Development & Aid, Environment, Headlines, Latin America & the Caribbean

AGRICULTURE-BRAZIL: Zero Tillage Fights Erosion, Boosts Crop Yields

Mario Osava

RIO DE JANEIRO, May 25 2004 (IPS) - ”The soil was just disappearing from under my feet, and I realised that with another torrential rainfall, I wouldn’t have any land to plant on anymore,” Herbert Bartz, the Brazilian farmer known as the pioneer of the ‘zero tillage’ system in his country, told IPS.

The desperation caused by increasing erosion led him to start looking around for alternative farming techniques to keep his soil from turning into ”a fluid that just washed into the river.”

He travelled that year, 1971, to Britain and the United States to learn about the zero tillage system, which involves no plowing, and leaves crop residues on the soil surface as mulch. He brought back special machinery to start using the new technique.

Today, at the age of 67, he says it was not easy. The imported seeding machine cost him nearly 20,000 dollars, ”a lot of money back then,” on top of which he had to pay stiff import duties.

But since he had lost his entire 250 hectares of wheat to frost, ”I didn’t have any other option” and had to persevere while ”many were giving up” on the new technology because of the initial difficulties caused by weeds. ”I preferred to lose 20 percent of the crop to weeds than 80 percent due to erosion, the cancer of the earth,” he added.

Nearly half of Brazil’s grain output is now produced using the zero tillage system, according to the Brazilian Federation for Direct Planting (the name given to the technique in Brazil).

”A realistic estimate is that the area under direct planting is growing between five and ten percent a year,” agronomist Bady Cury, one of the Federation’s technical advisers, commented to IPS.

The technique expanded slowly in this South American country in the 1970s and 1980s, but began to catch on faster in the 1990s.

In the southern state of Paraná, where it first began to be used, 90 percent of crops are now grown under the zero tillage system, said Bartz, who predicts that by 2010, nearly all of Brazil’s agricultural output will be produced using the technique.

Zero tillage has played a ”decisive” role in the major rise in yields seen in Brazilian agriculture, by improving soil fertility and cutting costs, said Cury.

The country’s grain output has more than doubled since 1990, with almost no increase in the cultivated area, making the country a leader in farm exports, especially soy beans.

But the environment has also benefited. Besides controlling erosion, which improves the quality of water in the rivers by reducing sedimentation, emissions of greenhouse gases have been reduced due to the diminished use of fossil fuel-guzzling tractors and other farm machinery, Cury pointed out.

Gabriel Fernandes, an agronomist with the Advisory Services for Alternative Agriculture Projects (ASPTA), a non-governmental organisation, acknowledges the environmental benefits of the zero tillage system, which leaves crop residue on the fields to ”reactivate the biology of the soil,” thus preserving nutrients and curbing erosion.

But adoption of the technique has not solved the problem of excessive use of herbicides, and has been closely linked to extensive monoculture, Fernandes noted in an interview with IPS.

Only now are small farmers beginning to benefit from the new technique, with equipment being produced that is suitable for small farms.

In the state of Paraná, ASPTA supports projects combining zero tillage with crop management techniques that do away with herbicides by using plant species that ”inhibit invasive weeds,” said Fernandes.

To be successful, zero tillage requires crop rotation and reduced use of agrochemicals, as well as leaving soil cover in place as mulch and not plowing, said the agronomist.

”Intensive use of herbicides sterilises the soil,” which is why transgenic soy resistant to weedicides eliminates the benefits provided by the technique, he argued.

Bartz, however, likens the current resistance to genetically engineered crops to the opposition faced by zero tillage in the early days, when he was a ”solitary battler.”

Thirty years ago, ”the anti-progressive left” also claimed that ”direct planting posed a risk to human health,” he said.

In his opinion, the big boost back then was provided by ”the 1973 oil crisis.” Farmers discovered that zero tillage could cut spending on fuel by up to 65 percent, by eliminating plowing and a large part of the operations requiring farm machinery, besides the savings on labour costs.

The continued expansion of zero tillage is inevitable, according to Bartz, due more to financial or cost-cutting concerns than to benefits to the environment, because farmers who do not adopt the ”new philosophy” will be unable to compete.

To that are added the social benefits, now that research institutes and industry have adapted the technique and equipment like zero tillage seeding machines, which can now be used on family farms, and can even be pulled by plow animals, he noted.

In 2001, the United Nations Food and Agriculture Organisation (FAO) and World Bank commended Brazil’s direct planting system as a sustainable agriculture model that could be emulated by poor countries in Africa and Asia, said Bartz.

The social benefits of zero tillage have become the most important aspect, he added, and Brazil has begun to ”export” the technology to other countries, with a special focus on small farmers.