Lasting effects of controlled irrigation during rice-growing season on nitrous oxide emissions from winter wheat croplands in Southeast China

AbstractThe aim of this study was to compare the effects of cowpea green manure and inorganic nitrogen (N) fertilizers on yields of winter wheat and soil emissions of nitrous oxide (N2O). The comparisons included cowpea grown solely as green manure where all biomass was terminated at maturity by tillage, summer fallow treatments with 90 kg N ha−1 as urea (90-N), and no fertilization (control) at planting of winter wheat. Fluxes of N2O were measured by closed chamber methods after soil incorporation of cowpea in autumn (October–November) and harvesting of winter wheat in summer (June–August). Growth and yields of winter wheat and N concentrations in grain and straw were also measured. Cowpea produced 9.5 Mg ha−1 shoot biomass with 253 kg N ha−1 at termination. Although soil moisture was favorable for denitrification after soil incorporation of cowpea biomass, low concentrations of soil mineral N restricted emissions of N2O from cowpea treatment. However, increased concentrations of soil mineral N and large rainfall-induced emissions were recorded from the cowpea treatment during summer. Growth of winter wheat, yield, and grain N concentrations were lowest in response to cowpea treatment and highest in 90-N treatment. In conclusion, late terminated cowpea may reduce yield of winter wheat and increase emissions of N2O outside of wheat growing seasons due to poor synchronization of N mineralization from cowpea biomass with N-demand of winter wheat.

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Methane and Nitrous Oxide Emissions Reduced Following Conversion of Rice Paddies to Inland Crab–Fish Aquaculture in Southeast China

Environmental Science & Technology ◽

10.1021/acs.est.5b04343 ◽

2015 ◽

Vol 50 (2) ◽

pp. 633-642 ◽

Cited By ~ 40

Author(s):

Shuwei Liu ◽

Zhiqiang Hu ◽

Shuang Wu ◽

Shuqing Li ◽

Zhaofu Li ◽

...

Keyword(s):

Nitrous Oxide ◽

Nitrous Oxide Emissions ◽

Rice Paddies ◽

Southeast China

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Spring thaw and growing season N2O emissions from a field planted with edible peas and a cover crop

Canadian Journal of Soil Science ◽

10.4141/cjss06035 ◽

2008 ◽

Vol 88 (2) ◽

pp. 241-249 ◽

Cited By ~ 17

Author(s):

Elizabeth Pattey ◽

Lynda G Blackburn ◽

Ian B. Strachan ◽

Ray Desjardins ◽

Dave Dow

Keyword(s):

Nitrous Oxide ◽

Diode Laser ◽

Cover Crop ◽

Growing Season ◽

Dairy Manure ◽

Cattle Manure ◽

Tunable Diode Laser ◽

Nitrous Oxide Emissions ◽

Manure Application ◽

Continuous Measurements

Nitrous oxide emissions are highly episodic and to accurately quantify them annually, continuous measurements are required. A tower-based micrometeorological measuring system was used on a commercial cattle farm near Cô teau-du-Lac, (QC, Canada) during 2003 and 2004 to quantify N2O emissions associated with the production of edible peas. It was equipped with an ultrasonic anemometer and a fast-response closed-path tunable diode laser. Continuous measurements of N2O fluxes were made during the spring thaw following corn cultivation in summer 2002, then during an edible pea growing season, followed by cattle manure application, cover crop planting and through until after the next spring ploughing. The cumulative N2O emissions of 0.7 kg N2O-N ha-1 during the initial snowmelt period following corn harvest were lower than expected. Sustained and small N2O emissions totalling 1.7 kg N2O-N ha-1 were observed during the growing season of the pea crop. Solid cattle manure applied after the pea harvest generated the largest N2O emissions (1.9 kg N2O-N ha-1 over 10 d) observed during the entire sampling period. N2O emissions associated with the cover crop in the fall were mostly influenced by manure application and totalled 0.8 kg N2O-N ha-1. For the subsequent spring thaw period, N2O emissions were 0.8 kg N2O-N ha-1. This represents approximately 15% of the annual emissions for the edible pea-cover crop system, which totalled 5.6 kg N2O-N ha-1 over the measuring periods. There was little difference in spring thaw N2O emissions between the two growing seasons of corn and edible pea-cover crop. Key words: Nitrous oxide emissions, legumes, snowmelt, dairy manure, tunable diode laser, flux tower

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