A cultivation method for synergistically reducing methane emission and cadmium content in rice

Abstract

The present application relates to the rice cultivation technical field, specifically relates to a kind of rice field methane emission reduction and rice reduction cadmium synergic cultivation method.The rice field cultivation method of the present application includes the steps such as base fertilizer, water management, the base fertilizer includes ammonium sulfate and calcium magnesium phosphate fertilizer, the mass ratio of ammonium sulfate and calcium magnesium phosphate fertilizer is 1:(1.5-2), ammonium sulfate and calcium magnesium phosphate fertilizer are respectively applied into rice field in turn;The water management includes shallow irrigation and shallow irrigation after rice transplanting to milk maturity period.By the method that ammonium sulfate, calcium magnesium phosphate fertilizer is separately applied into rice field according to proper proportion, then cooperate with the method of stage control water flooding, the soil acidification caused by long-term application of ammonium sulfate and the fertilizer efficiency reduction caused by acid-base neutralization reaction are avoided in early growth period of rice, the growth and yield of rice are guaranteed, rice field methane emission and rice cadmium content are significantly reduced, and the population structure of soil microorganism is improved, the synergic effect of rice field methane emission reduction and rice reduction cadmium is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rice cultivation, and particularly relates to a cultivation method for reducing methane emission and reducing cadmium content in rice simultaneously. BACKGROUND

[0002] Rice is the first staple crop in China, and more than two-thirds of the population in China take rice as their main food. The stable yield of rice is directly related to the national economy and people's livelihood. Global warming has become an indisputable fact, and the main reason is the increase of greenhouse gas concentration in the atmosphere. Methane (CH4) is the second largest global greenhouse gas after carbon dioxide (CO2), and rice field is one of the most important anthropogenic CH4 emission sources, accounting for 10-13% of global anthropogenic CH4 emission. It is of great significance to realize methane emission reduction in rice field for mitigating global warming. According to the 2014 National Soil Pollution Status Survey Bulletin, cadmium (Cd) is the first among the eight inorganic pollutants, and it is easily absorbed and enriched by rice, and accumulated in the human body through the food chain. Long-term and large intake of rice with excessive cadmium will affect the metabolism of calcium and phosphorus in the human body, thereby causing diseases such as osteoporosis, osteomalacia and kidney stones, and seriously endangering people's health.

[0003] Conventional high-yield cultivation usually adopts the water management mode of "returning green with an inch of water, shallow water tillering, sufficient seedlings for field drying, heading and flowering with water, and dry and wet for seed setting". Current studies show that the pre-drying field flooding during the tillering stage of rice will significantly increase the methane emission in rice field, and the dry-wet alternate irrigation after the heading stage of rice will cause the cadmium enrichment in rice grains. How to economically and effectively reduce the methane emission in rice field and the cadmium content in rice is a problem that needs to be solved in current production.

[0004] Ammonium sulfate is a high-quality nitrogen fertilizer, and its aqueous solution is acidic with a pH value of 5.5, belonging to physiological acid fertilizer, which is suitable for various soils and crops. Current studies show that the application of ammonium sulfate in rice field can increase the number of sulfate-reducing bacteria in the soil of rice field, and the sulfate-reducing bacteria and the methane-producing bacteria need to compete for the same substrate during growth and reproduction, thereby reducing the concentration of substrate required by the methane-producing bacteria, and further significantly reducing the methane emission in rice field. However, due to the general acidification of soil in southern rice-growing areas, long-term application of ammonium sulfate will cause the decrease of soil pH, and the decrease of pH will significantly increase the content of effective cadmium in the soil, thereby aggravating the cadmium pollution in rice.

[0005] Calcium-magnesium phosphate fertilizer is a multi-element fertilizer, and its aqueous solution is alkaline with a pH value of 8-8.5, belonging to physiological alkaline fertilizer, which can improve acid soil. Therefore, the application of physiological alkaline fertilizer can avoid soil acidification, but if the physiological acid and alkaline fertilizers are mixed and applied directly, it will cause acid-base neutralization reaction, thereby reducing the fertilizer efficiency.

