CIMMYT E-News, vol 4 no. 7, July 2007

Infrared sensors help better target fertilizer for wheat on large commercial farms in northern Mexico, cutting production costs and reducing nitrogen run-off into coastal seas.

Farmers of the Yaqui Valley, Sonora State, northern Mexico, and fish in the Sea of Cortez: what ties could they possibly share? Well, if CIMMYT wheat agronomist Iván Ortíz-Monasterio and fellow researchers at Stanford University and Oklahoma State University achieve their aims, both farmers and fish may breathe a little easier.

Ortíz-Monasterio and his partners have been testing and promoting with Yaqui Valley farmers a sensor that measures light reflected from wheat leaves and thereby gauges the health and likely yield of the plants. The device is calibrated to capture red wavelengths, which indicate chlorophyll content, and infrared wavelengths, a measure of biomass. The readings are run through a mathematical model to provide a recommendation about whether or not the crop requires a mid-season application of fertilizer.

Yaqui Valley wheat farmers work large holdings (averaging around 100 hectares), use irrigation and mechanization, and grow improved varieties with fertilizer, fungicides, and other inputs. They typically get excellent yields—on the order of 6 tons per hectare. Despite this, they are feeling squeezed by the rising costs of diesel fuel, water, fertilizer, and other inputs, and many are actually in debt; so they are fervently seeking ways to save money.

Too much of a good thing?

“Farmers here typically apply 230 kilograms of nitrogen per hectare, and 150 kilograms of this goes on 20 days before sowing,” explains Arturo Muñoz Cañez, a consulting agronomist who works a lot of the time with the Asociación de Organismos de Agricultores del Sur de Sonora, an umbrella group that includes seven farmer credit unions serving producers on some 140,000 hectares in the region. “Our studies with Iván have shown that local wheat crops actually use only about one-third of that fertilizer.”

Where does the rest go? Some evaporates into the atmosphere, in the form of nitrous oxide, a notorious greenhouse gas that is nearly 300 times more damaging than carbon dioxide. Another part leaches as nitrate into groundwater, and much of the rest dissolves in run-off irrigation and rainwater, eventually finding its way to the west coast of Sonora and into the sea. There it may fertilize oxygen-hungry algae that can suffocate other marine life and cut into fishermen’s catches.

From Mexico to the world

With the help of Ortíz-Monasterio, Muñoz, and other agronomists, Yaqui Valley farmers used the sensor on 174 plots in 2006-07, comparing readings from a fully-fertilized comparison strip with those from the rest of the field at 45 days after sowing—a point at which most important differences in crop development are evident. They then followed the resulting recommendations concerning how much additional fertilizer was needed, if any. In 66% of the cases, the recommendation was to apply nothing more. At harvest, yields from both the fully-fertilized strips and 86 test plots were compared by weighing the grain. “92% of the farmers got good yields—that is, comparable to those of fully-fertilized strips—and on average saved around US$ 75 per hectare in fertilizer they did not apply,” says Muñoz. That’s a US$ 7,500 savings for a 100-hectare farm.

Ortíz-Monasterio attributes the success partly to residual fertility in the local soils, but would like to see eventual adoption of more precise, resource-conserving agricultural practices—including direct seeding without tillage, retaining crop residues on the soil surface, and improved water use efficiency—on at least half of the total 200,000 hectares of the Yaqui and nearby Mayo Valleys. “The Yaqui Valley has been a sort of laboratory for the rest of the world,” says Ortíz-Monasterio, who has worked for several years with researchers in Pakistan to adapt the sensor for the country’s extensive irrigated wheat lands. “A lot of what was first developed here—high-yielding wheat varieties, sowing on raised beds, and now the sensor—has gone on to be used in other wheat farming regions of the developing world. In some ways, what happens here is a reflection of how successful or not CIMMYT is.”

Ortíz-Monasterio is also promoting a lower-cost alternative for farmers who may not be able to work with a sensor: “You simply establish a well-fertilized strip in your field. If the rest of your crop looks comparable in health and development to plants in the strip, then you don’t need to apply more fertilizer. If there is any difference, then you apply what you would normally apply. In this way, we’d help at least half the irrigated wheat farmers in the world.”

