A method for water-saving cultivation of rice in saline-alkali soil

Abstract

The application relates to a method for water-saving cultivation of paddy rice in saline-alkali soil, and belongs to the technical field of paddy rice cultivation. The method can effectively plant paddy rice in light and moderate saline-alkali soil through soil improvement of the saline-alkali soil, and can realize underground irrigation mode and ground irrigation mode, is simple to install, is easy to operate in the field, can irrigate according to the root growth depth of the paddy rice, can keep the root area of the paddy rice in a light salt or salt-free environment through precise irrigation, and can irrigate 8-10 times during the growth period of the paddy rice according to the natural rainfall, with an irrigation amount of about 280-320 m 3 / 667m 2 , more than 50% of water can be saved compared with common flooding irrigation, water and fertilizer integration can be realized during fertilizer application, water and fertilizer can be saved, and water and fertilizer efficiency can be improved, water resource utilization efficiency can be improved and the rice yield can be increased through control of irrigation time and depth. The water requirement characteristics of the paddy rice during each growth period can be flexibly adjusted, the rainfall utilization rate can be significantly improved compared with traditional continuous irrigation, the leakage amount can be reduced, and the waste of water resources can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rice cultivation, in particular to a method for water-saving cultivation of rice in saline-alkali soil. BACKGROUND

[0002] There is a large area of saline-alkali soil in northern China, mainly for planting cotton, but in recent years the cotton benefit is reduced, and "cotton field is replaced by rice" is the demand of farmers. The traditional rice planting method is flooding cultivation, which consumes a large amount of water. In the 1970s, a water-saving cultivation technology-rice film mulching cultivation technology was introduced from Japan. In the 1990s, rice film mulching cultivation technology has been rapidly developed in China. At the end of the 20th century, film mulching cultivation technology has formed a complete system in different low-yield, water-deficient and high-cold type paddy fields in the south and north.

[0003] Chinese patent CN103798090A introduces a comprehensive planting method of rice film mulching in saline-alkali soil, which comprises the following steps: applying base fertilizer to the field, transplanting rice seedlings to the field, and applying urea; 3-5 days before transplanting, water is poured to soak the field, and film is mulched before rice is transplanted. The method is to wash salt by large water first, and then to mulch film and transplant rice. The large water for washing salt requires a large amount of water, which does not meet the current needs of water-saving cultivation, and in addition, the manual operation for rice transplanting increases the labor intensity.

[0004] Chinese patent CN104969809A introduces a rice film mulching high-yield direct seeding technology, which basically comprises the following steps: after washing salt with large water, a compartment surface with a width of 165 cm, a compartment ditch with a width of 27 cm and a depth of 17 cm is formed, the film is manually mulched when the compartment surface is not submerged, the film edge is inserted into the mud by hand to a depth of 3-5 cm while mulching, a wooden planting device is used to punch holes after mulching, and rice seeds are manually sown into the film holes, and fine soil or humus soil is covered. The difference between this technology and CN103798090A is basically the sowing of rice seeds and the transplanting of rice seedlings, and basically still requires large water for washing salt; the amount of water for irrigation during the growth period will be larger, because the compartment surface needs to be submerged for irrigation, and if only the compartment ditch is irrigated, the compartment surface will be salted. SUMMARY

[0005] The present application solves the above technical problems and provides a method for water-saving cultivation of rice in saline-alkali soil.

[0006] To solve the above technical problems, the technical scheme provided by the present application is as follows:

[0007] A method for water-saving cultivation of rice in saline-alkali soil, comprising the following steps:

[0008] S1, soil improvement:

[0009] The soil of the moderate to severe saline-alkali land is first improved, the salt content in the soil is reduced by planting salt-alkali absorbing plants, the plants are directly ploughed as green manure after growing, unfermented organic fertilizer is applied and ploughed into the soil to allow the microorganisms to produce organic acid in the reproduction process to convert the salt content, so that the saline-alkali land is reduced, and the converted land is obtained;

[0010] S2, land preparation and fertilization:

[0011] The converted land in the step S1 or the moderate or less saline-alkali land is deep ploughed, leveled and dredged to increase the permeability of the soil and promote the flow and drainage of water; meanwhile, a surrounding water weir is established around the field to intercept and effectively utilize the natural rainfall;

[0012] S3, salt washing and soil improvement:

[0013] The traditional large water soaking field for salt washing is not performed before the film mulching and direct seeding of the rice, but the water irrigation and salt washing are simultaneously performed after the seeding, so that the water for the separate soaking field for salt washing is saved. An underground irrigation mode and an aboveground irrigation mode are combined, the underground irrigation mode is that the drip irrigation pipe is buried at a depth of 60-70 cm underground, the distance between the drip irrigation pipes is 40-50 cm, the drip irrigation head is connected to the drip irrigation pipe, and the distance between the drip irrigation head and the ground is 5-10 cm; the aboveground irrigation mode is that the aboveground hose is established, the hose irrigates water on the film, and the water infiltrates into the soil through the seeding hole;

[0014] S4, seeding:

[0015] The rice mechanical film mulching and direct seeding all-in-one machine is selected, and the rotary ploughing, fertilization, seeding, film mulching, soil covering and pressing are completed at one time;

[0016] S5, water-saving irrigation

[0017] The water-saving irrigation mode includes a shallow water irrigation stage, a medium water irrigation stage, a deep water irrigation stage and a wet irrigation stage.

