roots, the samples were air-dried and passed through a 4 mm sieve for later use.

[0114] (2) Treatment settings: A total of 15 treatments were set up: 1) Blank control (no soil conditioner applied), 2) Soil conditioners prepared in Examples 1-10 and Comparative Examples 1-2 were 2.5 tons / mu, 3) Soil conditioner prepared in Example 1 was 1.5 tons / mu, and 4) Soil conditioner prepared in Example 1 was 3.5 tons / mu.

[0115] (3) Experimental method: Prepare several cultivation pots, and take 4 kg of the soil sample prepared in step (1) into each pot. Then, refer to the pot experiment method for corn planting, and add the same amount of chemical fertilizer as base fertilizer to each pot. According to the treatment settings in (2) above, apply the soil conditioner into the growth hole in proportion. Each treatment is repeated 4 times. After the corn matures, collect corn and soil samples respectively, and determine the corn yield (converted to yield per mu), corn selenium content, and soil nitrogen and phosphorus use efficiency.

[0116] Soil nitrogen use efficiency: according to the following formula E N = (N p + N s ) / (F N + N so )×100 is used for calculation, where E N For nitrogen use efficiency, N p N represents the nitrogen content of the crop after harvest. s F represents the nitrogen content of the soil after harvest. N The nitrogen content in the base fertilizer, N so Soil nitrogen content before planting;

[0117] Soil phosphorus use efficiency: according to the following formula E P = (P p + P s ) / (F P + P so ) × 100 for calculation, where E P For phosphorus utilization efficiency, P p P represents the phosphorus content of the crop after harvest. s F represents the phosphorus content in the soil after harvest. P The phosphorus content in base fertilizer, P so The soil phosphorus content before planting;

[0118] Nitrogen content in soil and fertilizer: determined using the semi-micro Kjeldahl method GB 7173-1987;

[0119] Phosphorus content in soil and fertilizer: determined by spectrophotometry according to GB 7852-1987;

[0120] Nitrogen content in corn: determined by sulfuric acid-hydrogen peroxide digestion method NY / T 2017-1011;

[0121] Phosphorus content in corn: determined by spectrophotometry according to NY / T 2017-1011.

[0122] The results are shown in Table 1.

[0123] Table 1

[0124]

[0125]

[0126] The data in Table 1 show that, compared with the blank treatment, the application of the soil conditioner involved in this invention can improve the nitrogen use efficiency, phosphorus use efficiency, maize yield, and maize selenium content of the soil. This means that this invention can improve the nitrogen and phosphorus use efficiency of red soil and synergistically increase maize yield through selenium enrichment. Among these, the application effect shows a gradient effect with increasing application amount of soil conditioner. Meanwhile, the application effects of 2.5 tons / mu and 3.5 tons / mu are quite similar. Considering the application cost in practical applications, the lower application amount (2.5 tons / mu) is selected as the optimal application amount.

[0127] Comparing the data of Example 1 with Comparative Examples 1-2, it can be seen that straw fermented fertilizer and livestock and poultry manure fermented fertilizer have a synergistic effect in terms of the combined effect of fly ash and in improving soil nitrogen use efficiency, phosphorus use efficiency, corn yield and corn selenium content.

[0128] Comparing the data from Example 1 with those from Examples 6-10, it can be seen that the fermentation methods of the straw fermentation fertilizer and livestock manure fermentation fertilizer used in this invention affect the soil conditioner's effect on improving soil nitrogen and phosphorus utilization efficiency and the selenium content and yield of planted crops to a certain extent.

[0129] Comparing the data from Example 1 with those from Examples 4-5, it can be seen that the fermentation raw materials of the straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer used in this invention also affect the effect of soil conditioners on improving soil nitrogen and phosphorus utilization efficiency and the selenium content and yield of planted crops to a certain extent.

