介绍： Fertile discussion: Fertile discussion
More productive African farms could help both people and planet
From The Economist 20161015

Audio:

0:00



Organic, locally sourced and woefully inefficient
SINCE the 1960s farm production has risen fourfold in Africa. But the continent still lags far behind the gain...

介绍： Fertile discussion: Fertile discussion
More productive African farms could help both people and planet
From The Economist 20161015

Audio:

0:00



Organic, locally sourced and woefully inefficient
SINCE the 1960s farm production has risen fourfold in Africa. But the continent still lags far behind the gains seen in South America and Asia. The extra food has appeared largely because more land has been planted or grazed, rather than because crop yields have improved. Instead, poor farming methods progressively deplete nutrients from soils; almost all arable land in Africa lacks irrigation, for example. This is a particular problem in a continent whose population is set to double by 2050 and which faces regular droughts, floods and heatwaves.

The world is already 1°C warmer than it was in pre-industrial times. As it heats further, weather cycles are set to speed up, leaving wet parts of the world wetter, and dry parts drier. At either end of the scale, extreme weather events will probably intensify. By 2050, even if temperature rise is successfully limited to 2°C, crop yields could slump by a fifth. The costs of climate change already come each year to 1.5% of the continent’s GDP, according to the European Commission, and adapting to it will cost another 3% each year until 2030. This is in spite of the fact that, overall, Africa is responsible for just 4% of global emissions annually.

Morocco is a prime place to discuss such issues. Not only is it hosting the next round of UN climate negotiations in November, it is also one of the world’s largest producers of phosphorus (a raw material used to make fertiliser). This is particularly important given that according to the UN’s Food and Agriculture Organisation, 124kg of artificial fertiliser is used worldwide per hectare of farmland on average each year, while in Africa the amount used is just 15kg. Getting hold of the stuff is a challenge throughout the continent, especially when crooked officials pocket subsidies for it. But high transport costs along potholed roads also help make fertiliser up to 50% more expensive in Tanzania and 80% more expensive in Mali than in Thailand, according to Amit Roy, formerly of the International Fertiliser Development Centre, an American charity which supports better farming practices.


Fertiliser is fantastically important. Boosting the productivity of Africa’s lands is not only necessary for feeding larger populations, but also a possible means of reducing emissions. Currently vast areas are cleared for new fields because too little grows in existing ones. But reducing deforestation in Africa by just a tenth would be equivalent to cutting a year’s worth of Brazil’s emissions, says Mostafa Terrab, head of the OCP Group, a huge Moroccan phosphate firm. (Cynics may well say that he has an interest in encouraging more people to buy fertiliser.) His company is dedicating a 1m-tonne fertiliser unit specifically to African customers.

Well-nourished soils are better at absorbing carbon dioxide rather than allowing it to enter the atmosphere. But the continent’s over-grazed, over-used soil currently means Africa only stores 175 gigatonnes of carbon each year of the 1,500 gigatonnes stored in the world’s soils. Smarter farming could change all that. But as is so often the case in Africa, the road to modernisation is full of potholes.


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