A Soiled Reputation: Adverse Impacts of Mineral Fertilizers in Tropical Agriculture

What are better ways to grow more food than by adding fertilizer? Especially in Africa, where yields are low and the demand for food is high? Mineral fertilizers have never been used as much as they are today. One reason for this is because governments in Africa and Asia want to boost their agricultural production and become less dependent on imports because of erratic and rising global market prices. They are allocating large amounts of their agricultural budgets to subsidize fertilizers in the hope of improving national food production.

At the same time, a debate rages among experts on the impact of mineral fertilizers and the problems they entail. There are those, on the one hand, who believe that getting smallholders in the tropics and subtropics to use more fertilizer is the best way to produce more food quickly, so overcoming hunger. Others think this is counterproductive. They argue that mineral fertilizers harm the environment, destroy soil fertility and are economically unviable for smallholder producers. They also claim that the public funding channelled into subsidizing fertilizers could be put to more economically profitable and sustainable use.

The negative effects of nitrogen fertilizers on the climate are undisputed. The production of nitrogen fertilizer uses a lot of energy, while fertilizing fields with nitrogen releases nitrous oxide – a gas that is 310 times more detrimental to the climate than carbon dioxide. And mineral fertilizer prices are linked to the price of oil because their production is so energy-intensive. As a result, the price of mineral fertilizers tends to rise along with oil prices. Despite this, the discussion remains centred on the issue of whether smallholder producers, who often farm their land very intensively, ought to use far more mineral fertilizer so they can preserve the soil’s fertility and produce more food. In view of the renaissance that fertilizer subsidies are experiencing in many tropical and subtropical countries, this study provides an overview of the economic and ecological barriers and of the potential for using mineral fertilizers in such regions. It also focuses on the particular situation of smallholder producers and the importance of improving soil quality in the long term so as to attain food security.

In the light of ecological limitations and ever-scarcer resources, current mineral fertilization practices are both economically and ecologically untenable for the future. Thus, mineral fertilizers pose a long-term threat to food security rather than improving it. This study seeks to illustrate this situation and show the close correlations between food security,environmental and climate protection, and soil fertility conservation.