See more from this Session: Biochar: Environmental Uses
ASA Section: Environmental Quality [Oral]
Effects of biochar amendment on ammonia volatilization from soil under ruminant urine application and its subsequent plant availability
Arezoo Taghizadeh-Toosi1, Tim J. Clough1, Robert R. Sherlock1, and Leo M. Condron1&2
1Dep. of Soil & Physical Sciences, Faculty of Agriculture & Life Sciences, P.O. Box 84, Lincoln Univ., Lincoln 7647, New Zealand; Arezoo.Taghizadehtoosi@lincolnuni.ac.nz, Timothy.Clough@lincoln.ac.nz, Rob.Sherlock@lincoln.ac.nz.
2Bio-Protection Research Centre, P.O. Box 84, Lincoln Univ., Lincoln 7647, New Zealand; Leo.Condron@lincoln.ac.nz.
Ammonia (NH3) can be generated at the soil
surface following the surface application of nitrogenous fertilizers or
ruminant urine deposition and can vary widely from 1.7% to 56% of the applied
nitrogen (N). The volatilization of NH3 represents the loss of a
potentially available agronomic N supply and an environmental source of
reactive N, since NH3-N may contribute to indirect losses of nitrous
oxide, a GHG. This study was conducted in two steps in order to
determine the effect of incorporating biochar (0, 15
and 30 t ha-1), into soil on (a) NH3 volatilization under
a ruminant urine application, and (b)
the subsequent plant availability of biochar adsorbed
NH3 volatilization from 15N-labelled ruminant urine,
applied to soil, was reduced by 45% after incorporating either 15 or 30 t ha-1
of biochar. The atom
% 15N enrichment of the NH3 volatilized was lower with biochar present, indicating less urine-N contributed to the NH3 flux. Furthermore, the biochar total N content and its 15N enrichment increased. When these 15N enriched biochar particles were placed in fresh soil, subsequent plant growth was not affected but the uptake of 15N in plant tissues increased, indicating that the adsorbed-N was plant available.
Incorporating biochar into the soil can significantly decrease NH3 volatilization from ruminant urine. However, future work is required to examine the persistence of the observed effect under field conditions, and to fully understand the mechanism(s) of the observed reduction in NH3 fluxes.