Accurate control method for moisture and salinity of natural salted land field

Abstract

The invention relates to the field of soil science and agricultural irrigation engineering, in particular to a natural salinized land field moisture salinity accurate control method which includes the steps of ditch surrounding, water distribution and salt adjustment, first drainage and then irrigation, night drainage and towards irrigation and no field drying in the whole process. Rice is planted in the salinized land with the moisture salinity controlled, the row spacing is 20 cm * 20 cm, and two seedlings are planted in each hole; according to the method, ditch surrounding, water distribution and salt regulation, first drainage and second irrigation, night drainage and towards irrigation and no field drying in the whole process are performed in the salted land, and rice is planted in the salted land in which water salinity control is performed, so that the water salinity in the salted land is controlled to be maintained in a specific salinity range; and the method can also be used for exploring the difference between the growth performance and yield formation of the rice varieties in a specific salinity environment, and has important significance on scientific research activities of accurately controlling field moisture salinity to screen salt-tolerant crop varieties and accelerating field screening identification and popularization of salt-tolerant germplasm resources.

Description

Technical Field

[0001] The present invention relates to the fields of soil science and agricultural irrigation engineering, and in particular to a method for accurately controlling water salinity in a field of naturally saline land. Background Art

[0002] Natural saline land refers to land with excessively high salt content due to natural environmental factors, which is often located in arid and semi-arid climate areas. The local rainfall is small and the evaporation is large. The salt in the groundwater accumulates on the soil surface due to evaporation. Among them, the salt mainly includes sodium chloride (NaCl), sodium sulfate (Na2SO4), sodium carbonate (Na2CO3), calcium chloride (CaCl2), etc. Arable land is an extremely precious means of production. The comprehensive utilization of saline land can effectively improve arable land resources and increase grain production.

[0003] Natural saline land has dispersed clay particles and low aggregate stability. The soil porosity, water permeability and air permeability are poor, which makes it difficult for water to penetrate evenly into the deep soil layer, and the salt cannot be fully dissolved and discharged. Therefore, the salt content in saline soil is often unevenly distributed. This unevenness increases the difficulty of regulating water and salt. Especially in the process of agricultural irrigation, salt will diffuse to different areas with water flow, further leading to unpredictable salinity accumulation, and problems such as poor consistency and stability of water salinity in saline land.

[0004] At present, the development and utilization of saline land has gradually shifted from the past management of saline land to adapt crops to saline land to the current breeding of salt-tolerant plants (such as rice) to adapt to saline land. The requirements for standardization and reliability of screening and identification of salt-tolerant crops are also higher. Most salt-tolerant germplasm resources are still in the laboratory cultivation stage and urgently need to be screened and identified in a field environment. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for accurately controlling water salinity in a natural saline land field, so as to solve the problems existing in the prior art of uneven soil salinity distribution, difficulty in regulating water salinity, poor consistency and stability of water salinity in saline land, and lack of screening and identification of salt-tolerant crops in a field environment.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for accurately controlling water salinity in a field of natural saline land, wherein the accurate water salinity control includes water distribution and salt adjustment in a surrounding ditch, drainage before irrigation, night drainage and morning irrigation, and no field sun exposure during the whole process;

[0008] The ditch is designed to be rectangular in shape, with a depth of 50 cm and a width of 30 cm;

[0009] A salinity measuring device is set up at intervals of 20m. The salinity of the water in the saline land is tested regularly by the salinity measuring device. By adjusting the water level in the surrounding ditch, salt water is prepared to supplement the salinity of the water in the field or collect the salt discharged from the soil;

[0010] Rice was planted in saline land with water salinity control, with a row spacing of 20 cm × 20 cm and two seedlings per hole;

[0011] The amount of fertilizer applied to the rice during the entire growth period is as follows: applying urea fertilizer with a nitrogen content of greater than or equal to 46%, with an amount of 150 kg of total nitrogen per hectare of field; applying superphosphate fertilizer with a phosphorus pentoxide content of greater than or equal to 16%, with an amount of 60 kg of phosphorus pentoxide per hectare of field; applying potassium chloride fertilizer with a potassium oxide content of greater than or equal to 60%, with an amount of 100 kg of potassium oxide per hectare of field.

