Rice-fish integrated farming method based on the double rice-three shrimp model

Abstract

This invention provides a rice-fish integrated farming method based on a double-rice, triple-shrimp model. It utilizes existing irrigation channels and raised paddy field embankments to increase the water level in the paddy fields without digging ditches, enabling grass planting and shrimp farming. The rice-shrimp integrated farming fields are divided into rice-shrimp co-cultivation and rice-shrimp rotation fields at a 2:5 area ratio. In the rice-shrimp co-cultivation fields, early rice is planted, broodstock shrimp are raised, and shrimp larvae are bred. In the rice-shrimp rotation fields, late rice is planted, and two crops of commercial shrimp are raised, providing high-quality broodstock for shrimp larvae breeding in the rice-shrimp co-cultivation fields. This integrated rice-fish farming model combines shrimp larvae bred in rice-shrimp co-cultivation with commercial shrimp farming in rice-shrimp rotation, forming an integrated farming model that produces one crop of early-bred shrimp larvae, two crops of commercial shrimp, and one season of double-variety rice annually. This invention pioneers a land-resource-saving and environmentally friendly rice-shrimp integrated farming development model with stable grain production and increased income, unique to Shanghai.

Description

Technical Field

[0001] This invention relates to the field of ecological planting technology, specifically to a rice-fish integrated farming method based on a double-rice-three-shrimp model. Background Technology

[0002] Rice-fish integrated farming is a modern, ecologically cyclical agricultural model that coordinates rice cultivation and aquaculture, as well as agronomy and fisheries, to construct a rice-fish co-cultivation and / or rotation system. It features "mutual promotion between rice and fish, stable grain production and increased efficiency, ecological protection, and quality and safety." In 2023, the Ministry of Agriculture and Rural Affairs released two key agricultural technologies related to aquaculture: "Key Technologies for Improving Quality and Efficiency in Ecological Rice-Fish Farming" and "Rotation and Symbiotic Technology of Crayfish + Rice + Macrobrachium rosenbergii," demonstrating the important role of rice-fish integrated farming in aquaculture.

[0003] Rice-shrimp farming, as an important rice-fish farming model, is widely used throughout the country. Currently, rice-shrimp farming mainly involves single-ditch rice-shrimp rotation and rice-shrimp co-cultivation for commercial shrimp farming. However, these two models often require the purchase of large quantities of shrimp fry, which is constrained by the shrimp fry market and is not conducive to the development of large-scale rice-shrimp farming. Furthermore, the integrated rice-shrimp farming model requires the modification of paddy fields by ditching. Current technical specifications allow for ditching within 10%, but in production, ditching should be avoided as much as possible, maintaining the original appearance of the paddy fields or combining high-standard farmland transformation with direct rice-shrimp farming. Summary of the Invention

[0004] This invention addresses the aforementioned problems by providing a rice-fish integrated farming method based on the land and climate characteristics of the Yangtze River Delta region, using a double-rice, triple-shrimp model.

[0005] The technical approach of this invention is as follows: Within a rice-growing area, the water level in the paddy fields is increased by utilizing existing irrigation canals and raising the field ridges without digging ditches, thus achieving the purpose of planting grass and raising shrimp. The rice-shrimp integrated farming fields are divided into rice-shrimp co-cultivation and rice-shrimp rotation at a ratio of 2:5. In the rice-shrimp co-cultivation fields, early rice is planted and broodstock shrimp are raised and shrimp larvae are bred; in the rice-shrimp rotation fields, late rice is planted and two crops of commercial shrimp are raised, while high-quality broodstock are provided for the rice-shrimp co-cultivation fields. Based on the research of the integrated rice-fish farming model combining shrimp larvae breeding through rice-shrimp co-cultivation and commercial shrimp farming through rice-shrimp rotation, the two integrated farming models are cyclically combined with the planting of high-quality Shanghai rice varieties Songzaoxiang No. 1 and Shenyou 26 or Shenyou 28, forming a new "double rice, three shrimp" integrated rice-shrimp farming model that produces one crop of early-bred shrimp larvae, two crops of commercial shrimp, and one season of two varieties of high-quality rice.

