A field-based comparison of ammonia emissions from six Irish soil types following urea fertiliser application

Abstract

Ammonia (NH3 ) emissions from a range of soil types have been found to differ under laboratory conditions. However, there is lack of studies comparing NH 3 emissions from different soil types under field conditions. The objective was to compare NH 3 emissions from six different soil types under similar environmental conditions in the field following urea fertiliser application. The study was conducted on a lysimeter unit and NH 3 emissions were measured, using wind tunnels, from six different soil types with varying soil characteristics following urea fertiliser application (80 kg N/ha). On average, 17.6% (% total N applied) was volatilised, and there was no significant difference in NH 3 emissions across all soil types. Soil variables, including pH, cation exchange capacity and volumetric moisture, were not able to account for the variation in emissions. Further field studies are required to improve the urea-NH 3 emission factor used for Ireland's NH 3 inventory.

Nitrous oxide emission factors of mineral fertilisers in the UK and Ireland: A Bayesian analysis of 20 years of experimental data

“…Here we show that wide scale use of urea fertilisers would result in significantly less N 2 O than AN applications; however, past studies have shown that yield and quality of crops are higher when AN is applied, especially for grasslands ( Chambers and Dampney, 2009 , Cowan et al, 2020 ). Urea is also associated with much higher ammonia (NH 3 ) emissions than AN ( Burchill et al, 2016 , Forrestal et al, 2016 ), and so an element of pollution swapping is estimated to occur if urea fertilisers were used to replace AN at a national scale. Previous studies have indicated that urea treated with microbial inhibitors may result in slightly higher yields and lower NH 3 emissions than untreated urea ( Cantarella et al, 2018 , Misselbrook et al, 2014 , Silva et al, 2017 ), but this is still uncertain (some experiments show reduced yield ( Harty et al 2016 )) and AN (or CAN) remains the fertiliser favoured by farmers in the UK for yield and crop quality.…”

Effects of Initial Soil Moisture, Clod Size, and Clay Content on Ammonia Volatilization after Subsurface Band Application of Urea

“…These correlations from the incubation studies were much stronger than the correlation in the present study ( P = 0.100, R 2 = 0.337), suggesting that although clay content can accurately predict NH 3 volatilization under controlled conditions, the relation becomes more variable under field conditions, where wind speed, soil and air temperature, and soil water content are all allowed to fluctuate. Indeed, a previous field study found no effect of soil clay content on NH 3 volatilization losses after urea application (Burchill et al, 2016). However, the clay content of the soils in the Burchill et al (2016) study ranged from 11 to 28%, which may not be a sufficient range to see an effect.…”

“…Indeed, a previous field study found no effect of soil clay content on NH 3 volatilization losses after urea application (Burchill et al, 2016). However, the clay content of the soils in the Burchill et al (2016) study ranged from 11 to 28%, which may not be a sufficient range to see an effect. The current study used soils where clay content ranged from 5 to 57%, which was a sufficient range to detect the effect of clay content on NH 3 losses under field conditions.…”

Ammonia emission factors from cattle production systems in Ireland – a review

“…The above observation suggests an over-estimation of EFs used in the Irish NH 3 inventory. There is therefore the need to generate additional datasets on NH 3 emissions from cattle buildings to validate the findings from Burchill et al (2017a). In the case of concrete farmyards or hard standings, mean EFs generated from the analysis of this review was 35% TAN.…”

“…Table 3 summarises NH 3 EFs generated from cattle buildings and concrete yards used by cattle under Irish conditions. Emissions from cattle buildings can vary to a considerable extent due to variations in factors such as building design/ size, number of cattle and wind velocity/direction (Burchill et al, 2017a). Burchill et al (2017a) quantified NH 3 EFs from four cattle buildings which varied in size, floor type as well as the type and number of livestock housed.…”