Strengthening the sloping land: ‘Weeds are friends, we only manage, not eliminate’

Growing weeds to have them grow trees

Ho Nhat Can (born 1966) lives in Hoai Tan ward, Hoai Nhon town (Binh Dinh province). He had been wandering around Ho Chi Minh City for a long time to earn a living. It was a sudden urge at the end of his life, he missed his homeland and the land where he grew up. He returned to his hometown to rent 6 ha of hilly land in Hoai Tan ward from the local government and bought another 6 ha of inter-regional land for cultivation.

At first, Can planted coconuts and avocados. When it was time for the harvest, he found that the efficiency was not high compared to the money spent on this hilly land, so in 2019, he decided to destroy all the old crops to plant 3,000 durian trees divided into 3 batches. The 700 durian trees planted in the first batch have now borne fruit for the third year, more than 1,000 trees are in the mature stage and another 1,000 trees are planted new.

According to Can's calculations, the price of durian this year is higher than last year, with traders buying on-site for VND 80,000/kg. By the end of the season, he expects to harvest 50 tons. This means he will pocket approximately VND 4 billion from a durian orchard with less than 1/3 of the total number of trees bearing fruit.

Taking us to visit the durian garden, Can said, “Since it is sloping land, it not only lacks nutrients but also shows a certain degree of difficulty in retaining moisture. If it rains, the water will quickly wash away, so in order to keep the soil moist, I let the weeds grow freely in the orchard. I only clear the weeds around the durian trees around the size of a winnowing basket, while the weeds in other parts of the orchard can grow wildly”.

He does not kill the weeds in the orchard, only manages their growth. When the weeds grow too high, he cuts it and keeps the roots so that they can continue to grow. “The roots of weeds penetrate the soil, creating space for the soil, creating a layer of oxygen for the durian to breathe. Farmers often clear the weeds in the garden because they think the weeds will ‘eat’ all the fertilizer. In fact, they only ‘eat’ a little fertilizer from the tree, but they will then become a large source of organic fertilizer to supplement the tree’s nutrition. Because after cutting the weeds, I spray the antagonistic fungus Trichoderma so that the weeds decompose into organic fertilizer. They eat one but return ten.”

The advantages of being an off-season durian growing area

Tran Ngoc Vien from Hoai Duc ward, Hoai Nhon town (Binh Dinh) is currently working at Welofarm Seed Supermarket in Cho Lach (Ben Tre). During his work, Vien has been exposed to many durian growing areas in the West, East, and Central Highlands. When he returned to Hoai Nhon town (Binh Dinh), he instantly realized the compatibility of durian and the hilly soil here.

“The climate and soil in Hoai Nhon are suitable for three durian varieties: Ri6, Thai and Musanking. The soil here is well-drained and does not get waterlogged when it rains, which is what the durian trees fear the most. The potassium and phosphorus content in the soil is fairly stable, the pH rate is standard, and there is no acidity,” said Vien.

In the case of Can’s durian orchard, not taking the advantages for granted, he diligently searches for more knowledge from experts, books and articles. He finds that durian trees often suffer from yellow leaf and root rot caused by Phytophthora fungus, but thanks to the high slope and good drainage, durian trees on hilly land are less susceptible to these diseases.

Durian is also often attacked by green leafhoppers when it sprouts new shoots but Can sees it as an easy problem. He uses dishwashing liquid to spray on the young leaves. The slippery nature of the dishwashing liquid prevents the leafhoppers from sticking to the leaves and causing damage. He also uses biological products to treat other common diseases.

According to Can, if durian is grown in an organic manner, orchard owners can save 40 - 50% of the fertilizer used. Orchard owners only need to spend less than VND 1.5 million on fertilizer per durian tree from the planting to the 5-year-old stage, and selling a dozen durians is enough to make up for the fertilizer cost.