[0006] Under the condition of waterlogging, the application of fertilizer containing sulfate ions can increase the abundance of sulfate-reducing bacteria in soil, thereby promoting the conversion of CdSO4 in soil into CdS with low solubility, so as to reduce the cadmium content in rice.

[0007] Sulfate-reducing bacteria are strict anaerobes. Although the application of ammonium sulfate under the condition of conventional high-yield cultivation can reduce the emission of methane in rice fields, the irrigation mode of dry-wet alternation after the heading stage will destroy the growth environment of sulfate-reducing bacteria and reduce the gene copy number of sulfate-reducing bacteria, thereby increasing the cadmium content in rice. Therefore, the application of ammonium sulfate alone in rice fields cannot achieve the synergy of reducing methane emission and reducing cadmium in rice.

[0008] At present, a few studies have mixed ammonium sulfate with other fertilizers to prepare a compound fertilizer for reducing methane emission in rice fields, but the problem of soil acidification caused by long-term application of ammonium sulfate and the increase of production cost cannot be avoided. In addition, the application effect of ammonium sulfate in reducing cadmium in rice has not been reported.

[0009] Therefore, the present application is proposed. SUMMARY

[0010] To solve the above technical problems, the present application provides a cultivation method for achieving the synergy of reducing methane emission and reducing cadmium in rice, which comprises the steps of applying base fertilizer and water management. The base fertilizer comprises ammonium sulfate and calcium-magnesium phosphate fertilizer, and the mass ratio of ammonium sulfate to calcium-magnesium phosphate fertilizer is 1:(1.5-2). The ammonium sulfate and calcium-magnesium phosphate fertilizer are applied into the rice field in sequence.

[0011] Specifically, the technical scheme of the present application is as follows:

[0012] The present application provides a cultivation method for achieving the synergy of reducing methane emission and reducing cadmium in rice, which comprises the step of applying base fertilizer. The base fertilizer comprises ammonium sulfate and calcium-magnesium phosphate fertilizer, and the mass ratio of ammonium sulfate to calcium-magnesium phosphate fertilizer is 1:(1.5-2). The ammonium sulfate and calcium-magnesium phosphate fertilizer are applied into the rice field in sequence.

[0013] The use of ammonium sulfate as a nitrogen source can achieve the reduction of methane emission in rice fields, but it can easily lead to a decrease in soil pH, thereby significantly aggravating cadmium pollution in rice. The use of ammonium sulfate as a nitrogen source, while applying a physiological alkaline fertilizer, can avoid soil acidification, but it can cause acid-base neutralization reaction, thereby reducing the fertilizer efficiency.

[0014] The present application discloses a method for reducing methane emission and cadmium content in rice simultaneously, which comprises the following steps: applying ammonium sulfate and calcium magnesium phosphate in a mass ratio of 1:(1.5-2) as base fertilizer in a rice field, and then applying water at a specific growth period of rice.

[0015] In the present application, the mass ratio of ammonium sulfate and calcium magnesium phosphate is 1:(1.5-2), preferably 1:2.

[0016] The present application does not particularly limit the specific source of ammonium sulfate and calcium magnesium phosphate, and the conventional commercially available products in the art can be used.

[0017] In the present application, ammonium sulfate and calcium magnesium phosphate are applied in the rice field in turn.

[0018] Preferably, the application of base fertilizer comprises the following steps: applying ammonium sulfate in the rice field, mixing ammonium sulfate with the soil in the 0-20cm plough layer, and then applying calcium magnesium phosphate in the rice field. The present application does not particularly require specific mechanical equipment for the mixing, and the conventional equipment for ploughing in the art such as rotary cultivator can be used.

[0019] Further, the rice cultivation method of the present application preferably further comprises the step of applying topdressing.

[0020] In order to obtain better fertilizer effect, in the present application, the total application amount of nitrogen fertilizer in base fertilizer and topdressing is preferably 10-15kg / acre, more preferably 10kg / acre, in terms of effective content of N.

