Rice-fish system facts for kids

A rice-fish system is a special way of farming that combines growing rice with raising freshwater fish in the same place. This method is very old and important. It's even recognized as a "Globally Important Agricultural Heritage System" by the FAO-GEF.

In a rice-fish system, rice and fish help each other. They live together in the same ecosystem, which is like their shared home. This way of farming brings many good things, including benefits for people, the economy, and the environment.

History of Rice-Fish Farming

People have been growing rice and fish together for more than 2,000 years! In China, ancient clay models of rice fields with tiny fish, like the common carp, have been found. These models were discovered in tombs from the ancient Han dynasty (206 BC – 220 AD).

No one knows the exact place where rice-fish farming first started. But it's believed to have begun in Asia, in countries like India, Thailand, northern Vietnam, and southern China. Many think it started in China because they were very good at aquaculture (raising fish) a long time ago.

Early Fish Species Used

Archaeologists have found that common carps were likely one of the first fish used in these systems. Records from the Wei dynasty (220 to 265 AD) talk about a small fish with yellow scales and a red tail. This fish was grown in rice fields in Pi County, near Chengdu, Sichuan Province, and used for making sauce.

The first detailed descriptions of rice-fish systems were written around 900 AD by Liu Xun during the Tang dynasty. Some think the practice started when farmers put extra young fish, called fry, into their ponds. They noticed the fish grew better in rice fields than in ponds. So, farmers started raising fish in rice fields on purpose, leading to the rice-fish system we know today.

How Rice-Fish Systems Spread

In other countries, this practice might have developed on its own, separate from China. Research suggests it spread from India to other Asian countries over 1,500 years ago. It slowly became popular among farmers. By the mid-1900s, rice-fish systems were used in over 28 countries across six continents. These continents include Africa, Asia, Australia, Europe, North America, and South America.

Historically, the common carp and the Mozambique tilapia were the most common fish raised. But as the practice spread, new local fish species were also introduced. For example, Malaysia started using the snakeskin gourami, and Egypt uses the Nile tilapia.

One of the first studies on rice-fish systems happened in 1935 in Songjian, Jiangsu Province. It looked at growing different types of carp, like black carp, grass carp, silver carp, bighead carp, and common carp. The results showed that it was a good idea.

Modern Developments in Rice-Fish Farming

Until the 1980s, rice-fish systems were fairly simple. Their main goal was to use space wisely and grow extra animal protein along with rice, which is a staple food. This was important as populations grew.

However, from the 1980s onwards, the system grew quickly. New animals were added, such as the Chinese mitten crab, the red swamp crayfish, and softshell turtles. New ideas and technologies also helped the industry boom. In China, the area used for rice-fish fields grew from 441,027 hectares (1,089,800 acres) to 853,150 hectares (2,108,200 acres) between 1983 and 1994. Production also increased a lot, from 36,330 tonnes (35,760 long tons; 40,050 short tons) to 206,915 tonnes (203,647 long tons; 228,085 short tons).

How Rice and Fish Help Each Other

Rice-fish systems are based on the idea that rice and fish have a mutually beneficial relationship. This means they both gain something from living in the same watery environment.

Benefits for Fish

The rice plants provide a safe home for the fish. They offer shade, which helps keep the water cooler. This creates a better environment for the fish. Rice plants also help by lowering the amount of ammonia in the water and nitrogen in the soil. This makes the water healthier for the fish. Fish also get extra food from insects that live on the rice plants.

Benefits for Rice

On the other hand, the fish help the rice by eating insects, pests, and weeds. For example, fish can help control brown planthoppers and prevent a rice disease called rice sheath blight. By controlling weeds, fish reduce the competition for nutrients. This means more nutrients are available for the rice, helping it grow better. The carbon dioxide (CO₂) released by the fish might also help the rice with photosynthesis.

The constant movement of the fish helps loosen the soil surface. This has several good effects:

• It increases oxygen levels in the water, which helps tiny living things (microorganisms) create more usable nutrients for the rice.
• It helps break down organic matter in the soil.
• It makes nutrients more available in the soil.
• It helps fertilizers work better.
• It promotes better root growth for the rice plants.

Fish also improve soil fertility. Their waste acts like a natural fertilizer, adding organic matter to the soil. This increases nitrogen, phosphorus, and potassium levels. The system creates a good way to recycle nutrients. Overall, having fish in rice fields leads to healthier soil, more different kinds of living things, and more sustainable food production.

The watery environment in rice-fish systems also has other living things. These include plankton (tiny plants and animals), tiny creatures living in the soil (benthic fauna), and microbes. All these play a part in making the soil more fertile and keeping production going.

Benefits of Rice-Fish Systems

Economic Benefits for Farmers

Rice-fish farming can bring more money to farmers. In Bangladesh, farmers using this system can earn over 50% more than those who only grow rice. In China, depending on the area, earnings can be 45% to 270% higher than just growing rice.

However, starting a rice-fish system can cost money at first. This might make it harder for poorer countries to begin using this method.

Benefits for Farmers' Workload

Rice-fish systems can also make farmers' lives easier. Fish act as natural weed and pest controllers, and they fertilize the soil. This can mean less manual labor for farmers. However, preparing the fields for fish and harvesting them can add some work.

Farmers' income can increase by more than 23% with these integrated systems. Plus, studies show that farmers and their families also get more fish protein in their diet, which is good for their health.

More Food and Better Use of Land

Using rice-fish systems helps grow more rice and fish. Studies have shown that rice yields can increase from 6.7 tons to 7.5 tons per hectare. At the same time, fish production can go from 0.75 tons to 2.25 tons per hectare. The fish help recycle nutrients, which boosts overall production.

This method also uses land very efficiently. You get two food sources from the same area, which makes the land more profitable.

Tourism Potential

The unique look of rice-fish fields can also attract tourists. This creates a new way for communities to earn money.

Environmental Benefits

Since fish help control pests and weeds, farmers need to use fewer chemicals like pesticides and herbicides. This is good for the environment because it reduces pollution from farming chemicals. It also helps increase the number of different plants and animals living in the area, which is called biodiversity.

Where Rice-Fish Systems Are Used

Helping Developing Countries

Rice-fish systems are being shared with less developed countries through programs like the FAO (Food and Agriculture Organization of the United Nations)/China Trust fund. About 80 Chinese experts have traveled to countries in Africa, Asia, and the South Pacific. They help set up rice-fish systems and share their farming knowledge. For example, in Nigeria, a program helped set up over 10,000 hectares of rice-fish fields. This almost doubled the production of rice and tilapia fish there.

Adapting to Climate Change

Climate change can threaten global food production with heavy rainfall and extreme weather. These changes can also lead to more pests. Researchers are studying if rice-fish systems can help in a future with rising temperatures.

Integrated rice-fish systems seem to be more reliable and stable than traditional rice farming. This means they might be better suited for future environmental changes and challenges. They can help reduce risks for small farmers and keep food production steady.