[0012] Furthermore, the urea is applied in a mass ratio of base fertilizer: tillering fertilizer: ear fertilizer = 1:1:1, the superphosphate is applied once as a base fertilizer, and the potassium chloride is applied in a mass ratio of base fertilizer: tillering fertilizer: ear fertilizer = 1:2:2.

[0013] Furthermore, the night drainage and morning irrigation includes draining the field water through the perimeter ditch at night when it is determined that the salinity of the water in the saline land is higher or lower than a predetermined salinity range, retaining only a 1-2 cm shallow water layer to maintain the soil moist, and irrigating the prepared salt water through the perimeter ditch in the morning.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. This application concentrates soil salt in a specific area by digging trenches around the saline land, and adjusts the water level in the trenches to configure salt water to supplement the salinity of water in the field or collect salt discharged from the soil, thereby reducing the waste of water resources and ensuring that the salinity of water in the saline land is kept within a predetermined reasonable range. The consistency of water salinity in the entire saline land is further ensured by measures such as drainage before irrigation, night drainage and morning irrigation, and no field exposure during the whole process.

[0016] 2. The present application controls the salinity of field water and plants rice on saline land under field water salinity control, and screens and identifies salt-tolerant rice by measuring the rice yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a data graph showing the effect of the salinity precision control method on the water salinity of natural saline land in Example 1 when the salinity precision control method is implemented and when the salinity precision control method is not implemented;

[0018] Figure 2This is a data graph showing the effect of the precise salinity control method on rice plant height at different stages under the conditions of implementing the precise salinity control method and not implementing the precise salinity control method in Example 1;

[0019] Figure 3 This is a data graph showing the influence of the tillering number of rice at different stages under the conditions of implementing the salinity precise control method and not implementing the salinity precise control method in Example 1;

[0020] Figure 4 This is a data graph showing the effect of the aboveground dry matter weight of rice at different stages under the conditions of implementing the salinity precise control method and not implementing the salinity precise control method in Example 1;

[0021] Figure 5 This is a data graph showing the effect of precise control of salinity of 2‰ and 5‰ on the water salinity of natural saline land after rice transplanting in Example 2;

[0022] Figure 6 The data graph of the effect of water salinity of 2‰ and 5‰ on rice plant height at different stages in Example 2;

[0023] Figure 7 The data graph of the effect of 2‰ and 5‰ water salinity on the tillering number of rice at different stages in Example 2;

[0024] Figure 8 This is a data graph showing the effect of water salinity of 2‰ and 5‰ on the aboveground dry matter weight of rice at different stages in Example 2. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] (1) Test location and time: Field tests will be conducted in 2023 at the National Salt-Alkali Tolerant Rice Technology Innovation Center in Dadan Village, Yacheng Town, Yazhou District, Sanya City, Hainan Province;

[0028] (2) Treatment settings: The experimental field is close to the sea and has natural saline soil with a salt content of about 1-1.5‰ w / v. It has the basic conditions for extracting water from seawater and groundwater. The nearby seawater and groundwater are extracted through pipes and water pumps for mixing, and the salinity is 3‰ w / v. The salt water is irrigated into the field. The salinity is precisely controlled at a concentration of 3‰ w / v (TR), and the control (CK) is not precisely controlled. Rice is planted in the experimental fields with two salinity managements at the same time, and the field test management lasts for 90 days;

[0029] (3) Specific operations: The rice variety is Super Excellent 1000 (CY1000). Plastic film is set around the rice nursery field to prevent rats. After the rice seeds are germinated, they are evenly sown in the flat rice nursery field. Before the seedlings have one leaf and one heart, the seedling field is kept free of obvious water layer to prevent the seedlings from being flooded. After the seedlings have one leaf and one heart, the seedling field is irrigated to maintain a shallow water layer. During the entire nursery field management period, measures are taken to prevent and control diseases, insects and weeds. When the seedlings reach the three-leaf and one-heart stage, they are transplanted to the salt water field, with a transplanting spacing of 20 cm × 20 cm, and 2 seedlings per hole. After transplanting, water and salinity control treatment is carried out until the rice matures and is harvested. Urea (total nitrogen ≥ 46.0%) is used as nitrogen fertilizer, with a dosage of 150 kg of total nitrogen per hectare of field, applied at a mass ratio of basal fertilizer: tillering fertilizer: ear fertilizer = 1:1:1; superphosphate (P2O5 ≥ 16.0%) is used as phosphate fertilizer, with a dosage of 60 kg of P2O5 per hectare, applied once as basal fertilizer; potassium chloride (K2O ≥ 60.0%) is used as potash fertilizer, with a dosage of 100 kg of K2O per hectare, applied at a mass ratio of basal fertilizer: tillering fertilizer: ear fertilizer = 1:2:2. According to the pest and disease disaster warnings issued by local agricultural technology extension service agencies and combined with field observations, pesticides are sprayed regularly from the middle of rice tillering, and the brand of the agent is changed periodically. During the flowering period of rice, measures such as laying bird-proof nets, hanging ribbons, and spreading rat poison are taken to prevent yield losses;

