Microsatellite data helped double yield for Indian farmers

A team of scientists has successfully used data from microsatellites to quantify and enhance yield gains for small farmers in India - a discovery that can help increase food production in a low-cost and sustainable way.

The team from university of Michigan, Mexico-headquartered the International Maize and Wheat Improvement Centre and Stanford and Cornell universities ran an experiment on 127 small-holder farms in India using a split-plot design over multiple years.

The study was done on small-holder wheat fields in the eastern Indo-Gangetic plains in the country.

In one half of the field, the farmers applied nitrogen fertilizer using hand broadcasting, the typical natural substance spreading method in this region.

In the other half of the field, the farmers applied a new and low-cost fertilizer spreader.

To measure the impact of the intervention, the researchers then collected the crop-cut measures of yield, where the crop is harvested and weighed in field, often considered the gold standard for measuring crop yields.

They also mapped field and regional yields using microsatellite and Landsat satellite data.

They found that without any increase in input, the spreader resulted in 4.5 per cent yield gain across all fields, sites and years -- closing about one-third of the existing yield gap.

They also found that if they used microsatellite data to target the lowest yielding fields, they were able to double yield gains for the same intervention cost and effort.

"Being able to use microsatellite data, to precisely target an intervention to the fields that would benefit the most at large scales will help us increase the efficacy of agricultural interventions, said lead author Meha Jain, assistant professor at the U-M School for Environment and Sustainability.

By being able to detect the impact and target interventions to locations where they will lead to the greatest increase or yield gains, satellite data can help increase food production in a low-cost and sustainable way.

Finding low cost ways to increase food production is critical given that feeding a growing population and increasing the yields of crops in a changing climate are some of the greatest challenges of the coming decades.

Microsatellites are small, inexpensive, low-orbiting satellites that typically weigh 100 kgs or less.

"About 60-70 per cent of total world food production comes from small holders, and they have the largest field-level yield gaps," said Balwinder Singh, senior researcher at the International Maize and Wheat Improvement Centre.

The study also showed that the average profit from the gains was more than the amount of the spreader and 100 per cent of the farmers were willing to pay for the technology again.

Jain said that many researchers are working on finding ways to close yield gaps and increase the production of low-yielding regions.

"A tool like satellite data that is scalable and low cost and can be applied across regions to map and increase yields of crops at large scale," she said in a paper published in the journal Nature Sustainability.

Other researchers were Amit Srivastava and Shishpal Poonia of the International Maize and Wheat Improvement Centre in New Delhi, Preeti Rao and Jennifer Blesh of the U-M School of Environment and Sustainability; Andrew McDonald of Cornell; and George Azzari and David Lobell of Stanford.