[0018] The shallow water irrigation stage is that the shallow water irrigation is performed by using the aboveground irrigation mode from the seeding and seedling emergence stage to the greening stage of the rice, and the salt washing is simultaneously performed, the irrigation amount of the shallow water is 15-20 m 3 / 667m 2 ;

[0019] The medium water irrigation stage is that the medium water irrigation is performed by using the underground irrigation mode from the greening stage to the jointing stage of the rice, the underground irrigation reduces the ground evaporation amount and improves the irrigation utilization efficiency, the irrigation amount of the medium water is 20-25 m 3 / 667m 2 ;

[0020] The deep water irrigation stage is in the stage from booting to flowering, deep water irrigation is carried out by combining aboveground irrigation with underground irrigation, first underground irrigation is carried out, then aboveground irrigation is carried out, so as to prevent salt return, the deep water irrigation amount is 25-35 m 3 / 667m 2 , the underground irrigation amount is 15-20 m 3 / 667m 2 , and the aboveground irrigation amount is 10-15 m 3 / 667m 2 .

[0021] The wet irrigation stage is in the stage from flowering to rice maturity, the soil water content is kept at 81-85% of the maximum water holding capacity, wet irrigation is carried out by using aboveground irrigation in a dry-wet alternating mode, so as to control soil hardening and salt return, and the wet irrigation amount is 10-20 m 3 / 667m 2 .

[0022] From the late rice maturity stage to harvesting, water is controlled and the field is exposed to the sun, and irrigation is not carried out.

[0023] S6, field management.

[0024] Preferably, the plant in the S1 step is one or more combinations of Suaeda salsa, Medicago sativa, Suaeda salsa var. altaica or Sesbania cannabina.

[0025] Preferably, the shallow water irrigation stage is in the stage from rice sowing to greening, shallow water irrigation is carried out by using aboveground irrigation, and salt washing is carried out at the same time, and the shallow water irrigation amount is 15-20 m 3 / 667m 2 .

[0026] Preferably, the medium water irrigation stage is in the stage from greening to jointing, medium water irrigation is carried out by using underground irrigation, the underground irrigation reduces the ground evaporation amount, and improves the irrigation utilization efficiency, and the medium water irrigation amount is 20-25 m 3 / 667m 2 .

[0027] Preferably, the deep water irrigation stage is in the stage from booting to flowering, deep water irrigation is carried out by combining aboveground irrigation with underground irrigation, first underground irrigation is carried out, then aboveground irrigation is carried out, so as to prevent salt return, the deep water irrigation amount is 25-35 m 3 / 667m 2 , the underground irrigation amount is 15-20 m 3 / 667m 2 , and the aboveground irrigation amount is 10-15 m 3 / 667m2 ;

[0028] Preferably, the wet irrigation stage is from flowering to maturity of the rice, keeping the soil moisture at 81-85% of the maximum water holding capacity, using dry-wet alternating method, using surface irrigation to keep the soil from hardening and salt returning, the wet irrigation amount is 10-20m 3 / 667m 2 .

[0029] Preferably, the field management includes irrigation, weeding and fertilization.

[0030] Preferably, the underground irrigation mode and the surface irrigation mode share one water source.

[0031] After using the above method, the present application has the following advantages:

[0032] The present application can effectively plant rice in light and moderate saline-alkali land by soil improvement, the underground irrigation mode and the surface irrigation mode are easy to install and operate, can irrigate according to the root growth depth of the rice, keep the root zone of the rice in a light salt or salt-free environment by precise irrigation, the water-saving method for rice in saline-alkali land can irrigate 8-10 times during the growth period of the rice according to the natural rainfall, the irrigation amount is about 280-320m 3 / 667m 2 , which is more than 50% of the ordinary flooding irrigation, can realize water and fertilizer integration during the topdressing, save water and fertilizer, improve the water and fertilizer efficiency, improve the water resource utilization efficiency and increase the rice yield by controlling the irrigation time and depth, can be flexibly adjusted according to the water requirement characteristics of each growth period of the rice, so as to achieve the purpose of water-saving and yield-increasing, compared with the traditional continuous irrigation, can significantly improve the rainfall utilization rate and reduce the seepage amount, thereby reducing the waste of water resources.

[0033] The above summary is intended to illustrate only and is not intended to limit the application in any way. Further aspects, embodiments and features of the application will be apparent from a review of the entire entire specification, which includes that which is described hereinbefore and that which is described below. DETAILED DESCRIPTION

[0034] Reference will now be made in detail to the specific embodiments of the application. While the application will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the application to these specific embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents, which can be included within the spirit and scope of the application as defined by the claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application can be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present application.

