CN110881373A - Two-season dry farming cultivation technical method for ratoon rice system - Google Patents

Abstract

The invention relates to a two-season dry farming technology method for a regenerated rice system, comprising: sowing regenerated rice seeds; water management; making the paddy field anhydrous at the stage of emergence and seedling establishment, and keeping the soil moisture content at more than 80 percent ; After the tillering stage, it is mainly rain-fed. When the leaves are obviously curled, the soil water content can be kept above 80% by one irrigation. In the booting stage, heading stage and grain-filling stage, rain-fed, when the leaves are obviously curled, continue to irrigate once to make the field moist. And keep soil moisture content above 80%; first season rice harvest: water management in regeneration season. Compared with the one-season rice dry farming and the conventional cultivation methods of early and late rice, the invention has the advantages that the stubble of the two seasons are closely connected, saves time and effort, improves the utilization efficiency of land and light and temperature resources, and increases the benefit output in agricultural production. Compared with the conventional regenerative rice cultivation mode, the invention adopts a reasonable water management method in two seasons, greatly reduces the input of irrigation water and artificial input, and significantly reduces the cost input in agricultural production.

Description

A two-season dry farming technology method for regenerative rice system

technical field

The invention relates to the technical field of a regenerated rice system, in particular to a two-season dry farming technical method for a regenerated rice system.

Background technique

Rice is one of the main food crops in my country, with a wide planting area, but there are many challenges in rice production; To further improve; in view of these outstanding problems in agricultural production, it is necessary to develop a light, economical and efficient rice water-saving cultivation mode to improve agricultural production efficiency, which is necessary to increase the attractiveness of agricultural production and carry out sustainable agricultural development.

In recent years, the economic and market potential of regenerative rice (regenerative rice is of high quality and low production input) has been gradually discovered; in addition, the application of regenerative rice cultivation mode is expanding year by year in some areas with two crops a year. However, in the regenerative rice cultivation mode, if two seasons of dry farming are realized, combining the advantages of the upland rice cultivation mode and the regenerative rice cultivation mode will further improve the comprehensive benefit of the rice dry cultivation mode. Therefore, on the basis of the theoretical system of rice dry farming and regenerative rice cultivation technology, the advantages and characteristics of the conventional flood irrigation and rice dry farming technology theoretical systems in the regenerative rice cultivation mode were compared and analyzed, and the two-season dry farming technology of the regenerative rice system was optimized. The new water management technology can solve the relationship between water saving, high yield and high efficiency in the process of rice dry farming, further improve the economic and social benefits of rice dry farming, and it is of great significance to promote the sustainable development of rice cultivation. Therefore, it is very necessary to propose a high-yield and high-efficiency two-season dry farming technique for regenerative rice system.

SUMMARY OF THE INVENTION

The invention provides a two-season dry farming technology method for a regenerative rice system, optimizes the water management technology of the two-season dry farming technology in a regenerative rice system, and can further improve the economic and social benefits of rice dry farming and promote rice cultivation. The sustainable development solves the technical problem of the relationship between water saving, high yield and high efficiency in the dry rice cultivation process in the prior art.

The solution of the present invention to solve the above-mentioned technical problems is as follows: a two-season dry farming technology method for regenerating rice system, comprising the following steps:

Step 1, sowing regenerated rice seeds;

Step 2, moisture management;

In the seedling stage and seedling stage, make the paddy field anhydrous, and keep the soil water content above 80%; after the tillering stage, it is mainly rain-fed, when the leaves are obviously curled, irrigate once to keep the soil water content above 80%; The booting stage, heading stage and grain-filling stage are mainly rain-fed. When the leaves are obviously curled, continue to irrigate once to make the field moist and keep the soil water content above 80%; the yellow-ripening stage is mainly rain-fed, and no irrigation is required;

Step 3, first season rice harvest:

Step 4, water management in the regeneration season, keep the water layer 3-5cm in time within 3 days after the first season is harvested, and then keep the soil moist until the top leaves grow and flatten and then rain-fed:

Step five, harvest.

