Feasibility of Applying a Stable Isotopic Tracer for Direct Determination of Dry Particulate Deposition to Soybean Plants.

A stable rare-earth isotopic tracer was used to measure the deposition of KNO particles on soybean leaves by direct measurement of the tracer on the plant surfaces by thermal-ionization mass spectrometry. Submicrometer particles, made from a solution containing 3 |mg mL neodymium isotope (Nd, 87.9%) and 1,000 mg mL KNO, were dispersed with a two-fluid nozzle and released upwind of a soybean field.