This is a set of intriguing numbers:
As of 2018, the total area of crayfish farming in China is 16.8 million mu, of which 12.61 million mu of shrimp farming in rice fields, accounting for 75%, exceeds 40% of the national integrated rice-fishing area; the crayfish farming area may reach 20 million by 2020 mu……
Crayfish is the favorite of the Chinese people on the table, and it is also the hope of many farmers to get rid of poverty and become rich. However, after five years of follow-up research, the above-mentioned figures made agricultural experts unhappy. Driven by short-term economic benefits, some places blindly expand the scale of shrimp farming in rice fields and expand the proportion of ditches and pits, which affects rice production and creates hidden dangers to food security.
1
"Shrimp farming in rice fields" has become "rice farming in shrimp fields"
Rice-fishing symbiosis has a long history in my country. "Historical Records" records that as early as 2000 years ago, "Guyue people" lived a self-sufficient life of "fried rice soup with fish". In 2005, Zhejiang Qingtian Rice-fishing Symbiosis System was assessed by the Food and Agriculture Organization of the United Nations as an important global agricultural cultural heritage and the first agricultural cultural heritage selected in China.
In recent years, my country's integrated rice-fishing cultivation has developed rapidly. Since 2015, the Institute of Resource Regional Planning of the Chinese Academy of Agricultural Sciences has joined forces with scientific research institutes such as Liaoning Academy of Agricultural Sciences, Yunnan Academy of Agricultural Sciences, Hubei Academy of Agricultural Sciences, Yangtze University, China Agricultural University, Shanghai Jiaotong University, and Chinese Academy of Sciences Precision Surveying Institute. Relevant experts from colleges and universities conducted investigations on typical integrated rice-fishing planting models in China.
Studies have found that rice-fishing symbiosis models such as rice field raising crabs and paddy field raising ducks can not only eliminate weeds, control insect pests, improve soil fertility, and improve water quality, but also promote rice growth. In recent years, the rapid development of "paddy field shrimp farming" is mostly a non-symbiotic model, which has the following negative effects on food security, soil quality and ecological environment:
One is to squeeze out basic farmland and reduce the planting area of overwintering crops. The original rice fields with good irrigation and drainage conditions, high soil fertility and paddy and dry rotation are converted to rice and shrimp integrated farming fields. Among the more than 10 million mu of shrimp farming rice fields in the main rice and shrimp production area in the middle reaches of the Yangtze River, more than half are derived from paddy and dry rotation. Basic farmland.
On May 29, 2018, Haokou Town, Qianjiang City, Hubei Province, the water level during the shrimp harvest season was significantly higher than the normal water level
The second is to affect rice production, and some rice is "planted but not harvested." Heavy shrimp and light rice are very common in the rice field shrimp culture model in our country, and there is even the phenomenon that rice is planted without harvesting and directly used as feed and shelter for crayfish. In order to increase the production of crayfish and facilitate the fishing, some producers have dug cultivation ditches in the rice fields and set aside access to waterways, even reducing the actual planting area of rice by more than 40%.
Third, long-term flooding destroys the soil, threatening the strategic security of "hiding grain in the ground". Practice has proved that paddy and dry rotation is an important way to improve soil fertility in paddy fields and an important guarantee for food security. Shrimp farming in paddy fields abandoned the overwintering and dry farming, and the soil was flooded for more than 320 days throughout the year. The longer the shrimp farming period in the paddy field, the less conducive to soil health.
"The most heartbreaking thing is the sacrifice of soil quality! Long-term flooding will cause great harm to soil health and will seriously threaten the food security strategy of storing grain on the ground." The non-point source pollution innovation team of the Institute of Resources and Regional Planning of the Chinese Academy of Agricultural Sciences Chief Scientist Liu Hongbin said.
The fourth is to exacerbate water shortages and threaten water environment security. Experts estimate that the annual water consumption per acre of shrimp farming rice fields is 600 to 700 tons more than that of paddy and dry rotation farmland. In some irrigation areas, water conflicts and even disputes caused by the large-scale disorderly development of rice farming shrimp have already appeared. A considerable number of farmers put in large amounts of bait and fertilizer, and frequently drained water and supplemented water during the breeding process, which further aggravated water pollution.
