Effect of fertilizer N rates and straw management on yield-scaled nitrous oxide emissions in a maize-wheat double cropping system

As a significant user of nitrogen (N) fertilisers, the Australian cotton industry is a major source of soil-derived nitrous oxide (N2O) emissions. A country-specific (Tier 2) fertiliser-induced emission factor (EF) can be used in national greenhouse gas inventories or in the development of N2O emissions offset methodologies provided the EFs are evidence based. A meta-analysis was performed using eight individual N2O emission studies from Australian cotton studies to estimate EFs. Annual N2O emissions from cotton grown on Vertosols ranged from 0.59kgNha–1 in a 0N control to 1.94kgNha–1 in a treatment receiving 270kgNha–1. Seasonal N2O estimates ranged from 0.51kgNha–1 in a 0N control to 10.64kgNha–1 in response to the addition of 320kgNha–1. A two-component (linear+exponential) statistical model, namely EF (%)=0.29+0.007(e0.037N – 1)/N, capped at 300kgNha–1 describes the N2O emissions from lower N rates better than an exponential model and aligns with an EF of 0.55% using a traditional linear regression model.

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Does 3,4-dimethylpyrazole phosphate or N-(n-butyl) thiophosphoric triamide reduce nitrous oxide emissions from a rain-fed cropping system?

Soil Research ◽

10.1071/sr17219 ◽

2018 ◽

Vol 56 (3) ◽

pp. 296 ◽

Cited By ~ 4

Author(s):

Guangdi D. Li ◽

Graeme D. Schwenke ◽

Richard C. Hayes ◽

Hongtao Xing ◽

Adam J. Lowrie ◽

...

Keyword(s):

Nitrous Oxide ◽

Grain Yield ◽

Crop Yields ◽

Cropping System ◽

N2o Emission ◽

Nitrous Oxide Emissions ◽

Wheat Crop ◽

N2o Emissions ◽

Urease Inhibitors ◽

Eastern Australia

Nitrification and urease inhibitors have been used to reduce nitrous oxide (N2O) emissions and increase nitrogen use efficiency in many agricultural systems. However, their agronomic benefits, such as the improvement of grain yield, is uncertain. A two-year field experiment was conducted to (1) investigate whether the use of 3,4-dimethylpyrazole phosphate (DMPP) or N-(n-butyl) thiophosphoric triamide (NBPT) can reduce N2O emissions and increase grain yield and (2) explore the financial benefit of using DMPP or NBPT in a rain-fed cropping system in south-eastern Australia. The experiment was conducted at Wagga Wagga, New South Wales, Australia with wheat (Triticum aestivum L.) in 2012 and canola (Brassica napus L.) in 2013. Results showed that urea coated with DMPP reduced the cumulative N2O emission by 34% for a wheat crop in 2012 (P < 0.05) and by 62% for a canola crop in 2013 (P < 0.05) compared with normal urea, but urea coated NBPT had no effect on N2O emission for the wheat crop in 2012. Neither nitrification nor urease inhibitors increased crop yields because the low rainfall experienced led to little potential for gross N loss through denitrification, leaching or volatilisation pathways. In such dry years, only government or other financial incentives for N2O mitigation would make the use of DMPP with applied N economically viable.

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Nitrous oxide emissions in response to ESN and urea, herbicide management and canola cultivar in a no-till cropping system

Soil and Tillage Research ◽

10.1016/j.still.2011.10.017 ◽

2012 ◽

Vol 118 ◽

pp. 97-106 ◽

Cited By ~ 17

Author(s):

Chunli Li ◽

Xiying Hao ◽

Robert E. Blackshaw ◽

John T. O’Donovan ◽

K. Neil Harker ◽

...

Keyword(s):

Nitrous Oxide ◽

Cropping System ◽

Nitrous Oxide Emissions ◽

No Till ◽

Herbicide Management

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Nitrous oxide emission as affected by tillage, corn-soybean-alfalfa rotations and nitrogen fertilization

Canadian Journal of Soil Science ◽

10.4141/s96-104 ◽

1997 ◽

Vol 77 (2) ◽

pp. 145-152 ◽

Cited By ~ 77

Author(s):

A. F. MacKenzie ◽

M. X. Fan ◽

F. Cadrin

Keyword(s):

Nitrous Oxide ◽

Sandy Loam ◽

Cropping Systems ◽

Pore Space ◽

Nitrous Oxide Emission ◽

Economic Losses ◽

Silty Clay ◽

Fertilizer N ◽

Management Procedures ◽

N Rates

Nitrous oxide (N2O) produced from agricultural activities represents a threat to the ozone layer and economic losses. Rates and magnitudes of N2O emissions of cropping systems must be determined to establish corrective management procedures. In 1994, N2O emissions were determined with corn (ZeaMays L.) and corn-legume rotations. Continuous corn was studied on four soils, two from a long-term experiment, a Ste. Rosalie heavy clay (Humic Gleysol) and a Chicot sandy loam (Grey-Brown Podzol), at 0, 170, 285 or 400 kg N ha−1, and two from a corn rotation study, a Ste. Rosalie clay (Humic Gleysol) and an Ormstown silty clay loam (Humic Gleysol). Treatments included no-till (NT) and conventional tillage (CT), monoculture corn (CCCC), monoculture soybean; corn-soybean; and soybean-corn-alfalfa phased rotations. Nitrogen rates of 0, 90, or 180 kg N ha−1 for corn and 0, 20, or 40 kg N ha−1 for continuous soybean were used, and soybean/alfalfa following corn no fertilizer N. Rates of N2O emission were measured from closed chambers through the growing season. About 0.99 to 2.1% of N added was lost as N2O. Nitrous oxide emission increased with increased soil water content, NO3 concentration and fertilizer N rates. Emission of N2O was higher with NT than with CT, and with corn than with soybean or alfalfa. A corn system using CT, legumes in rotation and moderate fertilizer N would reduce N2O emission. Key words: Greenhouse gases, soil nitrate, tillage methods, water-filled pore space, denitrification, rotations

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