[0021] The total application amount of phosphorus fertilizer in base fertilizer and topdressing is preferably 6-8kg / acre, more preferably 6kg / acre, in terms of effective content of P2O5.

[0022] The total application amount of potassium fertilizer in base fertilizer and topdressing is preferably 8-10kg / acre, more preferably 8kg / acre, in terms of effective content of K2O.

[0023] More preferably, the topdressing comprises tillering fertilizer and ear fertilizer.

[0024] Among them, the mass ratio of nitrogen fertilizer in base fertilizer, tillering fertilizer and ear fertilizer is 5:(2-3):(2-3), preferably 5:3:2, in terms of effective content of N.

[0025] Phosphorus fertilizer is applied as base fertilizer at one time.

[0026] Potassium fertilizer is applied in base fertilizer and tillering fertilizer; the mass ratio of potassium fertilizer in base fertilizer and tillering fertilizer is (5-6):(4-5), preferably 5:5, in terms of effective content of K2O.

[0027] Further, the nitrogen fertilizer in the base fertilizer is preferably ammonium sulfate, and the nitrogen fertilizer in the topdressing is preferably urea; the phosphorus fertilizer is preferably calcium magnesium phosphate; and the potassium fertilizer is preferably potassium chloride.

[0028] Further, in the preferred embodiment of the present application, the base fertilizer is applied 1-2 days before transplanting; the tillering fertilizer is applied 7-10 days after transplanting; and the ear fertilizer is applied in the 3rd-5th stage of young ear differentiation.

[0029] In the more preferred specific embodiment provided by the present application, the base fertilizer is applied 1 day before transplanting; the tillering fertilizer is applied 7 days after transplanting; and the ear fertilizer is applied in the 3rd stage of young ear differentiation.

[0030] The transplanting time is 25-30 days after rice seeding.

[0031] In the more preferred specific embodiment provided by the present application, the transplanting time is 25 days after rice seeding.

[0032] The preferred base fertilizer and topdressing types, application ratio and fertilization period can obtain better fertilizer efficiency, and significantly improve the soil pH at the heading stage of rice, reduce the cadmium content in rice, and significantly reduce the methane emission in the rice field.

[0033] The present application does not particularly limit the specific source of the nitrogen fertilizer, the tillering fertilizer and the ear fertilizer, and any conventional commercially available source can be used.

[0034] Preferably, the rice field cultivation method of the present application further comprises a water management step, which specifically comprises:

[0035] Submerged irrigation is performed from after transplanting to the tillering stage, and a water layer of 3-5 cm is maintained in the field.

[0036] Shallow water irrigation is performed from the booting stage to the milk stage, and a water layer of 2-3 cm is maintained in the field.

[0037] The present application can better avoid soil acidification caused by long-term application of ammonium sulfate and the reduction of fertilizer efficiency caused by acid-base neutralization reaction by separately applying ammonium sulfate and calcium magnesium phosphate into the rice field in appropriate proportions, and further helps to improve the population structure of soil microorganisms, thereby achieving the synergistic effect of reducing methane emission in the rice field and reducing cadmium in rice.

[0038] More preferably, the water management step further comprises:

[0039] The field is dried when the basic seedlings reach 80% of the planned effective ear number at the peak tillering stage, or less or not dried if the population does not reach the expected value. Drainage and drying are performed in the maturation period.

[0040] In a more specific embodiment provided by the present application, the rice field cultivation method provided by the present application preferably performs mechanical rotary tillage before sowing, the tillage depth is preferably 15-20 cm, more preferably 20 cm; the variety is preferably indica hybrid late rice; the transplanting time is preferably in the middle and late of July; the plant spacing is preferably 11-15 cm x 20-30 cm, more preferably 13.3 cm x 23.3 cm; the harvesting time is preferably in the middle and late of October; the tillering stage preferably sprays bispyribac-sodium and dimethomorph to prevent weeds; the tillering stage and the breaking stage preferably sprays emamectin benzoate and pymetrozine to control pests and diseases. The above cultivation and management mode can obtain good rice field cultivation effect, the methane emission of the rice field is lower, and the cadmium content in the rice is lower.

