As a result, agricultural activity now dominates more than a third of the Earth's landscape and has emerged as one of the central forces of global environmental change, say scientists at the Center for Sustainability and the Global Environment (SAGE) at the University of Wisconsin-Madison.
Navin Ramankutty, an assistant scientist at SAGE, says, "the real question is: how can we continue to produce food from the land while preventing negative environmental consequences such as deforestation, water pollution and soil erosion?"
To better understand that crucial trade-off, Ramankutty and other SAGE researchers are tracking the changing patterns of agricultural land use around the world, including a look at related factors such as global crop yields and fertilizer use. Distilling that information into computer-generated maps, the scientists will present their early findings during the fall meeting (Dec. 5-9, 2005) of the American Geophysical Union.
"In the act of making these maps we are asking: where is the human footprint on the Earth?" says Amato Evan, a SAGE researcher who merged available census and satellite data to create visuals reflecting the reach of pasture and croplands worldwide. Chad Monfreda, a graduate student at SAGE, is similarly mapping the location, range and yields of over 150 individual crops reared around the planet.
The exercise is already beginning to cast light on some emerging trends. Countries such as Argentina and Brazil, for instance, have increasingly cleared forests to grow soybean, a legume that has never been a traditional crop of Latin America. Scientists say the surge in soybean production there has a lot to do with the booming demand for soy all the way at the other end of the world - in China. Meanwhile, Monfreda notes, long-time soybean farmers in
Source:University of Wisconsin-Madison