Farmers kill weeds with new organic cotton sheets


Cotton mulch sheeting is becoming a popular way for organic farmers to remove weeds from their fields.

The product is also attracting the attention of manufacturers and trading firms looking for new business opportunities — even farmers in Italy and South Korea have shown interest — as consumers increasingly opt for chemical-free and better-tasting rice.

Cotton mulch sheeting, whose purpose is to aid in the difficult job of weeding, was born out of the joint efforts of entrepreneurs and an agriculture scholar.

In mid-May, Mitsue Ueoka, 60, a farmer in Ikazaki, Ehime Prefecture, skillfully covered a terraced paddy field with two cotton mulch sheets, each 100 meters long, 1 meter wide and weighing about 20 kg.

The two sheets, between which seed rice is placed, are spread over the field and molded to the shape of the terraced paddy. When water is flooded onto the fields, weeds are crushed by the sheets’ weight and die.

Once it is on the ground, the cotton is slowly eaten by bacteria and, in about 50 days, turns into a natural fertilizer that kills weeds, improves ventilation and drives out harmful insects.

“The timing was good,” said Terushi Mori, 68, an adviser to Marusan Sangyo Co., a producer of the sheets, explaining why the cotton maker decided to expand into producing the farming material.

The manufacturer of absorbent cotton for medical products and makeup puffs, based in Ozu, northwest of Ikazaki, launched a project in 1996 to develop a new material from its cotton byproducts to dispose of oil waste.

Around the same time, Yukindo Tsuno, 73, who holds a Ph.D. in agriculture, was exploring ways to reduce human labor in organic farming in Miyazaki Prefecture.

“I wanted to free heavy labor from farming in mountain areas,” he said.

Tsuno had come up with an idea to cover rice fields with recycled paper to kill weeds. However, the method could only be used on flat land.

Masahiko Imura, president of Imura Kogyo Co., a clothing manufacturer in Nagoya, visited Tsuno in 1998 with the idea of using cloth sheets on terraced fields.

Imura’s experiment using cloth mulch sheets of recycled cut cloth was successful. But the refuse contained chemical fibers and there was a fear of soil contamination, so cloth was abandoned.

Tsuno and Imura began looking for companies dealing in raw cotton. They found Marusan in early 2000 and asked the company to create an additive-free cotton sheet that could be spread over terraced paddy fields.

Marusan President Kimitaka Kikuchi, 71, agreed, with the idea that he could adapt the technology used to dispose of oil to the kill weeds.

He and Tsuno initially conducted experiments on flat fields to create a cotton mulch sheet.