[0041] Beneficial effects:

[0042] The present application provides a rice field methane emission reduction and rice cadmium reduction synergistic cultivation method, by separately applying ammonium sulfate and calcium magnesium phosphate fertilizer into the rice field in the base fertilizer, and combining with the method of stage control water flooding, the soil acidification caused by long-term application of ammonium sulfate in the early growth stage of rice and the reduction of fertilizer efficiency caused by acid-base neutralization reaction are avoided, at the same time, the shallow water flooding in the late growth stage of rice not only ensures the strict anaerobic environment, but also is beneficial to improve the population structure of soil microorganisms, realizing the synergistic effect of rice field methane emission reduction and rice cadmium reduction. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the present application or prior art, the drawings needed to be used in the embodiments or prior art description will be described below.

[0044] Figure 1 The difference comparison results of the methane emission flux of the rice field between different treatments of the present application.

[0045] Figure 2 The difference comparison results of the cumulative methane emission of the rice field between different treatments. DETAILED DESCRIPTION

[0046] The present application relates to a rice field methane emission reduction and rice cadmium reduction synergistic cultivation method.

[0047] In a more specific embodiment provided by the present application, the method comprises the following steps: deep application of ammonium sulfate in base fertilizer; base fertilizer is applied with calcium magnesium phosphate fertilizer; water flooding irrigation is adopted; and other conventional high-yield cultivation measures are combined.

[0048] More specifically, the method comprises:

[0049] Deep application of ammonium sulfate in base fertilizer: the nitrogen fertilizer in the base fertilizer is ammonium sulfate, and the application method is to apply ammonium sulfate into the rice field and mix uniformly.

[0050] Base fertilizer with calcium magnesium phosphate: the phosphorus fertilizer in the base fertilizer is calcium magnesium phosphate, and the application method is that the calcium magnesium phosphate and the ammonium sulfate are separately applied into the rice field according to a proper proportion.

[0051] Stage control water flooding irrigation: after the application of the ammonium sulfate, water flooding irrigation is carried out according to the growth period of the rice by setting different water layers.

[0052] Other conventional high-yield cultivation measures: including tillage mode, variety selection, transplanting time, plant spacing, disease and pest control, harvesting period, etc.

[0053] In a more specific preferred embodiment provided by the application, the rice field cultivation method comprises the following steps:

[0054] (1) applying ammonium sulfate and calcium magnesium phosphate as base fertilizer

[0055] Fertilizer types: ammonium sulfate and urea are applied as nitrogen fertilizer, calcium magnesium phosphate is applied as phosphorus fertilizer, and potassium chloride is applied as potassium fertilizer.

[0056] Application method: ammonium sulfate, calcium magnesium phosphate and potassium chloride are separately applied into the rice field when base fertilizer is applied; urea and potassium chloride are mixed and applied into the rice field when topdressing is applied.

[0057] Application time: base fertilizer is applied one day before transplanting; tillering fertilizer is applied seven days after transplanting; ear fertilizer is applied in the third stage of young ear differentiation.

[0058] Application amount: N 10 kg / acre, P2O5 6 kg / acre and K2O 8 kg / acre are applied.

[0059] Application proportion: nitrogen fertilizer is applied according to base fertilizer:tillering fertilizer:ear fertilizer=5:3:2, potassium fertilizer is applied according to base fertilizer:tillering fertilizer=5:5, phosphorus fertilizer is applied as base fertilizer at one time; base fertilizer is applied according to ammonium sulfate:calcium magnesium phosphate=1:2.

[0060] (2) water flooding irrigation

[0061] From the application of ammonium sulfate to the tillering period: water flooding irrigation is carried out, and a water layer of 3-5 cm is kept in the field; during the tillering peak period: the field is dried when the basic seedlings reach 80% of the planned effective ear number, and the field is less dried or not dried when the population does not reach the expectation; from the booting period to the milk ripening period: shallow water irrigation is carried out, and a water layer of 2-3 cm is kept in the field; during the maturation period: the water is drained in advance to dry.