[0130] Test Example 2

[0131] Potato planting trial:

[0132] (1) Soil sampling: 0-15 cm soil samples were collected from the Zengcheng experimental base of the Institute of Ecology, Environment and Soil, Guangdong Academy of Sciences. After removing stones and plant roots, the samples were air-dried and passed through a 4 mm sieve for later use.

[0133] (2) A total of 15 treatments were set up: 1) blank control (no soil conditioner applied), 2) soil conditioners prepared in Examples 1-10 and Comparative Examples 1-2, each with 2.5 tons / mu, 3) soil conditioner prepared in Example 1, each with 1.5 tons / mu, and 4) soil conditioner prepared in Example 1, each with 3.5 tons / mu.

[0134] (3) Experimental method: Prepare several cultivation pots, and take 4 kg of the soil sample prepared in step (1) into each pot. Then, referring to the pot experiment method for potato planting, add the same amount of chemical fertilizer as base fertilizer to each pot. According to the treatment settings in (2) above, apply the soil conditioner into the growth hole in proportion. Each treatment is repeated 3 times. After the potatoes mature, collect potato and soil samples respectively, and determine the potato yield (converted to yield per mu), potato selenium content, and soil nitrogen and phosphorus use efficiency.

[0135] Soil nitrogen use efficiency: according to the following formula E N = (N p + N s ) / (F N + N so )×100 is used for calculation, where E N For nitrogen use efficiency, N p N represents the nitrogen content of the crop after harvest. s F represents the nitrogen content of the soil after harvest. N The nitrogen content in the base fertilizer, N so Soil nitrogen content before planting;

[0136] Soil phosphorus use efficiency: according to the following formula E P = (P p + P s ) / (F P + P so ) × 100 for calculation, where E P For phosphorus utilization efficiency, P p P represents the phosphorus content of the crop after harvest. s F represents the phosphorus content in the soil after harvest. P The phosphorus content in base fertilizer, P so The soil phosphorus content before planting;

[0137] Nitrogen content in soil and fertilizer: determined using the semi-micro Kjeldahl method GB 7173-1987;

[0138] Phosphorus content in soil and fertilizer: determined by spectrophotometry according to GB 7852-1987;

[0139] Nitrogen content in potatoes: determined by sulfuric acid-hydrogen peroxide digestion method NY / T 2017-1011;

[0140] Phosphorus content in potatoes: determined by spectrophotometry according to NY / T 2017-1011.

[0141] The results are shown in Table 2.

[0142] Table 2

[0143]

[0144]

[0145] As shown in Table 2, compared with the blank treatment, the application of the soil conditioner involved in this invention can improve the nitrogen use efficiency, phosphorus use efficiency, potato yield, and potato selenium content of the soil. This means that this invention can improve the nitrogen and phosphorus use efficiency of red soil and synergistically increase potato yield through selenium enrichment. The application effect shows a gradient effect with increasing application amount of soil conditioner. Meanwhile, the application effects of 2.5 tons / mu and 3.5 tons / mu are quite similar. Considering the application cost in practical applications, the lower application amount (2.5 tons / mu) is selected as the optimal application amount.

[0146] Comparing the data of Example 1 with Comparative Examples 1-2, it can be seen that straw fermented fertilizer and livestock and poultry manure fermented fertilizer have a synergistic effect in terms of the combined effect of fly ash and in improving soil nitrogen use efficiency, phosphorus use efficiency, potato yield and potato selenium content.

[0147] Comparing the data from Example 1 with those from Examples 6-10, it can be seen that the fermentation methods of the straw fermentation fertilizer and livestock manure fermentation fertilizer used in this invention affect the soil conditioner's effect on improving soil nitrogen and phosphorus utilization efficiency and the selenium content and yield of planted crops to a certain extent.

[0148] Comparing the data from Example 1 with those from Examples 4-5, it can be seen that the fermentation raw materials of the straw fermentation fertilizer and livestock and poultry manure fermentation fertilizer used in this invention also affect the effect of soil conditioners on improving soil nitrogen and phosphorus utilization efficiency and the selenium content and yield of planted crops to a certain extent.

