NASA researchers study effects of biofuel crops

By Erin Voegele | January 03, 2009
Web exclusive posted Dec. 21, 2008, at 11:58 a.m. CST

NASA researchers presented preliminary findings of biofuel crop research at the 2008 fall meeting of the American Geophysical Union on Dec. 19. Christopher Potter, a research scientist at NASA's Ames Research Center, and his colleagues described how they are working to predict the agricultural productivity of areas in the Midwest that are converting cropland to biofuels feedstock production.

The research uses satellite data collected by NASA and computer models to follow the effects of land-use changes on carbon pools and greenhouse gas emissions. The satellite images are used to make observations of vegetation cover and map above-ground and subsurface carbon pools in croplands.

According to Potter, his team is using the satellite data to track how much crop land is being dedicated to biofuels crops, such as corn, soybeans and switchgrass. He said there are two fundamental aims of the technique the team is trying to develop. "One is how much is being produced on an acre by acre basis in any given crop," Potter said. "The other is how many new acres of a given crop are being planted, presumably for biofuel generation."

Potter said researchers normally deal with statistics that are collected by county agencies to measure these aspects of crop production, but they usually provide only a rough mapping of where the best croplands were located. His research should provide a clearer picture. "With the satellite imagery we can get down to a large farm plot and see individual plots and how they are producing," he said. "That gives a big advantage in understanding within a county where the best areas seem to be for generating high yields and sustaining those yields through several different kinds of years."

In addition to finding how much land is dedicated to each biofuel crop, the data provided by the satellite images should also be able to determine how much idle or abandoned cropland was brought back into production each year.

By plugging the data mined from the satellite imagery into a computer model, Potter said the research will be able to simulate how soils will be affected, taking into account biomass sources, such as corn stover, that are harvested rather than left in the field. "If the soils become progressively depleted over several years of cropping because more and more the plant materialis being taken away for biofuel, then the thinking is that will detrimentally affect the soil carbon," he said.

However, Potter said that alone, the data his team is collecting and analyzing won't be enough to identify what percentage of a given crop was planted or grown for use as a biofuel feedstock. To do that it would be necessary to team up with economist and market analysts and bring in additional statistics.

What the research will produce is a very accurate estimate of the amount of land brought into production each year, and the kind of crops that are grown on it. The team will also be able to predict the quality of soil on idle land before it's brought into production and how the conversion to crop land will affect that soil.

The team is analyzing satellite data from 2000 to the present. Potter expects the first stage of the research to be complete in approximately one year. "We are trying to use this data in a way that would benefit the environmental community and the growing community," Potter said. "We are pretty confident we can use these satellite records to help improve public policy and help improve industry decisions."