Pakistan, Malawi, and Ethiopia develop new tool for preventing hidden hunger

Munir Zia’s father always wanted his son to take over the family farm – three hectares of cotton, wheat, rice, and sugar cane in Pakistan’s fertile Punjab province. It's lucky for farmers around the world that he chose a different path.

Dr. Zia along with like-minded soil scientists in the United Kingdom and Malawi and beyond have helped develop a new approach for addressing “hidden hunger” – micronutrient deficiencies affecting more than 2 billion people around the world. Hidden hunger is most common in low-income countries and populations where diets are poor, and people do not consume enough foods rich in the vitamins and minerals they need to be healthy and fight disease.

Until recently, the toolbox for preventing micronutrient deficiencies was limited to diversifying diets, providing nutritional supplements, and fortification programs. While these efforts are effective, they can be expensive and struggle to reach the poorest of the poor who grow their own food.

Dr. Zia and his colleagues and collaborators’ approach adds another tool to this toolbox.

It involves identifying the mineral deficiencies in soil that exacerbate mineral deficiencies in crops and then formulating fertilizers to compensate for those key deficiencies. Using the specially formulated fertilizer, farmers can cost-effectively boost the nutrition – and in most cases the yields – of their crops quite literally as they grow in their fields.

Take Dr. Zia’s Pakistan for example, where wheat is the main source of calories and roughly half of the farmland used for wheat is deficient in zinc. It is no coincidence then, explained Dr. Zia, that a recent National Nutrition Survey reported that 22% of women of reproductive age and 19% of children under 5 year are zinc deficient. Zinc deficiency carries a heavy toll. It can stunt growth in children, cause life-threatening diarrhea, and impair immune systems.

The country’s food fortification program launched in 2016 fortifies wheat flour. Researchers agree that this "approach is undoubtedly an important part of the solution to hidden hunger in Pakistan.” However, it often doesn’t reach the poorest of the poor, farmers who grow their own wheat, or landless laborers who are often paid with a portion of the wheat harvest for their work.

Dr. Zia’s research has demonstrated that by applying a single treatment of fertilizer high in zinc to their zinc-deficient wheat fields, a process called “agronomic fortification,” farmers can not only increase the zinc levels in their wheat crop – by as much as 20% – but also improve their yields by as much as 20%. Spraying the wheat crop with zinc fertilizer at two key moments in the growth cycle has yielded an increase in zinc levels in the grains by as much as 45%.

Given such results, demand from farmers is surging.

Every year, Pakistan’s farmers send 25,000 soil samples for free macronutrient and micronutrient analysis to Dr. Zia’s laboratory network, which is based in a fertilizer company founded in 1978 by the Fauji Foundation to provide farm advisory services to smallholder farmers. With these samples, precise deficiencies in the soil are identified and farmers are encouraged to use fertilizer specially designed to compensate for their soil’s missing nutrients.

The samples have helped Dr. Zia – who works both as a research scientist for the Fauji Fertilizer Company and with the BiZiFED project investigating the effectiveness of bio-fortified grains developed by HarvestPlus, a program co-led by the International Food Policy Research Institute and the International Center for Tropical Agriculture – create a soil map of Pakistan showing what researchers have dubbed the “postcode lottery” – where soils are deficient in key micronutrients and where they are not.

Today, between 10% and 15% of Pakistan’s farmers are applying zinc fertilizer. The number is increasing every year, said Dr. Zia, thanks to both the free soil analysis and demonstration plots they have established across the country.

Research by collaborating nutritionist from Pakistan and the UK have shown that families eating wheat agronomically fortified with zinc as part of their regular diet can effectively increase their zinc dietary intake, although more research is needed to study long-term health outcomes.

If all wheat farmers in Pakistan adopted zinc fertilizers, researchers have estimated the prevalence of zinc deficiency in the population would be cut in half and wheat yields would increase by a value of about US$800 million.