[0035] As used in this description and the accompanying claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Unless defined otherwise, 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 application belongs.

[0036] Further details of the application are provided below in conjunction with the entire document.

[0037] In conjunction with the entire document, a method for water-saving cultivation of rice in saline-alkali soil includes the following steps:

[0038] S1, soil improvement:

[0039] For moderate to severe saline-alkali soil, first, soil improvement is performed by planting salt-alkali absorbing plants to reduce the salt content in the soil. After growing, the plants can be directly plowed as green manure, and unfermented organic fertilizer is applied and plowed into the soil to allow fermentation and the production of organic acids by microorganisms during reproduction to convert the salt content, thereby reducing the salt content and obtaining the converted land.

[0040] S2, land preparation and fertilization:

[0041] For the converted land in step S1 or saline-alkali soil below moderate, deep plowing, flattening, and digging of drainage ditches or channels are performed to increase the permeability of the soil and promote the flow and removal of water. At the same time, a surrounding water weir is established around the field to intercept and effectively utilize natural rainfall.

[0042] S3, salt washing and soil preparation:

[0043] Instead of traditional large water soaking and salt washing before film mulching and direct seeding of rice, water irrigation and salt washing are simultaneously performed after seeding, thereby saving water used for separate soaking and salt washing. An underground irrigation mode and an aboveground irrigation mode are combined. In the underground irrigation mode, the drip irrigation pipe is buried at a depth of 60-70 cm underground, the distance between drip irrigation pipes is 40-50 cm, the drip irrigation head is connected to the drip irrigation pipe, and the distance between the drip irrigation head and the ground is 5-10 cm. In the aboveground irrigation mode, an aboveground hose is established, the hose irrigates water on the film, and the water infiltrates into the soil through the seeding hole.

[0044] S4, sowing:

[0045] The rice mechanical film mulching and direct seeding integrated machine completes rotary tillage, fertilization, sowing, film mulching, soil covering and pressing in one operation.

[0046] S5, water-saving irrigation

[0047] The water-saving irrigation mode includes a shallow water irrigation stage, a medium water irrigation stage, a deep water irrigation stage and a wet irrigation stage.

[0048] The shallow water irrigation stage is a stage from rice sowing and seedling emergence to greening, shallow water irrigation is performed by using the above-ground irrigation mode, and salt washing is performed at the same time, the irrigation amount of the shallow water being 15-20 m 3 / 667m 2 .

[0049] The medium water irrigation stage is a stage from rice greening to jointing, medium water irrigation is performed by using the underground irrigation mode, the underground irrigation reduces the ground evaporation amount and improves the irrigation utilization efficiency, and the irrigation amount of the medium water being 20-25 m 3 / 667m 2 .

[0050] The deep water irrigation stage is a stage from booting to flowering, deep water irrigation is performed by using the combined mode of the above-ground and underground irrigation modes, the underground irrigation mode is used first, and then the above-ground irrigation mode is used, so as to prevent salt return, and the irrigation amount of the deep water being 25-35 m 3 / 667m 2 , the irrigation amount of the underground irrigation mode being 15-20 m 3 / 667m 2 , and the irrigation amount of the above-ground irrigation mode being 10-15 m 3 / 667m 2 .

[0051] The wet irrigation stage is a stage from flowering to rice maturity, the soil water content is kept at 81-85% of the maximum water holding capacity, the wet irrigation is performed by using the above-ground irrigation mode in the dry-wet alternating mode, so as to control soil hardening and salt return, and the irrigation amount of the wet irrigation being 10-20 m 3 / 667m 2 .

[0052] From the late maturity stage of the rice to harvesting, water control and field drying are performed, and irrigation is not performed.

[0053] S6, field management.

[0054] Preferably, the plant in the S1 step is one or more combinations of Suaeda salsa, Medicago sativa, Suaeda salsa var. altaica or Sesbania cannabina.

[0055] Preferably, the field management includes irrigation, weeding and fertilization.

[0056] Preferably, the underground irrigation mode and the aboveground irrigation mode share one water source.

[0057] The wet irrigation stage adopts a dry-wet alternating mode, and water is cut off at night to achieve the effect of no water seen before water. Wet irrigation can promote the timely transformation of rice from vegetative growth to reproductive growth. During the reproductive growth, the straight area index is high, the functional leaf is more, the number of primary tillers is more, and the root-shoot ratio is large. During the milk stage, the starch and cellulose content of the shallow wet irrigation plant increases, and the carbon-nitrogen ratio increases, creating conditions for high yield.

[0058] The field management includes irrigation, weeding and fertilization. The factors such as water, fertilizer, air and heat are reasonably adjusted, and the soil fertility is improved,

[0059] The daily temperature variation amplitude of the rice field soil temperature is large. The wet temperature difference is 6.4-7.3, and the water layer irrigation is only 5-6. The diurnal temperature difference: wet irrigation is 4.2-4.6, and the flooded irrigation is 3.8-4.0. The daily variation amplitude of soil temperature is large. During the heading to milk stage in the late growth period, the diurnal temperature difference of the wet irrigation is 2.6-3.1, and that of the flooded irrigation is 1.6-1.7. The shallow wet irrigation is beneficial to photosynthesis, and the large diurnal temperature difference is beneficial to dry matter accumulation. The shallow wet irrigation has good light, and the flooded irrigation has insufficient light.

