Hungry sheep and conservation agriculture in Mexico

Toluca station superintendent, Fernando Delgado, (left) and Bram Govaerts, cropping systems management specialist (right), ran the three-day course. Go to Photo slideshow on Conservation Agriculture Course

A recent intensive course at CIMMYT’s Toluca experiment station in central Mexico shows researchers and extension workers the real-life complexities of conservation agriculture for rainfed maize farming.

The tractor comes to life and lumbers slowly down the field in the blistering April sun of the central Mexican highlands, dragging a heavy multi-row seeder. A group of men and women, many wearing cowboy hats and jeans, falls in step behind it. The seeder’s discs cut long ruts in the rock-hard soil, and when the tractor stops the group crouches over the grooves left in the field. Clutching cameras and notebooks, they use their free hands to move the soil aside and check the spacing and depth of seeds in the channels.

“You can see that the seeds are not set deep enough to access residual soil moisture,” says a man with a white, wide-brimmed hat. “That means we have to adjust the implement a bit.” The speaker, Fernando Delgado, is supervisor of CIMMYT’s wheat research station at Toluca in central Mexico, and ironically a man maize farmers near the station and in other parts of Mexico look to for advice on conservation agriculture (CA). With his companion, CIMMYT cropping systems management specialist Bram Govaerts, and his field assistants, Delgado set to work to adjust the seeder, explaining each of the steps involved.

On this occasion, rather than farmers, Delgado and Govaerts’ audience comprised agricultural experts, from both the public and the private sectors, from key Mexican farming states such as Durango, Guanajuato, Hidalgo, Jalisco, and Mexico. They were there for a three-day workshop on CA for rainfed maize cropping systems. In the group were representatives from the state of Mexico agricultural research organization, ICAMEX; from SEDAGRO, the secretariat of agricultural development for the state; from Mexico’s national agricultural research institute, INIFAP; and university professors and students. There were also representatives from the private seed companies Monsanto, Aspros, and Tropico Seeds, and from the milling and pasta-making company La Moderna. After a day of theoretical discussions, all were rapt in the demonstration of direct seeding into crop residues and unplowed soils.

“We’ve worked with farmers, but this is a different level and a diverse group from many different parts of the Republic,” said Bram Govaerts, who organized the course. “We want to train researchers, machinery manufacturers, extension agents, and representatives of seed companies, and then pass on to them the work of disseminating conservation agriculture, once things get rolling.”

Wresting straw from ravenous sheep
“The principles of CA are universal and sound easy,” says Govaerts. “You eliminate plowing, keep crop residues on the soil, and use suitable crop rotations.” Proven benefits to farmers include significant cost and time savings, more stable yields over the medium-to-long term, improved soil structure and health (with reduced erosion), and better use of soil moisture and precipitation. Yet CA has been slow to catch on in Mexico, despite looming crises of soil degradation and water scarcity in agricultural areas.

To begin with, the culture of the plow—the perennial symbol of agriculture itself—is hard to break. Other issues include the risk-averse nature of rainfed maize farmers, who as a rule work relatively small holdings and eke out harvests using few inputs and under difficult conditions. Moreover, CA principles may be simple, but applying them in real life can be complex and may require considerable experimentation and fine-tuning, as the day’s direct seeding demonstration showed.

But the biggest constraint to adoption in rainfed maize cropping systems worldwide is competition for crop residues after grain is harvested. “Keeping some residues on the soil is essential for conservation agriculture,” says Govaerts. “They add organic matter, guard against erosion, and capture and retain moisture, among other useful functions. In fact, our long-term studies show that if you practice zero-tillage continuously without retaining any residues, after about five years the bottom suddenly drops out of your cropping system and crop yields plummet.”

Yet, livestock and other animals are major components of rainfed cropping systems, and crop residues have enormous value as forage to keep them healthy and productive. In many rural communities in developing countries, tradition allows animals to roam free after harvest and graze at will, and little if any residues are left. Plowing in residues might solve the problem, but CIMMYT studies also show that there is much less benefit from the residues that way.

“I’ve been retaining residues for the last five years or so,” says workshop participant Fermín Hernández, a farmer and agronomist who runs an office in Hidalgo state that sells seed and inputs and provides technical advice to other farmers. “I have no choice but to plow them in, because if I leave them on the surface, other people come at night and steal them, even though my land is fenced in. The temptation is just too strong; they say: ‘those residues would be great for my sheep, and you’ve got lots anyway!’ ”

The future of agriculture
Delgado has been promoting resource-conserving practices with farmers for eight years. In the beginning, CA was a way for him to save money on Toluca Station operations because it required less water, fuel, and machinery passes. Now, he visits schools to educate children about CA and gives presentations to upwards of 1,000 farmers a year. He listens carefully to questions from the course participants and has an easy way of relating to the group. “Conservation agriculture is the future,” he says. “As well as the environmental benefits, it makes farming more sustainable. If farmers use well-timed herbicides and do proper crop rotations, they can actually improve their yields.”

The course participants learned about how CA is being used on experiment stations and around the world, its impact on plant-soil systems, pest and weed control, zero-tillage and sowing maize on permanent beds, and prototypes of machinery that can be used for direct seeding. Participants also interacted with local farmers to learn from their experiences applying CA principles.

“I’ve had no experience in direct seeding, so this course was an opportunity for me to come listen to the experts,” said Juan José García, who works for INIFAP in seed production. “Bram and Fernando have very good ideas, and a lot of knowledge and experience. From here I can learn from them and take these ideas back to the farmers.”

For the past five years, García has been working to get farmers to plant in permanent raised beds by doing demonstrations and comparison plots. “It’s a challenge because many of them don’t believe it will work until they see it. Also, a lot of the young men have gone to the United States and that leaves the older generation that is less open to change and to new ideas.”

Still, García is optimistic about the possibility of spreading resource-conserving practices. “We can create new projects with the institutions where I live and adapt the details of implementation for farmers there. This is a long-term project, but we’ve got to start somewhere.”

Govaerts is positive about the role the Toluca station can play in spreading conservation agriculture.

“We want to build out a central Mexico ‘cropping systems hub,’ ” he says. “The idea is to have a focal point where all actors of the production system—farmers, scientists, policy-makers, machine builders, seed and fertilizer retailers, private companies, media, etc.—can work together, resolve issues, make the technology work, and then extend it to others.”

"We need for all the significant players to work together to give agriculture in Mexico a boost,” says Govaerts. “The goal is for a sustainable system that’s also profitable, because activities that are good for the environment won’t be applied by farmers unless they’re profitable. Conservation agriculture can have this special combination of profitability and sustainability.”

For more information: Bram Govaerts, Cropping Systems Management Specialist (b.govaerts@cgiar.org)

You might also be interested in the following reports on CIMMYT work in conservation agriculture:

Bringing Conservation Agriculture Home to Mexico

Clarion Call to Conservation in Mexico

Stemming the loss of African soils’ life blood

Zero-tillage: Averting dry wells and depleted soils in South Asia