Further, a step of nutrient management in regeneration season is also included between step 4 and step 5. Nitrogen is applied at 46kg/hm ² when the first season rice is harvested and watered.

Further, between step 2 and step 3, it also includes:

In the weeding step, the weed sealant is applied within 3-4 days after sowing, and the upland rice herbicide is applied when the rice has three leaves and one center;

Weeds in the seedling stage of middle rice are mainly barnyardgrass, chinensis and duck tongue, and corresponding high-efficiency, low-toxicity and low-residue pesticides are used for control;

During the tillering and jointing period, the main control of Radix chinensis and Duckweed is to use corresponding high-efficiency, low-toxicity, and low-residue pesticides for control;

Mainly control barnyardgrass, water sedge and lotus seed grass at full head stage, and select corresponding high-efficiency, low-toxicity and low-residue pesticides in time at the 2-3 leaf stage of weeds, and increase the dose by 5% on the basis of general pesticide use;

Pest control steps: in the late stage of rice booting, 5 days before the rice break and when the rice break is 40-60%, spray pesticides to control rice smut, sheath blight and rice blast; control rice thrips in the early growth period, and rice growth In the middle and late stage, when the number of clumps reached 1,000, pesticides were applied to control rice planthoppers and rice borers.

Further, between step 2 and step 3, there is also a step of managing pests and weeds in the regeneration season, 5 days before the rice break and when the rice break is 40-60%, spraying pesticides to control rice smut; in the later stage of rice growth, applying pesticides Control rice planthopper; focus on the control of barnyardgrass, sedge and hollow lotus at the full head stage, and use corresponding high-efficiency, low-toxicity, and low-residue pesticides to control weeds at the 2-3 leaf stage, and increase the use of general pesticides. 5% dose.

Further, in the two-season water management method of step 2 and step 4, the soil water content is maintained at more than 80% for 7 days during the first season sowing, and then the rain-fed water management method is adopted until the first season is harvested; water is applied immediately after the first season is harvested. And keep the water layer above 3cm for 10 days, and then use rain-fed water management until the first season harvest.

Further, in the two-season water management method of step 2 and step 4, phosphorus and potassium fertilizers are applied in the form of compound fertilizer as base fertilizer 1-2 days before sowing in the first season, and nitrogen fertilizer is applied in three times, and the first season is applied in the form of compound fertilizer. 96kgN/hm2 of base fertilizer was applied in the form, ^96kgN /hm2 of ear fertilizer was applied at the heading and flowering stage, and 46kgN/hm2 of bud-promoting fertilizer was applied within ³ days after the first season was harvested.

Further, before step 1, it also includes a soil preparation step, the land is leveled and raked before sowing, the bottom moisture is replenished, and the soil moisture is kept between 85-90%; fertilization step: fertilization adopts the application method of basic top dressing, and the basic fertilizer is applied in the soil preparation. After completion, it should be completed within 1-2 days before sowing. The application rate of basal fertilizer is 600kg/hm ² , and compound fertilizer (N:P:K=16:16:16) is generally used; among them, phosphorus and potassium fertilizers are applied in the form of basal fertilizer at one time. , and the application ratio of nitrogen fertilizer is basal fertilizer: ear fertilizer = 5:5, ear fertilizer is applied at 96kgN/hm ² , and top-dressing fertilizer is applied with water.

Further, after the fertilizing step, it also includes:

Variety selection steps, the variety selection is approved by the crop variety approval committee in the region or approved by the national crop variety approval committee for planting in the region, meeting the characteristics of light and temperature resources in the region, high-yield and high-quality water or water-saving drought-resistant early-middle rice varieties. The period is 120–135 days;

It can be understood that the characteristics of light and temperature resources include some climatic characteristics, such as the characteristics of photosynthetically active radiation and the characteristics of effective accumulated temperature.