[0062] (3) other conventional high-yield cultivation measures

[0063] The tillage method is machine rotary tillage, the tillage depth is 15-20 cm; the variety selection is high-yield and high-quality indica hybrid late rice; the transplanting time is in the middle and late of July; the plant spacing is 13.3 cm*23.3 cm; the disease, pest and weed control is to spray isoproturon and 2-methylthio-dimethylammonium salt to prevent weeds in the tillering stage, and to spray emamectin benzoate and pymetrozine to prevent diseases and pests in the tillering stage and the breaking stage; the harvesting period is in the middle and late of October.

[0064] The technical solutions provided by the present application are described in detail below in combination with examples, but they cannot be understood as limitations to the protection scope of the present application. If not specifically indicated, the experimental methods used in the examples are conventional methods; the materials, reagents and the like used can be obtained from commercial channels.

[0065] Example 1

[0066] The comparative test of the example was carried out in Xicun Town, Yuanzhou District, Yichun City, Jiangxi Province from June to November 2022, the total cadmium content of the background soil of the test site was 0.89 mg / kg, and the available cadmium content was 0.52 mg / kg.

[0067] Cell setting: the test cell area is 30 m 2 (6 m*5 m), three times of repetition.

[0068] Preparation before sowing: the paddy field is ploughed flat by machine rotary tillage, and the ridge is erected around the cell after the mud sinks, the height of the ridge is 30 cm, the width is 30 cm, and the ridge is covered with film.

[0069] Variety selection: the test variety is hybrid late rice variety Yexiangyoufenzhan, which has the characteristics of strong tillering ability, high yield, excellent rice quality and the like.

[0070] Transplanting and harvesting time: the late rice is sowed on June 25, transplanted on July 25, and harvested on October 20.

[0071] Plant spacing: the plant spacing of transplanting is 13.3 cm*23.3 cm, and 2 seedlings are transplanted in each hole.

[0072] Fertilizer types: the nitrogen fertilizer is applied with ammonium sulfate and urea (ammonium sulfate is applied as base fertilizer, and urea is applied as topdressing), the phosphorus fertilizer is applied with calcium magnesium phosphate, and the potassium fertilizer is applied with potassium chloride.

[0073] Fertilizer amount: N 10 kg / acre, P2O5 6 kg / acre, and K2O 8 kg / acre are applied.

[0074] Application time: the base fertilizer is applied one day before transplanting; the tillering fertilizer is applied 7 days after transplanting; the ear fertilizer is applied in the third stage of young ear differentiation.

[0075] Application ratio: nitrogen fertilizer is applied as base fertilizer: tillering fertilizer: earing fertilizer = 5:3:2; potassium fertilizer is applied as base fertilizer: tillering fertilizer = 5:5; phosphorus fertilizer is applied as base fertilizer once. Base fertilizer is applied as ammonium sulfate: calcium magnesium phosphate fertilizer = 1:2.

[0076] Application method: ammonium sulfate is applied separately from calcium magnesium phosphate fertilizer and potassium chloride into the paddy field when base fertilizer is applied, and the soil and fertilizer are mixed uniformly after application; urea and potassium chloride are mixed and applied into the paddy field when topdressing is applied.

[0077] Water management: flood irrigation is carried out from base fertilizer application to tillering stage, and 3-5 cm water layer is maintained in the field; the field is dried when the basic tiller number of rice reaches 80% of the planned effective panicle number during the peak tillering stage; shallow irrigation is carried out from the booting stage to the milk stage, and 2-3 cm water layer is maintained in the field; and the field is drained and dried at the mature stage. Single irrigation and single row are adopted for irrigation to prevent water and fertilizer from leaking.

[0078] Comparative example 1

[0079] Conventional high-yield cultivation treatment (control):

[0080] Except that urea is used as base fertilizer, other management measures are consistent with example 1.