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

[0007] The rice-fish integrated farming method based on the double rice-three shrimp model provided by this invention is characterized by the following specific farming steps:

[0008] A. Rice paddy transformation

[0009] There is no need to dig a circular ditch in the aquaculture field, but the field ridges must be raised and reinforced: In rice-crayfish co-cultivation fields, each field ridge is an isosceles trapezoid with a slope ratio of 4, which meets the requirement that the water level for crayfish farming is 0.8 to 1 meter. At the same time, an escape-proof net is built around the rice field in rice-crayfish co-cultivation fields to prevent crayfish from climbing over and escaping; In rice-crayfish rotation fields, each field ridge is also an isosceles trapezoid with a slope ratio of 2, and no escape-proof facilities are made.

[0010] B. Rice-shrimp co-cultivation

[0011] In the rice-shrimp co-cultivation field, parent shrimp are raised and shrimp larvae are bred, and the early rice variety Songzaoxiang No. 1 is planted. The rice is sown in late April and transplanted in late May. Ecological prevention and control are adopted in the planting and management process, and no pesticides are used. Farmyard manure is used and no chemical fertilizers are used. The red swamp crayfish are mainly fed soybean cake and wheat grains, and shrimp feed is added appropriately.

[0012] Rice is harvested in October. Before harvesting, the water level is gradually lowered, and the fields are kept free of standing water for 7 to 10 days before harvesting. After the rice is harvested, the fields are plowed and Elodea is planted at a spacing of 4 meters between plants and 8 meters between rows. After planting, the fields are gradually irrigated until the highest water level is reached. The parent shrimp and juvenile shrimp that have entered the burrows in the rice fields are then guided to grow and overwinter in the rice fields outside the burrows. Some soybean milk is sprinkled on the fields as food for the juvenile shrimp and to cultivate food organisms.

[0013] C. Rice-shrimp rotation

[0014] Two crops of commercial shrimp are raised in rice-shrimp rotation fields, with late-season rice varieties Shenyou 26 or Shenyou 28 planted alongside, providing high-quality broodstock for the rice-shrimp co-culture fields. In the rice-shrimp rotation, shrimp fry are harvested from the previous year's rice-shrimp co-culture fields. The first crop of commercial shrimp is stocked in late March, with approximately 5,500 juvenile shrimp (240 shrimp / kg) per mu (approximately 0.067 hectares) of rice paddy. The required number of juvenile shrimp are stocked at once in the same field, and the shrimp are fed commercial shrimp feed twice a day, morning and evening. The first crop of commercial shrimp is harvested in late April. After harvesting, larger, high-quality shrimp are selected from the commercial shrimp and used as broodstock, then released into the co-culture fields. Simultaneously, shrimp fry are harvested from the co-culture fields according to the same stocking schedule and transferred to the rotation fields for the second crop of commercial shrimp. The second crop of commercial shrimp is stocked in mid-May and harvested in mid-June, with the same rearing method as the first crop, again selecting large, high-quality shrimp as broodstock.

[0015] Rice is sown in seedling trays in late May and transplanted to rotation fields in late June, following normal rice planting methods. Rice is harvested in November. 7-10 days before harvest, all standing water in the fields is completely drained. After rice harvest, the land is tilled and Elodea is planted. The water level is gradually raised to its maximum to support the aquatic plants during winter and to cultivate the water environment for commercial shrimp farming in preparation for the following year's commercial shrimp farming.

