Determination of soil nitrogen availability index

Abstract

Summary The determination of NH 4 + -N and NO 3 − -N contents after the short incubation tests (14d at 28 °C) may be taken for the calculation of a nitrogen availability index (N pm ) in clay loam soil. The aggregate size was suggested under 2 mm. Moisture should be kept at 60 % of the maximum capillar water capacity. The coefficients of variations of N pm varied between 10–11%. Four replications were necessary (L.S.D. at 0.01 % level).