Seed drying steps: The seeds are full, uniform, consistent in grain shape, free of disease and insect particles, and no broken seeds, and ensure that the seeds are dried for 8-9 hours before soaking;

Soaking seeds: Put the seeds into flowing water during the day and add 4% prochloraz aqueous solution to soak the seeds for 24-36 hours;

Seed dressing: After the seeds are infiltrated, use the registered rice seed dressing agent for seed dressing, and adjust the concentration of the seed dressing agent according to the instructions of different products to prevent and control underground pests and diseases at the seedling stage.

Further, in the seeding step of step one:

The climatic characteristics of the region on the sowing date and the heading date of the middle rice varieties should be arranged reasonably to avoid the influence of high and low temperature (high temperature > 30 degrees, low temperature < 22 degrees), avoid heading in the high temperature period, and late sowing should ensure the lowest temperature at the heading period Not lower than 22–23°C (indica) and 20°C (japonica).

Further, in the weeding step, the weed sealant is: pyrimethamine-propiochlor wettable powder, the application amount is 0.75kg/hm2, sprayed with 0.0025g/mL solution; the upland rice herbicide is: Meifeng Qianjing-25% Cyhalofop-butyl water emulsion, the application rate is 1.65kg/hm ² , sprayed with 0.055g/mL solution;

Wherein, in the pest control step, the pesticide for controlling rice smut is spraying epoxiconazole with an application amount of 0.75kg/hm ² , and spraying with 0.0025g/mL aqueous solution; the pesticide for controlling rice planthopper is thiazide Wet powder, application rate 0.75kg/hm ² , sprayed with 0.0025g/mL aqueous solution.

The beneficial effects of the present invention are as follows: the present invention provides a two-season dry farming technical method for regenerating rice system, which has the following advantages:

1. Compared with one-season rice dry farming mode and the conventional cultivation mode of early and late rice, the two seasons of the present invention are closely connected, save time and effort, are beneficial to further improve the utilization efficiency of land and light and temperature resources, reduce agricultural production input, and increase agricultural production. benefit output.

2. Compared with the conventional regenerative rice cultivation mode, the present invention greatly reduces the input of irrigation water and artificial input by adopting a reasonable water management method in the first season and the regeneration season, that is, the cultivation mode of the regenerative rice dry farming. Cost inputs in agricultural production.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, and to implement according to the content of the description, the preferred embodiments of the present invention are described in detail below. Specific embodiments of the present invention are given in detail by the following examples.

Detailed ways

The following is a description of the principles and features of the present invention, and the examples are only used to explain the present invention, but not to limit the scope of the present invention. The invention is described in more detail by way of example in the following paragraphs. The advantages and features of the present invention will become apparent from the following description and claims.

It should be noted that when a component is referred to as being "fixed to" another component, it can be directly on the other component or there may also be a centered component. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a co-existence of an intervening component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a co-existing centered component. The terms "vertical," "horizontal," "left," "right," and similar expressions are used herein for illustrative purposes only.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The present invention provides one of the following examples and comparative examples, which were carried out in the experimental field of Huazhong Agricultural University in Wuhan City, Hubei Province in 2019 (112°45′ east longitude, 31°58′ north latitude), the area of the experimental field is 0.1hm2, and the experimental field is cultivated Basic physical and chemical properties of soil layer (0-20cm): soil pH value is 6.03, organic matter 39.84g/kg, total nitrogen 1.32mg/kg, available phosphorus 8.25mg/kg, available potassium 90mg/kg, bulk density 1.12g/cm ³ .

Example 1

The two-season dry farming technique of the regenerative rice system is as follows:

1. Land preparation:

On April 12, 2019, agricultural machinery was used for land preparation, the land was leveled and raked, the bottom moisture was replenished, and the soil moisture was kept between 85-90%, so that the soil was in a state of waiting for sowing.

