A method for controlling leers in rice fields in northeast single-cropping rice areas

Abstract

The application provides a rice field water spongia prevention and treatment method suitable for northeast single-cropping rice areas, which comprises the following steps: harvesting rice after maturity, crushing and throwing straw to obtain straw crushed material; combining phosphorus fertilizer with full amount of straw for autumn application and autumn cutting and burying for returning to field; during the soil freezing period in the following spring, carrying out ploughing operation with a depth of 10-15 cm; during the spring planting period, carrying out field soaking, starting mud, and then transplanting; before rice tillering, draining the field surface water, and then irrigating after field drying. The method is simple and easy to implement and promote, and by means of the weed resistance advantage of straw returning to field, the method can improve soil and enhance fertility, and promote agricultural resource recycling. By adopting the near-natural management idea, the traditional path of pesticide prevention and treatment of water spongia is abandoned, and the risk of pesticide pollution is avoided from the source, and the prevention and treatment effect on rice field water spongia is remarkable. Not only can the method promote rice yield increase, but also can effectively reduce the expenditure of farmers in the aspects of chemical fertilizer and water spongia prevention and treatment, and realize the win-win of economic and ecological benefits.

Description

Technical Field

[0001] This invention belongs to the field of paddy field filament control technology, specifically relating to a method for controlling paddy field filaments suitable for single-season rice areas in Northeast China. Background Technology

[0002] Spirogyra is a common and noxious weed in paddy fields in Northeast China. In Heilongjiang Province, it infests approximately 39 million mu (about 2.67 million hectares) of paddy fields annually, causing serious damage to about 1 million mu (about 667,000 hectares). Spirogyra has low nutrient requirements but is highly sensitive to phosphorus. Topical application of phosphate fertilizer, in particular, easily induces its growth. During the rice tillering stage, its widespread proliferation often blocks sunlight and air, lowering paddy field water temperature and dissolved oxygen levels. Furthermore, Spirogyra itself not only competes for nitrogen and phosphorus but, in severe cases, can also encase rice roots, restricting normal tillering and causing stunted growth and seedling death. Currently, the main methods for controlling Spirogyra in paddy fields are the application of algaecides and manual removal. Algaecides are effective, but long-term use increases Spirogyra's resistance, and improper use can cause secondary pollution. Manual removal is time-consuming and labor-intensive, and Spirogyra easily proliferates rapidly through fragmentation. Therefore, how to control Spirogyra in paddy fields using near-natural methods is a pressing problem that needs to be solved.

[0003] Chinese invention patent CN202111598318.0 discloses a pharmaceutical composition for controlling Spirogyra in paddy fields. The composition is characterized by being made from the following raw materials per 1L: 170-210g erythromycin thiocyanate, 190-230g sodium diacetate, 180-220g organic solvent, 8-12g compound vitamins, 50-70g emulsifier, with the balance being water. The disadvantages of this composition are that it contains biotoxic substances that inhibit the life activities of organisms in the aquatic environment and cause biotoxicity problems. It poses a potential pollution risk, and the dead Spirogyra releases large amounts of nitrogen- and phosphorus-containing organic pollutants, further damaging the environment. Chinese invention patent CN201310379079.9 discloses a method for preventing Spirogyra in paddy fields through pre-plowing fertilization. The method includes the following steps: cultivating strong seedlings in the seedbed, meticulous land preparation in the paddy field, pre-plowing fertilization, tilling, setting up a screen filter pond, post-plowing irrigation and harrowing, weed control, transplanting, water layer management, application of fertilizer during the heading stage, pest and disease control, and harvesting. In particular, the pre-plowing fertilization step involves applying 85%–90% of the planned nitrogen fertilizer, 100% of the phosphorus fertilizer, and 100% of the potassium fertilizer to the soil surface in one go before tilling. This is done manually or by agricultural machinery, with manual patching to ensure no overlap or omissions. The disadvantages of this method are that it requires high precision in land preparation, places additional demands on water management facilities, increases initial investment, and has a relatively complex technical process, making it unsuitable for widespread application. Chinese invention patent CN202111491357.0 discloses a method for integrated weed control in organic paddy fields. The implementation steps of this method include: after the previous season's rice harvest, weed control is carried out in both the field and along the field ridges; before rice planting, fully decomposed organic fertilizer is applied to the paddy field, followed by land preparation and sun-drying to remove weed roots and stems; the paddy field is then covered with mulch, rice seedlings are transplanted, and the field is flooded; during the rice growing season, weed control along the field ridges and intermittent sun-drying are combined to purify the paddy field water environment, and manual weeding is carried out once if necessary; before the rice harvest, manual weeding is conducted in the field to remove mature weed inflorescences. The disadvantages of this method are that the organic fertilizer decomposition process requires professional handling and time; otherwise, it may introduce pathogens or affect oil film formation. Furthermore, this method has high costs and a high operational threshold, and the technical process is relatively complex.