For more information: Iván Ortíz-Monasterio, wheat agronomist (i.ortiz-monasterio@cgiar.org)

May, 2004

Drought, arguably the greatest threat to food production worldwide, was the focal point of a high-level, weeklong workshop supported by the Rockefeller Foundation and CIMMYT, commencing May 24, in Cuernavaca, Mexico.

Approximately 140 scientists from Asia, Africa, and Latin America–working on various aspects of drought tolerance in plants–met to present their research results and discuss ways forward with their colleagues. The meeting, entitled the “Resilient Crops for Water-Limited Environments workshop,” looked mainly at maize, rice, and wheat, which account for more than half of the calories consumed by people in the developing world, and are the basis for their food security and livelihoods. Scientists comprehensively addressed drought, looking at drought tolerance from the ground-level perspective of incorporating farmer participation into varietal development, to the heights of molecular genetics, and how plant genes interact and respond to water stress.

The workshop was opened by Dr. Gordon Conway, President, The Rockefeller Foundation, and Dr. Masa Iwanaga, Director General of CIMMYT.

Dr. Conway, in his address, declared a “war on drought.” He explained that 70% of the one billion African and Asians in extreme poverty (less than $1/day) live in rural areas, and that agriculture is their primary route to improved nutrition and income. For developing world farmers, drought wreaks havoc, forcing them to sell off their meager assets, such as livestock or their own off-farm labor, and forego health care and their children’s education. Often the results are far more dire: hunger, malnutrition, and even starvation. In the 1960s and 70s, the Green Revolution saved hundreds of millions from famine, said Conway, but many living in less favored environments were bypassed as much of the success was based on adequate water and soil fertility. What is needed now is a Doubly Green Revolution to lift up the African and Asian smallholders left behind. Drought tolerant crops are key to this cause .

Dr. Iwanaga recounted the long and close relationship between CIMMYT and The Rockefeller Foundation, dating back to the pre-CIMMYT era and the Foundation’s support for Norman Borlaug’s work on semi-dwarf cereals, leading to the Green Revolution. That success led to the birth of CIMMYT and the CGIAR, with considerable backing again provided by the Foundation.

Even today, Dr. Iwanaga pointed out, the Foundation remains one of CIMMYT’s most important supporters, both financially, but more importantly, in the confluence of the Foundation’s goals and CIMMYT’s research activities. Both institutions see drought tolerant crops, soil fertility, and the development of seed markets and distribution systems as essential pillars for improving productivity for smallholder farmers, thereby providing a path out of poverty to better livelihoods for the developing world’s rural poor.

Extended abstracts from the workshop are forthcoming and will be made available to the public before year’s end.

November, 2004

How could a wheat research station in the middle of a maize-growing state become a resource for its neighbors? Campaigning for conservation agriculture and maize hybrids, CIMMYT’s Toluca Station superintendent Fernando Delgado Ramos is changing the way some farmers think about the plow. What started out as a crop rotation for a wheat experiment is now turning heads for its advances in maize yields.

Julián Martínez is one of the farmers to have noticed. He has seen tremendous differences in his efforts since adopting hybrid maize seeds and direct seeding methods on raised soil beds, which he started two years ago. Early in the season he was ashamed of his crop, but now smiles with pride when people pass on the nearby road, touching the tip of his hat and grinning. His results last year planting hybrids directly into raised soil beds were so abundant that the landowner increased the rent, which compelled Martínez to shift his efforts to a nearby ejido, or communal land. Small as the area may be, another bumper crop came this year, with not a bit of lodging in his straight and strong stocks of maize. Well-protected, fuller husks are another benefit of the particular hybrid Martínez has chosen. Driving through Toluca, located in a mountain valley, it’s obvious that lodging is a prevalent problem here. Even when leaning maize stocks were no longer Martínez’s problem and his yield doubled to eight tons per hectare, many local farmers have not taken the practices he and Delgado espouse seriously.