2
Press to stop crayfish breeding "fast forward button"
The disorderly development of shrimp farming in rice fields in some places has changed from "shrimp farming in rice fields" to "shrimp farming in rice fields". This not only violates the basic principle of "not competing for food with people and not competing for land with food" for integrated rice-fishing farming. Bring huge hidden dangers to green agriculture and high-quality development.
From 2012 to 2018, the total area of crayfish farming in the main production areas of the five southern provinces increased by 284%, and the expansion has not stopped.
Zhu Jianqiang, a professor at Yangtze University, said that while shrimp farming in rice fields is developing rapidly, the market has fallen into an unstable state. Affected by the concentration of harvest time, cold storage and processing, natural disasters, consumer markets, etc., the purchase price of crayfish fluctuates between 12 yuan and 70 yuan per kilogram, and farmers have to bear great market risks.
In 2018, a survey conducted by the Hubei Provincial Fisheries Technology Promotion Station showed that only one-third of shrimp farmers can make money. The phenomenon of crayfish "floor prices" has become increasingly prominent in the past two or three years. Affected by the new crown pneumonia epidemic, the market price of shrimp larvae in mid-to-late March 2020 is only 12 yuan per kilogram, which is half of the normal year.
In May 2020, the Jingzhou Agricultural and Rural Development Center, Jingzhou Crayfish Industry Association and other units formed an expert group. After investigation, the "Research Report on the Current Development of Jingzhou Crayfish Industry" was formed. It is believed that the price of adult crayfish in 2020 Overall it is significantly lower than 2019. The report also warned that it is necessary to avoid "emphasizing shrimps and light rice" and to give consideration to rice and shrimps. Do not blindly pursue the production of crayfish. Deep water is often used during the rice growth period, which will cause human-induced waterlogging in the rice fields and severely reduce rice production.
3
Find out the reasonable planning of the family
Food security is the bottom line that cannot be broken. The General Office of the Ministry of Agriculture and Rural Affairs has issued the "Notice on Regulating the Development of the Comprehensive Rice-Fishing Industry" in 2019 to promote the standardized development of the comprehensive rice-fishing industry. It is necessary to find out the development status of rice farming in our country as soon as possible, formulate a comprehensive rice farming plan, and implement policies on the classification of rice-fishing symbiosis and non-symbiosis models.
The first is to find out the family status and make a scientific assessment. Through remote sensing, drone aerial photography and field surveys, we can find out the distribution area of the comprehensive rice cultivation and its overlap with the grain production functional area as soon as possible, and clarify the business entity, operating life, model type, proportion of ditch and pit, resource input and Product output, scientifically evaluate the economic and ecological benefits of integrated rice-fishing cultivation.
The second is to implement classified policies to stabilize grain and increase efficiency. The state and local governments should issue policies to support and guide farmers and new agricultural operators to select aquatic animal species based on local conditions, strictly implement the rule that ditch and pits account for no more than 10%, and it is strictly forbidden to increase non-symbiotic rice fishing areas in grain production functional areas .
The third is to strengthen planning and scientific guidance. Liu Hongbin suggested that a national plan for comprehensive rice cultivation should be formulated as soon as possible, guided by "reciprocal benefits from rice and fisheries, stabilizing grain and increasing income", and on the premise of "not competing for food with people, not competing for land with food", and scientifically divide suitable development areas and restrictions In the development zone, gradually build a green development model and policy guarantee mechanism.
The fourth is to support science and technology and lead by special projects. The integrated rice-fishing cultivation involves soil fertilization, cultivation, plant protection, aquatic products, breeding, ecology, environment, economics and other disciplines. At present, the problem of interdisciplinary collaborative research is highlighted. It is recommended to incorporate rice-fishing green cultivation into the national modern agricultural industrial technology system. The chain develops key technology research and development.
Half a month to talk about reporters: Li Bin Guo Yujing