The verdict is in: Conservation agriculture trials
needed for the long run

Standing between two maize fields and surrounded by neighboring farmers, Arturo Romero Peralta explains his experiences with a new agronomic method that trumps traditional farming practices like as the removal of  crop residues—stalks, husks, leaves—and regular tillage. Peralta is one of nearly 40 farmers partnering with CIMMYT to host demonstration plots in a collaborative effort to test and disseminate conservation agriculture (CA) practices in Mexico.

Two years ago CIMMYT started weaving a web that connects local farmers, researchers, and technicians throughout Mexico. The network, anchored by several long-term conservation agriculture (CA) trials at three CIMMYT hubs (two in central Mexico and one in the North), allows the exchange of CA information and technology. It has already helped over 150 families adopt CA practices on nearly 1,000 hectares, primarily on maize fields in central Mexico. CA is an agronomic system based on reduced tillage, sensible crop rotations, and keeping crop residues or cover crops on the soil's surface. CA practices, which are based on these three principles, are being refined and promoted by CIMMYT’s global Conservation Agriculture Program, launched in early 2009.

“The idea is to have a controlled field situation where we can try out various cropping practices, supported by modules (farmers’ fields with monitored CA plots) with a farmer and a technician,” says Bram Govaerts, CIMMYT cropping systems management specialist. But it’s not easy to convince farmers to allocate part of their land for an unfamiliar cropping practice. This is where the long-term trials come into play.

Sustainability is rooted in consistency

CIMMYT maintains several long-term trials to determine which agronomic practices produce stable, high yields with low environmental impact. Since farming is an economic activity, the ideal system must also produce high revenues for the farmer. After more than 15 years of continuous trials, CA-based practices have proven to be the best for maize, wheat, and small grains in all CIMMYT tested conditions. Sown side-by-side for many years with conventionally-managed plots, these trials show striking differences between the two farming systems. For example, in comparison plots at CIMMYT’s El Batán research station in the central Mexican highlands, plants grown under farmers’ practices died during a recent drought, while those under CA practices are still standing.

Additionally, in trials comparing conventional and CA systems for growing wheat under irrigation in northern Mexico, the practice of removing all residues from permanent beds performed well for the first five years, but crashed in the sixth. These continuous trials allow researchers to recommend and promote systems that are truly sustainable and give local farmers the opportunity to examine the plots and decide for themselves which system is better. The hope is that they will agree to test CA practices on their own land, serving as an example for their neighbors and thereby expanding CA awareness and adoption.

Soils stay still, CA picks up speed
“It should be a law that all farmers use conservation agriculture,” says Paulino Sánchez Vásquez, a maize farmer from Atotonilco, Hidalgo, who attended the field event in Peralta’s field. Vásquez comes from a family of farmers and manages 25 rainfed hectares of maize, 5 of which are grown under CA practices.

“This land is not ours,” says Vásquez, gesturing to the surrounding fields. “It is only on loan to us, and we will leave it for our children.” He is one of the 75% of participating Mexican farmers from the central Mexico rainfed maize hub who after only one year of CA experimentation think CA has promise, according to a survey by CIMMYT socio-economist Dagoberto Flores Velázquez.

Like other collaborating farmers, Vásquez has agreed not to till the soil in his CA trial plots for 5 years, a vital but initially difficult part of CA, since it requires an overhaul of traditional field practices and produces little immediate gain. Some farmers who agreed to try zero tillage—no soil movement at all—with other CA practices abandoned the attempt after the first year, because they did not fully understand the system and lacked proper technical support, says Flores Velázquez. Along with the Mexico CA team, he is trying to reconnect with these farmers and offer them proper assistance. They are doing this through increased field visits and extension materials, such as agriculture comic books specifically adapted for particular socioeconomic areas and a monthly CA magazine.

Those farmers who are able to maintain fields under CA management can save both time and money. Central Mexican maize farmers using CA experienced a savings of between $110 USD and $300 USD per hectare last year compared to farmers with conventional plots. Additionally, according to Vásquez, reduced tillage and leaving residues on the field improves the soil and, as an extra benefit, leaves the farmer with more free time for relaxation or gainful activities.

Another tool for CA extension is an online database of the farmer modules—locations where farmers agree to sow with CA practices, assisted by partnering technicians—based on the popular application Google Earth. This virtual globe shows not only the location of each farmer module, but with a simple click users can access vital information about the modules, such as fertilizer applications, yield, and any problems encountered.  Technicians and researchers can easily analyze CA results under various conditions, share the information with farmers, and further the adoption of relevant CA practices so more farmers can benefit.

No shortcuts
Though the value of these CA trials has been proven, there is no guarantee they will continue. Long-term trials need long-term funding, something the program currently lacks.

“With long-term trials there is no flexibility. Either you do them or you don’t," Govaerts says, "And if you stop a trial for even a single crop cycle, it’s over forever. It isn’t like next year you can say you have the money again and restart the trials.”

In 2009 the long-term trials provided the base for over 40 training and capacity building events in Mexico, but dissemination doesn’t stop there. Since 1996 the plots have been used as a training platform for over 80 researchers from more than 20 countries who came to CIMMYT’s Mexican headquarters to study agronomy and sustainable management of natural resources. Numerous thesis and student research projects from all over the world have also used the trials. Additionally, with CIMMYT’s help, CA information and practices from the Mexico-based trials are being tested and adopted by farmers in Africa and Asia. "We don’t just work for Mexico,” Govaerts says. “We work for the world.”

For more information: Bram Govaerts, cropping systems management specialist (b.govaerts@cgiar.org)