Laboratory and field quantification of N2O emissions from sheep urine
Fig. 1 Automated chambers at the semi-improved
The urine collected from Welsh Mountain ewes is being applied to the soil within automated chambers (Fig. 1) to monitor N2O fluxes and to establish N2O emission factors for sheep urine deposited to upland regions. Both real and artificial urine are being applied, and urine applications will occur under contrasting seasons at the enclosed upland site (semi-improved) and the mountain site (unimproved). These data will be used to calculate direct N2O emission factors from sheep urine deposited in the uplands.
Fig. 2 DENIS controlled laboratory incubation system.
Replicated soil cores will be taken from contrasting areas in the upland field sites, and brought to the DENIS controlled laboratory incubation system (Fig. 2) at Rothamsted Research, North Wyke. The soil cores will be used in experiments to determine the relative importance of soil and urine factors on the emission of direct nitrous oxide from the soil. Factors to be investigated include soil water filled pore space, temperature, compaction, urine N content, urine volume and repeated urine deposition to the same area.