[0081] Comparative example 2

[0082] Iron sulfate treatment:

[0083] Except that iron sulfate is used to replace ammonium sulfate, in order to maintain the consistency of the nitrogen content of base fertilizer, urea is applied as base fertilizer, and other management measures are consistent with example 1.

[0084] The results of each test are as follows (comparative example 1 is represented by "control", comparative example 2 is represented by "iron sulfate", and example 1 is represented by "ammonium sulfate"):

[0085] Table 1 Difference comparison of soil pH at peak tillering stage and heading stage of rice among different treatments (t / hm 2 )

[0086] Treatment Tillering peak Heading stage Control 5.81±0.34a 4.26±0.28b Ferric sulfate 5.68±0.25a 4.70±0.08a Ammonium sulfate 5.55±0.14a 4.61±0.02a

[0087] Table 2 Difference comparison of aboveground dry matter accumulation of rice at each growth stage among different treatments (t / hm 2 )

[0088] Treatment Tillering peak Heading stage Control Ferric sulfate Ammonium sulfate 1.03±0.23a 4.41±0.61a 10.51±0.61a 9.49±1.45a Treatment 1.01±0.15a 3.46±1.09a 9.60±1.48a 9.63±1.70a Tillering peak 1.09±0.23a 4.89±1.12a 11.46±1.63a 9.72±1.89a

[0089] Table 3 Difference comparison of yield and its constituent factors of rice among different treatments

[0090]

[0091] Table 4 Difference comparison of soil redox potential in paddy field among different treatments (mV)

[0092] Heading stage Control Ferric sulfate Ammonium sulfate -83.32±6.73b -50.28±6.28b Treatment -49.82±8.48a -30.68±7.79a Control -58.70±4.52a -45.58±5.39b

[0093] Table 5 Comparison of soil microbial gene copy number difference between different treatments

[0094] Ferric sulfate Methane-producing bacteria (10 8 / g)]]> Methanotrophic bacteria (10 8 / g)]]> Sulfate-reducing bacteria (10 8 / g)]]> Ammonium sulfate 6.12±0.51a 3.35±0.22b 1.5±0.09b Treatment 5.64±0.79a 4.33±0.29a 2.45±0.15a Rice cadmium content (mg / kg) 5.36±0.92a 3.88±0.23a 2.33±0.29a

[0095] Table 6 Comparison of rice cadmium content difference between different treatments

[0096] Control Ferric sulfate Ammonium sulfate 1.08±0.10a Figure 1 0.88±0.02b Figure 1 0.76±0.11b

[0097] Note: In the above tables, the same column of different small letters after the number indicates significant difference (P <0.05) between treatments.

[0098] Table 1 shows that compared with the conventional control, ammonium sulfate treatment significantly increased the soil pH at the filling stage by 8.22%.

[0099] Table 2 shows that there is no significant difference in dry matter accumulation of aboveground parts of rice at different growth stages between different treatments.

[0100] Table 3 shows that there is no significant difference in yield and yield component factors of rice between different treatments.

[0101] Table 4 shows that compared with the conventional control, ammonium sulfate treatment significantly increased the soil redox potential at the tillering stage and the heading stage by 40.21% and 38.99%, respectively.

[0102] Table 5 shows that compared with the conventional control, ammonium sulfate treatment has a decreasing trend in soil methane-producing bacteria, but the difference is not significant; ammonium sulfate treatment significantly increased the gene copy number of methanotrophic bacteria and sulfate-reducing bacteria at the tillering stage by 15.82% and 55.33%, respectively.

[0103] Table 6 shows that compared with the conventional control, ammonium sulfate treatment can significantly reduce the cadmium content in rice by 29.63%.

[0104] Figure 2 Comparison of methane emission flux difference between different treatments in rice field.

[0105] From Figure 2 It can be seen that compared with the conventional control, ammonium sulfate treatment significantly reduces the methane emission flux in rice field. The methane emission flux of the control treatment in the whole growth period of rice shows a "double peak type", reaching a maximum peak of 26.38 mg / m 2 / h on August 3; the ammonium sulfate treatment shows a "single peak type" in the whole growth period of rice, reaching a maximum peak of 12.79 mg / m 2 / h on August 8.

