Influence of temperature and soil type on inhibition of urea hydrolysis by N-(n-butyl) thiophosphoric triamide in wheat and pasture soils in south-eastern Australia
HC Suter, P Pengthamkeerati, C Walker, D Chen
Soil Research | CSIRO PUBLISHING | Published : 2011
Incubation experiments were conducted to assess the effectiveness of N-(n-butyl) thiophosphoric triamide (NBPT) for inhibiting hydrolysis of urea in three wheat-growing soils and one pasture soil in south-eastern Australia, under a range of temperatures (5, 15, 25°C). The effectiveness of NBPT decreased with increasing temperature and with increasing urease activity. In the acidic pasture soil with high urease activity (186 μN/g soil.h) and high organic carbon content (11%), NBPT (0.1% w/w urea) had little impact on urea hydrolysis rates over all temperatures, with <1% urea remaining at Day 14. In the alkaline, wheat-cropping soils with lower urease activity (54-90g μN/g soil.h) and lower or..View full abstract
The authors acknowledge Ms Sirikanda Watcharathai and Dr Xing Chen for assistance in the running of the experiments, and acknowledge financial support from ARC, GRDC, DAFF, and Incitec Pivot Limited.