2. Fertilization:

Base fertilizer was applied on April 13, 2019, and the base fertilizer was compound fertilizer (N:P:K=16:16:16), and the application rate was 600kg/hm2; phosphorus and potassium fertilizer was applied as base fertilizer at one time, and nitrogen fertilizer was divided into base fertilizer and ear fertilizer. The ratio was 5:5, and nitrogen fertilizer was topdressed on July 20, 2019, and 96kgN/hm2 was applied with irrigation water at the heading and flowering stage of rice.

3. Variety selection:

The seeds of indica three-line hybrid rice Hanyou 73 were selected, which were provided by Shanghai Agricultural Biogene Center, with first-class drought resistance, strong tillering ability, strong stems, fertilizer resistance and lodging resistance, and the full growth period was about 123 days.

4. Sun seed:

On April 13, 2019, put the seeds into mesh bags and hang them on the drying rack for 9 hours (9:00-18:00). Avoid placing them directly on the cement floor when drying the seeds, as scalding the seeds will affect germination.

5. Seed soaking:

On April 14, 2019, the seeds were put into a 4 wt% prochloraz aqueous solution, the prochloraz aqueous solution was immersed in the seeds, and the seeds were soaked at 25°C for 24 hours.

6. Seed dressing:

Seed dressing was done on April 16, 2019. After the seeds were infiltrated, the registered rice seed dressing agent was used for seed dressing, and the concentration of the seed dressing agent was adjusted according to the instructions of different products to control underground pests and diseases at the seedling stage.

7. Sowing:

On April 16, 2019, the seeds were sown by artificial drilling, the seed amount was 30kg/hm2, and the row spacing was 25cm.

8. Weeding:

On April 17, 2019, the weed sealer Pyridoxine and Protochlor wettable powder was applied at an application rate of 0.75kg/hm ² and sprayed with a 0.0025g/mL solution;

The upland rice herbicide Meifeng Qianjing-25% Cyhalofop-butyl water emulsion was sprayed when the rice had three leaves and one center at an application rate of 1.65kg/hm ² , and was sprayed with a solution of 0.055g/mL.

9. Moisture management:

At the emergence stage and the seedling stage (even seedling stage), the paddy field is anhydrous, but the field is kept moist (the field water holding capacity is 80-90%, and the soil water potential is less than 1.0kPa); after the tillering stage, rain-fed is mainly used, and when the leaves are obviously curled It is enough to irrigate the field once to make the field moist, and it is not necessary to keep the water layer and the field for drying; rain-fed is mainly in the booting stage, heading stage and grain-filling stage. Floor;

Irrigation is not required at the yellow maturity stage.

10. Pest control:

In the late stage of rice booting, 5 days before the rice break and when the rice break was 40% to 60%, Epoxiconazole was sprayed with an application rate of 0.75kg/hm ² and a 0.0025g/mL aqueous solution to prevent and control rice. aspergillosis;

In the late stage of rice growth, when the number of clumpworms reached 1000, the thiazide wettable powder was immediately applied at an application rate of 0.75kg/hm ² , and sprayed with a 0.0025g/mL aqueous solution.

11. Harvest of first season rice:

On August 25, 2019, more than 95% of the rice ears were yellow and ripe, leaving 40cm of stubble for manual harvesting.

12. Paddy field treatment:

After harvesting, the straws are crushed and returned to the fields to fertilize the soil.

13. Moisture management in regeneration season:

On August 25, 2019, the water layer was kept at 3–5cm, and the water layer disappeared and the soil was kept moist until the top leaves grew and flattened (about 10 days), and then rained.

14. Nutrient management in regeneration season:

On August 25, 2019, nitrogen was applied at 46kg/hm ² at the same time of water supply.

15. Management of pests and weeds in the regeneration season:

5 days before the rice break and when the rice break is 40-60%, spray pesticides to prevent rice smut; in the later stage of rice growth, use pesticides to prevent rice planthoppers; at the full head stage, focus on controlling barnyard grass, water sedge and hollow lotus seeds For weeds, the corresponding high-efficiency, low-toxicity, and low-residue pesticides should be selected in time at the 2-3 leaf stage of weeds, and the dose can be increased by 5% on the basis of general pesticide use.