[0030] The specific operation steps for the control measures of water salinity in saline fields in this experiment are as follows:

[0031] S1. Water distribution and salt regulation in ditch: The saline land covers an area of ​​about 1 mu. A small agricultural excavator is used to dig a ditch around the field. The ditch is designed to be rectangular, 50 cm deep and 30 cm wide. A salinity measuring device is set up every 20 meters to detect the water salinity of the saline land. By adjusting the water level in the ditch, salt water is configured to supplement the water salinity in the field or collect the salt discharged from the soil, and the drainage and irrigation strategies of the ditch are adjusted to keep the water salinity within the established reasonable range (3±0.5‰w / v);

[0032] S2. Drain first, then irrigate: When it is found that the salinity of the saline land is higher or lower than the predetermined salinity range, the water in the field is first drained through the surrounding ditch, and fresh water or high-concentration salt water is pumped into the surrounding ditch through pipeline facilities to make the salt water of the required concentration, and then irrigate the saline land to ensure the consistency of the water salinity of the entire field;

[0033] S3. Night drainage and morning irrigation: When the salinity of the saline land is found to be higher or lower than the established salinity range, the field water is drained through the perimeter ditch at night (8-10 pm), leaving only a 1-2 cm shallow water layer to keep the soil moist, and the prepared salt water is irrigated through the perimeter ditch in the morning (6-8 am);

[0034] S4. No field drying during the whole process: During the whole process of controlling the water salinity in the saline field, the field shall not be drained and dried during the day;

[0035] S5. Measurement and analysis: After rice transplanting, record the salinity of the saline soil at 10 a.m. and 6 p.m. every day, take the average value of the two time periods, and record it as the field water salinity of the day.

[0036] The specific operation steps of this experiment for the saline field without implementing water salinity control measures are as follows: the saline field covers an area of ​​about 1 mu, surrounded by ridges, and a salinity measuring device is set up at intervals of 20 meters. During the test period, the salinity of 3‰ w / v salt water is continuously irrigated and a 5cm water layer is maintained;

[0037] During the rice panicle differentiation, flowering and maturity stages, 12 rice stems (about 0.48 m2) were randomly selected from the experimental field. 2 ) disease-free and uniformly growing rice plants, clean the rice samples, use a ruler to measure the plant height of each rice sample and record the number of tillers, cut the roots of the rice samples with scissors, divide the plants into leaves, stems and panicles (flowering stage and maturity stage), put them into mesh bags and place them in an oven, fix the samples at 105°C for 30 minutes, adjust the temperature to 80°C and dry the samples to a constant weight, take them out and cool them to room temperature, weigh and calculate the total dry weight of the aboveground parts;

[0038] At the rice maturity stage, 3 m 2The plants (about 75 plants) with uniform growth were placed under natural conditions for sun drying and threshing. The rice grains were weighed after being winnowed and removed of impurities. The moisture content of the rice grains was measured using a grain moisture meter (PM-8188-A, KETT, Japan), converted into the mass of grains with a moisture content of 14.0%, and the actual yield was calculated. Six plants with uniform growth were randomly selected in each experimental plot, and the number of ears per unit area was recorded and calculated. The rice ears were threshed manually, and the full grains and empty grains in the rice were separated by water selection. After drying, the half-full grains and empty grains were separated by seed wind separation purity meter (CFY-Ⅱ, Zhejiang Top Instrument Co., Ltd., China). The mass of full grains, half-full grains and empty grains was weighed and recorded, and small samples were taken from them: 3 samples of full grains (30 g), half-full grains (10 g) and empty grains (5 g) were weighed respectively, and the number of grains in the small samples was manually counted, and the total number of full grains, half-full grains and empty grains were calculated. The specific calculation method of yield components is as follows:

