Chronovoltammetric determination of oxygen flux density in the soil
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Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, P.O. Box 201, 20-290 Lublin 27, Poland
Acceptance date: 1999-04-23
Int. Agrophys. 1999, 13(3): 237–281
A chronovoltammetric method for the determination of oxygen flux density (OFD) in the soil is proposed. The method is based on the current-potential relationship recorded on a platinum indicator electrode placed in the soil. The Pt electrode is polarized with electrical potential linearly decreasing from 0 V down to the level at the beginning of water electrolysis (about -0.7 V). Electrical current flowing across the electrode due to the electrode reduction processes of molecular oxygen is re- corded. Mean magnitude of this current is the base for the calculation of the OFD in the soil. The results obtained were compared with oxygen diffusion rate (ODR) data read with the application of the amperometric method of Lemon and Erickson, where reduction current is read at the Pt cathode potential fixed at a level at random chosen from -650 to 400 mV interval. The results obtained using both methods showed a distinct correlation. At the same time the chronovoltammetric OFD data were less scattered then the voltamperometric ODR ones.