[0016] The water management during rice cultivation follows the principle of "moistening seedlings, shallow water for tillering, sufficient seedlings for drying the field, medium water for heading, deep water for flowering, and dry-wet filling." Specific management methods are as follows: the water level for rice transplanting is 2-3 cm; immediately after transplanting, water is added to ensure greening, with the water level controlled at 4-6 cm, ensuring the seedling heart is not submerged; after the seedlings have greened, the paddy field water level is allowed to naturally drop to 3 cm to increase water and mud temperature and promote tillering; after effective tillering, the field is drained and dried for 2-3 days; when the rice leaves change from dark green to yellowish-green, water should be immediately added to 5 cm and maintained at a shallow level; during the early stage of panicle differentiation, the water level is increased to 15-30 cm and maintained at this level until the rice matures.

[0017] The beneficial protections and effects of this invention are as follows:

[0018] This invention studies an integrated rice-fish farming model that combines rice-shrimp co-breeding with shrimp larvae cultivation and rice-shrimp rotation with commercial shrimp farming. It avoids paddy field ditching and instead utilizes the raised paddy field ridges created during standard farmland renovation to establish suitable water levels for shrimp farming. By cyclically combining two integrated farming models with the planting of high-quality Shanghai rice varieties Songzaoxiang No. 1 and Shenyou 26 or Shenyou 28, a novel integrated rice-shrimp farming model is formed, producing one crop of early-breeding shrimp larvae, two crops of commercial shrimp, and one season of two varieties of high-quality rice annually. This pioneering model for stable grain production and increased income through integrated rice-shrimp farming is characterized by land resource conservation and environmental friendliness, unique to Shanghai. Attached Figure Description

[0019] Figure 1 The technical roadmap for integrated rice-fish farming based on the double rice-three shrimp model is shown. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0021] Combination Figure 1 The specific steps of the rice-fish integrated farming method based on the double rice-three shrimp model in this embodiment are as follows:

[0022] 1. Rice paddy transformation

[0023] The paddy fields are standard rectangular plots. Circular ditches are not required within the aquaculture plots, but the paddy field embankments must be raised and reinforced, as follows: In rice-crayfish co-cultivation fields, each paddy field embankment is an isosceles trapezoid, with an upper base width of 1 meter, a lower base width of 1.6 meters, a height of 1.2 meters, and a slope ratio of 4. The water level for crayfish farming reaches 0.8–1 meter. The perimeter of the rice-crayfish co-cultivation fields is enclosed by a thickened polyethylene plastic film fencing to prevent crayfish from escaping. In rice-crayfish rotation fields, each paddy field embankment is also an isosceles trapezoid, with an upper base width of 1 meter, a lower base width of 1.6 meters, a height of 0.6 meters, and a slope ratio of 2. No escape prevention measures are implemented in rice-crayfish rotation fields.

[0024] Ensure proper inlet and outlet drainage in the paddy field to guarantee smooth water flow during the aquaculture process. Install screens at these inlets and outlets to prevent shrimp larvae from escaping and to prevent wild fish and fish eggs from flowing into the field. Screens should also be installed at the inlet and outlet of the irrigation ditches. For aquatic plant cultivation, choose common algae such as Elodea nuttallii, planting them in the field at a spacing of 4 meters between plants and 8 meters between rows. After planting, gradually raise the water level until the algae completely cover the field.

[0025] 2. Rice-shrimp integrated farming model

[0026] 2.1 Rice-shrimp co-cultivation

[0027] In 2022, the rice-shrimp co-cultivation model covered an area of ​​200 mu. In the rice-shrimp co-cultivation fields, parent shrimp were raised and shrimp fry were bred. This not only provided the cooperative with self-bred shrimp fry for commercial shrimp farming, preventing the impact on commercial shrimp farming due to the inability to purchase early spring shrimp fry, but also allowed the bred shrimp fry to be sold, increasing income.