“My father thought I was crazy when I started,” Martínez says. “‘What are you doing with this?!’ he asked me. He thought I wasn’t being a good farmer, that I was doing bad work,” Martínez admits, and explains that at first he wasn’t allowed to rent his father’s three hectares. In May and June, when early-maturing local varieties dwarfed his late-maturing hybrids, he was worried, “but not anymore,” he says. By the end of the 2003 harvest, his father and brother were convinced. Martínez’s mentor throughout this process, Delgado sees these experiences as valuable because “if one farmer takes up the technology, I am happy, and the idea will spread itself.” Next year he anticipates helping two farmers in Jalisco convert over 250 hectares to permanent soil beds. Big strides for an idea that has started out small.

An Off-station Sideline Brings Local Benefits

Delgado is a leader among an array of seasoned and experienced field workers at Toluca Station, many who have been working there for over 20 years. Their combined experience and constancy have been enormously beneficial to Toluca’s success developing wheat for acidic soil and high rainfall environments. It has only been in the last few years that Delgado has made progress helping the maize farmers around the station, something he accomplishes as a sort of sideline after completing a full day of balancing office and fieldwork. Farmers gravitate to this tall Mexican, who knows his stuff after working at CIMMYT for 14 years. Educated in agronomy, he started out in a joint program between the International Center for Agricultural Research in the Dry Areas and CIMMYT, providing Latin America with improved barley strains, and now he has risen to superintendent at Toluca.

After exhausting other sources of information and assistance, it is the serious farmers, bent on improving their harvests, who flock to Delgado. Most Toluca Valley farmers do not fully depend on agriculture; rather, they supplement their day jobs with these side ventures. The ambitious ones want to improve their yields, but most just sow to fill the land and hope for a moderate harvest. Still, each year about 600 farmers attend presentations led by Delgado on conservation agriculture. Although their established methods do not allow them to thrive, local farmers are reluctant to change, he explains. “I put their hand to the land and show them. It’s not impossible to change their minds.”

Putting Aside the Plow

But it is intensive work, conversing, going through all options and strategies of this new idea, sometimes for five hours at a time. The “culture of the plow” is ingrained in Mexican life, and to uproot it is hard work. This is why Delgado works with children as well, going to schools and introducing his ideas. “To change the culture is to put conservation agriculture into the minds of children,” he says, “It is beautiful to explain to children, for they appreciate how they eat, and what they eat.”

Delgado’s movement toward conservation agriculture started as a way to save money in operations at the Toluca Station through use of less water, fuel, and machinery passes. Fifty percent of the station’s land is used for wheat experiments, and the other half is devoted to crop rotations to sustain the land. It was in this section that Delgado started using direct seeding methods on raised beds to rescue money for other projects. After a couple of harvests, 10 tons of grain was recovered per hectare, compared to an average of 5–8 before. Conservation agriculture had captured his attention.

It is obvious that the planet has been disturbed by human existence, and conservation agriculture is “a little bit to support the world,” Delgado says. He feels very passionately about this, his words coming slowly and deliberately. “Conservation agriculture is the future,” he affirms, “It is common sense, it is how we help the environment.” Its goals include preservation, improvement and more efficient use of resources such as soil, water, and fuel for machinery. As well as the environmental benefits, conservation agriculture makes farming more sustainable with better yields. To realize these goals, a permanent soil cover must be allowed to develop, which makes plowing obsolete. This is the detail farmers find most difficult to swallow, because tilling the land is the way they and their parents have survived. They assume that not using a plow to turn the soil allows weeds to overrun a field, and find the idea of planting seeds into a field with last year’s stubble untidy. But using conservation agriculture with well-timed herbicides and proper crop rotations can actually improve yields.

“People visit the station, and the farmers want to be better than CIMMYT,” Delgado laughs. A friendly rivalry has grown out of Toluca’s success, and now the farmers want to better their own yields to exceed the research station’s results. He thinks this is “nice, because the healthy competition has transformed the farmers to better their techniques. A little revolution in Toluca, but a big change in the farmer’s mind. Farmer to farmer to farmer.” he says. The same people who, a few years ago, were saying how crazy the innovative farmers were, are now asking how they can try the new technology.