[0060] Disease control can apply water enemy to prevent and control water mite, which can effectively control the occurrence of water mite and other diseases and reduce the influence of diseases on the growth of rice.

[0061] The underground irrigation mode and the aboveground irrigation mode share one water source.

[0062] Specifically, the rice mechanical film mulching and direct seeding integrated machine is prior art, which can complete the operations such as land preparation, film mulching and seeding at the same time. The rice mechanical film mulching and direct seeding integrated machine is divided into two types. One type is to first film mulch and then precisely seed on the film. The other type is to first seed, then film mulch and spread soil, so that the seeds break the film and germinate by themselves. Example 1

[0063] The underground irrigation mode in the embodiment of the present application further comprises a pressure regulator for controlling the working pressure of the dripper within a proper range (usually 1-3 kg); an air valve installed at the high point of each electromagnetic valve control area to prevent the soil impurities from entering the dripper and causing blockage due to siphon effect when the system is closed. A flushing valve installed at the end of the electromagnetic valve controller area for periodically flushing the drip irrigation system to prevent blockage. The flushing valve can be manually or automatically controlled. An electromagnetic valve for dividing the drip irrigation system into different areas and realizing automatic opening and closing. A controller for setting the irrigation program and automatically opening or closing the electromagnetic valve to realize automatic operation of the irrigation system. In cooperation with an irrigation weather station or other related sensors, the drip irrigation system can be controlled more intelligently. A filter for cleaning the impurities in the irrigation water source to prevent blockage. A 150-mesh or laminated filter must be installed in each electromagnetic valve controller area. If non-tap water is used as the water source, a corresponding head filter system must be configured at the head of the system in addition to the installation of the mesh or laminated filter in each electromagnetic valve controller area. A fertilizer applicator. The rotating fertilizer applicator can be used for fertilization or chlorine treatment through the irrigation system. A pump. If the water source pressure of the irrigation system cannot meet the irrigation requirements, a pump may be needed. A check valve installed at the head of the system to prevent backflow of the irrigation water, which can cause water pollution or damage to the pump and other equipment.

[0064] The construction steps of the drip irrigation are as follows:

[0065] 1) Install the water intake point and the main pipe. The burial depth of the main pipe can be determined according to the actual situation.

[0066] 2) Install the stop valve, electromagnetic valve, filter and pressure regulator, etc.

[0067] 3) Install the branch pipe (water inlet pipe and drainage pipe). During installation, the interfaces are blocked to prevent impurities from entering.

[0068] 4) Install the drip irrigation pipe. During installation, the interfaces are blocked to prevent impurities from entering.

[0069] 5) Install the air valve.

[0070] 6) After thoroughly flushing the branch pipe, connect the drip irrigation pipe to the branch pipe.

[0071] 7) Install the flushing valve, and then thoroughly flush the system again.

[0072] 8) Distribution test: after installation, open the system and observe the water outlet of the dripper and the uniformity of water distribution.

[0073] 9) Trench backfilling: after the test is completed, backfill the branch pipe and the drip irrigation pipe. Example 2

[0074] A method for water-saving cultivation of rice in saline-alkali soil, comprising the following steps:

[0075] S1, soil improvement:

[0076] For moderate to severe saline-alkali soil, first soil improvement is carried out by planting alkali-absorbing sueda to reduce salt content in the soil. After growing, it can be directly plowed as green manure, and unfermented organic fertilizer is applied and turned into the soil to allow fermentation, so that microorganisms produce organic acids during reproduction to convert salt and reduce saline-alkali, thereby obtaining the converted land.

[0077] S2, land preparation and fertilization:

[0078] For the converted land in step S1 or saline-alkali soil below moderate, deep plowing, flattening and digging drainage ditches or channels are carried out to increase the permeability of the soil and promote water flow and drainage. Meanwhile, a surrounding water weir is established around the field to intercept and effectively utilize natural rainfall.

[0079] S3, salt washing and soil preparation:

[0080] Instead of traditional large water soaking field salt washing before rice film mulching and direct seeding, water irrigation and salt washing are carried out simultaneously after seeding to establish a combination mode of underground irrigation and aboveground irrigation. The underground irrigation mode is that the drip irrigation pipe is buried at a depth of 70 cm, the drip irrigation pipe spacing is 50 cm, the drip irrigation head is connected to the drip irrigation pipe, and the drip irrigation head is 10 cm away from the ground. The aboveground irrigation mode is to establish an aboveground hose, which irrigates water on the film, and the water infiltrates into the soil through the seeding hole.

[0081] S4, seeding:

[0082] A rice mechanical film mulching and direct seeding integrated machine is selected, which adopts film mulching first and then precision seeding on the film, and completes rotary plowing, fertilization, seeding, film mulching, soil covering and pressing in one operation.