[0004] In summary, the above invention patents show that the main methods for controlling Spirogyra are to use drug combinations or a combination of pre-plowing fertilization and land preparation. However, drug combinations may burden the environment, and existing combination methods are complex and not suitable for widespread application. Summary of the Invention

[0005] The technical problem this invention aims to solve is to address the shortcomings of existing technologies by providing a method for controlling Spirogyra in paddy fields in the single-season rice-growing areas of Northeast China. This method is easy to implement, utilizes the weed-resistant properties of straw returned to the field, not only improving soil fertility but also achieving the recycling of agricultural resources. By adopting a near-natural approach, it mitigates the pesticide pollution problem caused by pesticide control of Spirogyra and demonstrates good efficacy in controlling Spirogyra in paddy fields. It contributes to increased rice yields, saves production costs, and reduces farmers' costs associated with fertilizer application and Spirogyra control.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for controlling Spirogyra in paddy fields applicable to single-season rice areas in Northeast China, the method being as follows: 1. A method for controlling Spirogyra in paddy fields applicable to single-season rice areas in Northeast China, characterized in that the method comprises: S1. After the rice matures, it is harvested, the straw is crushed and scattered to obtain straw crushed material; S2, Autumn application of phosphate fertilizer and autumn cutting and burying of all straw: In autumn, apply 1 / 3 to 2 / 3 of the phosphate fertilizer during the entire growth period of rice. Use a tiller to break up the root stubble and loosen the soil layer. The working depth is 20cm to 25cm. Use a machine that integrates a disc harrow, a horizontal pressing component and a screed to evenly mix and bury the straw root stubble, phosphate fertilizer and the straw crushed material obtained in S1 into the 0cm to 25cm soil layer, and then level the field surface. S3. During the soil thawing period in the following spring, land preparation work is carried out at a depth of 10cm to 15cm. S4. During the spring planting season, the fields are soaked to remove slurry, and then rice seedlings are transplanted. S5. In the early stage of rice tillering, drain the water from the field surface, dry the field, and then irrigate. Preferably, before the S3 land preparation operation, the remaining phosphate and nitrogen fertilizers from the entire growth period are first spread on the soil surface, and then the land preparation and returning operation is carried out, mixing the fertilizers into the soil during the land preparation operation.

[0007] Preferably, the amount of phosphate fertilizer applied to S1 throughout its entire growth period is 3 kg / mu to 5 kg / mu (calculated as P2O5).

[0008] Preferably, the depth of the paddy field in S4 is 3cm to 5cm, and the depth of the slurry formation is 2cm to 5cm.

[0009] Preferably, the drying time in S5 is 4 to 6 days.

[0010] Compared with the prior art, the present invention has the following advantages: The method of this invention is easy to implement. Utilizing the weed-resistant properties of straw returned to the field, it not only improves soil fertility but also achieves the recycling of agricultural resources. By adopting a near-natural approach, it mitigates the pesticide pollution problem caused by pesticide control of Spirogyra. Combined with autumn application of phosphate fertilizer, the control efficacy against Spirogyra in paddy fields can reach over 95%. This contributes to increased rice yield, saves production costs, and reduces farmers' costs associated with fertilizer application and Spirogyra control.

[0011] The present invention will be further described in detail below with reference to the embodiments. Detailed Implementation

[0012] Example 1 The experimental site information for this embodiment is: Alaxin Village, Daxing Town, Tailai County, Qiqihar City, Heilongjiang Province. It belongs to the mid-latitude continental monsoon climate zone, characterized by dry and windy springs, hot and dry summers, windy and highly variable autumns, and cold and snowless winters. The average annual accumulated temperature is 2930.6℃, the average annual temperature is 4.9℃, the average annual frost-free period is 145 days, the average annual sunshine duration is 2908.8 hours, and the average annual precipitation is 392.6 mm. It has a complete irrigation and drainage system. The tested soil is submerged paddy soil. The physicochemical properties of the topsoil are: organic matter 16.2 g·kg⁻¹. -1 Total nitrogen 2.28 g·kg -1 Hydrolyzable nitrogen 198 mg·kg -1 Available phosphorus 42 mg·kg -1 Available potassium 166 mg·kg -1 The test site area is 708.7 m². 2 .