[0028] In rice-shrimp co-cultivation fields, the Songzaoxiang No. 1 early rice variety, characterized by robust stems, strong tillering ability, lodging resistance, disease resistance, high yield, and excellent quality, was selected for planting. Rice was sown on April 23rd and transplanted on May 22nd. In the rice-shrimp co-cultivation fields, ecological pest control was employed, avoiding pesticides; methods such as using pheromones and placing insect traps were employed. Farmyard manure was used instead of chemical fertilizers. Red swamp crayfish were raised using ecological methods, primarily feeding them soybean cake and wheat grains, with appropriate amounts of shrimp feed.

[0029] Rice is harvested in October. Before harvesting, the water level is gradually lowered, and 7-10 days prior to harvest, all standing water in the fields is completely drained. After harvesting, the fields are plowed and planted with Elodea nuttallii, then gradually flooded until the maximum water level is reached. This guides the parent shrimp and juvenile shrimp that have entered the burrows in the rice paddies to the outside rice paddies to grow and overwinter. During this period, some soybean milk is appropriately sprinkled, which not only serves as food for the juvenile shrimp but also helps cultivate other food organisms.

[0030] 2.2 Rice-shrimp rotation

[0031] In 2022, the rice-shrimp rotation area was 500 mu, with two crops of commercial shrimp raised in the rice-shrimp rotation fields, and Shenyou 26 or Shenyou 28 late rice varieties were planted in combination, providing high-quality parent stock for the rice-shrimp co-cultivation fields.

[0032] After the rice harvest in 2021, the land was cultivated and planted with Elodea nuttallii, and the water level was gradually raised to its maximum to maintain the aquatic plants for overwintering and to cultivate a suitable aquatic environment for commercial shrimp farming. In the 2022 rice-shrimp rotation, the first batch of commercial shrimp was stocked on March 25th. Self-bred "post-rice shrimp larvae" were transferred to the rotation fields, ensuring approximately 5,500 juvenile shrimp (240 shrimp / kg) per acre of rice paddy, with all required juvenile shrimp stocked at once in each field. The shrimp were fed commercial shrimp feed twice a day, morning and evening. The first batch of commercial shrimp was harvested on April 25th. After harvesting, larger, high-quality shrimp were selected as broodstock and released into the co-cultivation fields. Simultaneously, shrimp larvae from the co-cultivation fields were transferred to the rotation fields according to the same stocking schedule for the second batch of commercial shrimp farming. The second batch of commercial shrimp was stocked on May 10th and harvested on June 15th, with the same farming method as the first batch, again selecting large, high-quality shrimp as broodstock.

[0033] Rice seedlings were sown in trays on May 20th and transplanted to rotation fields on June 20th, following normal rice planting methods. Water management should adhere to the principles of "moistening seedlings for survival, shallow water for tillering, sufficient seedlings for drying the field, medium water for heading, deep water for flowering, and alternating wet and dry water for grain filling." Water should be withheld 5-7 days before harvest. Specific management methods are as follows: the water level at transplanting should be 2-3 cm; immediately after transplanting, water should be added to ensure greening, with the water level controlled at 4-6 cm, ensuring the seedling heart is not submerged; after the seedlings have greened, allow the paddy field water level to naturally drop to 3 cm to increase water and mud temperature and promote tillering; after effective tillering, drain the water and dry the field for 2-3 days; when the rice leaves change from dark green to yellowish-green, immediately refill the field to 5 cm and maintain a shallow water level; during the early panicle differentiation stage, raise the water level to 15-30 cm and maintain this level until rice maturity. Rice is harvested in November. Before the harvest of late-season rice, the water level in the fields is gradually lowered, and the water in the fields is completely drained 7 to 10 days before harvest. After the rice harvest, the land is tilled and Elodea is planted. The water level is gradually raised to its maximum to support the aquatic plants for overwintering and to cultivate the water environment for commercial shrimp farming in preparation for the following year's commercial shrimp farming.

