Effect of previous urine application on ammonia volatilisation from 3 nitrogen fertilisers

Abstract

Abstract An enclosure method was used to measure the daily volatilisation losses of ammonia (NH3) from 3 fertilisers (urea, diammonium phosphate, and ammonium sulphate). These fertilisers were broadcast on pasture in spring at a rate of 3 g/m2 N (30 kg/ha). The NH3 loss was measured in the absence or presence of sheep urine applied 1 week before the fertiliser. The surface soil pH was monitored in situ using a flat surface glass electrode. The cumulative loss of NH3-N over an 11-day period from non-urine-treated and urine-treated soil was 0.22 and 0.80 g/m2 for urea, 0.07 and 0.30 g/m2 for diammonium phosphate, and less than 0.01 and 0.03 g/m2 for ammonium sulphate respectively. After urea application, maximum fluxes of 0.08 (on Day 3) and 0.31 g/m2 per day N (on Day 2) occurred in the absence and presence of urine pretreatment respectively. Maximum fluxes occurred within 1 day of diammonium phosphate application, and were 0.03 and 0.09 g/m2 per day in treatments without and with urine respectively. The d...