[0013] This embodiment describes a method for controlling Spirogyra in paddy fields in the single-season rice region of Northeast China. The method is as follows: S1. Harvest the rice promptly after it matures, crush and spread the straw to obtain straw crushed material with a length of 5cm to 10cm. S2, Autumn application of phosphate fertilizer + autumn cutting and burying of all straw: The experiment began in October 2022. Autumn application of phosphate fertilizer was adopted, with 1 / 3 to 2 / 3 of the total phosphate fertilizer applied during the rice's growth period (specifically, 1 / 3 of the total phosphate fertilizer applied in this example). A tiller was used to break up the stubble and loosen the soil layer at a depth of 0-25cm. A machine combining a disc harrow, a horizontal pressing component, and a screed was used to evenly mix and bury the straw stubble, phosphate fertilizer, and the crushed straw obtained in S1 to a soil layer of 0-25cm, and then the field surface was leveled. The total amount of phosphate fertilizer applied throughout the entire growth period is 3 kg / mu to 5 kg / mu based on P2O5. In this example, the total amount of phosphate fertilizer applied throughout the entire growth period is 3 kg / mu based on P2O5. S3. Land preparation: During the soil thawing period in the following spring (mid-April), land preparation is carried out at a depth of 10cm to 15cm. Before land preparation, the remaining phosphate and nitrogen fertilizers from the entire growth period are spread on the soil surface, and then the land preparation and return to the field are carried out, mixing the fertilizers into the soil during the land preparation. S4. During the spring planting season (early May), the paddy field was soaked to a depth of 5cm, and the slurry depth was maintained at 5cm. Then the rice seedlings were transplanted. The rice variety used for the test was Zhongkefa No. 5. In this embodiment, the depth of paddy field soaking can be 3cm to 5cm, and the depth of slurry formation can be 2cm to 5cm; S5. In the early tillering stage of rice (late May), drain the water from the field surface, let the field dry for 4 days, and then irrigate. Other management is the same as in the local area.

[0014] In this embodiment, the field can be dried for 4 to 6 days, until the soil in the field cracks.

[0015] Comparative Example 1 The test site information in this embodiment is the same as in Embodiment 1, located next to the test site in Embodiment 1, with identical soil properties, and the test site area is 709.9 m². 2 .

[0016] This embodiment describes a method for controlling Spirogyra in paddy fields in the single-season rice region of Northeast China. The method is as follows: S1. Harvest the rice promptly after it matures, crush and spread the straw to obtain straw crushed material with a length of 5cm to 10cm. S2, Full amount of straw cut and buried in the field in autumn: Loosen the soil layer, the working depth is 25cm, and then return the straw to the field. Cut the straw stubble longitudinally, rotary till, and mix the longitudinally cut straw stubble and the straw crushed material obtained in S1 evenly and bury it in the loosened soil layer, and then scrape the field surface level. S3. Spring application of phosphate fertilizer + land preparation: In the following spring, during the soil thawing period (mid-April), first spread phosphate fertilizer (3 kg / mu) for the entire growth period on the soil surface, and then carry out land preparation work at a depth of 15 cm, mixing the phosphate fertilizer into the soil during the land preparation work. S4. During the spring planting season (early May), the paddy field was soaked to a depth of 3cm, and the slurry depth was maintained at 5cm. Then the rice seedlings were transplanted. The rice variety used for the test was Zhongkefa No. 5. S5. In the early tillering stage of rice (late May), drain the water from the field surface and let the field dry for 4 days until the soil in the field cracks. Then irrigate. Other management is the same as in the local area.

[0017] Comparative Example 2 The experimental site information and experimental time for this comparative example are the same as those for Example 1, the soil properties are consistent, and the experimental site area is 581.7 m². 2 .

[0018] The method for controlling Spirogyra in paddy fields in this comparative example is the same as in Example 1, except that: in step S5, the paddy field is not dried during the early tillering stage of rice, while the other steps are the same as in Example 1.

[0019] Comparative Example 3 The experimental site information and experimental time of this comparative example are the same as those of Comparative Example 1, the soil properties are the same, and the experimental site area is 657.4 m². 2 .

[0020] The method for controlling Spirogyra in paddy fields in this comparative example is the same as that in Comparative Example 1, the difference is that in step S2, the soil layer is not loosened and the straw stubble is not cut longitudinally. Instead, the straw crushed material obtained in S1 is simply covered on the soil surface to get through the whole winter.

[0021] Comparative Example 4 The experimental site information and experimental time of this comparative example are the same as those of Comparative Example 1, the soil properties are the same, and the experimental site area is 709.7 m². 2 .

[0022] The method for controlling Spirogyra in paddy fields in this comparative example is the same as that in Comparative Example 1, except for steps S1-S2; the other steps are the same. S1. Harvest the rice promptly after it matures, and pack the straw away from the field. S2. No land preparation is carried out in autumn; rice stubble is left for winter without tillage.

[0023] Comparative Example 5 The experimental site information and experimental time of this comparative example are the same as those of Comparative Example 1, the soil properties are the same, and the experimental site area is 656.7 m². 2 .

[0024] The method for controlling Spirogyra in paddy fields in this comparative example is the same as that in Comparative Example 1, except for steps S1, S2, and S5. The other steps are the same. S1. Harvest the rice promptly after it matures, and pack the straw away from the field. S2. No land preparation is carried out in autumn; rice stubble is left for winter without tillage. S5. No field drying is carried out in the early stage of rice tillering; other management is the same as in the local area.