[0039] Number of ears per unit area = number of sample ears / sampling area;

[0040] Number of spikelets per ear = total number of spikelets per unit area / number of ears per unit area;

[0041] Fruit setting rate (%) = number of full grains / total number of spikelets × 100;

[0042] Thousand-grain weight = mass of full grains in sample / number of full grains × 1000.

[0043] (4) Analysis of test results:

[0044] The water salinity in the field was tested and recorded. The water salinity of the treatment with precise salinity control was within the established reasonable range (3±0.5‰w / v), and the average water salinity within 90 days was 3.04‰w / v. In the control treatment, the water salinity increased with the extension of the critical time, and finally reached 6.4‰w / v. The average water salinity within 90 days was 4.93‰w / v. The results are as follows Figure 1 .

[0045] like Figure 2 As shown in the figure, during the panicle differentiation period of rice, the plant height TR of CY1000 was 11.99% higher than that of CK; during the flowering period of rice, the plant height TR of CY1000 was 6.30% higher than that of CK; during the maturity period of rice, the plant height TR of CY1000 was 5.66% higher than that of CK; in summary, by adopting the precise control method of field water salinity in saline land, the plant height of rice at multiple key growth stages was significantly higher than that of rice without precise salinity control, which further verified the salinity detection results.

[0046] like Figure 3As shown in the data, during the panicle differentiation period of rice, the tiller number TR of CY1000 was 14.99% higher than that of CK; during the flowering period of rice, the tiller number TR of CY1000 was 16.88% higher than that of CK; during the maturity period of rice, the tiller number TR of CY1000 was 18.12% higher than that of CK; in summary, by adopting the precise control method of field water salinity in saline land, the tiller number of rice at multiple key growth nodes was significantly higher than that of rice without precise salinity control, which further verified the salinity detection results.

[0047] like Figure 4 As shown in the data, during the panicle differentiation period of rice, the aboveground dry weight TR of CY1000 was 40.31% higher than that of CK; during the flowering period of rice, the aboveground dry weight TR of CY1000 was 32.28% higher than that of CK; during the maturity period of rice, the aboveground dry weight TR of CY1000 was 10.56% higher than that of CK; in summary, by adopting the precise control method of field water salinity in saline land, the aboveground dry weight of rice at multiple key growth stages was significantly higher than that of rice without precise salinity control, which further verified the salinity detection results.

[0048] As shown in Table 1, at the rice maturity stage, the rice yield under the precise salinity control treatment was 60.47% higher than that of the control treatment. Among the yield components, the number of effective panicles per unit area of ​​CY1000 under TR treatment was 17.92% higher than that of CK treatment; the number of grains per panicle of CY1000 under TR treatment was 32.11% higher than that of CK treatment; the fruit setting rate of CY1000 under TR treatment was 8.48% higher than that of CK treatment; the thousand-grain weight of CY1000 under TR treatment was 7.25% higher than that of CK treatment. In summary, the rice yield and its component factors were significantly higher than those of rice without precise salinity control by adopting this method of precise control of field water salinity in saline land, and the difference in yield reached a significant level, which further verified the salinity detection results.

[0049] Table 1 Effects of different water salinity control measures on rice yield and its components

[0050]

[0051] Note: Lowercase letters indicate significant differences at the 0.05 level, the same below.

[0052] Example 2

[0053] (1) Test location and time: Field tests will be conducted in 2024 at the Leyi Village Test Station in Liguo Town, Ledong Li Autonomous County, Hainan Province;

[0054] (2) Salt concentration setting: The nearby seawater and groundwater are pumped through pipes and water pumps for mixing, and the salt water concentration is set to 2‰w / v and 5‰w / v for irrigation into the field;

[0055] (3) Test varieties: Jingyou 007 (SY007) and Shuangliangyou 91 (SLY91);

