Method for reducing ammonia volatilization of rice-duckweed system and increasing rice yield

Abstract

The invention discloses a method for reducing ammonia volatilization of a rice-duckweed system and increasing the rice yield, and belongs to the technical field of rice planting.The method comprises the following steps that S1, a rice field is prepared, base fertilizer is applied, rice seeds obtained after germination accelerating are evenly applied in the rice field, irrigation, intermittent supplementary irrigation and seedling raising are conducted; s2, preparing a rice seedling bed, applying a base fertilizer, uniformly spreading fresh duckweed in the rice seedling bed, irrigating, performing intermittent supplementary irrigation, and performing a survival test; s3, when the survival test succeeds, fresh duckweed is applied in a supplementary mode to be quantitative; s4, in a seedling stage, transplanting the rice seedlings into the rice seedling bed on which quantitative fresh duckweed is applied, and performing intermittent supplementary irrigation; s5, in the tillering stage, within five days after tillering is started, nitrogen fertilizer is applied, and intermittent supplementary irrigation is conducted; s6, intermittent supplementary irrigation is conducted in the jointing stage and the booting stage; s7, three days before the heading stage, nitrogen fertilizer is applied, and intermittent supplementary irrigation is conducted; s8, performing intermittent supplementary irrigation in a heading stage, a flowering stage, a filling stage and a mature stage until harvesting; the rice yield is increased while ammonia volatilization is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of rice cultivation, and specifically relates to a method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield. Background Art

[0003] People's demand for rice is increasing day by day. Stabilizing and increasing rice yield plays an irreplaceable and important role in meeting food demand and maintaining social stability and development.

[0004] During the rice cultivation process, in order to meet the nutrient requirements of rice growth and stabilize and increase rice yield, the application of nitrogen fertilizer is essential. However, under the current traditional rice cultivation mode, the unreasonable use of nitrogen fertilizer is widespread, which leads to serious ammonia volatilization problems. Ammonia volatilization refers to the process in which ammonium nitrogen in the soil is converted into ammonia gas under the action of microorganisms and volatilizes from the soil surface into the atmosphere. Ammonia volatilization not only causes serious waste of nitrogen resources, reduces the utilization rate of nitrogen fertilizer, increases agricultural production costs, but also ammonia gas returns to the ground and water bodies through wet and dry deposition, causing problems such as soil acidification and water eutrophication, destroying the ecological balance and affecting biodiversity.

[0005] In view of this, a method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield is designed to solve the above problems. Summary of the Invention

[0006] To solve the problems raised in the above background art, the present invention provides a method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield, which has the characteristics of reducing ammonia volatilization and increasing rice yield.

[0007] To achieve the above object, the present invention provides the following technical solution: A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield, comprising the following steps:

[0008] S1: Select a paddy field with flat terrain, fertile soil and convenient irrigation, prepare the field, apply basal fertilizer, evenly spread the germinated rice seeds in the paddy field, irrigate, intermittently supplement irrigation, and raise seedlings;

[0009] S2: Select a seedling nursery with flat terrain, fertile soil and convenient irrigation, prepare the field, apply basal fertilizer, evenly spread fresh duckweed in the seedling nursery, irrigate, intermittently supplement irrigation, and conduct a survival test;

[0010] S3: If the survival test is successful, supplement and spread fresh duckweed to a fixed amount;

[0011] S4: In the seedling stage, transplant the rice seedlings into the seedling nursery where a fixed amount of fresh duckweed has been spread, and intermittently supplement irrigation;

[0012] S5: In the tillering stage, apply nitrogen fertilizer within five days after tillering starts, and intermittently supplement irrigation;

[0013] S6: At the jointing stage and booting stage, intermittent supplementary irrigation is carried out.

[0014] S7: Three days before the heading stage, nitrogen fertilizer is applied and intermittent supplementary irrigation is carried out.

[0015] S8: At the heading stage, flowering stage, filling stage and maturity stage, intermittent supplementary irrigation is carried out until harvesting.

[0016] Furthermore, in the step S2, the base fertilizer includes nitrogen fertilizer, phosphate fertilizer and potassium fertilizer. Among them, the nitrogen fertilizer is urea, the phosphate fertilizer is superphosphate, and the potassium fertilizer is potassium chloride.

