A little bit of fertilizer can do wonders
(July 10, 2002) Is mineral fertilizer the answer to the worlds food problems? Or does itcause unacceptable harm to the environment? Three experts tell us.
 LESS ISN'T ALWAYS MORE:Increased use of mineral fertilizer in sub-Saha-ran Africa can boost yields and feed more people. (Photo:Jarle Ree) |
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"Basically, there are two problems with fertilizer," says Dr. Peter Hazell, who is director of the Environment and production Technology division of the International Food Policy Research Institute in Washington, D.C. "One is the environmental effect of over use and poor management. The second is underuse. Most of Africa falls into the second category."
Fertilizer use in Sub-Saharan Africa averages 11.6 kilos of NPK nutrients per hectare of cropland, compared to 158.4 kilos in Europe and 265 kilos in East Asia. And much of the fertilizer that is used in Africa goes on a few cash crops like cotton and tobacco; very little goes on staple food crops.
"A little NPK would do wonders for agriculture in Sub-Saharan Africa," he points out. "Greater use of fertilizer here poses no threat at all. The danger is quite the opposite."
Under-fertilization on the African continent not only results in low yields, but also leads to deforestation, soil erosion and loss of nutrients. Moreover, since traditional farming methods can no longer produce enough to feed the growing population on the land available, farmers have to expand their crop area, leading to deforestation and cultivation of hillsides.
The International Food Policy Research Institute estimates that the demand for food will increase by 70 percent in developing countries by the year 2020.
 Peter Hazell, International Food Policy Research Institute |
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However, more fertilizer is not a simple solution. Around 80 percent of small farms in rain-fed areas of Africa cannot be reached by road, and the farmers do not have ready access to the fertilizer market. Fertilizer can therefore cost as much as five times the world price. And where it is used, the additional produce cannot be easily transported and sold.
Low external-input methods
While the necessary infrastructure is built up on the African continent, Hazell believes that more efficient use of traditional farming and other low external-input methods are better.
Examples include farming systems that integrate crops, livestock and farm trees; intercropping, green manures and crop rotation; improved fallows and cover crops; better water management; and not least – judicious use of supplementary inputs such as phosphate and lime where needed to balance the soil. Nitrogen is provided through animal and green fertilizers (leguminous plants). Such methods alone cannot, according to Hazell, meet the needs of the growing population, however.
Parts of Asia represent the other end of the scale. Modern agricultural technologies make it possible to provide enough food for everyone (if it were shared more equally).
However, poor management and excessive use of fertilizers and pesticides has led to pollution of waterways and disturbed ecosystems. Certain irrigation practices have led to salt build-up in the soil and falling groundwater levels. In some areas, previously good farm land has even had to be abandoned.
Hazell points to education as a key factor. Fertilizers and pesticides have been heavily subsidized and provided in large quantities. They are used indiscriminately in many areas.
"Private companies have an important role to play here," he points out. "They often pass on valuable advice and knowledge together with the sales of fertilizer. Hazell himself once worked on a farm in England. "I remember we got the most useful advice from ICI rather than the Ministry of Agriculture," he recalls.
Africa and Asia represent two poles in agriculture, but the answer lies in a less polarized approach, according to Hazell, with better integration of traditional, ecological and scientific approaches to agriculture. In other words, less ideology and a greater willingness to work together.
 Dr. Jens Aune, Center for International Environment and Development Studies |
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Mineral fertilizers necessary for sustainable agriculture
Dr. Jens B. Aune, agro-ecologist and researcher at Noragric, the Center for International Environment and Development Studies at the Agricultural University of Norway (NLH), stresses the ecological distinction between the use of pesticides and mineral fertilizer.
"In contrast to mineral fertilizer, the chemical compounds used in pesticides are not found in nature. There are also a number of good ecological methods to combat disease, pests and weeds that could be used more widely," he says.
Mineral fertilizers, on the other hand, are only replacing substances that are naturally found in healthy soil and are lost during farming. To a limited extent, these minerals can be replaced through organic fertilizers.
However, Aune points out that organic farming without use of mineral fertilization cannot feed the world's growing population. "Population growth in many developing countries is about 3 percent per year, and it would be extremely difficult – if not impossible – to achieve such a growth rate in food production with an agriculture based on organic fertilizers alone.
"Enormous areas of forest would be lost if international agriculture were to depend on ecological farming methods alone. This would lead to raised emissions of greenhouse gases, reduced biodiversity, and loss of recreational areas," he says.
In terms of healthy food, he also believes that what we eat is far more important than how it was produced. For example, a study by the National Council on Nutrition and Physical Activity concluded that the number of cancer cases in Norway could be reduced by about 5,000 per year if consumption of fruit and vegetables increased by 65 percent.
"There is not, however, any evidence to show that changing the diet to organically produced food has equivalent advantages for health," he says.
Aune concludes that: "We should focus on developing sustainable agriculture characterized by less use of pesticides, responsible use of mineral fertilizer, better crop rotations and greater consideration of ethics in animal husbandry."
 Dag Nagoda, Future in Our Hands |
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Long-term perspective
"In the long term, we are afraid that the environmental consequences of the Green Revolution may create a greater problem than the one it has aimed to address," says Dag Nagoda, research coordinator at the organization The Future in Our Hands in Norway. He points to studies from the International Rice Research Institute in the Philippines, showing a 4 to 5 percent decline in long-term productivity despite increasing applications fertilizers and pesticides.
"We are not opposed to mineral fertilizer where it is used appropriately," he says, agreeing that Sub-Saharan Africa would benefit from greater use of mineral fertilizer. "However, this is not the whole answer. Mineral fertilizer should be used as a supplement to organic methods. Besides, infrastructure, purchasing power, land reforms and not least education are also significant factors."
Nagoda would like to see more research on the use of mineral fertilizer in intercropping – growing two complimentary crops together – and methods of responsive fertilization. He points out that the focus has been on highly mechanized technology that is only suited for intensive, monoproduction on large farms.
"Feeding the world is a complex issue," he concludes. "It is not just a question of food production, but also of distribution. "Many tons of cereals are exported from poor countries to rich ones for meat production. Meat consumption in America is 130 kilos per person per year, compared to 1 kilo per person per year in India (70 kilos in Norway). Food should not be treated on the same terms as any other industrial product."
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