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Current Issue February 2012
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Soil Quiz

Test your knowledge about soil by taking our ten-question quiz.

Managing Editor, NGM.com Rob Covey <![CDATA[Producer & Editor]]> Carolyn Fox <![CDATA[Writer & Researcher]]> Leigh Brock Flash Developer Stefan Estrada Styling Kitry Krause Research Consultants Brad Scriber Rattan Lal /2008/09/soil/img/nurse-child-470.jpg Photograph by Steve Raymer /2008/09/soil/img/crop-patterns-470.jpg Crops weave patterns across contoured fields Photograph by B. Anthony Stewart /2008/09/soil/img/potato-harvest-470.jpg Photograph by Dean Conger /2008/09/soil/img/harvester-corn-470.jpg A farmer pulls a harvester over his cornfields. Photograph by Emory Kristof /2008/09/soil/img/haiti-dominican-republic-470.jpg Photograph by James P. Blair /2008/09/soil/img/syria-farmers-470.jpg Farmers in Syria till a field of sun-baked soil using shovels and rope. Photograph by Dean Conger /2008/09/soil/img/toxic-crust-470.jpg A toxic white crust runs through the irrigated fields in Grand Valley, Colorado. Photograph by Jim Richardson /2008/09/soil/img/escalante-erosion-470.jpg Erosion in the drainage area of the Escalante River. Photograph by James P. Blair /2008/09/soil/img/pretzels-470.jpg German pretzels stacked for sale at a Pennsylvania Dutch festival. Photograph by H. Edward Kim /2008/09/soil/img/lateritic-pedestals-470.jpg Lateritic pedestals formed by the erosion of soil from areas unprotected by rocks or vegetation. Photograph by James P. Blair 9 Excellent work. You are a soil expert. With a little work, you will be a soil pro. You are off to a good start. You may want to try again. 1 69.7 percent 79.7 percent 89.7 percent 99.7 percent 4 0 250 million 550 million 850 million 1 billion 3 2 50 years 200 years 350 years 500 years 4 3 Corn Potatoes Tomatoes Lettuce 1 4 9 percent 11 percent 17 percent 21 percent 2 5 Syria Iraq Egypt India 2 6 Agroforestry Cover crops Increased irrigation Manure application 3 7 20 percent faster 30 percent faster 40 percent faster 50 percent faster 3 8 1,575 pounds 1,750 pounds 2,155 pounds 2,175 pounds 4 9 3