Adaptation, to make fit by modification, not adoption, is suggested for the farmers to make a seamless transition to conservation agriculture. Rather than purchasing all new equipment to replace what they already have, Delgado promotes the adjustment of their current machinery. “For the small farmer, to spend USD 1,800 on a new machine is not an option. But to insert a piece that can be bought for half that is practical, and they can afford it.” Delgado says. This enables the small- and medium-sized farmers like Julián Martínez to start off in conservation agriculture. CIMMYT wheat agronomist Ken Sayre applauds Delgado’s efforts. “People like Fernando still believe that improving the crop production situation directly in farmers’ fields is the most valuable way to achieve impact,” he says. His practical initiatives are certainly helping many farmers to increase their productivity and profitability.

CIMMYT E-News, vol 3 no. 12, December 2006

Wheat lines that resisted virulent stem rust last season have now succumbed.

Observations from wheat rust screening trials in Kenya indicate even more of the world’s wheat is at risk from a stem rust attack than originally thought. Scientists from CIMMYT and its partners, studying wheat planted at the Njoro Agriculture Research Centre, report that more than 85% of sample wheats, including cultivars from the major wheat producing regions of the world, have succumbed to the stem rust known as Ug99. Most importantly some wheat lines which showed resistance to Ug99 stem rust a year ago now appear to be susceptible to the disease.

In August, 2005 an expert panel raised the first alarm about the new, virulent form of stem rust that could devastate world wheat crops. These new observations could mean the threat to the global wheat harvest is now significantly greater.

The Njoro Research Centre is in an area of Kenya where the virulent form of stem rust fungus is endemic. For the past three years scientists have used the station to expose wheat to the disease to see which is susceptible and most importantly, which is not. In March of 2006 more than 11000 different types of wheat and relatives of wheat from all over the world were planted and exposed to the fungus.

Studies are still underway to clarify the situation but it appears that at least one of the major stem rust resistance genes that has protected many of the world’s wheats for decades is no longer effective against the rust fungus at Njoro. This new development enhances the significance of what is already recognized as a dangerous threat to future global wheat harvests.

Wheat grows on more than 200 million hectares in both the developed and the developing world and the new data indicate that very little of that area is planted to varieties which resist the stem rust found at Njoro. Though stem rust may not be able to thrive in all parts of the world, scientists estimate that well over half of the total wheat area could suffer rust epidemics if susceptible varieties planted there are exposed to the pathogen.

“I was shocked at what I saw this season,” says Rick Ward, coordinator of the CIMMYT-ICARDA led Global Rust Initiative. “Essentially we have to find a way to replace all of the world’s wheat.”

Stem rust is one of the most dreaded of all plant diseases. In the mid-1950s it wiped out up to 40% of the North American spring wheat crop. Thanks in large part to the wheat breeding work of Nobel Peace Prize laureate, Dr. Norman Borlaug and those who followed him, the disease has not been a significant threat for almost half a century. Breeders combined several sources of resistance to the fungus into new varieties of wheat. Unfortunately, over time, the rust pathogen evolved and mutated and in 1999 scientists found a strain in Uganda (Ug99) that could bypass much of that resistance. The spores of the Ug99 fungus can travel great distances on the wind. The pathogen has already spread from Uganda into Kenya and Ethiopia. An outbreak of yellow rust originated in the same region of eastern Africa and eventually spread across the Arabian Peninsula and into the major wheat-growing areas of India and Pakistan. Studies of wind patterns in the region have led scientists to conclude that the new pathogen will eventually threaten wheat crops on a global scale.

CIMMYT and the International Center for Agricultural Research in the Dry Areas (ICARDA), together with partners such as the Kenya Agricultural Research Institute (KARI) are leading a global effort to characterize the rust pathogen; to track its spread and to find new sources of resistance to the disease and breed them into new wheats. This is especially important to farmers in the developing world who have little access to fungicides that could help reduce the damage.

“The good news is that some samples at Njoro did resist the fungus,” says CIMMYT wheat scientist, Ravi Singh. “That has given us a good place to start.” In fact Njoro is also the site where potential resistant breeding lines are now undergoing test.

For more information, Rick Ward (r.w.ward@cgiar.org)