Evaluation of simple quick tests for determining the nitrogen mineralisation potential in soils in controlled environments

Abstract

Four simple quick test methods were evaluated for their ability to predict the N mineralisation potential of six pastoral soils under controlled glasshouse or incubation conditions. Soil samples were taken to determine N mineralisation potential and extractable NH₄ ⁺ by different extractants. The relationships between N mineralisation potential and extractable NH₄ ⁺ were assessed. Autoclave ex‐tracted‐NH₄ ⁺ (R² = 0.70; P < 0.001), HCl extracted‐NH₄ ⁺ (R² = 0.83; P < 0.001) and NaHCO₃ (R² = 0.81; P < 0.001) methods were the best indicators of N mineralisation rate. The potential of these simple quick tests to be used as rapid, simple indices of N mineralisation rate in pastoral soils need to be further evaluated under field conditions where inputs of N fertiliser and farm effluents occur.

Keywords:

• nitrogen
• soils
• availability indices
• quick test
• mineralisation

Notes

Author for correspondence.