by Diane Clay
As printed in The Oklahoman, April 25, 2006.

Researchers at the Samuel Roberts Noble Foundation have designed a smart plant to show farmers when their crops are low on nutrients.

The plant is expected to increase crop yields and save farmers thousands of dollars each year in fertilizer costs.

The plants, which can be clovers, alfalfa, soybeans or other legumes, have been genetically engineered to include a gene that can sense levels of nutrients in the soil. The first nutrient being tested is phosphorus.

If phosphorus is very low in soil, farmers can end up with only half to 60 percent of the crop they planned.

Smart plants will "sense" the level of phosphorus, which turns on another gene that causes the plant to change leaf color from green to a deep purple when the level is low. Other changes are possible.

The change will allow farmers to pinpoint areas where phosphorus is needed so they can apply fertilizer only to those areas instead of blanketing the field.

Scientists plan to make the color change gradual, so farmers can see different levels of nutrients.

"It's like a light switch and light bulb. We are adding the switch that would turn on to phosphorous, then the color change would be the expression, so that's the light bulb that comes on," said Jeff Ball, a soil and crop specialist at the Samuel Roberts Noble Foundation.

The smart plants are edible and can be harvested with the rest of the crop.

Ball said scientists hope to plant entire fields of smart plants, then watch for a reaction and snap images of the fields from satellites. The satellite images would easily show the darker color where phosphorus is extremely deficient and lighter colors where only a little is needed.

The information would be used by farmers when the next batch of crops is planted.

Once researchers at the Noble Foundation perfect the process to create the phosphorus smart plants, they hope to develop them to detect levels of other nutrients.

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