Plant tissue analysis for nitrate and phosphate using anion-exchange membrane

Abstract

An extraction procedure for removal and measurement of inorganic nitrate and phosphate in plant leaves using anion-exchange membrane was developed and assessed as a tissue test for N and P availability to sunola and wheat. Relationships between tissue nitrate and phosphate concentrations and yields were determined for sunola grown on a Saskatchewan soil, with five rates of N and P fertilizer supply, in a growth chamber experiment. Relationships between tissue nitrate concentration and yield were determined for wheat in a field trial, with six rates of N fertilizer supply. The nitrate and phosphate concentrations in the leaf tissue were measured at the time of seventh leaf stage to estimate the current N and P status of the plants. The results showed significant relationships between the membrane extractable nitrate and phosphate in the leaf and the supply of available N and P in the soils.