[0017] Furthermore, in the step S2, the application rate of nitrogen fertilizer is 135 kg / hm -2 in terms of N, the application rate of phosphate fertilizer is 65 kg / hm -2 in terms of P2O5, and the application rate of potassium fertilizer is 65 kg / hm -2 .

[0018] Furthermore, in the step S3, the application rate of fresh duckweed is 200 g / m -2 .

[0019] Furthermore, in the step S4, the transplanting density of rice seedlings is 300,000 holes / hm -2 .

[0020] Furthermore, in the step S4, fresh duckweed covers ≥ 80% of the area of the seedling field before the tillering stage.

[0021] Furthermore, in the step S5, the nitrogen fertilizer is urea, and the application rate of nitrogen fertilizer is 58 kg / hm -2 .

[0022] Furthermore, in the step S7, the nitrogen fertilizer is urea, and the ratio of the application rate of nitrogen fertilizer to the application rate of nitrogen fertilizer at the tillering stage is 7:3.

[0023] Furthermore, in the steps S1, S2, S4, S5, S6, S7 and S8, the intermittent supplementary irrigation is carried out when the soil moisture content of the seedling field drops to 90% of the saturated moisture content, and the irrigation is stopped until the water depth above the seedling field surface reaches 60 mm.

[0024] Furthermore, in the steps S1, S2, S4, S5, S6, S7 and S8, the intermittent supplementary irrigation is carried out by a drone carrying a sprinkler device to irrigate evenly back and forth above the seedling field.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. The present invention grows rice based on the rice-duckweed symbiotic system. A physical barrier can be formed between the duckweed and the rice seedlings, which can isolate the radiation of the sun to the seedling field, reduce the temperature of the seedling field, and at the same time can reduce gas exchange and the diffusion rate of ammonia, that is, reduce the occurrence of ammonia volatilization. Moreover, the duckweed can produce oxygen through photosynthesis, improve the reduction state of the soil in the seedling field, provide nutrients for rice production, and increase the rice yield.

[0027] 2. The present invention grows rice through intermittent irrigation, which can regulate the growth and decomposition of duckweed to achieve the effect of regulating the physical and chemical properties of the soil and the water on the surface of the seedling field, including reducing the ammonium nitrogen and pH of the water on the surface of the field, etc., achieving the effect of reducing ammonia volatilization loss, improving nitrogen fertilizer utilization rate and rice yield.

[0028] 3. When supplementary irrigation is carried out in the present invention, the drone is equipped with a sprinkler irrigation device to carry out supplementary irrigation from above the seedling field, which can simulate natural rainfall, so that the water is evenly sprinkled on the seedlings and the soil. It can not only make the seedlings gradually adapt to the increase in water content and will not be damaged due to sudden large amounts of accumulated water or water flow impact, but also helps to maintain the looseness and air permeability of the soil in the seedling field. At the same time, it can wash away the dust and impurities on the rice leaves, keep the leaves clean, which is beneficial to the physiological activities such as photosynthesis and respiration of the seedlings, promote the growth and development of the seedlings, and increase the rice yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is the flowchart of the method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] The present invention provides the following technical solutions: A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield, comprising the following steps:

[0032] S1: Select a paddy field with flat terrain, fertile soil and convenient irrigation, prepare the field, apply basal fertilizer, evenly spread the germinated rice seeds in the paddy field, irrigate, intermittently carry out supplementary irrigation, and raise seedlings;

[0033] S2: Select a seedling field with flat terrain, fertile soil and convenient irrigation, prepare the field, apply basal fertilizer, evenly spread fresh duckweed in the seedling field, irrigate, intermittently carry out supplementary irrigation, and conduct a survival test;

[0034] S3: If the survival test is successful, supplement and spread fresh duckweed to a fixed amount;

[0035] S4: At the seedling stage, transplant the rice seedlings into the paddy field where a certain amount of fresh duckweed has been spread, and conduct intermittent supplementary irrigation.

[0036] S5: At the tillering stage, apply nitrogen fertilizer within five days after tillering begins, and conduct intermittent supplementary irrigation.

