The secret to successful freshwater crab farming in Nghe An province: Farmers' techniques for achieving high yields.

Mr. Binh converted 1.5 sao (approximately 1500 square meters) of rice paddy land into a crab farming pond. Photo: Thanh Phuc

On a 1.5 sao (approximately 1500 square meters) plot of rice land leased from the commune, starting in 2021, Mr. Nguyen Van Binh in My Chua hamlet, Thanh Tien commune, submitted an application to the authorities to convert it into a shallow pond, changing from rice cultivation to raising crabs and eels. With the approval of local leaders, he hired an excavator to dig a shallow pond (about 80cm deep from the field's edge). He reinforced the banks with concrete on top and lined the bottom with tarpaulin and corrugated iron to prevent snakes and rats from nesting around the banks.

In the middle of the pond, he dug a surrounding ditch to bring in and drain water, ensuring that the water in the pond was always circulating, preventing diseases for the crabs. After carefully preparing the pond, he both bought young crabs from local fishermen and personally caught crabs to select and release into the pond.

"Local crab species, with similar habitats and climates, adapt and grow more easily than buying crablings from Hai Phong or Hai Duong . Therefore, in the first batch, even without experience, the survival rate of the crabs reached 90%," Mr. Binh said.

Crab ponds are equipped with inlet and outlet channels, and surrounded by corrugated iron or concrete embankments to ensure the safety of the crabs. Photo: Hoai Thu

Raising crabs doesn't require much capital or labor; the feed is simple and can be homemade, such as rice bran, corn bran, or fishmeal, and they only need to be fed once every three days. Therefore, raising freshwater crabs only requires taking advantage of free time during the day.

The most important thing is to understand the growth characteristics of crabs. For example, during the molting period, bamboo tubes should be placed to provide shelter for the crabs, preventing them from eating each other's carcasses; during the breeding season, mature crabs should be selectively harvested to make room for the young crabs to develop. Crabs do not like hot weather, so water hyacinth should be introduced into the pond to provide shelter for them during the summer.

When planting duckweed, he carefully calculated the density of crabs in the pond, planting it in rows and furrows so that the duckweed would completely cover the surface of the pond. Photo: Thanh Phuc

"Even releasing duckweed into a pond requires technique. The duckweed must be released in sufficient quantities, ensuring the correct density, and in specific zones, not indiscriminately covering the entire surface of the pond. When duckweed covers the entire surface, crab growth is stunted due to reduced living space, and it's also difficult to observe the crabs and determine if they are diseased."

"During the final months of the farming cycle, it's necessary to increase the amount of animal feed in the crabs' diet to promote faster growth and firmer meat. At the same time, pay attention to regularly changing the water in the ponds and rice paddies once a week to stimulate molting and encourage strong feeding. Each time, change 1/4 to 1/3 of the water in the pond," Mr. Binh shared.

Raising freshwater crabs eliminates concerns about product demand, as they are favored by the market due to their firmer meat and higher nutritional value. More importantly, consumers don't have to worry about the crabs being contaminated with harmful chemicals used in agricultural production.

When crabs reproduce, they are selectively harvested for sale to prevent larger crabs from eating smaller ones. Photo: Hoai Thu

However, to get a good price for crabs, according to Mr. Binh's experience, farmers must proactively adjust the timing of stocking and harvesting. "When the rice in the fields hasn't been harvested yet, and field crabs are scarce because they're difficult to catch, the price is high. At this time, you can proactively harvest them, making them easier to sell and fetching a good price. Then, in November, the peak breeding season for crabs, you can buy juveniles to stock," Mr. Binh explained.

To increase income per unit area, Mr. Binh also raises mud eels in his crab ponds, as these are easy to raise and live deep in the mud, thus not affecting the crabs. According to Mr. Binh's calculations, with 3 batches of crabs per year, each batch weighing 200 kg, and selling at 100,000-120,000 VND/kg, he earns about 70 million VND. With an additional 30 million VND from selling mud eels, his 1.5 sao (approximately 1500 square meters) pond generates an income of about 100 million VND. This is 30-35 times higher than his previous two rice crops.

Each year, the income from crab farming ponds is approximately 100 million VND. Photo: Thanh Phuc

Mr. Nguyen Xuan Khanh, Chairman of the Thanh Chuong District Farmers' Association, said: "The model of raising freshwater crabs in rice paddies not only creates jobs and increases income, but also brings high economic efficiency to farmers and enriches and diversifies the range of aquaculture species for the agricultural sector."

At the same time, it contributes to the conservation and development of an economically valuable aquatic species, the freshwater crab, providing an additional source of highly nutritious and safe food for consumers… In the future, we will continue to guide, open technical transfer classes, and provide capital support to expand the model of breeding freshwater crabs for farmers."

Clip: Phuc - Thu

Source: https://baonghean.vn/bi-quyet-nuoi-cua-dong-trung-lon-cua-nong-dan-nghe-an-post277046.html