[0056] (4) Specific operations: Set up plastic film around the rice nursery to prevent rats, germinate the rice seeds and evenly sow them in the flat rice nursery field. Before the seedlings have one leaf and one heart, keep the seedling field free of obvious water layer to prevent the seedlings from flooding. After the seedlings have one leaf and one heart, irrigate the seedling field to maintain a shallow water layer. During the entire nursery field management period, take measures to prevent and control pests and diseases. When the seedlings reach the three-leaf and one-heart stage, transplant them manually into the salt water field, with a transplanting spacing of 20 cm × 20 cm, and 2 seedlings per hole. After transplanting, carry out corresponding salt water management treatment until the rice matures and is harvested. Urea (total nitrogen ≥ 46.0%) is used as nitrogen fertilizer, with a dosage of 150 kg of total nitrogen per hectare of field, applied at a mass ratio of basal fertilizer: tillering fertilizer: ear fertilizer = 1:1:1; superphosphate (P2O5 ≥ 16.0%) is used as phosphate fertilizer, with a dosage of 60 kg of P2O5 per hectare, applied once as basal fertilizer; potassium chloride (K2O ≥ 60.0%) is used as potash fertilizer, with a dosage of 100 kg of K2O per hectare, applied at a mass ratio of basal fertilizer: tillering fertilizer: ear fertilizer = 1:2:2. According to the pest and disease disaster warnings issued by local agricultural technology extension service agencies and combined with field observations, pesticides are sprayed regularly from the middle of rice tillering, and the brand of the agent is changed periodically. During the flowering period of rice, measures such as laying bird-proof nets, hanging ribbons, and spreading rat poison are taken to prevent yield losses;

[0057] The specific operation steps for the control measures of water salinity in saline fields in this experiment are as follows:

[0058] S1. Water distribution and salt regulation in ditch: The experimental field is close to the sea and belongs to natural saline soil with a salt content of about 1-1.5‰w / v. It has the basic conditions for extracting water from seawater and underground freshwater wells. The saline land covers an area of ​​about 3 mu. A small agricultural excavator is used to dig a ditch around the field. The ditch is designed to be rectangular, 50cm deep and 30cm wide. The salinity of the saline land is detected by the reserved salinity measurement equipment. The salinity is allocated by adjusting the water level in the ditch, replenishing the salinity of the field or collecting the salt discharged from the soil, and adjusting the drainage and irrigation strategies of the ditch to keep the salinity within the established reasonable range (2±0.5‰w / v and 5±0.5‰w / v).

[0059] S2. Drain first, then irrigate: When it is found that the salinity of the saline land is higher or lower than the predetermined salinity range, the water in the field is first drained through the surrounding ditch, and fresh water or high-concentration salt water is pumped into the surrounding ditch through pipeline facilities to make the salt water of the required concentration, and then irrigate the saline land to ensure the consistency of the water salinity of the entire field;

[0060] S3. Night drainage and morning irrigation: When the salinity of the saline land is found to be higher or lower than the established salinity range, the field water is drained through the perimeter ditch at night (8-10 pm), leaving only a 1-2 cm shallow water layer to keep the soil moist, and the prepared salt water is irrigated through the perimeter ditch in the morning (6-8 am);

[0061] S4. No field drying during the whole process: During the whole process of controlling the water salinity in the saline field, the field shall not be drained and dried during the day;

[0062] S5. Measurement and analysis: After rice is transplanted to the saltwater field, record the salinity of the water in the saline land at 10 a.m. and 6 p.m. every day until maturity. Take the average value of the two time periods and record it as the field water salinity of the day.

[0063] At the middle tillering stage, panicle differentiation stage, heading stage and maturity stage of rice, 12 rice stems (about 0.48 m2) were randomly selected from the experimental field. 2 ) Disease-free and uniformly growing rice plants were selected. After cleaning the rice samples, the plant height of each rice sample was measured with a ruler and the number of tillers was recorded. The roots of the rice samples were cut with scissors, and the plants were divided into leaves, stems and panicles (flowering stage and maturity stage). The samples were put into mesh bags and placed in an oven. The samples were withered at 105°C for 30 minutes, then the temperature was adjusted to 80°C to dry the samples to a constant weight. The samples were taken out and cooled to room temperature, and the total dry weight of the aboveground parts was weighed and calculated.