[0037] S6: At the jointing stage and booting stage, conduct intermittent supplementary irrigation.

[0038] S7: Three days before the heading stage, apply nitrogen fertilizer, and conduct intermittent supplementary irrigation.

[0039] S8: At the heading stage, flowering stage, filling stage and maturity stage, conduct intermittent supplementary irrigation until harvesting.

[0040] Specifically, in step S2, the base fertilizer includes nitrogen fertilizer, phosphate fertilizer and potassium fertilizer. Among them, the nitrogen fertilizer is urea, the phosphate fertilizer is superphosphate, and the potassium fertilizer is potassium chloride.

[0041] Specifically, in step S2, the application rate of nitrogen fertilizer is 135 kg / hm -2 in terms of N, the application rate of phosphate fertilizer is 65 kg / hm -2 in terms of P2O5, and the application rate of potassium fertilizer is 65 kg / hm -2 .

[0042] Specifically, in step S3, the application amount of fresh duckweed is 200 g / m -2 .

[0043] Specifically, in step S4, the transplanting density of rice seedlings is 300,000 hills / hm -2 .

[0044] Specifically, in step S4, fresh duckweed covers ≧ 80% of the paddy field area before the tillering stage.

[0045] Specifically, in step S5, the nitrogen fertilizer is urea, and the application rate of nitrogen fertilizer is 58 kg / hm -2 .

[0046] Specifically, in step S7, the nitrogen fertilizer is urea, and the ratio of the application amount of nitrogen fertilizer to the application amount of nitrogen fertilizer at the tillering stage is 7:3.

[0047] Specifically, in steps S1, S2, S4, S5, S6, S7 and S8, the intermittent supplementary irrigation is carried out when the soil moisture content of the paddy field drops to 90% of the saturated moisture content, and stops until the water depth above the paddy field surface reaches 60 mm.

[0048] Specifically, in steps S1, S2, S4, S5, S6, S7 and S8, the intermittent supplementary irrigation is carried out by a drone equipped with a sprinkler device to evenly irrigate back and forth above the paddy field.

[0049] Example 1

[0050] A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield, comprising the following steps:

[0051] S1: Select a paddy field with flat terrain, fertile soil and convenient irrigation. Prepare the field and apply basal fertilizers, including nitrogen fertilizer, phosphate fertilizer and potassium fertilizer. Among them, the nitrogen fertilizer is urea, and the application rate is 135 kg hm -2 in terms of N, the phosphate fertilizer is superphosphate, and the application rate is 65 kg hm -2 in terms of P2O5, the potassium fertilizer is potassium chloride, and the application rate is 65 kg hm -2 in terms of K2O. Evenly spread the germinated rice seeds in the paddy field and irrigate. When the water content of the seedling field soil drops to 90% of the saturated water content, use a drone equipped with a sprinkler irrigation device to evenly irrigate back and forth above the seedling field until the water depth above the paddy field surface reaches 60 mm, and then stop and raise seedlings;

[0052] S2: Select a seedling field with flat terrain, fertile soil and convenient irrigation. Prepare the field and apply basal fertilizers, including nitrogen fertilizer, phosphate fertilizer and potassium fertilizer. Among them, the nitrogen fertilizer is urea, and the application rate is 135 kg hm -2 in terms of N, the phosphate fertilizer is superphosphate, and the application rate is 65 kg hm -2 in terms of P2O5, the potassium fertilizer is potassium chloride, and the application rate is 65 kg hm -2 in terms of K2O. Evenly spread fresh duckweed in the seedling field and irrigate. When the water content of the seedling field soil drops to 90% of the saturated water content, use a drone equipped with a sprinkler irrigation device to evenly irrigate back and forth above the seedling field until the water depth above the paddy field surface reaches 60 mm, and then stop and conduct a survival test;

[0053] S3: If the survival test is successful, supplement and spread fresh duckweed to 200 g m -2 ;

[0054] S4: In the seedling stage, transplant the rice seedlings into the seedling field with 200 g m -2 of fresh duckweed spread at a transplanting density of 300,000 holes hm -2 . When the water content of the seedling field soil drops to 90% of the saturated water content, use a drone equipped with a sprinkler irrigation device to evenly irrigate back and forth above the seedling field until the water depth above the paddy field surface reaches 60 mm, and then stop. Before the tillering stage, the fresh duckweed covers ≧ 80% of the seedling field area;