[0034] 3. Benefit Analysis

[0035] 3.1 Analysis of the benefits of rice-shrimp co-cultivation

[0036] According to statistics, in 2022, the rice yield in rice-shrimp co-cultivation fields was 650 jin per mu, the average shrimp fry yield was 350 jin per mu, the total output was 70,000 jin, the average size of the shrimp fry was 110-130 shrimp per jin, and the average price of the shrimp fry was 20 yuan per jin. The total output of adult shrimp harvested from the co-cultivation fields the following year was 6,000 jin, with an average yield of 30 jin per mu, the average size of the adult shrimp was 12 shrimp per jin, the proportion of shrimp weighing 35g or more was 90%, and the price was 40 yuan per jin.

[0037] 3.2 Analysis of the Benefits of Rice-Shrimp Rotation

[0038] According to statistics, in the 2022 rice-shrimp rotation crop, the total yield of the first crop of marketable shrimp was 175,000 jin (82,000 catties), with an average size of 20 shrimp per jin (0.5 catties), 25% of which were over 35g, an average yield of 350 jin per mu (125 catties / acre), and a selling price of 20 yuan per jin (10 yuan / catties). The total yield of the second crop of marketable shrimp was 75,000 jin (37,000 jin), with an average size of 18 shrimp per jin (0.5 catties), 30% of which were over 35g, an average yield of 150 jin per mu (125 catties / acre), and a selling price of 18 yuan per jin (18 yuan / catties). The rice yield in 2022 was 1200 jin per mu (600 catties / acre).

[0039] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A method for integrated rice and fish culture based on a double rice and triple shrimp model, characterized in that, This integrated rice-shrimp farming method utilizes existing irrigation ditches and raised paddy field embankments to increase the water level, enabling grass planting and shrimp farming. The rice-shrimp integrated farming fields are divided into rice-shrimp co-cultivation and rice-shrimp rotation fields at a 2:5 area ratio. In the rice-shrimp co-cultivation fields, early rice is planted, broodstock shrimp are raised, and shrimp larvae are bred. In the rice-shrimp rotation fields, late rice is planted, and two crops of commercial shrimp are raised, providing high-quality broodstock for shrimp larvae breeding in the rice-shrimp co-cultivation fields. This integrated rice-fish farming model combines shrimp larvae bred in rice-shrimp co-cultivation with commercial shrimp farming in rice-shrimp rotation, resulting in an annual production of one crop of early-bred shrimp larvae, two crops of commercial shrimp, and one season of double-variety rice. The specific planting and breeding steps are as follows: A. Rice paddy transformation There is no need to dig a circular ditch in the aquaculture field, but the field embankments must be raised and reinforced: In rice-crayfish co-cultivation fields, each paddy field embankment is an isosceles trapezoid with a slope ratio of 4, ensuring that the water level for crayfish farming reaches 0.8 to 1 meter. At the same time, an escape-proof net is constructed around the paddy field in rice-crayfish co-cultivation fields to prevent crayfish from climbing over and escaping; In rice-crayfish rotation fields, each paddy field embankment is also an isosceles trapezoid with a slope ratio of 2, and no escape-proof facilities are installed. B. Rice-shrimp co-cultivation In rice-shrimp co-cultivation fields, broodstock shrimp are raised and shrimp larvae are bred, while early rice varieties are planted. Rice is sown in late April and transplanted in late May. Ecological pest control is employed during the planting and management process, eliminating the use of pesticides; farmyard manure is used, and chemical fertilizers are avoided. The red swamp crayfish are raised... The main food source for shrimp farming is soybean cake and wheat grains, supplemented with appropriate amounts of shrimp feed. Rice is harvested in October. Before harvesting, the water level is gradually lowered, and the fields are kept free of standing water for 7 to 10 days before harvesting. After the rice is harvested, the fields are plowed and Elodea is planted. The fields are gradually irrigated until the highest water level is reached. The parent shrimp and juvenile shrimp that have entered the burrows in the rice fields are then moved to the rice fields outside the burrows to grow and overwinter. C. Rice-shrimp rotation Two crops of commercial shrimp are raised in rice-shrimp rotation fields, with late-season rice varieties planted alongside to provide high-quality broodstock for the rice-shrimp co-culture fields. In the rice-shrimp rotation, shrimp larvae are harvested from the previous year's rice-shrimp co-culture fields. The first crop of commercial shrimp is stocked in late March, with all required larvae stocked at once in the same field. During the rearing period, the shrimp are fed commercial shrimp feed twice a day, morning and evening. The first crop of commercial shrimp is harvested in late April. After harvesting, larger, high-quality shrimp are selected from the commercial shrimp and used as broodstock, then released into the co-culture fields. Simultaneously, shrimp larvae from the co-culture fields are harvested and transferred to the rotation fields for the second crop of commercial shrimp. The second crop of commercial shrimp is stocked in mid-May and harvested in mid-June, with the same rearing method as the first crop, again selecting large, high-quality shrimp as broodstock. Rice is sown in seedling trays in late May and transplanted to rotation fields in late June, following normal rice planting methods. Rice is harvested in November, and the water in the fields is completely drained 7 to 10 days before harvest. After the rice harvest, the land is cultivated and Elodea is planted. The water level is gradually raised to its maximum to support the aquatic plants during the winter and to cultivate the aquatic environment for commercial shrimp farming, in preparation for the next year's commercial shrimp farming.