[0083] S5, water-saving irrigation

[0084] The water-saving irrigation mode includes a shallow water irrigation stage, a medium water irrigation stage, a deep water irrigation stage and a wet irrigation stage.

[0085] S6, field management,

[0086] From the late maturation stage to harvesting, water control and field drying are carried out without irrigation.

[0087] The shallow water irrigation stage is from rice seeding and seedling emergence to the greening stage, shallow water irrigation is carried out by using aboveground irrigation method, and salt washing is carried out at the same time. The shallow water irrigation amount is 20 m 3 / 667m 2 .

[0088] The middle water irrigation stage is from the greening to the jointing stage of rice, and the underground irrigation is used to irrigate the middle water, which reduces the ground evaporation and improves the irrigation efficiency, and the irrigation amount of the middle water is 25m 3 / 667m 2 ;

[0089] The deep water irrigation stage is from the booting to the flowering stage, and the aboveground and underground irrigation are combined to irrigate the deep water, the underground irrigation is used first, and then the aboveground irrigation is used to prevent salt return, and the irrigation amount of the deep water is 35m 3 / 667m 2 , the underground irrigation amount is 20m 3 / 667m 2 , and the aboveground irrigation amount is 15m 3 / 667m 2 ;

[0090] The wet irrigation stage is from the flowering to the maturation stage of rice, the soil water content is kept at 85% of the maximum water holding capacity, the dry and wet alternating method is used, the aboveground irrigation is used to keep the soil from being hardened and salt returning, and the irrigation amount of the wet irrigation is 20m 3 / 667m 2 . Example Three

[0091] A method for water-saving cultivation of rice in saline-alkali soil, comprising the following steps:

[0092] S1, soil improvement:

[0093] The soil of the moderate and severe saline-alkali land is first improved, the salt content in the soil is reduced by planting alfalfa which can absorb salt and alkali, and the grown alfalfa can be directly plowed as green manure, and unfermented organic fertilizer is applied and plowed into the soil to allow the microorganisms to produce organic acid in the reproduction process to convert the salt content, so as to reduce the salt and alkali content and obtain the converted land.

[0094] S2, land preparation and fertilization:

[0095] The converted land in the step S1 or the land with moderate or less saline-alkali is deep plowed, leveled and dredged to increase the permeability of the soil and promote the flow and drainage of water, and a surrounding weir is built around the field to intercept and effectively use the natural rainfall.

[0096] S3, salt washing and soil preparation:

[0097] The rice is not washed with traditional large water before film mulching and direct seeding, but is washed with water and salt after sowing, and a mode of combination of underground irrigation and aboveground irrigation is established, the underground irrigation mode is that the drip irrigation pipe is buried at a depth of 60 cm underground, the drip irrigation pipe spacing is 40 cm, the drip irrigation head is connected to the drip irrigation pipe, and the drip irrigation head is 5 cm away from the ground; the aboveground irrigation mode is to establish an aboveground hose, the hose irrigates water on the film, and the water infiltrates into the soil through the sowing hole;

[0098] S4, sowing:

[0099] A rice mechanical film mulching and direct seeding all-in-one machine is selected, sowing is performed first, then film mulching and soil scattering are performed, the seeds are allowed to break the film and emerge by themselves, and rotary tillage, fertilization, sowing, film mulching, soil covering and pressing are completed in one operation;

[0100] S5, water-saving irrigation

[0101] The water-saving irrigation mode includes a shallow water irrigation stage, a medium water irrigation stage, a deep water irrigation stage and a wet irrigation stage;

[0102] S6, field management,

[0103] From the late maturation stage to the harvesting of the rice, water control and field drying are performed, and irrigation is not performed;

[0104] The shallow water irrigation stage is from the sowing and emergence stage of the rice to the greening stage, shallow water irrigation is performed by using the aboveground irrigation mode, and salt washing is performed at the same time, the irrigation amount of the shallow water is 15m 3 / 667m 2 ;

[0105] The medium water irrigation stage is from the greening stage to the jointing stage of the rice, medium water irrigation is performed by using the underground irrigation mode, the ground evaporation amount is reduced, and the irrigation utilization efficiency is improved, the irrigation amount of the medium water is 20m 3 / 667m 2 ;

[0106] The deep water irrigation stage is from the booting stage to the flowering stage, deep water irrigation is performed by using the combination of the aboveground and underground irrigation modes, underground irrigation mode irrigation is performed first, and then aboveground irrigation mode irrigation is performed, so as to prevent salt return, the irrigation amount of the deep water is 25m 3 / 667m 2 , the underground irrigation mode irrigation amount is 15m 3 / 667m 2 , and the aboveground irrigation mode irrigation amount is 10m 3 / 667m 2 ;

[0107] The wet irrigation stage is from the flowering stage to the mature stage of the rice, keeps the soil moisture at 81% of the maximum water holding capacity, adopts a dry-wet alternating mode, and uses an above-ground irrigation mode to carry out wet irrigation, so as to control soil hardening and salt return, and the wet irrigation amount is 10m 3 / 667m 2 . Embodiment four:

