Martian soil analyzed by NASA's Phoenix lander could likely support plant life under the right conditions, scientists said Thursday.

"We basically have found what appears to be the nutrients to support life," said Samuel Kounaves, lead scientist for the wet chemistry lab from Tufts University.

This is a microscopic view of fine-grained material at the tip of the robot arm scoop on Phoenix. Credit: NASA/JPL-Caltech/University of Arizona/Max Planck Institute

Kounaves said the experiment, which adds water to create a muddy mixture with the Martian soil, found magnesium, sodium, potassium and chloride in a sample retrieved from about one inch under the planet's surface.

Basic life forms also require organic elements like carbon, nitrogen and oxygen, while plants need trace amounts of several other minerals, Kounaves said.

The wet chemistry lab is housed inside Phoenix's Microscopy, Electrochemistry and Conductivity Analyzer, or MECA, instrument.

The instrument includes four wet chemistry cells, each designed for a single analysis sequence.

The instrument found a pH level of between 8 and 9 in the soil, comparable to seawater or baking soda on Earth.

The alkaline soil would be hospitable to a wide range of organisms if placed on Earth, according to Kounaves.

"If you had it here on Earth, you could grow something in it very straightforwardly. There's nothing about that's toxic," Kounaves said.

With the addition of a few organic building blocks like those found on Earth, a wide variety of life forms could flourish in Martial soil, scientists said.

"If we found that it was acidic like sulfuric acid and like Clorox bleach, then the organism would have to be really special," Kounaves said. "This means that there's a broader range of organisms that could grow in this soil."

"You might be able to grow asparagus in it really well, but strawberries probably not very well," Kounaves said.

Asparagus, green beans and turnips thrive in alkaline soil, but berries prefer more acidic soil, Kounaves said.

"The reason we did that experiment is not entirely about growing plants. That's part of it, but it's also to ask what native Martian microbes might be able to live and survive and grow in that same soil," said Michael Hecht from NASA's Jet Propulsion Laboratory.

Microbes could survive deep under the Martian surface, where they would be shielded from dangerous ultraviolet radiation, Kounaves said.

Phoenix also completed studying a soil sample delivered to one of the probe's other instruments two weeks ago.

The Thermal and Evolved-Gas Analyzer, or TEGA, instrument includes eight high-temperature ovens to heat soil to 1,800 degrees Fahrenheit.

"This is really the first time anybody has ever heated part of another planet up to such high temperatures," said William Boynton, TEGA lead scientist from the University of Arizona.

Boynton reported the instrument discovered no ice in the sample, but he said that result was not surprising because the soil was exposed to the thin Martian atmosphere long enough for any ice to evaporate.

TEGA found small amounts of water vapor and carbon dioxide as the oven heated the soil.

"This soil has clearly interacted with water in the past," Boynton said.

More than 33 days have passed since the $457 million mission touched down on the northern polar plains of Mars.

Leslie Tamppari, Phoenix project scientist at JPL, said the probe has made good progress during the mission's first month of surface operations.

Phoenix has dug two trenches using its robotic arm, made regular atmospheric observations with an automated weather station, and completed about 55 percent of a true color panorama of the landing site, Tamppari said.