Desperately stupid argument: Trace amounts of atmospheric plant food would devastate African crop growth?

[Bogus] Climate Change Models Find Staple Crops Face Ruin On Up To One Million Square Kilometers Of African Farmland

ScienceDaily (June 2, 2009) — A new study by researchers from the Nairobi-based International Livestock Research Institute (ILRI) and the United Kingdom's Waen Associates has found that by 2050, hotter conditions, coupled with shifting rainfall patterns, could make anywhere from 500,000 to one million square kilometers of marginal African farmland no longer able to support even a subsistence level of food crops. However, the land, on which some 20 to 35 million people currently live, may still support livestock.

From UN.org, 2004: Agriculture: Africa's 'engine for growth'

Much can be done to increase African farm yields through simple methods of improving soil fertility and better utilizing the continent's available water. Currently, only 12.6 mn hectares of agricultural land are under managed systems of water and land development. The vast bulk of farmland is left to the vagaries of weather, including insufficient rainfall and flooding that may strip away topsoils, as well as unsustainable farming methods that gradually deplete soil nutrients.

Some 874 mn hectares of land are deemed suitable for agriculture, but 83 per cent of that area is subject to serious limitations such as poor soil fertility.
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The reasons for such stagnation are multiple, says the CAADP: continuing dependence on uncertain rainfall, nutritional deficiencies in Africa's soils, small and dispersed domestic markets, the instability and decline of world prices for African agricultural exports, the small size of most farms, farmers' frequent lack of organization, the lack of rural roads, neglect of the particular needs of women farmers (who produce most of the continent's food), and the spread of HIV/AIDS.