David E. Steitz

Headquarters, Washington, DC
November 5, 1999

(Phone: 202/358-1730)

Steve Roy

Marshall Space Flight Center, Huntsville, AL

(Phone: 256/544-0034)

RELEASE: 99-130


As many drought-stricken farms in America limp through the
last harvest of the 20th century, researchers are using remote
sensing technology developed for the space program to help improve
crop management and increase profitability.

The availability of inexpensive agricultural products for
consumers in the next century could depend on such capabilities —
potentially meaning the difference between “boom” and “bust” for
American farmers in the new millennium.

At the Global Hydrology and Climate Center at NASA’s Marshall
Space Flight Center, Huntsville, AL, NASA scientists are
collaborating with university researchers to apply remote sensing
technology to a sophisticated agricultural technique called
precision farming.

In precision farming, growers break fields down into regions,
or “cells,” analyzing growth characteristics of each cell and
improving crop health and yield by applying precise amounts of
seed, fertilizer and pesticides as needed. Traditionally, farmers
have lacked the ability to make those close analyses of specific
cells. When they fertilized their crops, they simply spread it
uniformly across the entire field. “Now, using remote sensing
feedback, we can tailor that input more precisely,” says Doug
Rickman, lead researcher for the Global Hydrology and Climate

Such precise crop maintenance benefits society in another
way: “Excess nitrogen can leak into groundwater,” says Paul Mask,
professor of agronomy at Auburn University in Auburn, AL. “Other
fertilizers can increase pollution problems, threatening public
health. By adding only the amount of fertilizer the land and the
crop can effectively use, we can reduce such problems.”

“We can point to areas that will always have low yield,” adds
Mask. “If the maximum capability of an area is 50 bushels an
acre, there is no need to fertilize for 120 bushels. It does no

“The true potential is not simply improving yield,” Rickman
agrees. “It’s improving stewardship of the land.”

Remote sensing is the gathering of data for analysis by
instruments that are not in physical contact with the objects of
investigation; in modern parlance, the term commonly refers to the
gathering of data via planes or orbiting satellites. Remote
sensing is used to measure electromagnetic radiation, including
the thermal energy that is reflected or emitted in varying degrees
by all natural and synthetic objects, such as crops.

That makes remote sensing ideal for Rickman’s research. “We
can fly over an area and precisely map its plant quality and soil
makeup — including estimation of mineral variation and organic
carbon content — in two-meter increments,” he says. “Farmers
have sought this ability for 30 years.”

When NASA began studying precision agriculture techniques in
the 1970s, the practice was hampered by researchers’ inability to
accomplish such precise mapping. Measuring yield was also
inconvenient, time-consuming and often imprecise.

“To measure a single field of 80 to 100 acres, you might take
six soil samples from
different parts of the field, send them to a lab, and wait days or
weeks for the results,” Rickman says. “And six samples don’t give
you a very accurate measure anyway — soil quality can vary
dramatically all across that area.”

The advent of global positioning systems and remote sensing
technology changed all that. “Now farmers can intelligently
control their systems,” Rickman says, “before they ever plant a

“This is applied research,” says Dr. J.M. Wersinger of Auburn
University, the project coordinator. “We could have done our
experiments in an antiseptic laboratory environment, but we
understood from the beginning that we needed to involve real
farmers in the program. They are full partners in this endeavor.”

NASA and its partners recognize that the research is still in
its infancy. Rickman and his colleagues are still exploring “the
breadth of potential understanding yet to be gained from the new
technology,” he says.

“With current technology, nations can show the estimated
yield of Kansas or Kazakhstan,” Rickman says. “But that doesn’t
help the individual farmer. We’re seeking to provide a system that
will help farmers improve the efficiency of their fields and their
crop management techniques. In the end, that will benefit
– end –