16. Harvest:

On October 25, 2019, more than 95% of the rice ears were yellow and ripe, and were harvested manually, and the straw was returned to the field again.

Example 2

The operation and steps of embodiment 2 are identical with those of embodiment 1, and the only difference is the variety of rice, and the conventional rice variety Huang Huazhan of high yield and high quality that was adopted in implementation 2 was purchased from Nongfeng Seed Management Department, Hongshan District, Wuhan City, and the conventional rice variety of weak drought resistance was purchased. Rice is resistant to fertilizer, lodging, and super high ^- yield in production. The whole growth period is about 130 days.

Comparative Example 1

The conventional cultivation techniques of regenerated rice are as follows:

1. Land preparation:

On April 12, 2019, agricultural machinery was used for land preparation, the land was leveled and raked, the bottom moisture was replenished, and the soil moisture was kept between 85-90%, so that the soil was in a state of waiting for sowing.

2. Fertilization:

Base fertilizer was applied on May 9, 2019. The base fertilizer was compound fertilizer (N:P:K=16:16:16), and the application rate was 600kg/hm2; phosphorus and potassium fertilizer was applied as base fertilizer at one time, and nitrogen fertilizer was divided into base fertilizer and ear fertilizer. The ratio was 5:5, and nitrogen fertilizer was topdressed on July 20, 2019, and 96kgN/hm2 was applied with irrigation water at the heading and flowering stage of rice.

3. Choose a variety:

The indica three-line hybrid rice Hanyou 73 seeds were selected, which were provided by the Shanghai Agricultural Bio-Gene Center. The indica three-line hybrid rice with first-class drought resistance has strong tillering ability, strong stems, and is resistant to fertilizer and lodging. The whole growth period is 123 days or so.

4. Sun seed:

On April 13, 2019, put the seeds into mesh bags and hang them on the drying rack for 9 hours (9:00-18:00). Avoid placing them directly on the cement floor when drying the seeds, as scalding the seeds will affect germination.

5. Seed soaking:

On April 14, 2019, the seeds were put into a 4% prochloraz aqueous solution, the prochloraz aqueous solution was immersed in the seeds, and the seeds were soaked at 25°C for 24 hours.

6. Germination:

On April 16, 2019, first wash the seeds with warm water (25-30°C) for 2-4 times, then wrap them with a wet towel (to avoid water loss during seed germination) to hold the seeds, and then place the seeds in a constant temperature incubator , germination for 36-72 hours (indica rice takes a shorter time, japonica rice takes longer), when the radicle is one long and the germ is half long, the seeds are taken out and sown.

7. Raising seedlings:

From April 18th to April 19th, 2019, the seeds that have been sprouted will be raised in the seedling fields (the amount of seeds used is 52 plants/m2).

8. Transplanting:

On May 11, 2019, the transplanting and transplanting began, and the plant-row spacing was 13cm×30cm.

9. Weeding and pest control:

On May 24, 2019, a mixed herbicide prepared by using butachlor 1.5L/hm2, oxapyr 1.5L/hm2, benzsulfuron 0.9kg/hm2 and oxkexing 0.225kg/hm2 was used in paddy field preparation. Spray immediately when the muddy water is not clear, and keep 3-5cm water layer in the field when spraying, and keep it for 5-7 days; the prevention of pests and diseases adopts the following methods, in the late stage of rice booting, about 5 days before the rice break, and the rice When the breach is about 50%, spray epoxiconazole (application rate 0.75kg/hm2, sprayed with 0.0025g/mL solution) or other high-efficiency, low-toxicity and low-residue pesticides in accordance with national regulations to control rice smut. In the later stage of rice growth, when the number of clumpworms reaches 1000, immediately use thiazide wettable powder (application rate 0.75kg/hm2, it is recommended to spray with 0.0025g/mL solution) or other high-efficiency, low-toxicity, Low-residue pesticides control rice planthopper.