[0064] During the rice maturity period, 3m 2 The plants (about 75 plants) with uniform growth were placed under natural conditions for sun drying and threshing. The rice grains were weighed after being winnowed and removed of impurities. The moisture content of the rice grains was measured using a grain moisture meter (PM-8188-A, KETT, Japan), converted into the mass of grains with a moisture content of 14.0%, and the actual yield was calculated.

[0065] At the rice maturity stage, six plants with uniform growth were randomly selected in each experimental plot, and the number of ears per unit area was recorded. The rice ears were threshed manually, and the full grains and empty grains in the rice were separated by water selection. After drying, the half-full grains and empty grains were separated by seed wind separation purity meter (CFY-Ⅱ, Zhejiang Top Instrument Co., Ltd., China). The mass of full grains, half-full grains and empty grains was weighed and recorded, and small samples were taken from them: 3 samples of full grains (30 g), half-full grains (10 g) and empty grains (5 g) were weighed respectively, and the number of grains in the small samples was manually counted, and the total number of full grains, half-full grains and empty grains were calculated. The specific calculation method of yield components is as follows:

[0066] Number of ears per unit area = number of sample ears / sampling area;

[0067] Number of spikelets per ear = total number of spikelets per unit area / number of ears per unit area;

[0068] Fruit setting rate (%) = number of full grains / total number of spikelets × 100;

[0069] Thousand-grain weight = mass of full grains in sample / number of full grains × 1000.

[0070] (5) Analysis of test results:

[0071] 1. As Figure 5 As shown, the water salinity in the field was detected and recorded every day after rice transplanting, and the water salinity was within the established range, i.e., 2 ± 0.5‰ w / v and 5 ± 0.5‰ w / v;

[0072] 2. If Figure 6 As shown in the figure, in the middle tillering stage of rice, the plant height of SY007 and SLY91 decreased by 4.14% and 6.04% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively; in the panicle differentiation stage of rice, the plant height of SY007 and SLY91 decreased by 4.33% and 7.53% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively; in the heading stage of rice, the plant height of SY007 and SLY91 decreased by 5‰w / v salt stress compared with 2‰w / v salt stress, respectively. The plant heights of SY007 and SLY91 decreased by 7.23% and 10.40%, respectively. At the maturity stage of rice, the plant heights of SY007 and SLY91 decreased by 7.53% and 9.38%, respectively, under 5‰w / v salt stress compared with 2‰w / v salt stress. In summary, after precise control of field water salinity in saline land, the plant heights of rice at multiple key growth stages under 5‰w / v salt stress were significantly lower than those under 2‰w / v salt stress.

[0073] 3. Such as Figure 7As shown in the figure, in the middle tillering stage of rice, the tiller numbers of SY007 and SLY91 decreased by 34.60% and 27.80% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively; in the panicle differentiation stage of rice, the tiller numbers of SY007 and SLY91 decreased by 28.91% and 30.14% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively; in the flowering stage of rice, the tiller numbers of SY007 and SLY91 decreased by 5‰w / v salt stress compared with 2‰w / v salt stress, respectively. The tiller numbers of SY007 and SLY91 decreased by 33.33% and 39.32%, respectively; at the rice maturity stage, the tiller numbers of SY007 and SLY91 decreased by 14.37% and 16.99%, respectively, under 5‰w / v salt stress compared with 2‰w / v salt stress; in summary, after precise control of field water salinity in saline land, the tiller numbers of rice at multiple key growth nodes under 5‰w / v salt stress were significantly less than those under 2‰w / v salt stress;

[0074] 4. Such as Figure 8 As shown in the figure, at the middle tillering stage of rice, the tiller numbers of SY007 and SLY91 decreased by 34.69% and 38.83% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively; at the panicle differentiation stage of rice, the aboveground dry matter weight of SY007 and SLY91 decreased by 27.26% and 47.11% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively; at the flowering stage of rice, the aboveground dry matter weight of SY007 and SLY91 decreased by 27.26% and 47.11% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively. The aboveground dry weight of SY007 and SLY91 decreased by 33.71% and 79.15% respectively under 5‰w / v salt stress compared with 2‰w / v salt stress at the rice maturity stage. In summary, after precise control of field water salinity in saline land, the aboveground dry weight of rice at multiple key growth stages under 5‰w / v salt stress was significantly lower than that under 2‰w / v salt stress.

