Duckweed is a plant that grows naturally in Cambodia’s lakes and ponds and is often used as feed for chickens, ducks and pigs by farmers who collect it from the places where it grows wild. One man, however, has decided to grow duckweed intentionally in order to produce animal feed, which he estimates could earn him over 10 million riel per month.
Planted in rows divided by plastic sheets and sitting 20cm off the ground within a blue net house almost two metres tall, Phean Soviet’s duckweed farm located in Slak Kranh village of Samprorch commune in Kampong Thom province’s Stoung district.
Soviet – a former porter who traded one kind of backbreaking labour for another when he shifted to farming – told The Post that the plant grows very abundantly in the fields nearby and wherever there is water, but nobody has ever tried growing it themselves.
Soviet said that after returning home in 2019 he visited his relatives in a rural part of Kampong Chhnang province where he saw a lot of duckweed in ponds and canals. It then occurred to him that if the plant were to be cultivated through agricultural methods it might be profitable.
“At that time, I was just thinking about it, but there was no clear plan yet. I raised fish for sale and I lost nearly two million riel trying to do that and that’s when I decided to try duckweed instead,” he said.
Soviet stated that at first he just planted duckweed as a test and did not know what kind of farming techniques were used to grow such a plant. During this pilot phase, he put duckweed in a pond and added cow dung and chicken manure for fertiliser, but the duckweed’s leaves turned red and the plants died.
He later studied which fertilisers are compatible with duckweed and discovered that sakula, golden dragon and maffer fertilisers will help it grow and they are all natural and produced locally.
According to Soviet, he spent 500,000 riel to buy materials and began clearing his farmland to make ponds, about 10 metres wide on average but some more than 20 metres wide, with the length ranging from 30 metres to 50 metres depending on the land. He just recently made seven more ponds around 20 square metres in size.
He said that the technique for making a pond is that at first you have to make the ground even and then use bamboo or boards to make a wall with a height of 20 cm from the ground. Later, you must lay plastic sheeting across the pond’s bottom and pump in water to a height of about 10 and a half cm, then put duckweed in the pond and let it grow.
At a height of 10 and a half cm of water in an area of one square metre he uses 100 grams of fertiliser, but if the pond is 10 metres wide and 10 metres long then it is equivalent to using two kilograms of fertiliser with 600 grams of salt. That is the recipe for growing duckweed. For water sources he uses a canal that can be pumped in all seasons.
He said that duckweed does not have seeds, but it can be planted by using duckweed that is 10 to 15 days old by tying it up in a plastic bag and putting it out in the sun and then cutting off its roots and leaves.
When the roots and leaves are cut off, then it can be planted and it will grow into many plants. Harvest time comes after 10 to 15 days from the date of planting and all of the duckweed must be harvested and then you must clear the pond for replanting.
He added that he now has a half-hectare pond for growing duckweed, which he sells for 5,000 riel per kilogram and he can earn about 10 million riel.
Soviet is also willing to teach anyone who’d like to know how to grow duckweed for free so they can supply themselves or start their own business. He noted that duckweed can be used as feed for aquatic animals like fish, frogs, eels and lobsters as well as poultry like chickens, ducks, geese and quail, and in larger amounts it would also be suitable for pigs.