Nitrous oxide emissions from temperate grassland ecosystems in the Northern and Southern Hemispheres

Emissions of nitrous oxide (N2O), a potent greenhouse gas, are a challenge associated with application of nitrogen (N) fertilizers to soil. However, N source selection can play a role in reducing these emissions. Nitrous oxide emissions were measured from ammonium (ammonium sulfate) and nitrate (calcium nitrate) fertilizers over one year in temperate grassland using the closed static chamber method. Nitrogen was applied at a system representative rate of 220 kg ha−1 y−1 in six split applications. Cumulative annual N2O-N emissions were 0.29 kg ha−1 for the control, 1.07 kg ha−1 for the ammonium fertilizer and significantly higher at 2.54 kg ha−1 for the nitrate fertilizer. The annual emission factor (EF) for the ammonium fertilizer was 0.35% vs 1.02% for the nitrate fertilizer, a 66% reduction in the EF for ammonium vs nitrate and a 2.9 times higher EF for nitrate compared with ammonium. No difference in grass yield or N uptake was detected between fertilizers. This study shows that an ammonium fertilizer produces the same yield and N efficiency as a nitrate fertilizer with lower N2O emissions. The results also demonstrate that the nitrate portion of fertilizers is a key factor in N2O emissions in temperate grassland. This work is the first of its kind detailing the annual EF of both a solely ammonium-N and a solely nitrate-N fertilizer we could find.

Download Full-text

Ammonium-Based Compound Fertilisers Mitigate Nitrous Oxide Emissions in Temperate Grassland

Agronomy ◽

10.3390/agronomy11091712 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1712

Author(s):

Amanuel W. Gebremichael ◽

Niharika Rahman ◽

Dominika J. Krol ◽

Patrick J. Forrestal ◽

Gary J. Lanigan ◽

...

Keyword(s):

Nitrous Oxide ◽

N Uptake ◽

Temperate Grassland ◽

Nitrous Oxide Emissions ◽

Anthropogenic Source ◽

N2o Emissions ◽

Moisture Condition ◽

Calcium Ammonium Nitrate ◽

Soil Moisture Condition ◽

Long Term Study

Nitrogen fertiliser application represents the largest anthropogenic source of nitrous oxide (N2O) emissions, and the magnitude of these emissions is dependent on the type of fertilisers applied in the agroecosystems. Despite N-P-K compound fertilisers being commonly used in agricultural soils, a lack of information exists regarding their effects on N2O emissions. This study aims at examining the effects of different commonly used N-P-K compound fertiliser formulations with contrasting nitrate to ammonium ratios (0.05 to 0.88) on N2O emissions, yield, and nitrogen use efficiency (NUE) in temperate grassland and to compare these variables with common straight N fertilisers. Compound fertilisers with varying NPK inclusion rates (18-6-12, 10-10-20, 24-2.2-4.5, and 27-2.5-5), and calcium ammonium nitrate (CAN) and urea + N-(n-butyl) thiophosphoric triamide (NBPT) were applied at 80 kg N ha−1 to experimental plots in managed grassland on two occasions in a growing season. Fluxes of N2O during the experiment period, yield and NUE following two harvests were measured. The cumulative N2O emission from urea + NBPT, 18-6-12, 10-10-20, and 24-2.2-4.5 treatments were significantly reduced by 44%, 43%, 37%, and 31% compared with CAN treatment under conducive soil moisture condition. Under the same soil condition, 18-6-12 and 10-10-20 treatments showed higher yield, N uptake, and NUE although did not significantly differ from the other fertiliser treatments. Our results suggest that ammonium-based compound fertilisers have a potential to reduce N2O emissions while maintaining yields. Further long-term study is needed to capture the full magnitude of variations in N2O emissions, including ammonia (NH3) volatilization from nitrate and ammonium-based compound fertiliser applications from multiple soil types and under different climatic conditions.

Download Full-text

A regionally disaggregated inventory of nitrous oxide emissions from agricultural soils in Germany – a GIS-based empirical approach

Erdkunde ◽

10.3112/erdkunde.2014.02.04 ◽

2014 ◽

Vol 68 (2) ◽

pp. 125-144 ◽

Cited By ~ 9

Author(s):

Sebastian Brocks ◽

Hermann F. Jungkunst ◽

Georg Bareth

Keyword(s):

Nitrous Oxide ◽

Agricultural Soils ◽

Empirical Approach ◽

Nitrous Oxide Emissions

Download Full-text

Effects of Straw Recycling of Winter Covering Crop on Methane and Nitrous Oxide Emissions in Paddy Field

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2011.01666 ◽

2011 ◽

Vol 37 (9) ◽

pp. 1666-1675

Author(s):

Hai-Ming TANG ◽

Xiao-Ping XIAO ◽

Wen-Guang TANG ◽

Guang-Li YANG

Keyword(s):

Nitrous Oxide ◽

Paddy Field ◽

Nitrous Oxide Emissions

Download Full-text

Biochar and urease inhibitor mitigate NH3 and N2O emissions and improve wheat yield in a urea fertilized alkaline soil

Scientific Reports ◽

10.1038/s41598-021-96771-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Khadim Dawar ◽

Shah Fahad ◽

M. M. R. Jahangir ◽

Iqbal Munir ◽

Syed Sartaj Alam ◽

...

Keyword(s):

Nitrous Oxide ◽

Grain Yield ◽

Block Design ◽

N Uptake ◽

Nitrous Oxide Emissions ◽

N2o Emissions ◽

Urease Inhibitor ◽

Alkaline Soil ◽

Total N ◽

N Assimilation

AbstractIn this study, we explored the role of biochar (BC) and/or urease inhibitor (UI) in mitigating ammonia (NH3) and nitrous oxide (N2O) discharge from urea fertilized wheat cultivated fields in Pakistan (34.01°N, 71.71°E). The experiment included five treatments [control, urea (150 kg N ha−1), BC (10 Mg ha−1), urea + BC and urea + BC + UI (1 L ton−1)], which were all repeated four times and were carried out in a randomized complete block design. Urea supplementation along with BC and BC + UI reduced soil NH3 emissions by 27% and 69%, respectively, compared to sole urea application. Nitrous oxide emissions from urea fertilized plots were also reduced by 24% and 53% applying BC and BC + UI, respectively, compared to urea alone. Application of BC with urea improved the grain yield, shoot biomass, and total N uptake of wheat by 13%, 24%, and 12%, respectively, compared to urea alone. Moreover, UI further promoted biomass and grain yield, and N assimilation in wheat by 38%, 22% and 27%, respectively, over sole urea application. In conclusion, application of BC and/or UI can mitigate NH3 and N2O emissions from urea fertilized soil, improve N use efficiency (NUE) and overall crop productivity.

Download Full-text