[0055] S5: In the tillering stage, apply nitrogen fertilizer within five days after the start of tillering. The nitrogen fertilizer is urea, and the application rate of the nitrogen fertilizer is 58 kg hm -2 in terms of N. When the water content of the seedling field soil drops to 90% of the saturated water content, use a drone equipped with a sprinkler irrigation device to evenly irrigate back and forth above the seedling field until the water depth above the paddy field surface reaches 60 mm, and then stop;

[0056] S6: At the jointing stage and booting stage, when the soil moisture content in the seedling field drops to 90% of the saturated moisture content, use the drone-mounted sprinkler irrigation equipment to evenly irrigate back and forth above the seedling field until the water depth above the seedling field surface reaches 60 mm and then stop;

[0057] S7: Three days before the heading stage, apply nitrogen fertilizer. The nitrogen fertilizer is urea, and the ratio of the nitrogen fertilizer application amount to the nitrogen fertilizer application amount at the tillering stage is 7:3. When the soil moisture content in the seedling field drops to 90% of the saturated moisture content, use the drone-mounted sprinkler irrigation equipment to evenly irrigate back and forth above the seedling field until the water depth above the seedling field surface reaches 60 mm and then stop;

[0058] S8: At the heading stage, flowering stage, filling stage and maturity stage, irrigate when the soil moisture content in the seedling field drops to 90% of the saturated moisture content until the water depth above the seedling field surface reaches 60 mm and then stop until harvesting.

[0059] Applying basal fertilizer includes nitrogen fertilizer, phosphate fertilizer and potassium fertilizer, denoted as N1, applying fresh duckweed, denoted as D1, irrigating when the soil moisture content in the seedling field drops to 90% of the saturated moisture content, denoted as W90, and drone supplementary irrigation, denoted as U1.

[0060] Example Two

[0061] The difference between this example and Example One is:

[0062] Intermittent supplementary irrigation is to irrigate when the soil moisture content drops to 80% of the saturated moisture content and stop when the water depth above the field surface reaches 60 mm, denoted as W80.

[0063] Example Three

[0064] The difference between this example and Example One is:

[0065] Intermittent supplementary irrigation is to irrigate when the soil moisture content drops to 70% of the saturated moisture content and stop when the water depth above the field surface reaches 60 mm, denoted as W70.

[0066] Example Four

[0067] The difference between this example and Example One is:

[0068] Conventional flooding irrigation, denoted as W0.

[0069] Example Five

[0070] The difference between this example and Example One is:

[0071] The basal fertilizer includes phosphate fertilizer and potassium fertilizer. The phosphate fertilizer is superphosphate, and the application amount is 65 kg hm -2 , and the potassium fertilizer is potassium chloride, and the application amount is 65 kg hm -2, denoted as N0.

[0072] Example Six

[0073] The difference between this example and Example One is that:

[0074] No fresh duckweed is spread in the seedling field, denoted as D0.

[0075] Example Seven

[0076] The difference between this example and Example Five is that:

[0077] No fresh duckweed is spread in the seedling field, denoted as D0.

[0078] Example Eight

[0079] The difference between this example and Example Two is that:

[0080] No fresh duckweed is spread in the seedling field, denoted as D0.

[0081] Example Nine

[0082] The difference between this example and Example Three is that:

[0083] No fresh duckweed is spread in the seedling field, denoted as D0.

[0084] Example Ten

[0085] The difference between this example and Example Four is that:

[0086] No fresh duckweed is spread in the seedling field, denoted as D0.

[0087] Example Eleven

[0088] The difference between this example and Example Four is that:

[0089] The base fertilizer includes phosphate fertilizer and potassium fertilizer. The phosphate fertilizer is superphosphate, and the application rate is 65 kg hm based on P2O5 -2 , and the potassium fertilizer is potassium chloride, and the application rate is 65 kg hm based on K2O -2 , denoted as N0.