[0108] A method for water-saving cultivation of rice in saline-alkali soil, comprising the following steps:

[0109] S1, soil improvement:

[0110] For moderate to severe saline-alkali soil, first carry out soil improvement, reduce the salt content in the soil by planting high-alkali puccinellia that absorbs salt and alkali, and directly plow the grown plants as green manure, apply unfermented organic fertilizer, and turn it into the soil to allow it to ferment and allow microorganisms to produce organic acid in the process of reproduction to convert salt, so as to reduce salt and alkali and obtain the converted land;

[0111] S2, land preparation and fertilization:

[0112] For the converted land in step S1 or the moderate or less saline-alkali land, carry out deep plowing, flattening and digging of drainage ditches or channels to increase the permeability of the soil and promote the flow and removal of water; at the same time, build a surrounding water weir around the field to intercept and effectively utilize natural rainfall;

[0113] S3, salt washing and soil preparation:

[0114] Before rice film mulching and direct seeding, do not carry out traditional large water soaking field salt washing, but carry out water irrigation and salt washing at the same time after sowing, and establish a mode combining underground irrigation and above-ground irrigation, the underground irrigation mode is that the drip irrigation pipe is buried at a depth of 65cm underground, the distance between drip irrigation pipes is 45cm, the drip irrigation head is connected to the drip irrigation pipe, and the distance between the drip irrigation head and the ground is 8cm; the above-ground irrigation mode is to establish an above-ground hose, the hose irrigates water on the film, and the water infiltrates into the soil through the seeding hole;

[0115] S4, sowing:

[0116] Select a rice mechanical film mulching and direct seeding all-in-one machine to complete rotary tillage, fertilization, sowing, film mulching, soil covering and pressing in one operation;

[0117] S5, water-saving irrigation

[0118] The water-saving irrigation mode includes a shallow water irrigation stage, a medium water irrigation stage, a deep water irrigation stage and a wet irrigation stage;

[0119] S6, field management,

[0120] From the late mature stage of the rice to the harvest, carry out water control and field drying, and do not carry out irrigation;

[0121] The shallow water irrigation stage is from the rice seeding and germination to the greening stage, shallow water irrigation is carried out by using the ground irrigation mode, and salt washing is carried out at the same time, and the irrigation amount of the shallow water is 18m 3 / 667m 2 ;

[0122] The medium water irrigation stage is from the greening to the jointing stage of rice, medium water irrigation is carried out by using the underground irrigation mode, the ground evaporation amount is reduced, and the irrigation utilization efficiency is improved, and the irrigation amount of the medium water is 23m 3 / 667m 2 ;

[0123] The deep water irrigation stage is from the booting to the flowering stage, deep water irrigation is carried out by using the combination of the ground and underground irrigation modes, underground irrigation is carried out first, and then ground irrigation is carried out, so that the salt return is prevented, and the irrigation amount of the deep water is 28m 3 / 667m 2 , the irrigation amount of the underground irrigation mode is 16m 3 / 667m 2 , and the irrigation amount of the ground irrigation mode is 12m 3 / 667m 2 ;

[0124] The wet irrigation stage is from the flowering to the maturation stage of rice, the soil water content is kept at 81-85% of the maximum water holding capacity, the dry-wet alternating mode is adopted, wet irrigation is carried out by using the ground irrigation mode, the soil compaction and salt return are controlled, and the irrigation amount of the wet irrigation is 15m 3 / 667m 2 . Example Five

[0125] A method for water-saving cultivation of rice in saline-alkali soil, comprising the following steps:

[0126] S1, soil improvement:

[0127] The soil of the moderate and severe saline-alkali land is first improved, the salt content in the soil is reduced by planting alfalfa which can absorb salt and alkali, the grown alfalfa can be directly ploughed as green manure, unfermented organic fertilizer is applied and ploughed into the soil to allow the microorganisms to produce organic acid in the reproduction process to convert the salt content, so that the salt and alkali content is reduced, and the converted land is obtained;

[0128] S2, land preparation and fertilization:

[0129] The converted land in the step S1 or the land with moderate or less saline-alkali is deep ploughed, leveled and dredged to increase the permeability of the soil and promote the flow and drainage of water; meanwhile, a surrounding weir is built around the field to intercept and effectively utilize the natural rainfall;

[0130] S3, salt washing and soil preparation:

[0131] The rice is not washed with traditional large water before film mulching and direct seeding, but is washed with water and salt at the same time after sowing, to establish a mode combining underground irrigation and aboveground irrigation, the underground irrigation mode being that the drip irrigation pipe is buried at a depth of 68 cm underground, the drip irrigation pipe spacing is 48 cm, the drip irrigation head is connected to the drip irrigation pipe, and the drip irrigation head is 8 cm away from the ground; the aboveground irrigation mode being that an aboveground hose is established, the hose irrigates water on the film, and the water infiltrates into the soil through the sowing hole;

[0132] S4, sowing:

