Nitrous oxide emissions and dynamics of soil nitrogen under15N-labeled cow urine and dung patches on a sandy grassland soil

2008 ◽  
Vol 171 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Christine Wachendorf ◽  
Carola Lampe ◽  
Friedhelm Taube ◽  
Klaus Dittert
2014 ◽  
Vol 152 (S1) ◽  
pp. 159-171 ◽  
Author(s):  
D. R. SELBIE ◽  
K. C. CAMERON ◽  
H. J. DI ◽  
J. L. MOIR ◽  
G. J. LANIGAN ◽  
...  

SUMMARYNitrous oxide (N2O) emissions associated with urine nitrogen (N) deposition during grazing are a major component of greenhouse gas emissions from domestic livestock. The present study investigated the relationship between urine N loading rate and the efficacy of a nitrification inhibitor, dicyandiamide (DCD), on cumulative N2O emissions from a grassland soil in Ireland over 80 and 360-day periods in 2009/10 and 2010/11. A diminishing curvilinear relationship between urine N rate and cumulative N2O emissions was observed in both years. Despite this increase in cumulative N2O emissions, the emission factor (EF3) for N2O decreased with increasing urine N rate from, on average, 0·24 to 0·10% (urine applied at 300 and 1000 kg N/ha, respectively), during an 80-day measurement period. This was probably the result of a factor other than N, such as carbon (C), limiting the production of N2O. The efficacy of DCD varied with urine N loading rate, and inter-annual variability in efficacy was also observed. Dicyandiamide was effective at reducing N2O production for 50–80 days after urine application, which accounted for the major period of elevated daily flux. However, DCD was ineffective at reducing N2O production after this period, which was likely a result of its removal from the soil via degradation and leaching.


2016 ◽  
Vol 56 (3) ◽  
pp. 350 ◽  
Author(s):  
J. Luo ◽  
S. Ledgard ◽  
B. Wise ◽  
S. Lindsey

Animal urine deposited on pastoral soils during grazing is recognised as a dominant source of nitrous oxide (N2O) emissions. The nitrification inhibitor, dicyandiamide (DCD), is a potential mitigation technology to control N2O emissions from urine patches on grazed pastures. One delivery option is to include DCD in animal feed so that the DCD is targeted directly in the urine patch when excreted in the animal urine. The hypothesis tested in the present study was that DCD in urine, excreted by cows that were orally administered with DCD, would have the same effect as DCD added to urine after the urine is excreted. The study also aimed to determine the most effective DCD rate for reducing N2O emissions. Fresh dairy cow urine (700 kg N per ha) was applied to a free-draining silt loam pastoral soil in Waikato, New Zealand, in May (late autumn) or July (winter) of 2014, and was mixed with DCD at rates of 0, 10, 30 and 60 kg/ha. In late autumn, there was an equivalent treatment of urine (containing 60 kg DCD per ha) from DCD-treated cows. A static chamber technique was used to determine gaseous N2O emissions. An annual emission factor (EF3; the percentage of applied urine N lost as N2O-N) of 0.23% or 0.21% was found following late-autumn or winter applications of urine without DCD. Late-autumn application of urine containing DCD from oral administration to cows had the same significant reduction effect on N2O emissions as did DCD that was mixed with urine after excretion, at the equivalent DCD application rate of 60 kg/ha. Application of urine with DCD mixed with the urine after excretion at varying DCD rates showed a significant (P < 0.05) linear decrease in both N2O emissions and EF3 values.


Sign in / Sign up

Export Citation Format

Share Document