Passing through the market in a village, I came across the local harbor where boats were waiting. Brown water flowing from the Mekong River washed around my feet. A tiny boat made headway through the waterway that branched off from the main stream. There were nipa palms growing on the bank while water hyacinths floated on the riverside. When its bow ran ashore, I alighted from the boat. I was in front of the garden of a farmer with whom I wanted to meet.

Than Phu Thanh Village is located in the south of Con Tho Province, a central area of the Mekong Delta in Vietnam. This is a riverside village where water from the Mekong runs in all directions.

In recent years, cyclical farming known as the Vo-Ao-Chuong (VAC) Farming System is expanding in this area. Dr. Takeshi Watanabe, senior researcher of Japan International Research Center of Agriculture, Forestry and Fisheries (JIRCAS), highly values this system, expressing that ”it is one of those areas where the nitrogen cycle is working well.”

VAC's V is interpreted as vegetable and fruit gardening in the backyard, A as aquaculture in the pond and C as feeding cattle such as pigs and ducks. It is sometimes called the VACR Farming System, with R signifying rice. Waste rice and rice bran feeds pigs, the waste of which becomes food for fish in the pond while, every year, dirt in the pond is dredged to become a fertilizer for growing fruit. This is small scale complex farming that seeks to combine efficient use of farmers' nitrogen matters with a reduction in chemical fertilizers and agricultural chemicals.

A pig cottage near a fishpond, which is typical of the VACR farming system. Photo by Uchinaya at the farm of Mr. Mr. Nguyen Van Ut, Than Phu Thanh Village.

Mr. Duong Van Quang, 46, said he started cultivation of catfish and tilapia in addition to hog raising, after ”he saw his friend making a good business out of it.” His wife Mai, 50, is keeping three hogs. Looking up at the nipa-covered roof, she said, ”I want to turn it into a brick house, if I make good money.”

Mr. Nguyen Van Ut, a fruit growing farmer, 47, installed two years ago a bio-gas digester which he was encouraged to introduce as a set with VACR. ”By fermenting pig waste and letting it drain into the water, it can keep the water in the pond clean,” he said.

It costs about 4,500 yen Japanese currency and its life span will be four to five years. It is not cheap, but its heating power is quite strong. ”It is more convenient than wood. I will after that time put another in place.”

The VACR, taking into consideration traditional farming methods, has been developed by local institutes such as the Farming System Research and Development Institute of Can Tho University as a system to increase income while at the same time protecting the environment. As a result of dissemination started in 1990, it is estimated that 30% of farmers living in the Mekong Delta area utilize this system.

“This is a system for small-size farmers. If it works well, net income will be doubled,” said Vo-Tong Xuan, who is Rector of An Giang University and has been engaged in its development in earlier days.

How about its effects on the environment? According to Dr. Watanabe, who in 1999 conducted surveys of the nitrogen cycle in the area, he found that nitrogen, most of which was produced by animal feeding, only amounted to 39 kilograms per hectare, which was the final quantity of nitrogen left in the farmland. A limited amount of nitrogen is brought in from outside through chemical fertilizers and feedstuffs. The cycle there had therefore been performing better than that in Japan, where 150 kilograms was calculated as the nitrogen taken from livestock only.