[0133] A rice mechanical film mulching and direct seeding all-in-one machine is selected to complete rotary tillage, fertilization, sowing, film mulching, soil covering, and pressing in one operation;

[0134] S5, water-saving irrigation

[0135] The water-saving irrigation mode includes a shallow water irrigation stage, a medium water irrigation stage, a deep water irrigation stage, and a wet irrigation stage;

[0136] S6, field management,

[0137] From the late maturation stage to the harvesting of the rice, water control and field drying are performed, and irrigation is not performed;

[0138] The shallow water irrigation stage is from the sowing and seedling emergence stage of the rice to the greening stage, shallow water irrigation is performed by using the aboveground irrigation mode, and salt washing is performed at the same time, the irrigation amount of the shallow water being 19 m 3 / 667m 2 ;

[0139] The medium water irrigation stage is from the greening stage to the jointing stage of the rice, medium water irrigation is performed by using the underground irrigation mode, the underground irrigation reduces the ground evaporation amount and improves the irrigation use efficiency, the irrigation amount of the medium water being 25 m 3 / 667m 2 ;

[0140] The deep water irrigation stage is from the booting stage to the flowering stage, deep water irrigation is performed by using the combination of the aboveground and underground irrigation modes, the underground irrigation mode is used first, and then the aboveground irrigation mode is used to prevent salt return, the irrigation amount of the deep water being 32 m 3 / 667m 2 , the irrigation amount of the underground irrigation mode being 17 m 3 / 667m 2 , and the irrigation amount of the aboveground irrigation mode being 14 m 3 / 667m 2 ;

[0141] The wet irrigation stage is from the flowering stage to the mature stage of the rice, keeps the soil moisture at 81-85% of the maximum water holding capacity, adopts a dry-wet alternating mode, and uses the above-ground irrigation mode to carry out the wet irrigation, so as to control the soil compaction and salt return, and the irrigation amount of the wet irrigation is 18m 3 / 667m 2 . Embodiment six:

[0142] A method for water-saving cultivation of rice in saline-alkali soil, comprising the following steps:

[0143] S1, soil improvement:

[0144] The soil of the medium and heavy saline-alkali land is first improved, the salt content in the soil is reduced by planting sorghum that can absorb salt and alkali, and the sorghum can be directly plowed as green manure after growing up, and unfermented organic fertilizer is applied and plowed into the soil to allow the microorganisms to produce organic acid in the reproduction process to convert the salt content, so as to reduce the salt and alkali content and obtain the converted land.

[0145] S2, land preparation and fertilization:

[0146] The converted land in the step S1 or the land with moderate or less saline-alkali is deep plowed, leveled and dredged to increase the permeability of the soil and promote the flow and drainage of water; meanwhile, a surrounding weir is built around the field to intercept and effectively utilize the natural rainfall.

[0147] S3, salt washing and soil preparation:

[0148] Before the rice film mulching and direct seeding, the traditional large water soaking field for salt washing is not performed, but the water irrigation and salt washing are simultaneously performed after the seeding, and a mode combining the underground irrigation and the above-ground irrigation is established, the underground irrigation mode is that the drip irrigation pipe is buried at a depth of 70cm underground, the distance between the drip irrigation pipes is 50cm, the drip irrigation head is connected to the drip irrigation pipe, and the distance between the drip irrigation head and the ground is 5cm; the above-ground irrigation mode is that the above-ground hose is established, the hose irrigates water on the film, and the water infiltrates into the soil through the seeding hole.

[0149] S4, seeding:

[0150] The rice mechanical film mulching and direct seeding all-in-one machine is selected to complete the rotary tillage, fertilization, seeding, film mulching, soil covering and pressing in one operation.

[0151] S5, water-saving irrigation

[0152] The water-saving irrigation mode includes a shallow water irrigation stage, a medium water irrigation stage, a deep water irrigation stage and a wet irrigation stage.

[0153] S6, field management,

[0154] From the late mature stage of the rice to the harvesting, the water is controlled and the field is dried, and no irrigation is performed.

[0155] The shallow water irrigation stage is from the rice sowing and seedling emergence to the greening stage, shallow water irrigation is carried out by using the ground irrigation mode, and salt washing is carried out at the same time, and the irrigation amount of the shallow water is 15m 3 / 667m 2 ;

[0156] The medium water irrigation stage is from the rice greening to the jointing stage, medium water irrigation is carried out by using the underground irrigation mode, the ground evaporation amount is reduced, and the irrigation use efficiency is improved, and the irrigation amount of the medium water is 20m 3 / 667m 2 ;

[0157] The deep water irrigation stage is from the booting to the flowering stage, deep water irrigation is carried out by using the combination of the ground and underground irrigation modes, the underground irrigation mode is used first, and then the ground irrigation mode is used, so that the salt return is prevented, and the irrigation amount of the deep water is 35m 3 / 667m 2 , the irrigation amount of the underground irrigation mode is 20m 3 / 667m 2 , and the irrigation amount of the ground irrigation mode is 15m 3 / 667m 2 ;

[0158] The wet irrigation stage is from the flowering to the rice maturing stage, the soil moisture is kept at 81-85% of the maximum water holding capacity, the wet irrigation is carried out by using the ground irrigation mode in the dry-wet alternating mode, the soil hardening and the salt return are controlled, and the irrigation amount of the wet irrigation is 10m 3 / 667m 2 .

