Comparison of a combination pH electrode and field effect transistor electrode for the determination of soil pH and lime requirement

Abstract

Abstract A commercial laboratory robot has been used to compare the responses of two different types of electrode for the determination of soil in water pH (pHw), and soil in SMP buffer solution pH (pHSMP). The latter is integral to a popular method for the determination of soil lime requirement. A combination pH electrode is compared with a solid state, ion selective field effect transistor electrode. Response times and hysteresis effects are discussed.