[0106] ​ Comparison of methane cumulative emission amount difference between different treatments in rice field.

[0107] By ​ It can be seen that, compared with the conventional control, the ammonium sulfate treatment significantly reduces the cumulative methane emission by 56.68%.

[0108] In summary, the ammonium sulfate treatment can guarantee the growth and yield of rice, significantly increase the soil pH and redox potential, significantly inhibit the growth of methane-producing bacteria, significantly promote the growth of methane-oxidizing bacteria and sulfate-reducing bacteria, significantly reduce the methane emission flux, cumulative methane emission and cadmium content of rice, and achieve the synergy of methane emission reduction in paddy fields and cadmium reduction in rice.

[0109] The above-described embodiments only express several embodiments of the present application, facilitate specific and detailed understanding of the technical solutions of the present application, but cannot be understood as a limitation on the patent protection scope of the invention. It should be noted that, for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application.

Claims

1. A rice field methane emission reduction and rice cadmium reduction synergistic cultivation method comprising a base fertilizer application step and a water management step, characterized in that, The base fertilizer comprises ammonium sulfate and calcium magnesium phosphate, and the mass ratio of the ammonium sulfate to the calcium magnesium phosphate is 1:(1.5-2); the ammonium sulfate is applied into the paddy field first, then the ammonium sulfate is mixed with the soil in the 0-20 cm plough layer, and then the calcium magnesium phosphate is applied into the paddy field. The water management step comprises: flooding irrigation from after transplanting to tillering stage, and keeping 3-5 cm water layer in the field; and / or, shallow water irrigation from booting stage to milk stage, and keeping 2-3 cm water layer in the field.

2. The method of claim 1, wherein, The method further comprises a topdressing step; the total application amount of nitrogen fertilizer in the base fertilizer and the topdressing is 10-15 kg / mu in terms of the effective content of N; and / or, the total application amount of phosphorus fertilizer in the base fertilizer and the topdressing is 6-8 kg / mu in terms of the effective content of P2O5; and / or, the total application amount of potassium fertilizer in the base fertilizer and the topdressing is 8-10 kg / mu in terms of the effective content of K2O.

3. The method of claim 2, wherein, The topdressing comprises tillering fertilizer and ear fertilizer; the mass ratio of the base fertilizer, the tillering fertilizer and the ear fertilizer is 5:(2-3):(2-3) in terms of the effective content of N; and / or, the phosphorus fertilizer is applied in one time as the base fertilizer; and / or, the potassium fertilizer is applied in the base fertilizer and the tillering fertilizer; the mass ratio of the base fertilizer to the tillering fertilizer is (5-6):(4-5) in terms of the effective content of K2O.

4. The method of claim 3, wherein, The base fertilizer is applied 1-2 days before transplanting; and / or, the tillering fertilizer is applied 7-10 days after transplanting; and / or, the ear fertilizer is applied in the 3rd-5th stage of young ear differentiation.

5. The method of claim 4, wherein, The nitrogen fertilizer in the base fertilizer is ammonium sulfate, and the nitrogen fertilizer in the topdressing is urea; and / or, the phosphorus fertilizer is calcium magnesium phosphate; and / or, the potassium fertilizer is potassium chloride.

6. The method of claim 5, wherein, Mechanical rotary tillage is performed before sowing, and the tillage depth is 15-20 cm.

7. The method of claim 6, wherein, The variety is selected from indica hybrid late rice; the transplanting time is in the middle and late of July; and / or, the plant spacing is 11-15 cm x 20-30 cm; and / or, the harvesting time is in the middle and late of October.

8. The method according to any one of claims 1 to 7, characterized in that, Bifenox and dimethomorph are sprayed in the tillering stage; and / or, emamectin benzoate and pymetrozine are sprayed in the tillering stage and the breaking stage.

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