10. Moisture management:

At the peak tillering stage, when the field population reaches 70–80% of the effective ears, the field will be sun-dried for 6 days. In other growth periods, the field should be kept in a water layer of 3–5 cm, and the water layer should not be irrigated and maintained at the yellow maturity stage.

11. Harvest:

On August 30, 2019, more than 95% of the rice ears were yellow and ripe, and the rice was harvested manually.

12. Paddy field treatment:

After harvesting, the straws are crushed and returned to the fields to fertilize the soil. The first season rice should be watered in time within 3 days after the harvest, and the water layer should be kept at 3-5cm.

13. Moisture management in regeneration season:

On August 31, 2019, the water layer was maintained at 3-5cm until the yellow ripening stage.

14. Nutrient management in regeneration season:

On August 31, 2019, nitrogen was applied at 46kg/hm ² at the same time of water supply.

15. Management of pests and weeds in the regeneration season:

5 days before the rice break and when the rice break is 40-60%, spray pesticides to prevent rice smut; in the later stage of rice growth, use pesticides to prevent rice planthoppers; at the full head stage, focus on controlling barnyard grass, water sedge and hollow lotus seeds For weeds, the corresponding high-efficiency, low-toxicity, and low-residue pesticides should be selected in time at the 2-3 leaf stage of weeds, and the dose can be increased by 5% on the basis of general pesticide use.

16. Harvest:

On October 25, 2019, more than 95% of the rice ears were yellow and ripe, and were harvested manually, and the straw was returned to the field again.

Comparative Example 2

The operation and steps of Comparative Example 2 are the same as those of Comparative Example 1. The only difference is the variety of rice. In Comparative Example 2, Huanghuazhan seeds were selected, which were purchased from Nongfeng Seed Management Department, Hongshan District, Wuhan City. Conventional rice with weak drought resistance was produced. It shows fertilizer resistance, lodging resistance and super high yield performance, and the whole growth period is about 130 days.

Yield and economic benefits of super-high-yielding or water-saving and drought-resistant rice varieties under different cultivation modes

Note: F: conventional flood irrigation; D: dry rice farming; HHZ: Huang Huazhan; HY73: Hanyou 73

First season: Compared with conventional flood irrigation, the yield and total income of rice dry farming decreased by 24.6%, but the total expenditure decreased by 44.8%, the net income increased by 13.5%, and the economic benefit increased by 37.1%. Compared with HHZ, the output of HY73 increased by 1.4%, the total expenditure increased by 15%, the net income decreased by 14.6%, and the economic benefit decreased by 13.3%. Under dry farming conditions, compared with HHZ, the yield of HY73 increased by 10.5%, the total expenditure increased by 29.3%, the net income decreased by 4.2%, and the economic benefit decreased by 14.5%.

Regeneration season: Compared with conventional flooding, the yield and total income of rice dry farming decreased by 20.7%, but the total expenditure decreased by 77.7%, the net income increased by 2.3%, and the economic benefit increased by 25.6%. Compared with HHZ, the output of HY73 has increased by 3.9%, the total expenditure has no difference, the net income has increased by 4.9%, and the economic benefit has increased by 14.2%. Under dry farming conditions, compared with HHZ, the yield of HY73 increased by 21.4%, the total expenditure was no different, the net income increased by 23.6%, and the economic benefit increased by 21.5%.

Two seasons combined: Compared with conventional flooding and irrigation, rice dry farming yield and total income decreased by 24.8%, but total expenditure decreased by 54.2%, net income increased by 2.3%, and economic benefit increased by 64.8%. Compared with HHZ, the output of HY73 increased by 0.23%, the total expenditure increased by 11.2%, the net income decreased by 6.5%, and the economic benefit decreased by 11.6%. Under dry farming conditions, compared with HHZ, the yield of HY73 increased by 9.9%, the total expenditure increased by 24.7%, the net income increased by 4.3%, and the economic benefit decreased by 11.8%.