[0149] The applicant declares that the technical solution of this invention is illustrated by the above embodiments, but this invention is not limited to the above embodiments, that is, it does not mean that this invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

[0150] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0151] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A soil conditioner for improving soil nitrogen and phosphorus use efficiency and synergistically increasing crop yield through selenium enrichment, characterized in that, The soil conditioner comprises, by mass parts: 50-70 parts fly ash, 20-40 parts fermented straw fertilizer, and 5-15 parts fermented livestock and poultry manure fertilizer; the fly ash contains a selenium content of not less than 4 mg / kg.

2. The soil conditioner according to claim 1, characterized in that, The fermented straw fertilizer is prepared by fermentation of any one or at least two of corn straw, rice straw, or wheat straw. Preferably, the fermented straw fertilizer is prepared by fermenting corn straw.

3. The soil conditioner according to claim 2, characterized in that, The fermentation process employs the following three-stage fermentation method: Fermentation was carried out on days 1 to N1 at a temperature of 40-50℃ and a humidity of 60-70%. Fermentation was carried out on days N1+1 to N2 at a temperature of 55-65℃ and a humidity of 60-70%. Fermentation was carried out on days N2+1 to N3 at a temperature of 35-45℃ and a humidity of 60-70%. Where N1 is selected from any integer from 4 to 8, N2 is selected from any integer from 18 to 22, and N3 is selected from any integer from 25 to 30; Preferably, during the fermentation process, the compost pile is turned over every 5-7 days.

4. The soil conditioner according to claim 1, characterized in that, The fermented livestock and poultry manure fertilizer is prepared by fermentation treatment using any one or at least two of the following raw materials: cow manure, sheep manure, or poultry manure. Preferably, the fermented livestock and poultry manure fertilizer is prepared by fermenting cow manure as raw material.

5. The soil conditioner according to claim 4, characterized in that, The fermentation process employs the following three-stage fermentation method: Fermentation was carried out on days 1 to N1 at a temperature of 40-50℃ and a humidity of 60-70%. Fermentation was carried out on days N1+1 to N2 at a temperature of 55-65℃ and a humidity of 60-70%. Fermentation was carried out on days N2+1 to N3 at a temperature of 35-45℃ and a humidity of 60-70%. Where N1 is selected from any integer from 4 to 8, N2 is selected from any integer from 18 to 22, and N3 is selected from any integer from 25 to 30; Preferably, during the fermentation process, the compost pile is turned over every 5-7 days.

6. The soil conditioner according to any one of claims 1-5, characterized in that, The fly ash contains lead ≤120 mg / kg, cadmium ≤0.3 mg / kg, mercury ≤2.4 mg / kg, arsenic ≤30 mg / kg, and chromium ≤200 mg / kg.

7. The soil conditioner according to any one of claims 1-6, characterized in that, The soil conditioner contains the following components: selenium content ≥ 0.4 mg / kg, lead content ≤ 120 mg / kg, cadmium content ≤ 0.3 mg / kg, mercury content ≤ 2.4 mg / kg, arsenic content ≤ 30 mg / kg, chromium content ≤ 200 mg / kg, organic matter content ≥ 1.4%, total nitrogen content ≥ 0.074%, available phosphorus content ≥ 3 mg / kg, available potassium content ≥ 33 mg / kg, pH value 5.5-8.5, moisture content ≤ 30%, and particle size ≤ 5 mm.

8. A method for improving soil nitrogen and phosphorus use efficiency and synergistically increasing crop yield through selenium enrichment, characterized in that, The method includes: applying the soil conditioner according to any one of claims 1-7 into the growth hole of the crop seedling using a hole application method, and thoroughly mixing it with the substrate soil in the growth hole.

9. The method according to claim 8, characterized in that, The application rate of the soil conditioner is 1.5-3.5 tons / mu, preferably 2.0-3.5 tons / mu.

10. The method according to claim 8, characterized in that, The crop includes corn or potatoes; Preferably, the soil is red soil.

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