16/8/2019
By: Inga Vesper
Subsidies for manufacturing companies could help improve access to
fertiliser in developing countries without increasing environmental stress, a team of international
researchers has proposed.
In an article reviewing scientific evidence, the
team presented a strategy to manage global fertiliser use while minimising
nitrogen pollution — a common side effect. They
note that it will be essential to increase access to fertilisers in developing
countries in order to provide more food for a growing population.
The researchers highlight
intergovernmental cooperation and incentives for companies to
provide cheap, high-quality fertilisers as essential measures to tackle poor
soils and food shortages.
“Restoring soil nutrients with sustainable fertiliser practices is critical to promoting food security and the manifold benefits that this has for society,”
Benjamin Houlton, director, University of California’s John Muir Institute of the Environment
Benjamin Houlton, lead author of the article and director of the
University of California’s John Muir Institute of the Environment, said: “In
many developing economies, lack of access to commercial fertilisers has
resulted in less-than-optimal yields, and highly depleted soils which lack
nutrient capital. Restoring soil nutrients with sustainable fertiliser
practices is critical to promoting food security and the manifold benefits that
this has for society.”
The problem explored in the article is that chemical
fertilisers can have negative effects on the environment. Fertiliser is washed
off the soil by rain and runs into rivers, where it can pollute drinking water
and upset the ecosystem. In addition, powdered nitrogen fertiliser can be
carried by wind and cause aerial pollution, with health consequences for nearby
communities.
Therefore, the researchers say, improving access
to chemical fertilisers in developing countries must go along with appropriate
education, community work and consideration for local culture and farming practices.
However, according to
Houlton, affordability remains the biggest barrier for farmers in poorer
nations. He advocates policies, such as offering subsidies, that
encourage companies to invest in developing cheap products.
“This can spur innovation and grow jobs and
business opportunities,” he told SciDev.Net.
“Subsidies with phase-out provisions can help launch environmental careers and
inspire adoption of the most efficient agricultural technologies, with a key
emphasis on efficient fertiliser technologies.”
According to the UN’s
Food and Agriculture Organization, the combined global use of nitrogen, phosphorus and potassium
fertilisers reached 186.7 million tonnes in 2016. However, demand in Africa was
only around 3.6 million tonnes in the same year.
On the other hand, some regions in Asia — in
particular India and China — suffered from chemical fertiliser overuse in 2015
due to their farmers’ reliance on monocultures such as rice, according to the
study, published in Earth’s Future (23 July).
The researchers
admit that a balance needs to be struck between increasing access to
fertilisers and preventing overuse. Chemical fertiliser pollution can be
reduced by micro-application, where small amounts are placed closely to each
plant, and by using organic fertilisers such as farm waste products wherever
possible.
If correctly applied, fertiliser can revive depleted soils and thereby reduce
the need for farmers to cultivate new land at the expense of forests and other
habitats, believes Barbara Adolph, principal agro-ecology researcher at the
International Institute for Environment and Development in London.
“The generally recognised recommendation [to reduce pollution] is to use
organic matter and inorganic fertiliser together,” said Adolph, who has worked
in countries including Burkina Faso, Ghana and Malawi.
However, Adolph told SciDev.Net that many farms in developing
countries do not have access to sufficient organic matter. In some countries,
waste products such as stalks and leaves are used to fuel fires, feed livestock and
for fencing and roofing. In addition, traditional farms that have both
livestock and crops are in decline as farmers increasingly specialise, meaning
some farms may have too much manure, while others have none.
“There are a lot of technical problems in terms of transport and the
availability of biomass,” added Adolph. “This is where chemical fertiliser
comes in, to complement the use of organic matter. That’s really
good practice to avoid land degradation.
