Determination and mitigation of ammonia loss from urea applied to winter wheat with N-(n-butyl) thiophosphorictriamide

Abstract

This study conducted in the Wimmera, a major cropping area in western Victoria Australia, evaluated a backward Lagrangian stochastic (bLs) dispersion model for measuring ammonia (NH3) loss and compared NH3 losses from a wheat crop after top-dressing with urea or "Green Urea". Green Urea contained 45.8% nitrogen (N) as urea and "Agrotain" (N-(n-butyl) thiophosphorictriamide) @ 5.0 L/t. The two products (80 kg N ha-1) were applied to circular plots of 25 m radius and losses were determined for a period of 23 days using mass balance micrometeorological methods. When the NH3 concentration in the air at the stability independent height, 0.8 m above the crop, was used there was a strong relationsh..