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No-till in a time of climate change challenges thinking

Tillage practices – ploughing operations that disturb the soil – affect soil carbon, water pollution, and farmers’ energy and pesticide use, and therefore the approach to cultivation can have a major impact on the environment and also the productivity and profitability of the farm. Taking a big picture view of tillage can be valuable for challenging the perceived wisdom of current practices and creating the opportunity to ask if there are valid alternatives.

Maria “Pilu” Giraudo is a fifth generation farmer from central Argentina and she was recently awarded the prestigious Kleckner Award, an annual recognition given by Global Farmer Network to a farmer who shows leadership and vision. Giraudo was brought up on a ‘no-till’ farm. About 40 years ago her father had seen his soil eroding. He experimented with different cultivation practices until he found that drilling new seed directly into the ground, without disturbing it, reduced soil loss.

Giraudo has continued with ‘no-till’ cultivation of the 9,800-acre farm, which produces soybeans, wheat, barley, sorghum and livestock. As an agronomist, she also consults with farmers who collectively own about 50,000 acres in Argentina.

Glyphosphates? More science needed

She says: “One of the most important achievements of no-till system is the increase in yields, but what is better is that more soil stability is achieved. This is a crucial point for our industry. “We have experience and scientific evidence based on more than 30 years of no-till practice.”

In Europe the practice of no-till has been criticised for its heavy usage of glyphosate and this might be withdrawn from use. Giraudo suggests that more research is needed on alternatives.

“Glyphosate was key in the beginnings of the adoption of direct sowing for its broad spectrum of control, its low toxicity and residual activity. It would be a big mistake to ban the use of this chemical without proposing better alternatives.

“To date science does not give all the solutions for producing without herbicides, but we are improving day by day, using less and less. This is an opportunity for the industry. “Although no-till is the first non-negotiable technology within the system, there are plenty of others that can be applied separately or together over time to achieve sustainable production.

“Continuous ground cover is still not sufficient to keep weeds under control, but we are making progress in the use of different crops, with intensification on crop rotation (diversity and intensity) and including cover crops. This is highlighting for us the right path.”

No Till suitable for all crops?

Currently plants are bred for conventional farming and the machinery is designed also to support this. Does Giraudo consider that no-till needs adaptations?

“The most important element of no-till is that it is part of a system. And you must adapt it for each agro-ecological, commercial, cultural demands of each region of the planet. “Of course, the first step is to have not only the soil in good condition, but also a suitable seeder machine with the right weight and correct accessories.

“The seeds and the crops need a different management that conventional farming, from sowing to harvesting. This requires greater training and knowledge, also continuous monitoring for timely decision making. “It is amazing, you are learning each day from nature, science and how the hands of man can be improving, not destroying.”

In South America no-till has been practiced for many years and in the US the practice is increasing. In 2009 approximately 35.5 per cent of U.S. cropland (88 million acres) planted to eight major crops had no tillage operations1. However in Europe it has not had the same success. Giraudo considers that the situation is ripe for change. She comments that when her father changed his fields over to no-till, “many thought he was mad,” but now, many farmers are beginning to see no-till as a route for soil recovery in physical, biological and chemical ways.

According to a study (2) published in International Soil and Water Conservation Research in 2014, which looked at the changes in Argentine soil practice, no-till farming went from just a few hundred thousand hectares in 1990 to more than 23 million hectares, or around 79 per cent of the grain cropped area in 2010.

Much of this change is attributed to the Argentina No Till Farmers Association, an organisation of 3,000 members that Giraudo was president of until April 2016. Giraudo says: “There is a disconnection between the scientific and technical environment and the producers and vice versa. But the only barrier is people’s minds.”

References

1. “No-Till” Farming Is a Growing Practice – J.Horowitz, R.Ebel, A Report from the Economic Research Service

2. “The transformation of agriculture in Argentina through soil conservation” R. Peiretti., J. Dumanski. http://www.sciencedirect.com/science/article/pii/S2095633915300101