“Micronutrient deficiency is a major public health challenge,” said Dr. Zia. “We are showing farmers that the food they are growing may look good and healthy. But it isn’t as healthy as it could be.”

The first evidence of zinc deficiency in soil in Pakistan was identified by scientists with the International Rice Research Institute (IRRI) in 1969. Their breakthrough in understanding nutrient levels in rice was aided by the rice plant themselves, whose leaves display telltale brown spots if the plant is zinc deficient. Researchers from IRRI and the Pakistan Agricultural Research Council went on to find that zinc deficiency was a limiting factor in rice crop yields.

But no one connected zinc deficiency in soil and zinc deficiency in grains to zinc deficiency in humans until more recently. And no one suspected that much of the wheat grown in Pakistan, which displays no telltale signs when it is deficient in zinc, was – like rice – missing key micronutrients at a national scale until Dr. Zia began his research.

This comes at a time when climate change is set to exacerbate the challenge of hidden hunger. Rising CO2 levels in the atmosphere lower the protein and micronutrient concentration of key staple grains. Zinc concentrations in wheat are expected to fall by 9% and iron concentrations by 5-7%. Further exacerbating the problem is the heat. Recently the World Bank has warned that rising temperatures may also cut crop yields.

“Climate change-related malnutrition already costs Pakistan US$7.6 billion every year due to the lost labor, health care expenses, and lower productivity of human capital,” said Dr. Zia. “Since wheat in Pakistan provides about 50% of the calorific need of the population a reduction in wheat yields and nutrition could have significant impact on food security of the country.”

Another farmer turned soil scientist half a world away in Malawi, Lester Botoman, has made similar advances. A soil scientist with the Ministry of Agriculture, Botoman grew up on his parents’ lush two hectare farm, planted with tobacco, soybeans, groundnuts, and corn.

Botoman’s research, based on more than 1,800 geolocated samples of soil and matching geolocated crop samples, has shown that over 80% of the soil in Malawi is deficient in zinc and selenium. The national map he created of soil and crops confirmed his suspicions, “Where the soils are deficient in zinc, crops are deficient in the same,” said Botoman. “There is a very strong correlation.”

Unsurprisingly then, studies find that 60% of Malawians are deficient in zinc and a recent national survey found that 63% of women of reproductive age and 86% of preschool children were deficient in selenium, which can impair thyroid function, cognitive development in children, and increase the risk of anemia and the risk of stroke.

Climate change is making this worse with each year, said Botoman, by causing extreme weather, including frequent flooding that washes away the nutrient-rich topsoil.

To improve nutrition, the government of Malawi in 2016, banned NPKS fertilizer that is not enriched with zinc. In fact, today it is a criminal offense to sell basal fertilizer for corn that is not enriched with zinc. As a result, corn yields have increased by roughly 10% and the median zinc concentration of the corn being grown in Malawi has increased by about 15%.

Research in Malawi found that consumption of maize treated with selenium-enriched fertilizer doubled the levels of selenium in the people who ate the corn.

The research in Malawi was started by Dr. Allan Chilimba, a soil scientist with the Malawi government who found that a majority of Malawians are deficient in selenium. Dr. Chilimba then teamed up with Dr Alexander Kalimbira, a nutritionist at Lilongwe University of Agriculture and Natural Resources and other soil scientists to map selenium deficiency in the country.

Researchers in Ethiopia have made similar findings on selenium deficiency. Soil mapping in Ethiopia has also found that 70% of the soil in the country’s highlands are also zinc deficient and that a similar percentage of the population is zinc deficient, with strong regional variations.

All of this builds on research in Finland which has engaged in agronomic fortification to boost selenium levels since 1984.

“This work is finally breaking down the silos between agriculture experts and nutrition experts,” said Botoman. “Until recently most agriculture specialists focused exclusively on yield. But we also need to focus on the quality of the food we grow.”

 

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