[0159] Comparative example:

[0160] The cultivation method of the embodiment two is adopted, except that the hose micro-spraying device is not arranged, and the ordinary water flooding irrigation technology is adopted, the embodiment one is the method of arranging the present application, and the different points of the embodiment two to the embodiment six are that the parameters and the specific water consumption are different.

[0161] Table 1 water consumption, yield and cost of producing rice

[0162] Example Two Example Three Example Four Example Five Example Six Comparative Example Water consumption per mu (m 3 )]> 310 286 278 289 292 856 Yield (kg / acre) 568 542 536 547 548 532

[0163] As shown in Table 1, by the scheme of the present application, the water consumption per mu can be effectively reduced, and the water saving is nearly 70%.

[0164] The above describes the present application and its embodiments, which are not limited, and the shown in the full text is only one of the embodiments of the present application, and the actual structure is not limited. In general, if a person skilled in the art is inspired, without departing from the purpose of the present application, without creative design, similar structure and embodiments of the technical solution should belong to the protection scope of the present application.

Claims

1. A method for water-saving rice cultivation in saline-alkali land, characterized in that, Includes the following steps: S1, Soil Improvement: For moderately to severely saline-alkali land, the first step is to improve the soil by planting plants that absorb salt and alkali to reduce the salt content in the soil. After they grow, they can be directly plowed into the soil as green manure and unfermented organic fertilizer can be applied and turned into the soil to ferment. During the fermentation process, microorganisms produce organic acids, which transform the salt and reduce the salinity, resulting in transformed land. S2. Land preparation and fertilization: Deep plowing, leveling, and digging drainage ditches or canals are carried out on the land transformed in step S1 or on land with moderate to low salinity to increase soil permeability and promote water flow and drainage; at the same time, weirs are built around the fields to intercept and effectively utilize natural rainfall. S3, Salt washing and moisture creation: Instead of the traditional method of flooding the paddy field to wash away salt before direct seeding of rice under plastic film, irrigation and salt washing are carried out simultaneously after sowing, establishing a combined underground and above-ground irrigation model. The underground irrigation model involves burying drip irrigation pipes at a depth of 60-70cm underground, with a spacing of 40-50cm between drip irrigation pipes, and connecting drip irrigation heads to the drip irrigation pipes, with the drip irrigation heads 5-10cm above the ground. The above-ground irrigation model involves establishing above-ground flexible hoses, which irrigate the plastic film, and the irrigation water seeps into the soil through the sowing holes. S4, Sowing: Choose a rice mechanical mulching and direct seeding machine that can complete rotary tillage, fertilization, sowing, mulching, covering with soil, and compaction in one operation; S5, Water-saving Irrigation Water-saving irrigation models include shallow water irrigation stage, medium water irrigation stage, deep water irrigation stage, and wet irrigation stage; S6. Field Management From the late ripening stage of rice until harvest, water is controlled and the fields are dried out; irrigation is not carried out. The shallow water irrigation stage refers to the period from rice sowing and emergence to the greening stage, where shallow water is applied using surface irrigation methods, and salt leaching is carried out simultaneously with irrigation. The irrigation volume is 15-20 cubic meters. 3 / 667m 2 ; The aforementioned reclaimed water irrigation stage covers the period from rice greening to jointing, utilizing underground irrigation methods. This underground irrigation reduces surface evaporation and improves irrigation efficiency. The irrigation volume of the reclaimed water is 20-25 cubic meters per second. 3 / 667m 2 ; The deep-water irrigation stage, from the heading to the flowering period, utilizes a combination of surface and subsurface irrigation. Subsurface irrigation is performed first, followed by surface irrigation to prevent salinization. The deep-water irrigation volume is 25-35 cubic meters. 3 / 667m 2 The irrigation volume for underground irrigation is 15-20m³. 3 / 667m 2 The irrigation volume for surface irrigation is 10-15m³. 3 / 667m 2 ; The aforementioned wet irrigation stage, from flowering to rice maturity, maintains soil moisture at 81-85% of maximum water holding capacity. It employs alternating wet and dry irrigation methods, utilizing surface irrigation to control soil compaction and salinization. The irrigation volume for this wet irrigation is 10-20 cubic meters per second. 3 / 667m 2 .

2. The method for water-saving rice cultivation in saline-alkali land according to claim 1, characterized in that: The plant in step S1 is one or more of Suaeda salsa, alfalfa, Suaeda salsa or sesbania.

3. The method for water-saving rice cultivation in saline-alkali land according to claim 1, characterized in that: The field management mentioned includes irrigation, weeding, and fertilization.

4. The method for water-saving rice cultivation in saline-alkali land according to claim 1, characterized in that: The underground irrigation mode and the above-ground irrigation mode share the same water source.