[0025] Fifteen days after the field drying in Example 1, the Spirogyra coverage rate was measured at each test site of Example 1 and Comparative Examples 1-5 using a three-point sampling method. A 1m sample was taken at each point. 2The quadrats were used, and the average value was taken as the Spirogyra coverage rate. The 15-day Spirogyra coverage rate was determined by observing the coverage and control efficacy of Spirogyra 15 days after treatment. A grading system was established: 0 (no Spirogyra), 1 (1%–10% with slight Spirogyra), 3 (11%–25% with some green), 5 (26%–50% visible Spirogyra), 7 (51%–75% with a network), and 9 (76%–100% with widespread Spirogyra). The occurrence level of Spirogyra for each treatment was recorded and compared with Comparative Example 4 to calculate the control efficacy. Three representative points were selected at each test site, within a 1m radius. 2 Samples were taken and weighed within the specified area, and the control efficacy was calculated by comparing each treatment group with the control group. The control effect T was calculated based on the experimental data.

[0026] Formula for calculating control effectiveness: T = (C0 - C1) / C0 × 100% In the formula: T -- prevention and control effect %.

[0027] C0 -- Average weight of Spirogyra in the blank control group.

[0028] C1 -- Average weight of Spirogyra after treatment.

[0029] Formula for calculating control effectiveness: Control effectiveness = (Average coverage rate of Spirogyra in control area - Average coverage rate of Spirogyra in treatment area) / Average coverage rate of Spirogyra in control area × 100% Table 1 shows the average weight and control effect of different treatments at each test site. The results show that the control effect of Spirogyra in Experiment 1 was 95.09% 15 days after the field was dried in the early tillering stage. The control effect of the method of the present invention was significantly higher than that of Comparative Examples 1-5, and the control effect was significant.

[0030] Table 1. Average weight and control effect of Spirogyra in Example 1 and Comparative Examples 1-5 Note: "--" in the table indicates that Comparative Example 5 is used as a blank control.

[0031] Table 2 shows the yield data and effective tiller number of different treatments at the experimental site in Daxing Town, Tailai County. The yield was measured using the mechanical harvesting method. Impurities and empty grains were removed, and the rice was weighed on-site and the moisture content was measured. The yield results after converting to the standard moisture content (14.5%) are shown in Table 2. The yield measured by Example 1 of this invention, the actual yield, effective tiller number, and yield per mu are better than those of Comparative Examples 1-5.

[0032] Table 2 Yield Measurement Results of Daxing Town, Tailai County, Qiqihar City The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for controlling Spirogyra in paddy fields applicable to single-season rice areas in Northeast China, characterized in that, The method is as follows: S1. After the rice matures, it is harvested, the straw is crushed and scattered to obtain straw crushed material; S2, Autumn application of phosphate fertilizer and autumn cutting and burying of all straw: In autumn, apply 1 / 3 to 2 / 3 of the phosphate fertilizer during the entire growth period of rice. Use a tiller to break up the root stubble and loosen the soil layer. The working depth is 20cm to 25cm. Use a machine that integrates a disc harrow, a horizontal pressing component and a screed to evenly mix and bury the straw root stubble, phosphate fertilizer and the straw crushed material obtained in S1 into the 0cm to 25cm soil layer, and then level the field surface. S3. During the soil thawing period in the following spring, land preparation work is carried out at a depth of 10cm to 15cm. S4. During the spring planting season, the fields are soaked to remove slurry, and then rice seedlings are transplanted. S5. In the early stage of rice tillering, drain the water from the field surface, dry the field, and then irrigate.

2. The method for controlling Spirogyra in paddy fields applicable to single-season rice areas in Northeast China, as described in claim 1, is characterized in that... The amount of phosphate fertilizer applied to S2 throughout its entire growth period is 3 kg / mu to 5 kg / mu (calculated as P2O5).

3. The method for controlling Spirogyra in paddy fields applicable to single-season rice areas in Northeast China, as described in claim 1, is characterized in that... Before the S3 land preparation operation, the remaining phosphate and nitrogen fertilizers from the entire growth period are first spread on the soil surface, and then the land preparation and return operation is carried out to mix the fertilizers into the soil during the land preparation operation.

4. The method for controlling Spirogyra in paddy fields applicable to single-season rice areas in Northeast China, as described in claim 1, is characterized in that... The depth of the paddy field described in S4 is 3cm to 5cm, and the depth of the slurry formation is 2cm to 5cm.

5. A method for controlling Spirogyra in paddy fields applicable to single-season rice areas in Northeast China, as described in claim 1, characterized in that... The drying time for the field as described in S5 is 4 to 6 days.

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