2. The rice-fish integrated farming method based on the double-rice-three-shrimp model according to claim 1, characterized in that: wherein In step A, the top surface of each paddy field ridge in the rice-shrimp co-cultivation field is 1 meter wide, the bottom surface is 1.6 meters wide, and the height is 1.2 meters. At the same time, a thickened polyethylene plastic film is used to construct an escape-proof net around the paddy field of the rice-shrimp co-cultivation field. In rice-shrimp rotation fields, the top surface of each paddy field ridge is 1 meter wide, the bottom surface is 1.6 meters wide, and the height is 0.6 meters. Both rice-shrimp co-cultivation fields and shrimp-rice rotation fields have inlet and outlet ports, and screens are installed at the inlet and outlet ports, as well as at the inlet and outlet ports of the water collection ditches.

3. The rice-fish integrated farming method based on the double-rice-three-shrimp model according to claim 1, characterized in that: wherein In step B, the early rice variety selected is Songzaoxiang No. 1; When planting Elodea, plant it in the field with a plant spacing of 4 meters and a row spacing of 8 meters. After planting, gradually raise the water level until it is completely covered. During the overwintering period of broodstock and juvenile shrimp, sprinkle some soybean milk as feed for juvenile shrimp and cultivate food organisms.

4. The rice-fish integrated farming method based on the double-rice-three-shrimp model according to claim 1, characterized in that: wherein In step C, Shenyou 26 or Shenyou 28 are selected for late-season rice planting; When stocking shrimp fry, approximately 5,500 juvenile shrimp with a size of 240 shrimp per kilogram are stocked per mu of rice paddy.

5. The rice-fish integrated farming method based on the double-rice-three-shrimp model according to claim 1, characterized in that: wherein In step C, water management during rice cultivation follows the principle of "moistening seedlings to promote growth, shallow water for tillering, sufficient seedlings for drying the field, medium water for heading, deep water for flowering, and dry-wet irrigation for grain filling." Specific management methods are as follows: the water level for rice transplanting is 2-3 cm; immediately after transplanting, water is added to ensure greening, with the water level controlled at 4-6 cm, ensuring the seedling heart is not submerged; after the seedlings have greened, the paddy field water level is allowed to naturally drop to 3 cm to increase water and mud temperature and promote tillering; after effective tillering, the field is drained and dried for 2-3 days; when the rice leaves change from dark green to yellowish-green, water should be immediately added to 5 cm and maintained at a shallow level; during the early stage of panicle differentiation, the water level is increased to 15-30 cm and maintained at this level until the rice matures.

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