[0090] Example Twelve

[0091] The difference between this example and Example Ten is that:

[0092] The base fertilizer includes phosphate fertilizer and potassium fertilizer. The phosphate fertilizer is superphosphate, and the application rate is 65 kg hm based on P2O5 -2 , and the potassium fertilizer is potassium chloride, and the application rate is 65 kg hm based on K2O -2 , denoted as N0.

[0093] Example Thirteen

[0094] The difference between this embodiment and the first embodiment is as follows:

[0095] Conventional irrigation, denoted as U0.

[0096] The test results of the embodiment are as follows:

[0097]

[0098]

[0099] As can be seen from the above table: Under the W90D1N1U1 treatment, that is, after field preparation, 200 g m -2 of fresh duckweed is put into the paddy field, and 193 kg hm-2 of nitrogen fertilizer is applied (135 kg hm -2 is applied at the basal fertilizer stage and 58 kg hm -2 ) is applied at the tillering stage, 65 kg hm -2 of phosphate fertilizer and 65 kg hm -2 of potassium fertilizer. When the soil moisture content drops to 90% of the saturated moisture content, the unmanned aerial vehicle is equipped with a sprinkler irrigation device for irrigation until the water depth above the field surface reaches 60 mm and then stops. The rice yield is the highest and the ammonia volatilization loss is the lowest.

[0100] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield, characterized in that, It includes the following steps: S1: Select a paddy field with flat terrain, fertile soil and convenient irrigation. Till the field, apply basal fertilizer, evenly spread the germinated rice seeds in the paddy field, irrigate, conduct intermittent supplementary irrigation, and raise seedlings; S2: Select a seedling nursery with flat terrain, fertile soil and convenient irrigation. Till the nursery, apply basal fertilizer, evenly spread fresh duckweed in the nursery, irrigate, conduct intermittent supplementary irrigation, and conduct a survival test; S3: If the survival test is successful, supplement and spread fresh duckweed to a fixed quantity; S4: In the seedling stage, transplant the rice seedlings into the nursery where a fixed quantity of fresh duckweed has been spread, and conduct intermittent supplementary irrigation; S5: In the tillering stage, apply nitrogen fertilizer within five days after tillering begins, and conduct intermittent supplementary irrigation; S6: In the jointing stage and booting stage, conduct intermittent supplementary irrigation; S7: Three days before the heading stage, apply nitrogen fertilizer, and conduct intermittent supplementary irrigation; S8: In the heading stage, flowering stage, filling stage and maturity stage, conduct intermittent supplementary irrigation until harvesting.

2. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In step S2, the basal fertilizer includes nitrogen fertilizer, phosphate fertilizer and potassium fertilizer. Among them, the nitrogen fertilizer is urea, the phosphate fertilizer is superphosphate, and the potassium fertilizer is potassium chloride.

3. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In the step S2, the application rate of nitrogen fertilizer is 135 kg / hm in terms of N -2 , the application rate of phosphate fertilizer is 65 kg / hm in terms of P2O5 -2 , the application rate of potassium fertilizer is 65 kg / hm in terms of K2O -2 .

4. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In the step S3, the application rate of fresh duckweed is 200 g / m -2 .

5. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In the step S4, the transplanting density of rice seedlings is 300,000 hills per hectare -2 .

6. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In step S4, the fresh duckweed covers ≧ 80% of the area of the nursery before the tillering stage.

7. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In step S5, the nitrogen fertilizer is urea, and the application rate of the nitrogen fertilizer is 58 kg hm in terms of N -2 .

8. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In step S7, the nitrogen fertilizer is urea, and the ratio of the application amount of nitrogen fertilizer to that in the tillering stage is 7:

3.

9. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In steps S1, S2, S4, S5, S6, S7 and S8, the intermittent supplementary irrigation is carried out when the soil moisture content of the nursery drops to 90% of the saturated moisture content, and stops until the water depth above the nursery surface reaches 60 mm.

10. A method for reducing ammonia volatilization in a rice-duckweed system and increasing rice yield according to claim 1, characterized in that: In steps S1, S2, S4, S5, S6, S7 and S8, the intermittent supplementary irrigation is carried out by a drone carrying a sprinkler device to evenly irrigate back and forth above the nursery.

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