Field-scale verification of nitrous oxide emission reduction with DCD in dairy-grazed pasture using measurements and modelling
Donna L. Giltrap A E , Surinder Saggar A , Jagrati Singh A B , Mike Harvey C , Andrew McMillan C and Johannes Laubach DA Landcare Research, Private Bag 11052, Palmerston North 4442, New Zealand.
B University of Melbourne, Melbourne, Vic. 3010, Australia.
C NIWA, PO Box 14-901, Wellington, New Zealand.
D Landcare Research, PO Box 40, Lincoln 7640, New Zealand.
E Corresponding author. Email: GiltrapD@landcareresearch.co.nz
Soil Research 49(8) 696-702 https://doi.org/10.1071/SR11090
Submitted: 28 April 2011 Accepted: 24 October 2011 Published: 6 January 2012
Abstract
Nitrous oxide (N2O) from agricultural soils is a major source of greenhouse gas emissions in New Zealand. Nitrification inhibitors are seen as a potential technology to reduce these N2O emissions from agricultural soils. In previous studies on the effect of dicyandiamide (DCD) on N2O emissions from animal excreta, DCD was directly applied to urine. However, farmers apply DCD to grazed pastures shortly before or after grazing rather than applying it specifically to the urine patches. Accordingly, the objectives of this study were: (1) to test, using chamber measurements, whether the same level of N2O reduction is achieved under grazed conditions where excretal N is non-uniformly deposited, (2) to apply the process-based NZ-DNDC model to simulate the effect of DCD on emission reductions, and (3) to perform a sensitivity analysis on the NZ-DNDC model to investigate how uncertainties in the input parameters affect the modelled N2O emissions. Two circular 1260-m2 treatment plots were grazed simultaneously for 5 h, by 20 cattle on each plot. The following day, DCD was applied in 800 L of water to one of the plots at 10 kg/ha and N2O emissions were measured periodically for 20 days. The cumulative N2O emissions were 220 ± 90 and 110 ± 20 g N2O-N/ha for the untreated and DCD-treated plots, respectively (based on the arithmetic mean and standard error of the chambers). This suggests a reduction in N2O emission from DCD application of ~50 ± 40% from a single grazing event. However, this result should be treated with caution because the possibility of sampling error due to the chamber distribution cannot be excluded. NZ-DNDC simulated N2O emissions of 169 and 68 g N2O-N/ha for the untreated and DCD-treated areas, respectively, corresponding to a reduction of 60% in N2O emissions from DCD application. This level of reduction is consistent with that found in experiments with individual urine patches. N2O emissions found through use of NZ-DNDC were sensitive to uncertainties in the input parameters. The combined effect of varying the initial soil NO3– and NH4+, soil moisture, soil organic carbon, bulk density, clay content, pH, and water-filled pore-space at field capacity inputs within plausible ranges was to change the simulated N2O emissions by –87% to +150%.
Additional keywords: chambers, greenhouse gas mitigation, NZ-DNDC model, sensitivity analysis.
References
Abbasi MK, Adams WA (2000) Estimation of simultaneous nitrification and denitrification in grassland soil associated with urea-N using 15N and nitrification inhibitor. Biology and Fertility of Soils 31, 38–44.| Estimation of simultaneous nitrification and denitrification in grassland soil associated with urea-N using 15N and nitrification inhibitor.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXhvF2mtbY%3D&md5=6c8e2c6f9a29bb5b15fa35c8fd77dcceCAS |
Cookson WR, Cornforth IS (2002) Dicyandiamide slows nitrification in dairy cattle urine patches: effects on soil solution composition, soil pH and pasture yield. Soil Biology & Biochemistry 34, 1461–1465.
| Dicyandiamide slows nitrification in dairy cattle urine patches: effects on soil solution composition, soil pH and pasture yield.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XnsVWrs74%3D&md5=72c4ff9a3906d2417bd39ab6cd1f43bcCAS |
Giltrap DL, Saggar S, Singh J, Zaman M (2010) A preliminary study to model the effects of a nitrification inhibitor on nitrous oxide emissions from urine amended pastures. Agriculture, Ecosystems & Environment 136, 310–317.
| A preliminary study to model the effects of a nitrification inhibitor on nitrous oxide emissions from urine amended pastures.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXisFenur0%3D&md5=6ff26e4bbc0391c1b809aeeeaca559ddCAS |
Hewitt AE (1998) ‘New Zealand Soil Classification.’ 2nd edn. (Manaaki Whenua Press: Lincoln, New Zealand)
Kelliher FM, Clough TJ, Clark H (2007) Developing revised emission factors for nitrous oxide emissions from agricultural pasture treated with nitrification inhibitors. Report prepared for Ministry of Agriculture and Forestry, Wellington, New Zealand. Available at: www.maf.govt.nz/news-resources/publications
Kelliher FM, Clough TJ, Clark H, Rys G, Sedcole JR (2008) The temperature dependence of dicyandiamide (DCD) degradation in soils: A data synthesis. Soil Biology & Biochemistry 40, 1878–1882.
| The temperature dependence of dicyandiamide (DCD) degradation in soils: A data synthesis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXnt1eksbo%3D&md5=437a9bc403d23884654fe791590f38e1CAS |
Li CS, Frolking S, Frolking TA (1992) A model of nitrous-oxide evolution from soil driven by rainfall events. 1. Model structure and sensitivity. Journal of Geophysical Research – Atmospheres 97, 9759–9776.
MfE (2010) ‘New Zealand’s greenhouse gas inventory 1990–2008.’ (Ministry for the Environment: Wellington, New Zealand)
Saggar S, Andrew RM, Tate KR, Rodda NJ, Townsend JA (2004) Modelling nitrous oxide emissions from dairy-grazed pastures. Nutrient Cycling in Agroecosystems 68, 243–255.
| Modelling nitrous oxide emissions from dairy-grazed pastures.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhvF2lsr8%3D&md5=46609c11eac8aed9b07f13840b9e610cCAS |
Saggar S, Hedley CB, Giltrap DL, Lambie SM (2007) Measured and modelled estimates of nitrous oxide emission and methane consumption from a sheep-grazed pasture. Agriculture, Ecosystems & Environment 122, 357–365.
| Measured and modelled estimates of nitrous oxide emission and methane consumption from a sheep-grazed pasture.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXmsFKhtro%3D&md5=c345ccda3e475fab6110a7bf2ed6996aCAS |
Saggar S, Tate KR, Giltrap DL, Singh J (2008) Soil–atmosphere exchange of nitrous oxide and methane in New Zealand terrestrial ecosystems and their mitigation options: a review. Plant and Soil 309, 25–42.
| Soil–atmosphere exchange of nitrous oxide and methane in New Zealand terrestrial ecosystems and their mitigation options: a review.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXosVyhs74%3D&md5=16f5072a5ed7a6f24e8c87af19ac3045CAS |
Saggar S, Harvey M, Singh J, Giltrap D, Pattey E, Bromley T, Martin R, Dow D, Moss R, McMillan A (2010) Chambers, micrometeorological measurements, and the New Zealand Denitrification–Decomposition model for nitrous oxide emission estimates from an irrigated dairy-grazed pasture. Journal of Integrative Environmental Sciences 7, 61–70.
| Chambers, micrometeorological measurements, and the New Zealand Denitrification–Decomposition model for nitrous oxide emission estimates from an irrigated dairy-grazed pasture.Crossref | GoogleScholarGoogle Scholar |