Therefore, in terms of the net income and economic benefits of the two seasons, it is better to choose HY73 first for the dry farming conditions of the two seasons.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form; Some changes, modifications and equivalent changes made by the content are equivalent embodiments of the present invention; at the same time, any changes, modifications and equivalent changes made to the above embodiments according to the essential technology of the present invention. Evolution, etc., still fall within the protection scope of the technical solution of the present invention.

Claims (10)

1. A two-season dry farming technical method for a ratoon rice system is characterized by comprising the following steps:

step one, sowing regeneration rice seeds;

step two, managing water;

in the seedling stage and the seedling standing stage, the rice field is not provided with a water layer, and the field water capacity is kept to be more than 80%; the rain culture is taken as the main point after the tillering stage, and when the leaves are obviously curled, the field water holding capacity is kept above 80% by irrigating once; the booting stage, heading stage and grouting stage are mainly rain-fed, when the leaves are obviously curled, the irrigation is continued for one time to moisten the field and keep the field water-holding capacity to be more than 80%; the yellow mature period is mainly rain-fed, and irrigation is not needed;

step three, harvesting first season rice;

step four, managing the water in the regeneration season, timely watering within 3 days after harvesting in the first season, keeping the water layer at 3-5cm, and then maintaining the soil to be moist until the top leaves grow out and are spread flat for rain culture;

and step five, harvesting.

2. The two-season dry farming technical method for ratooning rice system as claimed in claim 1, wherein between the fourth step and the fifth step further comprises a ratooning season nutrient management step, wherein 46kg/hm of nitrogen is applied while watering the first season rice after harvesting²。

3. The two-season dry farming technical method for a ratoon rice system according to claim 1, further comprising, between step two and step three:

weeding, namely broadcasting a weed sealing agent within 3-4 days after sowing, and spraying a dry rice herbicide when 3 leaves and one core of rice are planted;

the weeds in the seedling stage of the middle-season rice are mainly barnyard grass, moleplant seed and monochoria vaginalis, and the corresponding high-efficiency, low-toxicity and low-residue pesticide is selected for preventing and treating;

the tillering and jointing stage mainly prevents and treats the moleplant seed and the monochoria vaginalis, and corresponding high-efficiency, low-toxicity and low-residue pesticide is selected for prevention and treatment;

the cockspur grass, the cyperus esculentus and the alternanthera philoxeroides are mainly controlled in the spike-aligning period, corresponding high-efficiency, low-toxicity and low-residue pesticides are selected for control in time in the 2-3 leaf period of the weeds, and the dosage is increased by 5 percent on the basis of the use of general pesticides;

a step of pest control, in which pesticides are sprayed to control false smut, sheath blight and rice blast 5 days before the opening of rice and 40-60% of the opening of rice in the late stage of rice booting; the pesticide is applied to prevent and control rice planthopper and chilo suppressalis when the quantity of the hundreds of parasites reaches 1000 in the middle and later stages of the growth of rice.

4. The two-season dry farming technical method for the ratoon rice system according to claim 1, characterized by further comprising a step of managing diseases, pests and weeds of the ratoon rice between the second step and the third step, wherein pesticide is sprayed to prevent false smut 5 days before the rice is broken and 40-60% of the rice is broken; in the later growth period of rice, pesticide is applied to prevent and control rice planthopper; the spike-adjusting period should be used for mainly preventing barnyard grass, cyperus esculentus and alternanthera philoxeroides, corresponding high-efficiency, low-toxicity and low-residue pesticides are used for preventing and controlling weeds in the 2-3 leaf period, and the dosage is increased by 5% based on the use of general pesticides.

5. The two-season dry farming technical method for a ratoon rice system according to claim 1, wherein in the two-season moisture management mode of the second step and the fourth step, the soil moisture content is maintained for 7 days above 80% when the seeds are sowed in the first season, and then the moisture management mode of rain culture is adopted until the seeds are harvested in the first season; immediately watering after harvesting in the first season, maintaining a water layer for more than 3cm for 10 days, and then adopting a rain-fed water management mode until harvesting in the first season.

