Catched twice the weight of shrimp in the rice field, and scattered crayfish seedlings during the 42 day window period between two seasons. The rice shrimp continuous cropping mode earned Chongming | rice | window period

Fish rice symbiosis is possible, and rice crab mixed culture is also possible. Can the operation of "rice+shrimp" be feasible? Seizing the short 42 day window period between two rice seasons, Chongming has developed an ecological shrimp for comprehensive cultivation of rice and shrimp.

Rice paddies with shrimp

On July 10th, the last day before the beginning of the summer, farmers were busy planting rice in the fields at the Minsheng Village Base in Xinhe Town, Chongming Island, Shanghai Ocean University. In about ten days, the selected seedlings of Macrobrachium rosenbergii will grow together with this batch of rice. Wang Chun, a senior engineer at Shanghai Ocean University, predicts that by the end of September, this batch of rice shrimp will accompany the fragrance of rice and walk on the dining table of the public.

After fishing for lobsters, we planted rice again.

In fact, the crayfish sprinkled in the previous season's rice fields succeeded in one go. As early as the end of June, also in this large area of farmland, the first batch of crayfish under the "one shrimp, one rice" continuous cropping model this year had entered the stomachs of foodies. Saving arable land, compound utilization, and improving quality and efficiency means that Chongming has achieved experimental results in the comprehensive cultivation of rice and shrimp.

[Rice field shrimp "grows" and the amount of catch doubles]

"In the past, I used to like spicy shrimp and added various seasonings to make thirteen fragrant crayfish. This time, the crayfish was boiled directly in clean water, and the taste and aroma were the best." Mr. Chang, a citizen who bought this type of shrimp for the first time, praised it a bit: "The cooked shrimp shell has a bright red color, and it tastes particularly elastic and chewy."

"Due to being in the experimental stage, our yield is not high yet. Currently, the yield per mu is only about 160 kilograms, so the daily supply of shrimp is in short supply." said Liu Qianyue, a graduate of the Aquaculture major at Hainan University in 2017, as the head of the base. His teacher Wang Chun said that this year is the first time that Chongming Island has conducted a continuous cropping experiment of "one shrimp, one rice" in a rice field without excavating a trench.

The obtained data from this wave of crayfish farming experiments shows that on February 20th of this year, water was irrigated to a height of about 20 centimeters in a 23 acre plowed rice field, and Ilex and Potamogeton were planted. The planting area of the two types of water grass accounted for 30% of the total rice field area; On April 24th, 1500 kilograms of crayfish fry were released, with a specification of 100 heads per kilogram; By June 5th, the aquaculture production will be completed.

As an old wizard who has been raising shrimp and crab for many years, Wang Chun smiled and told the Jiefang Daily Shangguan News reporter, "I am also surprised at how much these rice field shrimp have doubled." It turned out that during the breeding period, they fed 1800 kilograms of crayfish with mixed feed, recycled 3680 kilograms of crayfish, and gained a net weight of 1880 kilograms of crayfish. At the same time, the team also conducted experiments on the "green shrimp+rice" continuous cropping mode, planting water grass in a 7-acre rice field, dropping 200 kilograms of green shrimp seedlings, feeding 560 kilograms of green shrimp compound feed, and harvesting 720 kilograms of shrimp.

The experimental results showed that whether crayfish or green shrimp were raised in rice fields, the organic matter content in the soil of the rice fields significantly increased after the breeding period ended. There were no weeds in the rice fields, and after slight leveling, they could be transplanted by agricultural machinery or directly seeded with rice seeds, without the need to use herbicides before sowing as before. Even more gratifying is that these crayfish have undergone third-party sampling and all quality inspection items have passed, meeting the requirements for agricultural product marketing.

[5 technical safeguards, "protecting farmland and ecology"]

The harvest season of the "one shrimp, one rice" continuous cropping model in the first half of the year has passed, but there are still some "shrimp" that have missed the net in the rice fields. Due to the low water level, these crayfish are dancing and showcasing their vigorous vitality. Whether it's white scorching, garlic puree, or spicy, all have a bright red outer shell and tender shrimp meat, providing diners with a dual enjoyment of visual and taste. The initial trial was successful, and Wang Chun and his team began raising funds and conducting experiments on the "rice+Macrobrachium rosenbergii" co cultivation model in the second half of the year.

After fishing for lobsters and growing rice

The reporter from Jiefang Daily's Shangguan News learned that Hubei, Hunan, and Anhui provinces are major provinces in China for cultivating crayfish in rice fields, and their output value has exceeded that of locally cultivated hairy crabs. However, in areas such as Chongming District and Jinshan District in Shanghai, the "crayfish+rice" continuous cropping model has also been attempted, but it has not been continuously developed due to various reasons. Although we first raise shrimp and then grow rice, Chongming has its own "microclimate" and has strict requirements for ecological island construction and tail water discharge. Therefore, achieving true "full ecological aquaculture" is not an easy task.

"The local agricultural commission and town government have reminded and instructed us to protect basic farmland and not affect normal rice production." Wang Chun said, "As farmers, how could we not understand the truth behind it." He adopted five technical measures, including "no excavation of ditches, tailored improvement of farmland, selection and planting of water and grass", which not only ensured the extremely tight farmland area, but also maintained the "original ecology" of crayfish or green shrimp. ".

Liu Qianyue and others picked up lobsters

For example, they only raised the ridges around the rice fields appropriately to ensure that the water level remained at an average depth of 40 centimeters during crayfish or green shrimp farming. "Practice has proven that there is no need to dig trenches to cultivate crayfish or green shrimp in Chongming rice fields, which not only saves the cost of rice field remediation, but also maintains the original appearance and function of the rice field, ensuring the stable and timely production of rice." Wang Chun explained.

Liu Qianyue, who settled his "home" by the shrimp pond in the rice field, introduced that the feed they feed during the cultivation of crayfish or green shrimp is self-developed and patented high-quality low phosphorus shrimp and crab formula feed, ensuring the standard discharge of nitrogen and phosphorus in the aquaculture wastewater, and achieving a dual improvement in the quality of rice and fish. As a "new farmer", Liu Qianyue tasted the sweetness of "promoting agriculture through technology" after graduation and had a strong drive for independent entrepreneurship.