Science Buddies: "Ask an Expert"

Hello,
In my project I am determining the effect of fertilizer on the rate of uptake of iron. However, sending the plant tissue to a lab can get expensive and I am looking for alternative ways to determine the concentration of iron in the plant without sending it to a lab. Does anyone have any solutions or ideas? Thank you for your help.

To determine iron concentration in plant tissues, you need to rinse the leaves in dilute acid or detergent. Otherwise, dust contaminates will interfere with the results. Usually, young leaves are tested, because unlike old leaves, young leaves cannot re-distribute iron to other parts of the plant. Plants that are deficient in iron tend to have a yellowish color (especially in between veins) as well as iron concentrations less than 30 ppm. Normal young plant leaves would have iron concentrations of around 50 ppm. Iron deficiency in plants is sometimes related to soil quality. Alkalinity, low soil temperatures, other cations, and over-fertilization can result in iron becoming unavailable for absorption to the plant. To obtain iron, most plants increase root hair production at the expense of root hair extension, and these morphological changes result in the plant excreting protons into the soil, making the soil more acidic. Other plants (grasses) enhance iron absorption by secreting chelating agents that form complexes, and these complexes enter the plant cell with the aid of a transporter. In general, methods for determining iron concentrations in plants require laboratory equipment, but you can gage iron content by observing plant tissues, and by collecting data on the soil. My sources are listed below.

http://edis.ifas.ufl.edu/ss555
http://en.wikipedia.org/wiki/Iron_defic ... _disorder)