6. The two-season dry farming technical method for the ratoon rice system as claimed in claim 1, wherein in the two-season moisture management mode of step two and step four, the phosphorus-potassium fertilizer is applied as a base fertilizer within 1-2 days before the first-season seeding in the form of a compound fertilizer, the nitrogen fertilizer is applied in three times, and the base fertilizer of 96kgN/hm is applied in the first season in the form of a compound fertilizer²Applying spike fertilizer 96kgN/hm in the heading and flowering period²Applying a germination-promoting fertilizer of 46kgN/hm within 3 days after harvesting in the first season²。

7. The two-season dry farming technical method for the ratoon rice system as claimed in claim 1, further comprising a soil preparation step before the first step, wherein the soil is leveled and raked to be fine before sowing, the bottom moisture is supplemented, and the soil humidity is kept between 85% and 90%; fertilizing: the application of the base fertilizer is carried out in a base additional fertilizer application mode, the base fertilizer application is finished within 1-2 days before sowing after the soil preparation is finished, and the base fertilizer application amount is 600kg/hm²Compound fertilizers are generally adopted (N: P: K: 16: 16: 16); wherein, the phosphorus-potassium fertilizer is applied at one time in the form of a base fertilizer, and the application proportion of the nitrogen fertilizer is that the base fertilizer: spike fertilizer is 5: 5, applying the spike fertilizer at a ratio of 96kgN/hm²The top dressing is applied along with the water fertilization.

8. The two-season dry farming technical method for a ratoon rice system according to claim 7, further comprising, after the fertilizing step:

selecting varieties, namely selecting the varieties which are approved by the local crop variety approval committee or the national crop variety approval committee to be approved and suitable for planting in the local area, meeting the light-temperature resource characteristics of the area, and obtaining high-yield high-quality water or water-saving drought-resistant early-medium rice varieties with the growth period of 120-plus 135 days;

seed sunning: the seeds are full and uniform, have consistent seed types, are free from diseases and pests and are free from breakage, and the seeds are sunned for 8-9 hours before being soaked;

seed soaking: in the daytime, seeds are put into flowing clear water, 4 percent of prochloraz water solution is added for soaking the seeds for 24 to 36 hours;

seed dressing: after the seeds are soaked, the registered rice seed dressing agent is selected for dressing the seeds, and the concentration of the seed dressing agent is adjusted according to different product specifications so as to prevent and control underground pests and diseases in seedling stage.

9. The two-season dry farming technical method for ratooning rice system according to claim 1, wherein in the seeding step of step one:

the sowing date is reasonably arranged according to the climate characteristics of the sowing date region and the heading date of the medium-grade rice variety, so that the influence of high and low temperatures (the high temperature is more than 30 ℃, and the low temperature is less than 22 ℃) is avoided, heading at the high temperature is avoided, and the lowest temperature of the heading date is ensured to be not lower than 22-23 ℃ (indica rice) and 20 ℃ (japonica rice) in the late sowing.

10. A two-season dry-farming technical method for ratooning rice system according to claim 3, wherein in the weeding step, the weed killer is: pyriminobac-pretilachlor wettable powder with the application amount of 0.75kg/hm²Spraying 0.0025g/mL solution; the dry rice herbicide comprises: meofengqianjin g-25% cyhalofop-butyl water emulsion, the application amount is 1.65kg/hm²To do so bySpraying 0.055g/mL solution;

wherein the pesticide for preventing and treating false smut in the step of preventing and treating plant diseases and insect pests is epoxiconazole spraying, and the application amount is 0.75kg/hm²Spraying with 0.0025g/mL water solution; the pesticide for preventing and controlling the rice planthoppers is buprofezin wettable powder, and the application amount is 0.75kg/hm²Spraying was carried out with 0.0025g/mL of aqueous solution.