[0075] 5. As shown in Table 2, at the rice maturity stage, the yield of SY007 and SLY91 decreased by 62.67% and 55.03% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively. Among the yield components, the number of effective panicles per unit area of ​​SY007 and SLY91 decreased by 14.38% and 17.02% under 5‰w / v salt stress compared with 2‰w / v salt stress, respectively. The number of grains per panicle of SY007 and SLY91 decreased by The yield and its component factors of rice under 5‰w / v salt stress were significantly lower than those under 2‰w / v salt stress, and the difference reached a significant level.

[0076] Table 2 Effects of different water salinity on rice yield and its components

[0077]

[0078] In summary, the present invention provides a method for accurately controlling water and salinity in fields of natural saline land. The technical solution for field salinity management includes adjusting water and salt through ditch distribution, draining first and then irrigating, draining at night and irrigating in the morning, and not drying the fields during the whole process. The method is easy to operate and suitable for accurately controlling salt water with a specific concentration gradient for field irrigation in agricultural production and scientific research in natural saline land. Compared with not implementing precise salinity control measures, the salinity control measures can maintain the stability of field salinity. In addition, rice cultivation experiments were carried out in saline land where precise water and salinity control was implemented. The results showed that multiple indicators of rice, such as plant height, number of tillers, aboveground dry matter weight, yield and its component factors were significantly higher than those without precise salinity control. Implement precise salinity control measures; and under high-concentration salt water irrigation measures, many rice indicators such as plant height, number of tillers, aboveground dry matter weight, yield and its component factors are significantly lower than those under low-concentration salt water irrigation measures; compared with conventional saline land agricultural irrigation methods, it can save effort and effectively maintain the stability of field water salinity in saline land, meet the demand for saline concentration required for rice cultivation in specific farmland, and explore the differences in growth performance and yield formation of rice varieties under specific salt concentration environments. It is of great significance for scientific research activities such as accurately controlling field water salinity to screen salt-tolerant crop varieties, and accelerating the field screening, identification and promotion of salt-tolerant germplasm resources.

[0079] The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiment. Any equivalent modifications or changes made by ordinary technicians in this field based on the contents disclosed by the present invention should be included in the protection scope recorded in the claims.

Claims

1. A method for accurately controlling water salinity in a natural saline land field, characterized in that: The precise control of water and salinity includes water distribution and salt adjustment in the surrounding ditch, drainage before irrigation, night drainage and morning irrigation, and no field drying during the whole process; The ditch is designed to be rectangular in shape, with a depth of 50 cm and a width of 30 cm; A salinity measuring device is set up at intervals of 20m. The salinity of the water in the saline land is tested regularly by the salinity measuring device. By adjusting the water level in the surrounding ditch, salt water is prepared to supplement the salinity of the water in the field or collect the salt discharged from the soil; Rice was planted in saline land with water salinity control, with a row spacing of 20 cm × 20 cm and two seedlings per hole; The amount of fertilizer applied to the rice during the entire growth period is as follows: applying urea fertilizer with a nitrogen content of greater than or equal to 46%, with an amount of 150 kg of total nitrogen per hectare of field; applying superphosphate fertilizer with a phosphorus pentoxide content of greater than or equal to 16%, with an amount of 60 kg of phosphorus pentoxide per hectare of field; applying potassium chloride fertilizer with a potassium oxide content of greater than or equal to 60%, with an amount of 100 kg of potassium oxide per hectare of field.

2. The method for accurately controlling water salinity in a natural saline land field according to claim 1, characterized in that: The urea is applied in a mass ratio of base fertilizer: tillering fertilizer: ear fertilizer = 1:1:1, the superphosphate is applied once as a base fertilizer, and the potassium chloride is applied in a mass ratio of base fertilizer: tillering fertilizer: ear fertilizer = 1:2:

2.

3. The method for accurately controlling water salinity in a natural saline land field according to claim 1, characterized in that: The night drainage and morning irrigation method includes draining the field water through the perimeter ditch at night when it is determined that the salinity of the water in the saline land is higher or lower than the established salinity range, leaving only a 1-2 cm shallow water layer to maintain the soil moist, and irrigating the prepared salt water through the perimeter ditch in the morning.

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